sign in sign up
<<
Home , Abulia, Anomic aphasia, Aphasia, Conduction aphasia, Hemispatial neglect, Prosopagnosia

1 CHAPTER26 , Loss, , Frontal and Other Cerebral Disorders - - 8/4/17 12:21 PM ). If the as manifested as ; if the word approxi ; if the word . In most anomias, the ) views of the cerebral of the cerebral ) views bottom semantic paraphasia phonemic paraphasia ) and medial ( top can be tested by assessing the patient’s ability to is described as “fluent” if it maintains appropriate is described as “fluent” if it maintains appropriate Lateral ( The numbers cyto-architectonic refer to the Brodmann Comprehension FIGURE 26-1 FIGURE hemispheres. designations. Area 17 corresponds primary to the , 41–42 to the primary auditory the primary cortex, 1–3 to somatosensory cortex, and 4 to the primary motor cortex. of the The rest areas. contains association cingulate gyrus; ; CG, area; CC, Broca’s ; B, AG, fields (premotor cortex); frontal eye dorsolateral prefrontal cortex;DLPFC, FEF, ; LG, fusiform inferior parietal lobule; ITG, gyrus;FG, IPL, medial prefrontal cortex; middle temporal gyrus;; OFC, MPFC, MTG, posterior parietal cortex;orbitofrontal cortex; ; PPC, PHG, gyrus; peristriate cortex; striate cortex; supramarginal SPL, PSC, SC, SMG, superior temporal superior temporal gyrus;STS, ; STG, area. Wernicke’s temporopolar cortex; W, sulcus; TP, description of the object (“the thing for a circumlocutious provide ( word ”), or may come up with the wrong (“pen” for “pencil”), the word but related an incorrect patient offers is known as a naming Spontaneous output volume, phrase length, and melody or as “nonfluent” if it is sparse and halting and average utterance length is below four words. of integrity the note should also examiner The plurals, and posses prefixes, tenses, suffixes, (), order by word sives. follow conversation, asking yes-no questions (“Can a dog fly?” “Does objects it snow in summer?”), asking the patient to point to appropriate mates the correct answer but is phonetically inaccurate (“plentil” for mates the correct “pencil”), it is known as a name when shown an object the appropriate patient cannot retrieve by object when the name is provided but can point to the appropriate naming retrieval-based) (or known as a one-way is This examiner. the or semantic) naming deficit two-way (comprehension-based A deficit. name. the correct nor recognize exists if the patient can neither provide

. ------large-s are most are , located at Broca’s area Broca’s

, which becomes

Wernicke’s area Wernicke’s large-scale networks large-scale ) is the single most common anomia . The association cortex mediates the . The association cortex default mode network . The primary sensory and motor areas and motor areas . The primary sensory 2 (Fig. 26-1)

that contain interconnected cortical and subcortical that contain interconnected Aphasia, Memory Loss, Aphasia, Hemispatial Neglect, Syndromes and Frontal Other Disorders Cerebral M.-Marsel Mesulam association cortex 26 CLINICAL EXAMINATION CLINICAL ■ The clinical examination of language should include the assessment , repetition, of naming, spontaneous speech, comprehension, deficit of naming ( A and writing. finding in aphasic patients. When asked to name a common object, may word, the patient may fail to come up with the appropriate only when there are deficits in the formal aspects of language, such as are only when there Dys , or grammar. choice, comprehension, finding, word word lead to a by themselves not and mutism do speech arthria, of diagnosis of aphasia. In ~90% of right-handers and 60% of left-handers, aphasia occurs only after lesions of the left hemisphere. ■ of primary progressive aphasia (PPA) have shown that sen aphasia (PPA) of primary progressive syndrome subserved jointly faculty distributed widely a is comprehension tence critical for word and that the areas areas, and Wernicke’s by Broca’s located in the anterior rather than are comprehension inter are All components of the language network area. Wernicke’s frontal, the of parts surrounding with and other each with connected rise to lan gives network this to Damage lobes. parietal, and temporal diagnosed be should Aphasia aphasia. as known impairments guage language comprehension, is less clearly settled. Accounts of patients is less clearly settled. language comprehension, lesions identified with focal cerebrovascular and sentence the parietotemporal junction, as a critical hub for word inter involving this area Occlusive or embolic comprehension. with the ability to understand spoken or written language as well fere and state words meaningful thoughts through to express as the ability investigations of patients with the neurodegenerative ments. However, LANGUAGE AND LANGUAGE is depen sentences and of words and comprehension production The located along the peri dent on the integrity of a distributed network of the language-dominant (usually left) hemisphere. sylvian region is known as gyrus, One hub, situated in the inferior frontal impairs fluency of verbal output and the gram Damage to this region of sentences. The location of a second hub, critical for matical structure episodic memory, and (5) a prefrontal network for the executive con and (5) a prefrontal episodic memory, and comportment. Investigations based on functional of cognition trol imaging have also identified a requiring task specific engaged in a not is person the when activated of damage to to external events. The clinical consequences not yet fully defined. this network are FOR NETWORK THE LEFT PERISYLVIAN words,” “perceiving space,” or “storing .” Cognitive and space,” or “storing memories.” Cognitive “perceiving words,” intersecting by coordinated (domains) are behavioral functions cale neural networks anatomically defined Five components. (2) for language, network a perisylvian practice: (1) clinical to relevant network for spatial orientation, (3) an occipitotemporal a parietofrontal (4) a limbic network for explicit network for and object recognition, spread over an area of 2.5 m over an area spread is subsumed by modality- The rest cortex. constitute 10% of the cerebral collectively known and limbic areas paralimbic, selective, heteromodal, as the cognition, emotion, and comport that subserve integrative processes of these mental functions is necessary for systematic testing A ment. clinical assessment of the association cortex and its dis the effective no centers for “hearing are thinking, there to current According eases. The cerebral cortex of the human contains ~20 billion brain contains ~20 billion neurons cortex of the human The cerebral Harrisons_20e_ch26_p001-p009.indd 1 8/4/17 12:21 PM

------. Mass lesions, bound morphemes (Chap. 419) FLUENCY Preserved or increased Decreased Decreased Preserved Impaired Preserved No purposeful speech Preserved for word- except finding pauses Preserved Preserved NAMING Impaired Impaired Impaired Impaired Impaired Impaired Impaired Impaired Preserved Preserved Speech is nonfluent, labored, interrupted by interrupted Speech is nonfluent, labored, . , head trauma, and trauma, head hemorrhage, Intracerebral .

(Chap. 419) (Chap. Output may be reduced to a grunt or single word (“yes” or “no”), (“yes” or “no”), or single word to a grunt Output may be reduced The lesion site most commonly associated with Wernicke’s aphasia associated with Wernicke’s The lesion site most commonly a match or suck through a straw). The cause is most often infarction a straw). The cause is most often infarction a match or suck through convolution; “B” in Fig. 26-1) and inferior frontal (the area of Broca’s anterior perisylvian and due to occlu surrounding sion of the superior division of the MCA and abscess, also may be hemorrhage, intracerebral including tumor, of recovery aphasia is , When the cause of Broca’s responsible. language function generally peaks within 2–6 months, after which time successful than in limited. Speech therapy is more is further progress aphasia. Wernicke’s Broca’s Aphasia Broca’s pauses, and usually dysarthric. It is impoverished many word-finding Abnor nouns. in meaning-appropriate but enriched in function words deployment of and the inappropriate order mal word used to denote tenses, possessives, or plurals) lead to a endings (word and pithy but quite characteristic . Speech is telegraphic aphasia with Broca’s informative. In the following passage, a patient dotor sent me … dotor, describes his medical history: “I see … the tee days, doctor Two, Bosson. Go to hospital. Dotor … kept me beside. send me home.” intonations in an attempt to express which is emitted with different and repetition naming In addition to fluency, or disapproval. approval of spoken language is intact except Comprehension impaired. are sentences with a passive voice structure for syntactically difficult aphasia is not just an or embedded clauses, indicating that Broca’s and that it also may involve a com or “motor” disorder “expressive” aphasia deficit in decoding syntax. Patients with Broca’s prehension Insight depressed. and profoundly can be tearful, easily frustrated, aphasia. in contrast to Wernicke’s into their condition is preserved, dysarthric, the patient Even when spontaneous speech is severely when of words articulation normal relatively a display to able be may singing. This dissociation has been used to develop specific therapeutic Addi aphasia. (melodic intonation therapy) for Broca’s approaches deficits include right facial weakness, tional neurologic or hemiplegia, and a buccofacial apraxia characterized by an inability and facial to carry out motor commands involving oropharyngeal unable to demonstrate how to blow out (e.g., patients are musculature is the posterior portion of the language network. An embolus to the is the posterior portion of the language network. artery (MCA), to the poste inferior division of the middle cerebral is the most common rior temporal or angular branches in particular, etiology coexisting right A aphasia. other causes of Wernicke’s are common, and mild right hemianopia or superior quadrantanopia is the examination is nasolabial flattening may be found, but otherwise, The paraphasic, neologistic speech in an agitated often unrevealing. may examination neurologic patient with an otherwise unremarkable such as schizo disorder lead to the suspicion of a primary psychiatric mania, but the other components characteristic of acquired or phrenia disease usually settle the aphasia and the absence of prior psychiatric of language function is guarded. for recovery issue. Prognosis ------REPETITION OF SPOKEN REPETITION LANGUAGE Impaired Impaired Impaired Impaired Preserved Preserved Preserved Impaired Preserved describes

Alexia should be assessed is assessed by asking the Reading Impaired Impaired Preserved Impaired only for spoken language Impaired only for reading COMPREHENSION Impaired Preserved (except grammar) Impaired Preserved Preserved Repetition Comprehension is impaired for spoken and is impaired Comprehension (or ) is used to describe an acquired an acquired describe to used is dysgraphia) (or in the language network. are most applicable to this group, where gray matter where applicable to this group, most are Clinical Features of Aphasias and Related Conditions Commonly Seen in Cerebrovascular Accidents Cerebrovascular Seen in Conditions Commonly Aphasias and Related of Clinical Features Table 26-1 Table Gestures and pantomime do not improve communication. The and pantomime do not improve Gestures Aphasias can arise acutely in cerebrovascular accidents (CVAs) or (CVAs) accidents cerebrovascular in arise acutely can Aphasias TABLE 26-1 TABLE Pure word deafness Global Conduction Nonfluent (anterior) transcortical Fluent (posterior) transcortical Isolation Anomic Wernicke’s Broca’s deafness, psychiatric disease, or malingering. Patients with Wernicke’s deafness, psychiatric disease, or malingering. Patients with Wernicke’s words their thoughts in meaning-appropriate aphasia cannot express in any modality of input. and cannot decode the meaning of words components. as well as receptive has expressive This aphasia therefore impaired. and writing also are Repetition, naming, reading, decipher the meaning of a severely paraphasic statement. In some decipher the meaning of a severely agitation patients this type of aphasia can be associated with severe and paranoia. The ability to follow commands aimed at axial mus to The dissociation between the failure may be preserved. culature understand simple questions (“What is your name?”) in a patient who do when asked to over rolls or eyes, sits up, her or rapidly closes his it from differentiate aphasia and helps so is characteristic of Wernicke’s don’t need it anymore, she says. And with it when that was downstairs she says. don’t need it anymore, And they hap was my teeth-tick … a … den … dentith … my dentist. my two … two little pieces of pened to be in that bag … see? …Where the whole thing dentist that I use … that I … all gone. If she throws them away.” away … visit some friends of hers and she can’t throw that his or her language is incomprehensible patient may not realize and may appear angry and impatient when the examiner fails to Wernicke’s Aphasia Wernicke’s and sentences. Language output is fluent but is highly written words may lead to strings Paraphasic paraphasic and circumlocutious. aphasia.” Speech contains few of , which lead to “jargon voluminous but uninfor substantive nouns. The output is therefore mative. For example, a patient attempts to describe how his wife acci “We his dentures: away something important, perhaps dentally threw passes cerebral cortex as well as deep pathways inter as deep white matter pathways as well cortex cerebral passes listed The syndromes areas. cortical otherwise unaffected connecting in and jointly destroyed. abruptly and white matter at the lesion site are and laminar, diseases can have cellular, neurodegenerative Progressive set cortex, giving rise to a different for the cerebral specificity regional of aphasias that will be described separately. phonological loop aloud as well as comprehension. for deficits in reading and written words aloud or comprehend an inability to either read sentences; deficit in spelling. damage encom diseases. In CVAs gradually in neurodegenerative patient to repeat single words, short sentences, or strings of words such short sentences, or strings of words single words, patient to repeat with tongue twisters as “No ifs, ands, or buts.” The testing of repetition a better provides such as “hippopotamus” and “Irish constabulary” of aphasia. It is important assessment of and than patient’s does not exceed the that the number of words to make sure becomes a reflection of repetition attention span. Otherwise, the failure attention span (working memory) rather than an of the narrowed of a hypothetical indication of an aphasic deficit caused by dysfunction (“Where is the source of illumination in this room?”), or asking for this room?”), of illumination in is the source (“Where verbal definitions of single words.

2 PART 2 Cardinal Manifestations and Presentation of Diseases Harrisons_20e_ch26_p001-p009.indd 2 3 CHAPTER26 Aphasia, Memory Loss, Hemispatial Neglect, Frontal Syndromes and Other Cerebral Disorders ------8/4/17 12:21 PM encom is used to desig limb apraxia . The most common most The . is diagnosed when com involves apraxic deficits . A severe form of sympa severe A . syndrome, is characterized syndrome, This is the visual equivalent This is the visual equivalent apraxia

color anomia color is a severe form of acute speech is a severe designates a complex motor def alien hand Apraxia Ideomotor Aphemia Buccofacial apraxia sympathetic dyspraxia apraxia almost always is caused by lesions in the left hemisphere and hemisphere the left in lesions by is caused almost always apraxia especially Broca’s is commonly associated with aphasic syndromes, objects aphasia and . Because the handling of real by itself causes no major limitation is not impaired, of daily living activities. Patients with lesions of the anterior corpus callosum can display ideomotor apraxia confined to the left side of the a sign known as body, thetic dyspraxia, known as the or sensory dysfunction and that does not arise from the patient’s failure failure the patient’s arise from does not that and sensory dysfunction or of the task. to understand the nature of and stress fluidity, nate articulatory abnormalities in the duration, in the posterior It can arise with CVAs syllables that make up words. lobar degenera or in the course of frontotemporal area part of Broca’s tion (FTLD) with tauopathy. mutism). (often fluency impaired severely with presents that apraxia stage of hoarse and involves an intermediate Recovery is the rule intact, and so are and comprehension reading, whispering. Writing, or area of Broca’s in parts CVAs aphasic syndrome. this is not a true of parts other with connections its undercut that lesions subcortical site is on the medial the lesion Occasionally, the brain may be present. lobes and may involve the supplementary motor aspects of the frontal cortex of the left hemisphere. mands to perform a specific motor act (“cough,” “blow out a match”) or straw, or pantomime the use of a common tool (a comb, hammer, object cannot be followed. The in the absence of the real toothbrush) the command is ascertained by demon patient’s ability to comprehend one can strating multiple movements and establishing that the correct Some patients with this type of apraxia can imitate the be recognized. movement when it is demonstrated by the examiner and appropriate object, indicating that the show no impairment when handed the real intact. Some sensorimotor mechanisms necessary for the movement are a disconnection of the language forms of ideomotor apraxia represent pyramidal motor systems so that commands to execute network from understood but cannot be conveyed to the complex movements are areas. motor appropriate in movements of the face and mouth. Ideomotor passes apraxic deficits in movements of the arms and legs. Ideomotor appear to have improved. There may be no additional neurologic find neurologic may be no additional There improved. appear to have in the acute stages. common are paranoid reactions ings, but agitated cause. the most common lesions are Cerebrovascular Agraphia Without Pure Alexia a combination of dam The lesions (usually deafness. word pure of corpus the of sector posterior a to and cortex occipital left the to age the flow of visual input into the interrupt callosum—the splenium) a right hemianopia, but the core is usually language network. There patient can understand and The unaffected. language network remains objects in the left visual hemifield, spoken language, name produce the patient acts as if illiterate when asked and write. However, repeat, because the visual information even the simplest sentence to read visual hemifield) to the intact left (presented the written words from Objects in the left hemifield may the language network. cannot reach nonvisual associations in accurately because they activate be named turn can access the language network which in the right hemisphere, pathways anterior to the splenium. Patients with transcallosal through also may lose the ability to name colors, although they this syndrome a as known is This colors. match can alexia is a vascular lesion in the territory of the poste etiology of pure artery or an infiltrating neoplasm in the left occipital cor rior cerebral fibers of the as the crossing tex that involves the optic radiations as well artery also supplies medial splenium. Because the posterior cerebral alexia a patient with pure temporal components of the limbic system, but this is usually transient because , may experience an also the limbic lesion is unilateral. Apraxia and Aphemia extrapyramidal, cerebellar, icit that cannot be attributed to pyramidal, repeat spoken language but have no difficulty naming objects. In time, In objects. naming difficulty no have but language spoken repeat and may lipreading teach themselves deafness word pure patients with

------), nonflu Clinical Clinical echolalia represents the represents Isolation aphasia are similar to those of are are similar to those of Broca’s aphasia, to those of Broca’s similar are is the single most common The most common causes are either bilat either are causes common most The Speech output is fluent but contains many is fluent but contains Speech output This form of aphasia may be considered the This form of aphasia may be considered . fluent (posterior) transcortical aphasia fluent (posterior) transcortical right hemisphere are spared. Because auditory information cannot Because auditory spared. are right hemisphere it cannot be decoded be conveyed to the language network, however, to speech as if and the patient reacts representations, into neural word Patients cannot in an alien tongue that cannot be deciphered. it were eral or left-sided MCA strokes affecting the superior temporal gyrus. the superior temporal gyrus. affecting strokes eral or left-sided MCA the flow of of the underlying lesion is to interrupt The net effect the auditory association cortex to the language information from understanding written language network. Patients have no difficulty themselves well in spoken or written language. They and can express sounds to environmental and reacting interpreting have no difficulty of the if the primary and auditory association areas pauses are uncommon, so language output is fluent but paraphasic, but output is fluent language so uncommon, are pauses and uninformative. The lesion sites can be anywhere circumlocutious, language network, including the middle within the left hemisphere and inferior temporal gyri. and language disturbance seen in head trauma, metabolic encephalopathy, disease Alzheimer’s Deafness Word Pure to the surrounding frontal, parietal, and temporal cortex. Lesions are are parietal, and temporal cortex. Lesions frontal, to the surrounding patchy and can be associated with anoxia, carbon monoxide poisoning, or complete watershed zone infarctions. Anomic Aphasia Articu of the language network. “minimal dysfunction” syndrome intact, but confrontation are and repetition lation, comprehension, Word-finding impaired. finding, and spelling are naming, word represents a combination of the two transcortical aphasias. Compre represents is no purposeful speech output. and there impaired, hension is severely conversations ( fragments of heard The patient may parrot par least at are repetition for mechanisms neural the that indicating of the the pathologic function tially intact. This condition represents brain. of the other regions language network when it is isolated from is damage but there tend to be spared, areas Wernicke’s and Broca’s mentary motor cortex in the territory of the anterior cerebral artery. anterior cerebral mentary motor cortex in the territory of the Global and Isolation Aphasias and usually areas Wernicke’s and Broca’s combined dysfunction of distribution in the MCA the entire that involve strokes from results of Speech output is nonfluent, and comprehension left hemisphere. Related signs include right hemiplegia, impaired. language is severely hemisensory loss, and homonymous hemianopia. shed zone) and that involve the temporoparietal cortex temporoparietal shed zone) and neoplasms that involve the of common causes. The features are area posterior to Wernicke’s ent (anterior) transcortical aphasia The neu is intact and agrammatism is less pronounced. but repetition may be otherwise intact, but a right hemiparesis examination rologic intact language network also can exist. The lesion site disconnects the of the brain and usually involves the anterior areas prefrontal from supple the or territories anterior and MCA between watershed zone Transcortical Aphasias: Fluent and Nonfluent Fluent Transcortical Aphasias: of features intact. The lesion site disconnects is aphasia, but repetition Wernicke’s other temporoparietal network from of the language the intact core findings may include hemian neurologic Associated association areas. in the posterior water lesions (e.g., infarctions opia. Cerebrovascular the temporoparietal or dorsal perisylvian region, interferes with the with interferes region, perisylvian dorsal or temporoparietal the with area Broca’s loop interconnecting function of the phonological aphasia may a transient Wernicke’s Occasionally, area. Wernicke’s aphasia. The paraphasic output in into a conduction rapidly resolve meaning, but the ability to express with conduction aphasia interferes as the one displayed by patients with as severe this deficit is not nearly aphasia conduction signs in neurologic Associated aphasia. Wernicke’s site. to the primary lesion vary according Conduction Aphasia Conduction is intact, language spoken of comprehension , phonemic parapha elicits phonemic Naming impaired. is severely and repetition but reading is impaired, Reading aloud is impaired. sias, and spelling in a CVA lesion, usually The responsible is preserved. comprehension Harrisons_20e_ch26_p001-p009.indd 3 8/4/17 12:21 PM ------is posterior pure word pure provides provides Wernicke’s aphasia Wernicke’s is characterized by is characterized by cingulate cortex is characterized by preserved is characterized by preserved in Table 26-1. Of all PPA sub 26-1. Of all PPA in Table is characterized by preserved is characterized by preserved . to motor strategies for attentional behav agrammatic variant type of PPA where grammar, fluency and grammar, where type of PPA logopenic variant The semantic variant . mixed conduction aphasia The The The impairments of language in PPA have slightly have PPA of language in The impairments frontal eye fields frontal . Subcortical components of this network include the to a sensorimotor representation of salient extrapersonalsalient of representation sensorimotor a to (Chap. 430) Gerstmann’s syndrome Gerstmann’s or (Fig. 26-2) SPATIAL ORIENTATION SPATIAL network con Adaptive spatial orientation is subserved by a large-scale major cortical components. The taining three the space, extrapersonal the of mapping motivational a to access cortex parietal events, and the iors absent because the underlying deep white matter, frequently damaged frequently because the underlying deep white matter, absent impairment The repetition intact in PPA. relatively remains by CVAs, critical for phonological loop are area suggests that parts of Wernicke’s the aphasia or agrammatic PPA, In contrast to Broca’s functionality. of fluency is variable so that speech may appear entirely interruption normal if the patient is allowed to engage in small talk. Logopenic PPA 26-1 but usually has longer and the anomic aphasia of Table resembles the is impaired pauses. When repetition word-finding frequent more the aphasia resembles types, this is the one most commonly associated with the pathology of major three these to addition In cause. the be also can FTLD but AD, is also a subtypes, there This is most like the global jointly impaired. are comprehension word in the form of can present PPA 26-1. Rarely, aphasia of Table deafness FOR NETWORK THE PARIETOFRONTAL concrete objects. This is a part of the brain that was not included within objects. concrete because it is not a common the classic language network, probably an FTLD with frequently is The neuropathology site for focal CVAs. DNA-binding of the 43-kDa transactive response abnormal precipitates of type C. TDP-43 protein PPA Logopenic word-finding and severe but frequent syntax and comprehension and simplifications during sponta pauses, anomia, circumlocutions, sites are Peak neous speech. Repetition is usually impaired. junction and posterior temporal lobe, located in the temporoparietal area. of Wernicke’s partially overlapping with traditional location impairment of the comprehension However, progression progression IN PPA LANGUAGE For exam aphasias. those seen in CVA-caused patterns from different in is almost never seen aphasia of Wernicke’s syndrome ple, the full com and word that sentence comprehension confirming the view PPA, of the language network. regions by different controlled are prehension can be recognized. major subtypes of PPA Three Agrammatic PPA word intact but grammar impaired and fluency low consistently aphasia or anterior Broca’s resembles It most closely comprehension. or dys but usually lacks the right hemiparesis transcortical aphasia Peak of grammar. impairments profound more arthria and may have include the left inferior fron atrophy) loss (gray matter sites of neuronal a is usually is located. The neuropathology area Broca’s where tal gyrus AD pathology. but can also be an atypical form of FTLD with tauopathy Semantic PPA and profound comprehension fluency and syntax but poor single-word with This kind of aphasia is not seen naming impairments. two-way transcortical aphasia or posterior Wernicke’s from It differs CVAs. is intact. and repetition aphasia because speech is usually informative if the meaning is preserved of sentences is relatively Comprehension that fail to be understood allowing the not too dependent on words cues. contextual through gist of the conversation patient to surmise the in the course of casual small talk Such patients may appear unimpaired such undecipherable word but become puzzled upon encountering an located in the left sites are Peak atrophy as “pumpkin” or “umbrella.” crit a plays brain the of part this that indicating lobe, temporal anterior that denote words especially of words, in the comprehension role ical or Alzheimer’s disease (AD) pathology. Rarely, an identical syndrome identical syndrome an Rarely, Alzheimer’sor disease (AD) pathology. rapid (CJD) but with a more disease by Creutzfeldt-Jacob can be caused

------Chap. refers refers Ideational (impair corticobasal finger anomia , acalculia Aphasias caused by involves clumsiness in involves refers to aspects of lan to refers ?” contain an identical word word identical contain an ?” (impaired writing), (impaired clever give the mistaken impression of give the mistaken impression Pragmatics The combination of combination The ) and frontotemporal (behavioral; ) and frontotemporal dysgraphia Damage to subcortical components of the aprosodia Limb-kinetic apraxia (an inability to tell whether a hand, foot, or arm (an inability to tell whether a hand, foot, or clever.” and “He is “He and clever.” Chap. 423 is . refers to a deficit in the sequencing of goal-directed movements the sequencing of goal-directed to a deficit in refers right-left confusion ) , can also include language impairments as the disease Several neurodegenerative syndromes, such as typical Alzheimer- such as typical syndromes, Several neurodegenerative overall syndrome. A diagnosis of PPA is justified only if the language is justified only if the language diagnosis of PPA A overall syndrome. isolation, becomes the primary (i.e., aphasia) arises in relative disorder the concern that brings the patient to medical attention, and remains by either FTLD can be caused salient deficit for 1–2 years. PPA most 424 of the component ancillary an is aphasia the cases, In these progresses. sion. The neuropathology can be selective not only for gray matter but sion. The neuropathology also for specific layers and cell types. The clinico-anatomic patterns are 26-1. those described in Table from different therefore type (amnestic; fit the specific patterns described in Table 26-1. In a patient with a CVA, a patient with a CVA, 26-1. In fit the specific patterns described in Table with aphasia fluent a or dysarthria by accompanied aphasia anomic an should raise the suspicion of a subcortical lesion site. hemiparesis OF PPA AND DIAGNOSIS PRESENTATION CLINICAL start suddenly and display maximal deficits at the onset. These CVAs Aphasias caused by neu the “classic” aphasias described above. are progres diseases have an insidious onset and relentless rodegenerative being depressed or indifferent. Other aspects of pragmatics, especially or indifferent. being depressed the ability to infer the figurative aspect of a message, become impaired lobes. or frontal by damage to the right hemisphere Subcortical Aphasia language network (e.g., the and of the left hemi contain syndromes also can lead to aphasia. The resulting sphere) combinations of deficits in the various aspects of language but rarely ferences in the intonation with which the statements are uttered. Dam uttered. the intonation with which the statements are in ferences impairs area to Broca’s corresponding regions age to right hemisphere into spoken prosody meaning-appropriate the ability to introduce with language grammatically correct language. The patient produces in a monotone uttered choice, but the statements are accurate word effect. and with the ability to convey the intended stress that interferes Patients with this type of Pragmatics and Prosody and the figurative rather than guage that communicate attitude, affect, to the thumb” does not refer literal aspects of a message (e.g., “green pragmatics, actual color of the finger). One component of and intonation that influence attitude to variations of melodic stress aspect of verbal messages. For example, the two and the inferential “He statements of dif messages because choice and syntax but convey vastly different of the patient or examiner is on the right or left side of the body) is of the patient or examiner is on the right In making this diagnosis, it is impor known as Gerstmann’s syndrome. not naming deficits are tant to establish that the finger and left-right generalized anomia and that the patient is not otherwise part of a more arises acutely and in isolation, aphasic. When Gerstmann’s syndrome the inferior parietal lobule it is commonly associated with damage to in the left hemisphere. (especially the angular gyrus) emerge in the context of focal premotor cortex lesions or lesions cortex premotor focal of context the in emerge degeneration Syndrome Gerstmann’s ment of simple arithmetic), fingers such as the index and thumb), (an inability to name individual and cap at the opposite end, turning the point toward the writing surface, the writing surface, the point toward end, turning cap at the opposite and the patient may be seen trying to and writing may be disrupted, cap. removed the with pen or even end of the write with the wrong seen in the context of usually are problems These motor sequencing lesions associated dementias rather than focal confusional states and conditions. aphasic with pyra that cannot be attributed to sensory, the use of tools or objects dysfunction. This condition can or cerebellar midal, extrapyramidal, by additional features of motor disinhibition on the left hand. of motor disinhibition features by additional apraxia the individual compo executing who have no difficulty in patients is asked to pick when the patient sequence. For example, nents of the pen, placing the of uncapping the write, the sequence up a pen and

4 PART 2 Cardinal Manifestations and Presentation of Diseases Harrisons_20e_ch26_p001-p009.indd 4 5 CHAPTER26 Aphasia, Memory Loss, Hemispatial Neglect, Frontal Syndromes and Other Cerebral Disorders

------), 8/4/17 12:21 PM dressing dressing

. ), and the oculomotor apraxia and is much more and is much more optic is not by itself sufficient is not by itself sufficient B ). A patient with simultanag A ). simultaneous bilateral stimulation simultaneous and is a manifestation of the sen and is a manifestation construction apraxia . Bálint’s syndrome involves deficits in the . Bálint’s syndrome . In the former, the examiner provides either provides the examiner . In the former, simultanagnosia . Hemianopia is not by itself sufficient to cause the itself sufficient . Hemianopia is not by ) A . This occurs because the information needed for the iden ) Bálint’s syndrome Bálint’s B (Fig. 26-3 . A patient with this condition is unable to align the body axis to align the with this condition is unable patient A . visual target cancellation visual target BÁLINT’S SYNDROME, SIMULTANAGNOSIA, SIMULTANAGNOSIA, BÁLINT’S SYNDROME, A modification of the letter cancellation task described above can above described task cancellation letter the of modification A Bilateral parietal lesions can impair the integration of egocentric ■ apraxia as he or she with the axis of the garment and can be seen struggling its bottom or extends his or her arm into a fold of the holds a coat from rather than into its sleeve. Lesions that involve the posterior garment in copying simple line difficulties parietal cortex also lead to severe drawings. This is known as a In some patients with if the lesion is in the right hemisphere. severe confined to the are lesions, the drawing difficulties right hemisphere peripheral information ( who is For example, a patient for the trees.” nosia “misses the forest object may look at its cir shown a table lamp and asked to name the Some patients with simultanagnosia cular base and call it an ashtray. indicat probably objects they look at may vanish suddenly, that report point original the to return oculomotor the compute to inability an ing Movement and distracting of gaze after brief saccadic displacements. Simul of visual . exacerbate the difficulties stimuli greatly components of Bálint’s tanagnosia can occur without the other two syndrome. In this modifica be used for the bedside diagnosis of simultanagnosia. the than to be much larger made are A’s) (e.g., of the targets tion, some others (7.5–10 cm vs 2.5 cm [3–4 in. vs 1 in.] in height), and all targets embedded among foils. Patients with simultanagnosia display a are targets counterintuitive but characteristic tendency to miss the larger (Fig. 26-3 cannot be confined to the immediate targets tification of the larger the integration of visual information across line of gaze and requires in the detection of the difficulty multiple fixation points. The greater for the indicates that poor acuity is not responsible also targets larger is central rather impairment of visual function and that the problem than peripheral. The test shown in Fig. 26-3 to diagnose simultanagnosia because some patients with a frontal letters, perhaps may omit the strange looking large network syndrome that the two because they lack the mental flexibility needed to realize superficially being despite identical symbolically are targets of types different. One manifestation is with allocentric spatial coordinates. dency to leave an unusually wide margin on the left. Two bedside tests bedside tests on the left. Two margin an unusually wide dency to leave neglect are useful in assessing that are and visual, auditory, stimulation in the simultaneous bilateral unilateral or who patients , After right hemisphere and tactile modalities. side experience on either unilateral stimuli detecting difficulty no have the right. This as coming only from stimulus the bilaterally presented as phenomenon is known detec neglect. In the target aspect of hemispatial sory-representational with foils (e.g., other letters interspersed are A’s) (e.g., tion task, targets the and in.) sheet of paper, to 28.0-cm (8.5–11 of the alphabet) on a 21.5- on the targets to detect failure A targets. all the patient is asked to circle hemispatial in deficit (motor) exploratory the of manifestation a is left neglect to turn the head and is free because the patient detection failure target a distortion of reflect therefore detection failures eyes to the left. Target neglect with patients Some input. sensory of just not attention, spatial and may even deny owner also may deny the existence of hemiparesis as ship of the paralyzed limb, a condition known ■ APRAXIA, DRESSING APRAXIA, CONSTRUCTION FINDING AND ROUTE attention, especially Bilateral involvement of the network for spatial spatial disorientation its parietal components, leads to a state of severe known as ( environment the of scanning visuomotor orderly ( visual targets toward accurate manual reaching more with gaze of center the in information visual ability to integrate When asked to copy a simple line drawing, the patient fails to copy drawing, the patient to copy a simple line When asked a ten is there is asked to write, left, and when the patient detail on the

- - contralaterally The traditional The red and black areas show regions ) The subjects were asked to determine asked ) The subjects were extrapersonal space, whereas the extrapersonal space, whereas Top entire Patients with severe neglect may fail to neglect may fail Patients with severe Functional magnetic resonance imaging of language and spatial Functional magnetic resonance imaging of language (Courtesy MD; with permission.) of Darren Gitelman, ) The subjects were asked to shift spatial attention to a peripheral to shift asked ) The subjects were . According to one model of spatial cognition, the right hemisphere to one model of spatial cognition, the right hemisphere According . HEMISPATIAL NEGLECT HEMISPATIAL ■ Bottom hemispace is rare, even in left-handers with left hemisphere lesions. even in left-handers with left hemisphere hemispace is rare, Examination Clinical the left side of the body; fail to eat food placed shave, or groom dress, sentences. of half left the to read fail and tray; the of side left the on of the right hemisphere can compensate for the loss of the of the right hemisphere Right hemisphere attentional functions of the left hemisphere. directed left hemispatial contralesional give rise to severe lesions, however, does not contain ipsi left hemisphere neglect because the unaffected lateral attentional mechanisms. This model is consistent with clinical common, experience, which shows that contralesional neglect is more lasting after damage to the right hemisphere and longer severe, more neglect for the right Severe than after damage to the left hemisphere. to the cortical or subcortical components of this network. view that hemispatial neglect always denotes a lesion is inaccu rate attention within the directs attention mostly within the contralateral right directs left hemisphere lesions do not give rise to left hemisphere hemispace. Consequently, much contralesional neglect because the global attentional mechanisms distribution of attention within the extrapersonal space, giving rise todistribution of attention within the extrapersonal The hemispatial neglect, simultanagnosia and object finding failures. with allocentric (object-centered) integration of egocentric (self-centered) giving rise to impairments in route can also be disrupted, coordinates finding, the ability to avoid obstacles, and the ability to dress. ■ one outcome of damage Contralesional hemispatial neglect represents ( of the three epicenterstarget. This task led to the simultaneous activation of fields the attentional network: the posterior parietal cortex the frontal eye (P), gyruscingulate and the in the right predominantly (CG). The activations are (F), hemisphere. can undermine thestriatum and the thalamus. Damage to this network FIGURE 26-2 attention in neurologically intact subjects. of task-related significant activation. ( This language task led to the simultaneous synonymous. if two words were area (B) and Broca’s activation of the two epicenters network, of the language are exclusively in the left hemisphere. area (W). The activations Wernicke’s Harrisons_20e_ch26_p001-p009.indd 5 8/4/17 12:21 PM . Lewy posterior (Fig. 26-4) cannot recognize familiar , including, faces, familiar recognize cannot (PCA) syndrome, most commonly represents a variant most commonly represents (PCA) syndrome, A progressive form of spatial disorientation, known as the form of spatial progressive A THE OCCIPITOTEMPORAL NETWORK FOR FOR NETWORK THE OCCIPITOTEMPORAL AND OBJECT RECOGNITION FACE with patient A This of his or her own face in the mirror. sometimes, the reflection patients easily can deficit because prosopagnosic is not a perceptual a prosopagnosic identical. Furthermore, tell whether two faces are a familiar face by visual inspection alone patient who cannot recognize if allowed to recognition appropriate can use auditory cues to reach cortical atrophy degeneration in AD with unusual concentrations of neurofibrillary of the parieto-occipital cortex and the superior colliculus type) degeneration (corticobasal FTLD and CJD, (LBD), disease body hemispatial progressive displays patient The causes. possible other are finding impairments, usually and route neglect, Bálint’s syndrome, apraxia. and construction accompanied by dressing - - A 70-year-old woman with a 2-year history most of the small targets but able to circle of degenerative was B. B Cerebrovascular lesions and neoplasms lesions Cerebrovascular A A 47-year-old man with a large frontoparietal lesion in the right hemisphere was asked to circle all the ‘A’s. Only targets on the right are circled. This circled. on the right are Only targets the ‘A’s. all circle to asked was the right hemisphere in lesion frontoparietal large a with man A 47-year-old A. first several weeks. Bálint’s syndrome, dressing apraxia, and route apraxia, and route dressing first several weeks. Bálint’s syndrome, bilateral dorsal from likely to result more finding impairments are parietal lesions; common settings for acute onset include watershed artery territories, between the middle and posterior cerebral infarction hypoglycemia, and sagittal sinus thrombosis. Causes of Spatial Disorientation and the Posterior Corti Syndrome cal Atrophy common causes of hemispatial neglect. are in the right hemisphere Depending on the site of the lesion, a patient with neglect also may hemihypesthesia, and hemianopia on the left, but have hemiparesis, not invariant findings. The majority of these patients display these are of hemispatial neglect, usually within the considerable improvement ignored the larger ones. This is a manifestation of simultanagnosia. a manifestation of hemispatial and represent left side of the figure con universal deficit in reproducing is a more neglect; in others, there finding perspective. Impairments of route tours and three-dimensional an inability to which reflect of disorders, can be included in this group to external objects and landmarks. orient the self with respect FIGURE 26-3 is a manifestation of left hemispatial neglect.

6 PART 2 Cardinal Manifestations and Presentation of Diseases Harrisons_20e_ch26_p001-p009.indd 6 7 CHAPTER26 Aphasia, Memory Loss, Hemispatial Neglect, Frontal Syndromes and Other Cerebral Disorders

------8/4/17 12:22 PM limbic sys T) , which indicates retrograde amnesia retrograde

. In the absence of deficits . Patients with the amnestic ZHEIMER-TYPE-DA NESTIC anterograde amnesia anterograde AD>>>FTLD

THE AL AM amnestic state confabulation OF VIEW . For example, patients with amnestic states . For example, patients with amnestic states

(DEMENTIA MEDIAL A) implicit memory

ROPHY-PC AT TIAL . The behavioral affiliations of this network include the coordina . The behavioral affiliations CLINICAL EXAMINATION CLINICAL The memory disturbance in the amnestic state is multimodal andThe memory disturbance in the amnestic ■ L PA frontal network, as in the case of the Wernicke-Korsakoff syndrome or syndrome network, as in the case of the Wernicke-Korsakoff frontal traumatic . ■ patient with an amnestic state is almost always disoriented, espe A news. The antero cially to time, and has little knowledge of current four of list a with state can be tested amnestic an of component grade aloud by the examiner up to five times or until the read to five words in motivation, attention, language, or visuospatial function, the clinical the function, visuospatial or language, attention, motivation, in is always associated with diagnosis of a persistent global amnestic state within the hippocam bilateral damage to the limbic network, usually complex or the thalamus. Damage to the limbic network po-entorhinal con with their memories but interferes does not necessarily destroy form. The individual fragments of information in coherent scious recall what is despite the limbic lesions and can sustain preserved remain known as have skills even though they may new motor or perceptual can acquire that led to the acquisition no conscious knowledge of the experiences of these skills. components. The and anterograde retrograde includes the onset before experiences that occurred involves an inability to recall vulnerable to more events are of the amnestic state. Relatively recent consol extensively and more remote more than are amnesia retrograde complain room patient who comes to the emergency A idated events. the remember can but identity her or his remember cannot he that ing day almost certainly does not have a neurologic events of the previous cause of memory disturbance. The second and most important com ponent of the amnestic state is the new knowledge. Patients with and recall retain, an inability to store, what they ate a few hours ago or amnestic states cannot remember the details of an important event they may have experienced in the also may be a tendency to fill past. In the acute stages, there recent in memory gaps with inaccurate, fabricated, and often implausible information. This is known as of a to deny the existence tend and they forget that forget syndrome common more is Confabulation when questioned. problem memory with parts of the the underlying lesion also interferes in cases where collectively constitute a distributed network known as the collectively constitute a distributed network tem and endocrine function. tion of emotion, motivation, autonomic tone, the and network limbic the for specialization of area additional An to clinical practice is that of declarative one that is of most relevance disturbance A experiences. and episodes recent for memory (explicit) in this function is known as an - - - - - AD>>LBD>FTLD seman VISUO-S (POSTERIOR CORTICA

that result agnosias that result

SIA- PPA) associative PHA VIEW SIC L . A patient with anomia cannot name the patient A . PHA FTLD>AD LATERAL A IORA L DEMENTIA- bvFTD) RY PROGRESSIVE A FTLD>>AD BEHAV (PRIMA Four focal dementia syndromes and their most likely neuropathologic correlates. AD, Alzheimer’s disease; bvFTD, behavioral variant frontotemporal behavioral disease; bvFTD, Alzheimer’s neuropathologic correlates. AD, focal dementia syndromes and their most likely Four agnosias as opposed to the . Patients with fail to recognize faces and . Patients with semantic dementia fail to recognize visual object (FRONTOTEMPORA CAUSES AND RELATION TO SEMANTIC DEMENTIA TO AND RELATION CAUSES ■ AND AMNESIA (such as the hippocampus, , Limbic and paralimbic areas thalamus, the of nuclei medial and anterior the cortex), entorhinal and the medial and basal parts of the striatum, and the hypothalamus there is severe impairment in understanding words that denote objects in understanding words impairment is severe there of face preservation and in naming faces and objects but a relative is usually The anterior temporal lobe atrophy and object recognition. mostly the left it tends to affect bilateral in semantic dementia whereas dementia Acute onset of the semantic in semantic PPA. hemisphere can be associated with herpes simplex . syndrome MEMORY FOR EXPLICIT LIMBIC NETWORK lesions in the left. Degenerative diseases of anterior and inferior tempo and object associative prosopagnosia ral cortex can cause progressive associative agnosia and a flu agnosia. The combination of progressive impairment is known as comprehension ent aphasia with word tic dementia objects. denoting the meaning of words understand objects and cannot where the semantic type of PPA from This needs to be differentiated ■ and visual object agnosia of The characteristic lesions in prosopagnosia in the territory of the poste acute onset consist of bilateral infarctions Associated deficits arteries that involve the . rior cerebral can include defects (especially superior quadrantanopias) Rarely, and a centrally based color blindness known as . is prosopagnosia cases, such In unilateral. lesion is responsible the and object agnosia with associated with lesions in the right hemisphere, object but can describe its use. In contrast, a patient with visual agno object but can describe its use. In contrast, object or to describe sia is unable either to name a visually presented the from also can result disorders its use. Face and object recognition as known in which case they are simultanagnosia of Bálint’s syndrome, apperceptive temporal lobe lesions. inferior from no difficulty with the generic identification of a face as a face or a car or a face a face as generic identification of the with difficulty no the identity of an individual face or but may not recognize as a car, deficit a visual recognition This reflects the make of an individual car. of an that characterize individual members features for proprietary generalized and become more problems object class. When recognition objects, the condition is extend to the generic identification of common known as dementia; DAT, amnestic dementia of the Alzheimer-type; FTLD, frontotemporal lobar degeneration (tau or TDP-43 type); LBD, Lewy body disease; PCA, posterior cortical body disease; PCA, Lewy frontotemporal lobar degeneration (tau or TDP-43 type); LBD, amnestic dementia of the Alzheimer-type; FTLD, dementia; DAT, primary progressive aphasia. syndrome; PPA, atrophy is therefore prosopagnosia listen to the person’s voice. The deficit in the existence of a lesion that prevents modality-specific and reflects associative templates by the activation of otherwise intact multimodal have patients characteristically input. Prosopagnosic visual relevant FIGURE 26-4 Harrisons_20e_ch26_p001-p009.indd 7 8/4/17 12:22 PM ------, the frontal abulic syndrome frontal deficits of explicit memory. deficits of explicit memory. has been introduced to desig has been introduced secondary , the patient becomes socially disinhibited , the patient becomes salience network CLINICAL EXAMINATION CLINICAL The attentional deficits disrupt the orderly registration and retrieval and retrieval registration the orderly The attentional deficits disrupt The prefrontal network plays an important role in behaviors that role network plays an important The prefrontal ■ impersistence and perseveration. The ability for abstracting similarities is also undermined. proverbs and interpreting information and lead to of new The distinction of the underlying neural mechanisms is illustrated by amnestic patients who cannot remember the observation that severely superior if not have intact ago may minutes a few occurred events that working memory capacity as shown in tests of digit span. The use of sician must therefore be prepared to make a diagnosis of to make a diagnosis of frontal be prepared sician must therefore even when the mental state disease based on historic information alone examination. is quite intact in the office ■ as also known of developmentally primitive reflexes, The emergence the palm) signs, such as grasping (elicited by stroking release frontal patients seen primarily in the lips) are and sucking (elicited by stroking components premotor the into that extend lesions structural large with lobes or in the context of metabolic encephalopathies. of the frontal lobe lesions and frontal The vast majority of patients with prefrontal to the Damage do not display these reflexes. behavioral syndromes functions, including a variety of attention-related lobe disrupts frontal of manipulation and holding online transient (the memory working scanning and retrieval information), concentration span, the effortful information, the inhibition of immediate but inappropriate of stored Digit span (which should be seven and mental flexibility. responses, poor working mem reflecting is decreased, and five reverse) forward (which order of the year in reverse months of the ory; the recitation should take <15 s) is slowed as another indication of poor working letter the with starting words producing in fluency the and memory; a, f, or s that can be generated in 1 min (normally ≥12 per letter) is diminished even in nonaphasic patients, indicating an impairment in In long-term stores. information from and retrieve the ability to search is to raise the finger upon hear the instruction “go–no go” tasks (where ing one tap but keep it still upon hearing two taps), the patient shows a to the “no go” stimulus. characteristic inability to inhibit the response one criterion to Mental flexibility (tested by the ability to shift from another in sorting or matching tasks) is impoverished; distractibility by tendency for is a pronounced and there is increased; stimuli irrelevant that coordinates exceedingly complex aspects of human cognition of human cognition complex aspects exceedingly that coordinates The term and behavior. interactions with adjacent network and their of the frontal nate parts of Impairments and cingulate gyrus. cortices of the insula paralimbic demen frontal seen in neurodegenerative social conduct and empathy of the salience network. attributed to pathology tias are emotion. with thought of integration the and multitasking require lesions often cortex by prefrontal impaired Cognitive operations clinical common most The “.” as to referred are network take the form of to the prefrontal manifestations of damage In the distinct syndromes. two relatively and curiosity and displays initiative, creativity, patient shows a loss of In the and lack of empathy. blandness, , a pervasive emotional disinhibition syndrome frontal and the of judgment, insight, foresight, impairments and shows severe between intact intel of conduct. The dissociation ability to mind rules common sense lectual function and a total lack of even rudimentary functions, memory essential all of Despite the preservation striking. is experience and continues to display inap the patient cannot learn from behaviors without appearing to feel emotional pain, guilt, propriate conse lead to disastrous when those behaviors repeatedly or regret when situations only in real-life quences. The impairments may emerge and may not be apparent under minimal external control behavior is judg Testing of the medical office. environment within the structured a in detected a fire they do if would by asking patients what they ment is not envelope on the road theater or found a stamped and addressed wisely questions these answer who patients because informative very The phy settings. foolishly in real-life still act very may the office in interconnected (i.e., the head of the caudate and the dorsomedial and the dorsomedial the head of the caudate (i.e., interconnected network make up a large-scale the thalamus), collectively nucleus of

------refer only to the last three of only to the last three refer is a distinctive syndrome usually seen in seen usually syndrome distinctive a is prefrontal cortex prefrontal and CAUSES, INCLUDING ALZHEIMER’S DISEASE CAUSES, Transient global amnesia global Transient The most common cause of progressive memory impairments in the memory impairments The most common cause of progressive ■ frontal lobe syndrome frontal cortex that the parts of the cerebral these four components. These are phylogenetic expansion in primates, especially in show the greatest and orbitofron medial prefrontal, humans. The dorsolateral prefrontal, with which they are along with the subcortical structures tal areas, ings occasionally may lead to the incorrect diagnosis of a psychiatric ings occasionally may lead to the incorrect disorder. FOR NETWORK THE PREFRONTAL EXECUTIVE FUNCTION AND BEHAVIOR dorsolateral lobes can be subdivided into motor-premotor, The frontal components. The terms and orbitofrontal medial prefrontal, prefrontal, that occurred before the onset. The syndrome usually resolves within usually resolves the onset. The syndrome before that occurred by the 24–48 h and is followed by the filling in of the period affected is persistent loss of memory for the although there amnesia, retrograde noted in ~20% of are during the ictus. Recurrences events that occurred and perfusion abnormalities patients. Migraine, temporal lobe seizures, territory have been postulated as causes of in the posterior cerebral find transient global amnesia. The absence of associated neurologic language, attention, and visuospatial skills emerge as the neurofibril emerge language, attention, and visuospatial skills Less fre to additional neocortical areas. lary degeneration spreads amnestic dementias can also be caused by FTLD. quently, late middle age. Patients become acutely disoriented and repeatedly doing. The and what they are they are, where ask who they are, new amnesia (inability to retain spell is characterized by anterograde events recent relatively for amnesia retrograde a and information) elderly is AD. This is why a predominantly amnestic dementia is also amnestic AD. This is why a predominantly elderly is stage prodromal A (DAT). Alzheimer-type known as a dementia of the is known generally preserved, are when daily living activities of DAT, of the The predilection as amnestic mild cognitive impairment (MCI). degener cortex and hippocampus for early neurofibrillary entorhinal selective initially the for responsible is pathology AD typical by ation In time, additional impairments in impairment of episodic memory. eral lesions within one or more components in the limbic network. eral lesions within one or more unilateral left-sided hippocampal lesions can give rise Occasionally, tends to be transient. to an amnestic state, but the and distribution of the underlying neurologic Depending on the nature deficits, field have visual disease, the patient also may findings. limitations, or cerebellar ■ diseases that give rise to an amnestic state include tumors Neurologic thalamus, or medial (of the sphenoid wing, posterior corpus callosum, (in the territories of the anterior or pos temporal lobe), infarctions simplex encephalitis, herpes trauma, head arteries), terior cerebral autoimmune limbic encephalitis, encephalopathy, Wernicke-Korsakoff Pick’s disease. The one AD and and degenerative dementias such as of bilat is the presence common denominator of all these diseases metabolic encephalopathies and some types of frontal lobe damage and some types of frontal metabolic encephalopathies of impairments, especially at the stages lead to secondary memory the absence of limbic lesions. This sort even in encoding and retrieval, the amnestic state from can be differentiated of memory impairment tasks in the attention-related of additional impairments by the presence lobes. described below in the section on the frontal tiple choice in a patient who cannot recall them indicates a less severe severe less a indicates them recall cannot who patient a in choice tiple stage of memory. mostly the retrieval affects memory disturbance that can be assessed with ques component of an amnesia The retrograde or historic events. The anterograde to autobiographical tions related than prominent states is usually much more component of amnestic associated instances, occasionally component. In rare the retrograde retro or herpes simplex encephalitis, the with temporal lobe toxic- dominate. Confusional states caused by grade component may patient can immediately repeat the entire list without an intervening list without the entire immediately repeat patient can of 5–10 min occurs after a period the recall The next phase of delay. Amnestic patients in other tasks. the patient is engaged during which given a that they were even forget of the task and may fail this phase mul by words of the Accurate recognition to remember. list of words

8 PART 2 Cardinal Manifestations and Presentation of Diseases Harrisons_20e_ch26_p001-p009.indd 8 9 CHAPTER26 Aphasia, Memory Loss, Hemispatial Neglect, Frontal Syndromes and Other Cerebral Disorders

, - - - - 8/4/17 12:22 PM , M-M The Behavioral of Dementia The BF (eds): Principles of Behavioral and Cognitive Neurology oeve M et al: Direct current stimulation over the anterior tempo current M et al: Direct M-M et al: Case 1-2017: A 70-year-old woman with gradually 70-year-old A M-M et al: Case 1-2017: M-M: Behavioral neuroanatomy: Large-scale networks, asso networks, Large-scale neuroanatomy: Behavioral M-M: BL, B FURTHER READING FURTHER As in all other branches of medicine, a crucial step in patient care is care patient in step crucial a medicine, of branches other all in As esulam iller esulam ■ progressive loss of language. N Engl J Med 376:158, 2017. loss of progressive 2017. 2nd ed. Cambridge University Press, ciation cortex, frontal syndromes, the limbic system and hemispheric syndromes, ciation cortex, frontal specialization, in 2000, pp 1–120. University Press, Oxford York, Mesulam (ed). New ral areas boosts semantic processing in primary progressive aphasia. in primary progressive boosts semantic processing ral areas 80:693, 2016. Ann Neurol eichmann M M T contralateral hemisphere. Depression and sleep disorders can inten and sleep disorders Depression contralateral hemisphere. appropriate with be treated and should disorders cognitive the sify become absolutely necessary for the control modalities. If neuroleptics because of their lower preferable are of agitation, atypical neuroleptics in elderly neuroleptics with Treatment side effects. extrapyramidal against weighing the potential benefits patients with dementia requires the case to This is especially relevant the potentially serious side effects. sensitive unusually be can who dementia, body Lewy with patients of to side effects. done easily This is impairment. the of cause identify the underlying to head trauma or encephalitis but becomes particularly in cases of CVA, clinical progressive same the because dementias the in challenging entities. can be caused by one of several neuropathologic syndrome The advent of imaging, blood, and CSF biomarkers now makes it success and to make this question with reasonable possible to address specific etiological diag A AD, LBD, CJD, FTLD. specific diagnoses of clinical trials or medications physician to recommend the allows nosis A for the underlying disease process. the most appropriate that are clinical assessment that identifies the principal domain of behavioral and cognitive impairment followed by the judicious use of biomarker of the underlying disease allows a information to surmise the nature to patients with higher cognitive impairment. personalized approach ■ M structures, e.g., the right superior temporal gyrus with recovery from from recovery with temporal gyrus superior e.g., the right structures, a diseases show In contrast, neurodegenerative aphasia. Wernicke’s patient from at rates that vary greatly of impairment but progression to patient. Pharmacologicand non-pharmacologic interventions theythat complex so are chapter this in described deficits the of Some the patient and family but also the physician.may bewilder not only of evaluation careful a deficits requires of patients with such The care Each piece and diagnostic procedures. test results cognitive the history, context.in placed and cautiously interpreted be to needs information of anomia;an reflect may example, for memory,” “poor of complaint A a weakness of attention rather reflect on a learning task may poor scores may reflect or indifference depression of a report than explicit memory; mood or empathy; jocularity rather than a change in prosody impaired are Although there than good mood. poor insight rather may arise from non-pharmacologic studies, several interventionsfew well-controlled higher cortical deficits. These include speech have been used to treat comportmental for modification behavioral aphasias, for therapy and cognitive training for visuospatial disorientation and disorders, practical interventions, usually delivered More amnestic syndromes. daily living activities aim to improve therapy, occupational through devices and modifications of the home environment. assistive through especially in the Determining driving competence is challenging, and test driving on-the-road An diseases. dementing stages of early to this family members may help time decisions related from reports conditions such as PPA, In neurodegenerative very important activity. mixed stimulation has had current) transcranial magnetic (or direct The goal is to activate success in eliciting symptomatic improvement. of the regions or in unaffected at sites of atrophy neurons remaining Other mechanisms may involve functional reorganization in surviving functional reorganization may involve Other mechanisms use of homologous injury or the compensatory adjacent to the neurons ------, with , frontal network syndrome frontal deficiency, among others. Many deficiency, 12 CAUSES: TRAUMA, NEOPLASM, AND NEOPLASM, TRAUMA, CAUSES: Lesions in the or in the dorsomedial nucleus of the nucleus the dorsomedial the caudate nucleus or in Lesions in ■ from remote dysfunction (diaschisis) in brain regions that are inter that are (diaschisis) in brain regions dysfunction remote from in these patients Improvement connected with the site of initial injury. dysfunction. at least in part, a normalization of the remote may reflect, CARING FOR PATIENTS WITH DEFICITS OF WITH DEFICITS OF FOR PATIENTS CARING HIGHER CEREBRAL FUNCTION or of cognitive deficits following stroke Spontaneous improvement trauma is common. It is most rapid in the first few weeks but may continue for up to 2 years, especially in young individuals with single brain lesions. Some of the initial deficits in such cases appear to arise it is advisable to use the diagnostic term diagnostic the use advisable to is it within lesions can lie anywhere the understanding that the responsible lobe disease raises patient with frontal A this distributed network. diagnosis: the and blandness potential dilemmas in differential and the disinhibition as idio as depression, may be misinterpreted intervention may be delayed Appropriate pathic mania or acting out. tumor keeps expanding. while a treatable the single most common behavioral profile associated with a variety of variety a with associated profile behavioral common most single the bilateral multifocal brain diseases, including metabolic encephalopa and vitamin B multiple sclerosis, thy, tend to lobe syndrome patients with the clinical diagnosis of a frontal the either involve but cortex prefrontal involve not do that lesions have network or its connections subcortical components of the prefrontal “frontal of diagnosis a making avoid To brain. the of parts other with cortex disease, in a patient with no evidence of frontal lobe syndrome” degenerative diseases such as Parkinson’s disease and degenerative basal ganglia diseases such as lobe syn of the frontal Huntington’s disease display components of none hemispheres, cerebral the lesions of Bilateral multifocal drome. deficits enough to cause specific cognitive individually large which are with the connec interfere such as aphasia and neglect, can collectively integrating (executive) function of the prefrontal tivity and therefore usually of the abulic form, is therefore lobe syndrome, frontal A cortex. lobe syndrome, but almost always on a background of severe memory of severe but almost always on a background lobe syndrome, the in isolation in arise can syndrome bvFTD the Rarely, impairment. AD pathology. context of an atypical form of also can network) thalamus (subcortical components of the prefrontal mostly executive functions. affecting lobe syndrome frontal a produce why the changes in mental state associated with This is one reason neurodegenerative frontal syndrome is known as the behavioral vari syndrome frontal neurodegenerative dementia (bvFTD). The behavioral changes in ant of frontotemporal apathy to shoplifting, compulsive gam these patients can range from ritu lack of common sense, new remarkable bling, sexual indiscretions, leading usually alistic behaviors, and alterations in dietary preferences, items. food specific to rigid attachment taste for sweets or increased to eventually degeneration AD, neurofibrillary In many patients with and gives rise to components of the frontal cortex prefrontal to spreads bolic CVA is an unusual cause of the frontal lobe syndrome. When syndrome. lobe frontal the of cause unusual an is bolic CVA arise in conjunction with network of the frontal behavioral syndromes on the right lesion tends to be predominantly asymmetric disease, the include lobe syndromes settings for frontal side of the brain. Common tumors (including hydrocephalus, aneurysms, head trauma, ruptured meningiomas), groove metastases, glioblastoma, and falx or olfactory FTLD. The most prominent and focal degenerative diseases, especially FRONTOTEMPORAL dorsolat in damage with associated be to tends syndrome abulic The the disinhibition syndrome cortex, and eral or dorsomedial prefrontal syndromes These cortex. ventromedial or orbitofrontal in damage with exclusively after bilateral lesions. Unilateral tend to arise almost silent until the may remain cortex prefrontal lesions confined to the side; this explains why thromboem to the other pathology spreads the term “memory” to designate two completely different mental fac two completely different to designate the term “memory” holding of depends on the on-line memory Working ulties is confusing. explicit memory depends whereas for brief periods of time information information. of the and subsequent retrieval storage on the off-line ■ Harrisons_20e_ch26_p001-p009.indd 9