DOCSLIB.ORG

Clinical Neuroanatomy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Clinical Neuroanatomy Clinical Neuroanatomy Brain Circuitry and Its Disorders Bearbeitet von Hans J. ten Donkelaar 1. Auflage 2011. Buch. XXIV, 834 S. Hardcover ISBN 978 3 642 19133 6 Format (B x L): 21 x 27,9 cm Weitere Fachgebiete > Medizin > Klinische und Innere Medizin > Neurologie, Neuropathologie, Klinische Neurowissenschaft Zu Inhaltsverzeichnis schnell und portofrei erhältlich bei Die Online-Fachbuchhandlung beck-shop.de ist spezialisiert auf Fachbücher, insbesondere Recht, Steuern und Wirtschaft. Im Sortiment finden Sie alle Medien (Bücher, Zeitschriften, CDs, eBooks, etc.) aller Verlage. Ergänzt wird das Programm durch Services wie Neuerscheinungsdienst oder Zusammenstellungen von Büchern zu Sonderpreisen. Der Shop führt mehr als 8 Millionen Produkte. The Auditory System 7 Hans J. ten Donkelaar and Kimitaka Kaga Contents 7.1 Introduction 7.1 Introduction ......................................................................... 305 The ear or vestibulocochlear organ is composed of external, 7.2 The Cochlea and the Cochlear Nerve................................ 306 middle and inner parts (Fig. 7.1). The external ear consists of 7.2.1 The Middle Ear and the Cochlea: Mechanical the auricle and the external acoustic meatus with the outer Transmission of Sound ......................................................... 306 layer of the tympanic membrane. The middle ear is formed 7.2.2 Cochlear Hair Cells: Transduction and Amplification .......... 308 7.2.3 Spiral Ganglion Cells and the Cochlear Nerve: by the tympanic cavity, the auditory ossicles and the inner Neural Transmission ............................................................. 308 layer of the tympanic membrane. The inner ear comprises 7.2.4 The Auditory Periphery: Generation of Evoked Activity ..... 308 the labyrinth, a series of fluid-filled spaces in the petrous part 7.2.5 Hearing Loss ......................................................................... 309 of the temporal bone. The auditory part of the inner ear con- Clinical Case 7.1 Cerebellopontine Angle Tumour .............. 310 sists of the cochlea with the organ of Corti, which contains 7.3 The Brain Stem Auditory System ...................................... 312 hair cells as auditory receptors. Receptors sensitive to high 7.3.1 The Cochlear Nuclei: Diversification of Cochlear Input .................................................................. 312 frequencies are located near the cochlear base and those sen- 7.3.2 The Superior Olivary Complex: Recreation sitive to low frequencies near the apex of the cochlea. The of Auditory Space ................................................................. 313 hair cells are innervated by the peripheral processes of bipo- 7.3.3 The Upper Brain Stem: Integration lar ganglion cells in the spiral ganglion. Their central pro- of Ascending Auditory Pathway ........................................... 313 7.3.4 Brain Stem Topography: Generation cesses form the cochlear division of the vestibulocochlear of Evoked Potentials ............................................................. 314 nerve and terminate in the cochlear nuclei. The principal Clinical Case 7.2 Impaired Sound Localization auditory pathway passes from the cochlea, via the cochlear Following a Midline Pontine Lesion ..................................... 314 nuclei, the inferior colliculus and the medial geniculate body 7.4 The Forebrain Auditory System ........................................ 315 (MGB) to the contralateral auditory cortex on the dorsal sur- 7.4.1 The Auditory Thalamus ........................................................ 315 face of the superior temporal gyrus. Each MGB is bilaterally 7.4.2 The Acoustic Radiation ........................................................ 315 innervated, so that each hemisphere receives cochlear input 7.4.3 The Auditory Cortex: Sequential Levels of Auditory Processing ......................................................... 316 bilaterally. All of the components of the auditory pathway 7.4.4 Auditory Disorders Related to Stroke ................................... 319 are tonotopically organized. Clinical Case 7.3 Auditory Agnosia Caused At birth, humans have about 20,000 inner and outer hair by Bilateral Lesions Restricted to the cells in the organ of Corti, which often do not last a lifetime Auditory Radiations .............................................................. 321 Clinical Case 7.4 Neuropathology of Auditory Agnosia as they do not regenerate when lost (Stone et al. 1998). By Following Bilateral Temporal Lobe Infarction ..................... 322 the age of 65–75 years, many individuals have a bilateral, Clinical Case 7.5 Auditory Hallucinations high-frequency progressive hearing loss known as presbycu- Following a Metastasis in Heschl’s Gyrus ............................ 324 sis associated with hair cell attrition. Hair cell loss is the 7.5 The Descending Auditory System ......................................... 325 most common cochlear defect causing hearing impairment References ...................................................................................... 326 in presbycusis and noise-induced hearing loss. Hearing dis- orders due to brain stem lesions are rare because of the bilat- eral projections of the central auditory pathways. Midline H.J. ten Donkelaar (*) pontine lesions may result in impaired sound localization 935 Department of Neurology, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands due to interruption of the input of the superior olivary com- e-mail: [email protected] plex (see Sect. 7.3.2 and Clinical case 7.2). Disorders of H.J. ten Donkelaar, Clinical Neuroanatomy, 305 DOI: 10.1007/978-3-642-19134-3_7, © Springer-Verlag Berlin Heidelberg 2011 306 7 The Auditory System Fig. 7.1 Overview of the external, middle and internal ear (from Brödel 1946) auditory perception may follow strokes in the territory of the communicates with the tympanic cavity through two openings internal carotid arteries or of the vertebrobasilar system. The in its medial wall, the oval window or fenestra vestibuli and central disorders of auditory perception may result from the round window or fenestra cochleae. The oval window is lesions of either the right and the left or both cerebral hemi- closed by the base of the stapes, so that vibrations of the audi- spheres, usually involving parietotemporal cortical areas as tory ossicles are transmitted to the perilymph of the inner ear. illustrated in Clinical cases (see Sect. 7.4.4). Motion of the auditory ossicles is modified by two small middle ear muscles, the tensor tympani and the stapedius. The tensor tympani is the largest of the two. It is attached to 7.2 The Cochlea and the Cochlear Nerve the handle of the malleus and is innervated by the trigeminal nerve. The smaller stapedius attaches anteriorly to the head of 7.2.1 The Middle Ear and the Cochlea: the stapes and is innervated by the facial nerve. The stapedius Mechanical Transmission of Sound and tensor tympani motoneurons form separate cell groups, situated close to the facial and motor trigeminal nuclei, respec- The middle ear comprises the tympanic cavity, the tympanic tively (Lyon 1978; Mizuno et al. 1982; Shaw and Baker 1983). membrane, the three auditory ossicles, two middle ear muscles, The stapedius functions to protect the auditory receptors of the air-filled cavities formed by the mastoid antrum and mastoid inner ear against excessive stimulation caused by too strong air cells, and the auditory tube. The tympanic cavity commu- sound pressure. The sound pressure depends on the amplitude nicates with these air-filled cavities and through the auditory of the waves: the greater the amplitude, the higher the sound tube with the nasopharynx (Fig. 7.1). The three auditory ossi- pressure. The stapedius contracts in response to sounds above cles are the hammer or malleus, the anvil or incus and the stir- 70 dB (the intensity of loud conversation), damping the move- rup or stapes. The head of the malleus is anchored to the ments of the auditory ossicle chain. The tensor tympani con- tympanic membrane, whereas the base of the stapes is con- tracts to louder sounds, especially impulse noises. The acoustic nected to the fenestra vestibuli or oval window. Sound waves middle ear reflex includes projections from the ventral set the tympanic membrane into vibrating movements, which cochlear nucleus via the superior olivary nuclear complex to via the auditory ossicles are transmitted to the inner ear. The the motor nuclei of the trigeminal and facial nerves (Borg 1973). inner ear or cochlea is a fluid-filled tube that is coiled two and With electro-acoustic impedance measurements, stapedius a half times. In cross-section, it has a broad base, a pointed apex muscle ­contraction can be readily detected in response to and a central pillar called the modiolus. The osseous labyrinth ipsilateral or contralateral sound, giving objective information 7.2 The Cochlea and the Cochlear Nerve 307 Fig. 7.2 The foetal cochlear duct. At 16 weeks of develop- ment, the cochlear nerve (cn) fibres pass through a central pillar, the modiolus (mod), whereas their cells of origin form vm the spiral ganglia (spg). Below, details of the spiral organ are sve shown for 25 weeks of develop- cd ment. Abbreviations: bm basilar membrane; cd cochlear duct; ihc, st ohc inner and outer hair cells; bm st scala tympani; sva stria spg vascularis; sve scala vestibuli; tC tunnel of Corti; tm tectorial membrane; vm vestibular (Reissner)
Load more

Recommended publications
  • Neurovascular Anatomy (1): Anterior Circulation Anatomy
    Neurovascular Anatomy (1): Anterior Circulation Anatomy Natthapon Rattanathamsakul, MD. December 14th, 2017 Contents: Neurovascular Anatomy Arterial supply of the brain . Anterior circulation . Posterior circulation Arterial supply of the spinal cord Venous system of the brain Neurovascular Anatomy (1): Anatomy of the Anterior Circulation Carotid artery system Ophthalmic artery Arterial circle of Willis Arterial territories of the cerebrum Cerebral Vasculature • Anterior circulation: Internal carotid artery • Posterior circulation: Vertebrobasilar system • All originates at the arch of aorta Flemming KD, Jones LK. Mayo Clinic neurology board review: Basic science and psychiatry for initial certification. 2015 Common Carotid Artery • Carotid bifurcation at the level of C3-4 vertebra or superior border of thyroid cartilage External carotid artery Supply the head & neck, except for the brain the eyes Internal carotid artery • Supply the brain the eyes • Enter the skull via the carotid canal Netter FH. Atlas of human anatomy, 6th ed. 2014 Angiographic Correlation Uflacker R. Atlas of vascular anatomy: an angiographic approach, 2007 External Carotid Artery External carotid artery • Superior thyroid artery • Lingual artery • Facial artery • Ascending pharyngeal artery • Posterior auricular artery • Occipital artery • Maxillary artery • Superficial temporal artery • Middle meningeal artery – epidural hemorrhage Netter FH. Atlas of human anatomy, 6th ed. 2014 Middle meningeal artery Epidural hematoma http://www.jrlawfirm.com/library/subdural-epidural-hematoma
    [Show full text]
  • Bilateral Sudden Hearing Difficulty Caused by Bilateral Thalamic Infarction
    JCN Open Access LETTER TO THE EDITOR pISSN 1738-6586 / eISSN 2005-5013 / J Clin Neurol 2016 Bilateral Sudden Hearing Difficulty Caused by Bilateral Thalamic Infarction Jun-Hyung Lee Dear Editor, Sang-Soon Park Sudden-onset bilateral hearing difficulty has various possible causes, including infectious Jin-Young Ahn diseases of the inner ear, ototoxic medications, and Meniere’s disease.1,2 However, there have Jae-Hyeok Heo been only rare reports of vertebrobasilar arterial infarction that extensively invades the Department of Neurology, brainstem, or bilateral middle cerebral artery infarction that simultaneously invades both Seoul Medical Center, Seoul, Korea auditory cortexes.3-5 Herein we describe a case of bilateral sudden hearing difficulty due to cerebral infarction of the bilateral medial geniculate bodies. A 44-year-old male patient was admitted to Seoul Medical Center due to a 17-day history of sudden-onset hearing difficulty. About 1 year previously he had visited another hospital due to acute left-side paresthesia, and was diagnosed with and treated for diabetic neuropa- thy. A neurological examination revealed normal muscle strength in the bilateral upper and lower extremities, but paresthesia on his left side (both in the limbs and trunk) and hypes- thesia on the right side of the face. A brain MRI scan showed a chronic cerebral infarction at the right thalamic-midbrain junction and a subacute cerebral infarction at the left tha- lamic-midbrain junction (Fig. 1A, B, and C). An otolaryngological examination revealed chronic otitis media without structural abnormalities. His pure-tone audiogram indicated severe sensorineural hearing loss in both ears (Fig.
    [Show full text]
  • DISORDERS of AUDITORY PROCESSING: EVIDENCE for MODULARITY in AUDITION Michael R
    DISORDERS OF AUDITORY PROCESSING: EVIDENCE FOR MODULARITY IN AUDITION Michael R. Polster and Sally B. Rose (Psychology Department, Victoria University of Wellington, Wellington, New Zealand) ABSTRACT This article examines four disorders of auditory processing that can result from selective brain damage (cortical deafness, pure word deafness, auditory agnosia and phonagnosia) in an effort to derive a plausible functional and neuroanatomical model of audition. The article begins by identifying three possible reasons why models of auditory processing have been slower to emerge than models of visual processing: neuroanatomical differences between the visual and auditory systems, terminological confusions relating to auditory processing disorders, and technical factors that have made auditory stimuli more difficult to study than visual stimuli. The four auditory disorders are then reviewed and current theories of auditory processing considered. Taken together, these disorders suggest a modular architecture analogous to models of visual processing that have been derived from studying neurological patients. Ideas for future research to test modular theory more fully are presented. Key words: auditory processing, modularity, review INTRODUCTION Neuropsychological investigations of patients suffering from brain damage have flourished in recent years and helped to produce more detailed and neuroanatomically plausible models of several aspects of cognitive function. For example, models of language processing are often closely aligned with studies of aphasia (e.g., Caplan, 1987; Goodglass, 1993) and models of memory draw heavily upon studies of amnesia (e.g., Schacter and Tulving, 1994; Squire, 1987). Most of this research has relied on visually presented materials, and as a result visual processing disorders tend to be more well-documented and better understood than their auditory counterparts.
    [Show full text]
  • Creutzfeldt-Jakob Disease and the Eye. II. Ophthalmic and Neuro-Ophthalmic Features
    Creutzfeldt-Jakob c.J. LUECK, G.G. McILWAINE, M. ZEIDLER disease and the eye. II. Ophthalmic and neuro-ophthalmic features In this article, we discuss the various noted to be most marked in the occipital cortex. ophthalmic and neuro-ophthalmic A similar case involving hemianopia was manifestations of transmissible spongiform reported by Meyer et al.23 in 1954, and they encephalopathies (TSEs) as they affect man. coined the term 'Heidenhain syndrome'. This Such symptoms and signs are common, a term is now generally taken to describe any case number of studies reporting them as the third of CJD in which visual symptoms predominate most frequently presenting symptoms of in the early stages. Many studies suggest that Creutzfeldt-Jakob disease (CJD}.1,2 As a result, it the pathology of these cases is most marked in is likely that some patients will present to an the occipital lobes,1 2,22-33 and ophthalmologist. Recognition of these patients electroencephalogram (EEG) abnormalities may is important, not simply from the point of view also be more prominent over the OCcipital of diagnosis, but also from the aspect of 10bes.34 preventing possible transmission of the disease Many reports describe visual symptoms and 3 to other patients. The accompanying article signs in detail, and these will be dealt with provides a summary of our current below. In some cases, the description of the understanding of the molecular biology and visual disturbance is too vague to allow further general clinical features of the conditions. comment. Such descriptions include 'visual For ease of classification, the various disturbance',35-48 'visual problems',49 'visual symptoms and signs have been described in defects',5o 'vague visual difficulties',51 'failing three groups: those which affect vision, those vision',52 'visual loss',53,54 'distorted vision',25 which affect ocular motor function, and the c.J.
    [Show full text]
  • Cortical Auditory Disorders: Clinical and Psychoacoustic Features
    J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.51.1.1 on 1 January 1988. Downloaded from Journal of Neurology, Neurosurgery, and Psychiatry 1988;51:1-9 Cortical auditory disorders: clinical and psychoacoustic features MARIO F MENDEZ,* GEORGE R GEEHAN,Jr.t From the Department ofNeurology, Case Western Reserve University, Cleveland, Ohio,* and the Hearing and Speech Center, Rhode Island Hospitalt, Providence, Rhode Island, USA SUMMARY The symptoms of two patients with bilateral cortical auditory lesions evolved from cortical deafness to other auditory syndromes: generalised auditory agnosia, amusia and/or pure word deafness, and a residual impairment of temporal sequencing. On investigation, both had dysacusis, absent middle latency evoked responses, acoustic errors in sound recognition and match- ing, inconsistent auditory behaviours, and similarly disturbed psychoacoustic discrimination tasks. These findings indicate that the different clinical syndromes caused by cortical auditory lesions form a spectrum of related auditory processing disorders. Differences between syndromes may depend on the degree of involvement of a primary cortical processing system, the more diffuse accessory system, and possibly the efferent auditory system. Protected by copyright. Since the original description in the late nineteenth reports of auditory "agnosias" suggest that these are century, a variety ofdisorders has been reported from not genuine agnosias in the classic Teuber definition bilateral lesions of the auditory cortex and its radi- of an intact percept "stripped of its meaning".'3 14 ations. The clinical syndrome of cortical deafness in a Other studies indicate that pure word deafness and woman with bitemporal infarction was described by the auditory agnosias may be functionally related Wernicke and Friedlander in 1883.' The term audi- auditory perceptual disturbances.
    [Show full text]
  • The Auditory Agnosias
    Neurocase (1999) Vol. 5, pp. 379–406 © Oxford University Press 1999 PREVIOUS CASES The Auditory Agnosias Jon S. Simons and Matthew A. Lambon Ralph MRC Cognition and Brain Sciences Unit, Cambridge Auditory agnosia refers to the defective recognition of agnosia, some patients have been described with an apparently auditory stimuli in the context of preserved hearing. There language-specific disorder (Auerbach et al., 1982). Franklin has been considerable interest in this topic for over a hundred (1989—see Case P574 below) highlighted five different years despite the apparent rarity of the disorder and potential levels of language-specific impairment that might give rise diagnostic confusion with deafness or even Alzheimer’s to poor spoken comprehension. One of these, word meaning disease (Mendez and Rosenberg, 1991—see Case P593 deafness, is a form of ‘associative’ auditory agnosia that has below). Following Lissauer’s (1890) distinction between fascinated researchers ever since Bramwell first described ‘apperceptive’ and ‘associative’ forms of visual object agno- the disorder at the end of the nineteenth century (see sia, disorders of sound recognition have been divided between Ellis, 1984). impaired perception of the acoustic structure of a stimulus, To be a classic case of word meaning deafness, a patient and inability to associate a successfully perceived auditory should have preserved repetition, phoneme discrimination representation with its semantic meaning (Vignolo, 1982). and lexical decision, but impaired comprehension from Much research has centred on the ‘apperceptive’ form of spoken input alone (comprehension is normal for written auditory agnosia, although the study of such disorders has words and pictures: Franklin et al., 1996; Kohn and Friedman, not been aided by terminological differences in the literature.
    [Show full text]
  • Review Article Auditory Dysfunction in Patients with Cerebrovascular Disease
    Hindawi Publishing Corporation e Scientific World Journal Volume 2014, Article ID 261824, 8 pages http://dx.doi.org/10.1155/2014/261824 Review Article Auditory Dysfunction in Patients with Cerebrovascular Disease Sadaharu Tabuchi Department of Neurosurgery, Tottori Prefectural Central Hospital, 730 Ezu, Tottori, Tottori 680-0901, Japan Correspondence should be addressed to Sadaharu Tabuchi; [email protected] Received 17 April 2014; Accepted 24 September 2014; Published 23 October 2014 Academic Editor: Robert M. Starke Copyright © 2014 Sadaharu Tabuchi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Auditory dysfunction is a common clinical symptom that can induce profound effects on the quality of life of those affected. Cerebrovascular disease (CVD) is the most prevalent neurological disorder today, but it has generally been considered a rare cause of auditory dysfunction. However, a substantial proportion of patients with stroke might have auditory dysfunction that has been underestimated due to difficulties with evaluation. The present study reviews relationships between auditory dysfunction and types of CVD including cerebral infarction, intracerebral hemorrhage, subarachnoid hemorrhage, cerebrovascular malformation, moyamoya disease, and superficial siderosis. Recent advances in the etiology, anatomy, and strategies to diagnose and treat these conditions are described. The numbers of patients with CVD accompanied by auditory dysfunction will increase as the population ages. Cerebrovascular diseases often include the auditory system, resulting in various types of auditory dysfunctions, suchas unilateral or bilateral deafness, cortical deafness, pure word deafness, auditory agnosia, and auditory hallucinations, some of which are subtle and can only be detected by precise psychoacoustic and electrophysiological testing.
    [Show full text]
  • Handbook on Clinical Neurology and Neurosurgery
    Alekseenko YU.V. HANDBOOK ON CLINICAL NEUROLOGY AND NEUROSURGERY FOR STUDENTS OF MEDICAL FACULTY Vitebsk - 2005 УДК 616.8+616.8-089(042.3/;4) ~ А 47 Алексеенко Ю.В. А47 Пособие по неврологии и нейрохирургии для студентов факуль­ тета подготовки иностранных граждан: пособие / составитель Ю.В. Алексеенко. - Витебск: ВГМ У, 2005,- 495 с. ISBN 985-466-119-9 Учебное пособие по неврологии и нейрохирургии подготовлено в соответствии с типовой учебной программой по неврологии и нейрохирургии для студентов лечебного факультетов медицинских университетов, утвержденной Министерством здравоохра­ нения Республики Беларусь в 1998 году В учебном пособии представлены ключевые разделы общей и частной клиниче­ ской неврологии, а также нейрохирургии, которые имеют большое значение в работе врачей общей медицинской практики и системе неотложной медицинской помощи: за­ болевания периферической нервной системы, нарушения мозгового кровообращения, инфекционно-воспалительные поражения нервной системы, эпилепсия и судорожные синдромы, демиелинизирующие и дегенеративные поражения нервной системы, опу­ холи головного мозга и черепно-мозговые повреждения. Учебное пособие предназначено для студентов медицинского университета и врачей-стажеров, проходящих подготовку по неврологии и нейрохирургии. if' \ * /’ L ^ ' i L " / УДК 616.8+616.8-089(042.3/.4) ББК 56.1я7 б.:: удгритний I ISBN 985-466-119-9 2 CONTENTS Abbreviations 4 Motor System and Movement Disorders 5 Motor Deficit 12 Movement (Extrapyramidal) Disorders 25 Ataxia 36 Sensory System and Disorders of Sensation
    [Show full text]
  • Temporal Lobe Syndromes: Disturbances of Hearing and Vestibular Functions
    TEMPORAL LOBE SYNDROMES: DISTURBANCES OF HEARING AND VESTIBULAR FUNCTIONS CLASS : M.A SEMESTER-II PAPER : CC-6 (NEUROPSYCHOLOGY) UNIT-4 RAJNISH KUMAR ASSISTANT PROFESSOR DEPT. OF PSYCHOLOGY G.D.COLLEGE • The temporal lobes sit behind the ears and are the second largest lobe. • The temporal lobe is the region where sound is processed and, not surprisingly, it is also a region where auditory language and speech comprehension systems are located. • The auditory cortex is located on the upper banks of the temporal lobe and within the sylvian fissure. Just posterior to the auditory cortex is Wernicke's area for speech comprehension. Damage to the temporal lobes can result in: • Difficulty in understanding spoken words (receptive aphasia) • Disturbance with selective attention to what we see and hear • Difficulty with identification and categorization of objects • Difficulty learning and retaining new information • Impaired factual and long-term memory • Persistent talking • Difficulty in recognizing faces (prosopagnosia) • Increased or decreased interest in sexual behaviour • Emotional disturbance (e.g. Aggressive behaviour) • Auditory radiations run from the medial geniculate body to the auditory cortex ( areas 41 and 42) in the superior temporal gyrus. • Hearing is represented bilaterally in the temporal lobes (contralateral predominance). • Electrical stimulation of auditory area leads to vague auditory hallucination (tinnitus, sensation of roaring and buzzing ), and adjacent areas causes vertigo and a sensation of unsteadiness. • Unilateral destruction of the auditory cortex lead to difficulty in sound localization and a bilateral decrease of auditory acuity. • Bilateral disease lead to cortical deafness (may be unaware of their deficits). • Involvement of vestibular areas may cause difficulty in equilibrium and imbalance.
    [Show full text]
  • Behavioral Neuroanatomy: Large-Scale Networks, Association
    M. - MAR S E L M E SU LAM Faced with an anatomical fact proven beyond doubt, any physiological result that stands in contradiction to it loses all its meaning. ... So, first anatomy and then physiology; but if first physiology, then not without ana tomy. —BERNHARD VON GUDDEN(1824-1886), QUOTED BY KORBINIAN BRODMANN, IN LAU RENCE GAREY ‘S TRANSLATION I. INTRODUCTION The human brain displays marked regional variations in architecture, connectivity, neurochemistrv, and physiology. This chapter explores the relevance of these re- gional variations to cognition and behavior. Some topics have been included mostly for the sake of completeness and continuity. Their coverage is brief, either because the available information is limited or because its relevance to behavior and cog- nition is tangential. Other subjects, such as the processing of visual information, are reviewed in extensive detail, both because a lot is known and also because the information helps to articulate general principles relevant to all other domains of behavior. Experiments on laboratory primates will receive considerable emphasis, espe- cially in those areas of cerebral connectivity and physiology where relevant infor- mation is not yet available in the human. Structural homologies across species are always incomplete, and many complex behaviors, particularly those that are of greatest interest to the clinician and cognitive neuroscientist, are either rudimentary or absent in other animals. Nonetheless, the reliance on animal data in this chapter is unlikely to be too misleading since the focus will be on principles rather than specifics and since principles of organization are likely to remain relatively stable across closely related species.
    [Show full text]
  • Higher Cortical Visual Disorders: Case-Based Review
    HIGHER CORTICAL VISUAL DISORDERS: CASE-BASED REVIEW Sashank Prasad, MD Harvard Medical School Brigham and Women’s Hospital Boston, MA Marc Dinkin, MD Weill Cornell Medical School New York Presbyterian Hospital New York, NY Introduction The diagnosis of disorders of higher visual processing often poses a considerable clinical challenge.1, 2 Routine evaluations of visual function may not readily yield a diagnosis; a refined examination of visual function is necessary to correctly localize and identify these otherwise elusive syndromes. The original descriptions of these conditions depict how careful clinical observation, coupled with study of anatomical pathology at autopsy, yielded tremendous insights that were the foundation of the development of modern neurology. More recently, neuroimaging techniques including functional magnetic resonance imaging (fMRI) and positron emission spectrography (PET) have allowed further insights into complex structure-function relationships. Disorders of visual processing not only have significant clinical importance, but also shed light on neuroscientific questions regarding normal visual processing in the brain. The Dorsal and Ventral Streams The concept of the dorsal (“Where”) pathway and ventral (“What”) pathway was put forth by Ungerleider and Mishkin in their 1982 paper entitled “Two Cortical Visual Systems.”3 They proposed that occipitotemporal areas are selective for processing the identity of visual objects. Specific regions in the ventral stream are specialized for identifying faces, objects,
    [Show full text]
  • Pure Word Deafness with Auditory Object Agnosia After Bilateral Lesion of the Superior Temporal Sulcus
    cortex 73 (2015) 24e35 Available online at www.sciencedirect.com ScienceDirect Journal homepage: www.elsevier.com/locate/cortex Research report Pure word deafness with auditory object agnosia after bilateral lesion of the superior temporal sulcus * Alexander Gutschalk a, , Stefan Uppenkamp b, Bernhard Riedel c, Andreas Bartsch d, Tobias Brandt c and Marlies Vogt-Schaden a,c a Department of Neurology, University of Heidelberg, Heidelberg, Germany b Department of Medical Physics, University of Oldenburg, Oldenburg, Germany c Kliniken Schmieder Heidelberg, Heidelberg, Germany d Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany article info abstract Article history: Based on results from functional imaging, cortex along the superior temporal sulcus (STS) Received 5 June 2014 has been suggested to subserve phoneme and pre-lexical speech perception. For vowel Reviewed 17 December 2014 classification, both superior temporal plane (STP) and STS areas have been suggested rele- Revised 11 May 2015 vant. Lesion of bilateral STS may conversely be expected to cause pure word deafness and Accepted 3 August 2015 possibly also impaired vowel classification. Here we studied a patient with bilateral STS Action editor Jean-Francois lesions caused by ischemic strokes and relatively intact medial STPs to characterize the Demonet behavioral consequences of STS loss. The patient showed severe deficits in auditory speech Published online 13 August 2015 perception, whereas his speech production was fluent and communication by written speech was grossly intact. Auditory-evoked fields in the STP were within normal limits on Keywords: both sides, suggesting that major parts of the auditory cortex were functionally intact. Auditory agnosia Further studies showed that the patient had normal hearing thresholds and only mild Auditory cortex disability in tests for telencephalic hearing disorder.
    [Show full text]