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Dementia of Frontal Lobe Type J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.51.3.353 on 1 March 1988. Downloaded from Journal ofNeurology, Neurosurgery, and Psychiatry 1988;51:353-361 Dementia of frontal lobe type D NEARY, J S SNOWDEN, B NORTHEN, P GOULDING From the Department ofNeurology, Manchester Royal Infirmary, Manchester, UK SUMMARY A significant proportion of patients with presenile dementia due to primary cerebral atrophy do not have Alzheimer's disease. One form of non-Alzheimer dementia may be designated as dementia of frontal lobe type (DFT), on the basis of a characteristic neuropsychological picture suggestive of frontal lobe disorder, confirmed by findings on single photon emission tomography. The case histories of seven patients exemplify the disorder: a presentation of social misconduct and personality change, unconcern and disinhibition, in the presence of physical well-being and few neurological signs. Assessment revealed economic and concrete speech with verbal stereotypes, variable memory impairment, and marked abnormalities on tasks sensitive to frontal lobe function. Visuo-spatial disorder was invariably absent. Comparisons ofDFT and Alzheimer patients revealed qualitative differences in clinical presentation, neurological signs, profile ofpsychological disability, electroencephalography, single photon emission tomography and demography. DFT, which may represent forms of Pick's disease, may be more common than is often recognised. Protected by copyright. Although Alzheimer's disease represents the Accurate differentiation between dementing commonest form of dementia in the presenium, a diseases on clinical grounds is increasingly important significant minority of patients with primary degener- in view of the possibility of therapeutic intervention. ative dementia associated with cerebral atrophy do The purpose of this paper is to exemplify, by case not have that disease.' 3 In particular, patients who studies, the characteristics of DFT, and to distinguish present with a clinical picture suggestive of this distinct clinical syndrome from that of progressive selective damage to frontal regions of the Alzheimer's disease by comparing the results of brain have been shown by cerebral biopsy to have neuropsychological evaluation, SPET imaging and neither pathological nor chemical hallmarks of electroencephalography in the two disorders. Alzheimer's disease.3 The absence of Alzheimer pathology has been confirmed by studies of similar Patient group patients at necropsy,4 which have indicated the pres- ence of with or the Seven patients are described who conformed to a clinical fronto-temporal atrophy, without diagnosis of dementia of frontal lobe type. In all patients specific balloon-like cells pathognomonic of Pick's general medical examination was normal, and history and disease, and has led to the designation "dementia of physical examination excluded the presence of cerebro- http://jnnp.bmj.com/ frontal lobe type" (DFT). In clinically presumed cases vascular and systemic disease. No patient had a Hachinski9 of DFT the assumption of frontal lobe dysfunction is ischaemia score greater than three. In no patient was there a supported by brain imaging studies using single history of alcohol abuse, or of major head injury. Computed photon emission tomography (SPET).' The finding in tomographic findings were limited to the presence of mild those patients of selective reductions in uptake in the cerebral atrophy. In some cases (patients 1, 4 and 5) this was anterior cerebral hemispheres contrasts with the char- reported to be most prominent in the frontal lobes; in other cases no topographical differences in the extent of atrophy acteristic posterior cerebral hemisphere abnormality were noted. The designation of DFT was based on histori- in patients with clinically presumed and histologically cal, neurological and neuropsychological findings suggesting on September 27, 2021 by guest. verified Alzheimer's disease demonstrated both with a picture of selective frontal lobe dysfunction, and was single photon emission tomography5 and positron supported by findings on single photon emission tomog- emission tomography.68 raphic imaging which revealed selective reductions in uptake in the anterior cerebral hemispheres.5 The absence of Alzheimer pathology had been confirmed in two cases by Address for reprint requests: Dr D Neary, Department ofNeurology, Manchester Royal Infirmary, Manchester Ml 39WL, UK. cerebral biopsy. The patients described are drawn from a series of 15 Received 18 August 1987. patients, in whom the clinical picture of frontal lobe Accepted I October 1987 dementia was supported by the finding of selective anterior 353 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.51.3.353 on 1 March 1988. Downloaded from 354 Neary, Snowden, Northen, Goulding hemisphere abnormalities on SPET imaging. They are repre- and four words beginning with the letter F, each in one sentative clinically and demographically of a total of 26 minute. Design fluency"3 revealed striking perseveration: patients with a clinical diagnosis of dementia of frontal lobe she produced two pages of virtually identical rectangles, type, referred to a neurological department during a 5 year despite constant repetition of the instruction to produce period. different non-representational designs. Deterioration in her mental status was observed over a 1 year follow-up period. She became increasingly apathetic, A. Case reports maintained a fatuous expression and giggled inanely when Patient I A 55 year old female presented with a 2 year spoken to. Her test performance was characterised by history of mental slowing, increasing apathy, neglect of increasing economy of mental effort, although there was no personal hygiene and household chores. Occasional inconti- convincing evidence of specific linguistic or perceptuo- nence of urine led to no distress, embarrassment nor appro- spatial difficulties. On repeat administration of the Nelson priate explanation. Her mood was reported to be abnormal card sorting test she achieved one category only, and 56% of and variable; sometimes she was irritable, negativistic and errors were perseverative. She remained physically well, with uncooperative, and on other occasions jovial and amenable. no increase in neurological signs. She denied any change in personality, or mental and Patient 2 A 61 year old female presented with a 5 year physical health. She drove her car with less care, but without history of progressive change in personality and social becoming lost. She spoke less and more quietly. There was conduct. Formerly, she had taken pride in her personal no previous personal or family history of psychiatric illness. appearance, her home, and her job. She began to neglect Neurological examination revealed extensor plantar personal hygiene, ceased to carry out domestic tasks, and responses, a positive jaw jerk and prominent snout reflex. would spend her days wandering aimlessly. She tended to On mental examination she was inert, with a bland affect. misconstrue events, and expressed suspicion and irritability She lacked persistence in carrying out mental tasks, against her family. She had outbursts of rage which were although satisfactory performance could often be elicited socially embarrassing. She was forgetful, disclaimed with coaxing and encouragement. She did not volunteer previous events, and made false claims for non-existent conversation, and her answers to questions were economical happenings. She was hypochondriacally obsessed with pain and unelaborated. There was mild hypophonia and in the perineum, which had been extensively investigated, but Protected by copyright. dysprosody. She could designate left and right correctly and she denied mental symptoms. There was no personal history comprehension of sentences involving complex syntax was of psychiatric illness. Her mother had died aged 65 years of intact. Confrontation naming was normal. She could read a similar illness, and was noted to have wandered in the street and spell, although writing yielded striking perseveration: at night in night attire. Eccentric behaviour had been when asked to write about her job, she wrote "I mind about observed also in other family members. In no case had the weather" eight times in succession despite continual necropsy been undertaken. Neurological examination encouragement to write something different. In calculating revealed mildly accentuated tendon reflexes and a weakly she responded impulsively, making errors. When encour- positive jaw jerk. On mental examination she was restless, aged to check her responses she could generally make appro- impatient and disinhibited. She responded impulsively, priate corrections. Elementary perceptual and spatial launching into tasks without listening fully to the abilities were intact. She could identify line drawings of instructions. She displayed a press of speech, which was objects and faces of celebrities, could localise correctly towns frequently off the point, and contained stereotyped phrases on a map of Great Britain and reproduce non- and play-on-words, which amused her. Her thinking was representational hand postures accurately. Drawings were literal and concrete. In following verbal instructions she had normal, and she could represent the three dimensional difficulty grasping what was required, although formal aspect of a cube. She could reproduce simple Koh's block assessment of comprehension of syntax did not reveal figures. She could carry out whole
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