Multi-infarct dementia clinically simulating dementia of Alzheimer type. A comparison with angular gyrus syndrome

A 74-year-old right-handed man with multiple cerebral infarction who presented with dementia simulating dementia of Alzheimer type (DAT) is reported. He had been well until April 20, 1987 when he developed transient right hand palsy lasting overnight. Eleven days later, he became confused, disorientated, and amnestic. He was admitted to this hospital on June 8. Physical examination revealed hypertension (170/90mmHg). On neurological examination, his consciousness was clear but he was demented. He showed disorientation, amnesia, and urinary incontinence. His most prominent symptom was disturbance of speech, including fluent aphasia and alexia with agraphia. Additionally, he showed ideomotor apraxia, construction apraxia, right-left agnosia, finger agnosia, and acalculia. On July 9, he had a transient attack of right hemiplegia with confusion. The brain CT scan performed on admission was unremarkable except for cavum septi pellucidum and a small low density area in the right basal ganglia. However, single photon emission computed tomography (SPECT) by 123I-labeled N-isopropyl-p-iodoamphetamine disclosed hypoperfusion of the cerebral blood flow in the border zones of the temporoparietal and frontal lobes on the left. A follow-up brain CT scan taken one month later demonstrated low density in the new areas corresponding to hypoperfusion shown by SPECT. Although the clinical features of the present case resembled those of DAT, dementia in this case was regarded as the result of multiple cerebral infarction since it occurred acutely with mild motor deficits, and brain CT scans and SPECT showed lesions indicating focal cerebral ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tactile agnosia and tactile aphasia: symptomatological and anatomical differences.

Two patients with tactile naming disorders are reported. Case 1 (right hand tactile agnosia due to bilateral cerebral infarction) differentiated tactile qualities of objects normally, but could neither name nor categorize the objects. Case 2 (bilateral tactile aphasia after operation of an epidural left parietal haematoma) had as severe a tactile naming disturbance as Case 1, but could categorize objects normally, demonstrating that tactile recognition was preserved. Case 1 may be the first case of tactile agnosia clearly differentiated from tactile aphasia. CT scans of Case 1 revealed lesions in the left angular gyrus, and in the right parietal, temporal, and occipital lobes. Case 2 had lesions in the left angular gyrus and of posterior callosal radiations. Our findings suggest that tactile agnosia appears when the somatosensory association cortex is disconnected by a subcortical lesion of the angular gyrus from the semantic memory store located in the inferior temporal lobe, while tactile aphasia represents a tactual-verbal disconnection.     

Deep left parietal lobe syndrome: conduction aphasia and other neurobehavioural disorders due to a small subcortical lesion.

A patient with sudden onset of conduction aphasia in the context of an ischaemic stroke is reported. Other neurological and neuropsychological findings included bilateral ideomotor apraxia, right hemisensory defect and paradoxical left ear extinction on a dichotic listening test. Lesion location, as inferred from magnetic resonance imaging, involved a restricted subcortical area in the left parietal lobe, near the lateral wall of the cerebral ventricle. The anatomical correlate for each of the clinical findings is discussed in the light of classical anatomo-clinical correlations. It is concluded that this tetrad constitutes a specific syndrome which may be easily recognised and ascribed to a single lesion in the deep white matter of the left parietal lobe.     

Progressive supranuclear palsy with widespread cerebral lesions.

A 51-year-old woman with no history of any familial neurological diseases initially presented with numbness in her extremities, slowing of movements, comprehension deficit, memory disturbance, dyscalculia, muscle rigidity, hyperreflexia, Parkinsonian gait, increasing disorientation, left-right disturbance, finger agnosia, alexia, acalculia, apraxia, aspontaneity, euphoria, gait disturbance, aphasia, echolalia, and in the terminal stage, mutism, contracture of lower extremities and cachexia. She died of bronchopneumonia at the age of 55. The brain showed widespread cerebral lesions, consisting of nerve cell loss and neurofibrillary tangles in the frontal, parietal and occipital cortex, demyelination and gliosis in the frontal, parietal and occipital subcortical white matter in addition to the typical pathological findings of progressive supranuclear palsy (PSP): severe neuronal loss with gliosis and neurofibrillary tangles (NFTs) in the subthalamic nucleus, globus pallidus and substantia nigra. In conclusion, we present a case of PSP with unusual clinical features (extrapyramidal signs, frontal and parietal lobe syndromes without ophthalmoplegia) and neuropathologically widespread cerebral lesions in addition to the typical pathological findings of PSP. The differential diagnosis of PSP and Alzheimer's disease and other degenerative disorders is discussed.     

Auditory sound agnosia without aphasia following a right temporal lobe lesion

A 55-year-old right-handed man showed inability to recognize the meaning of non-verbal sounds without impairment of language comprehension after a cerebrovascular accident. His auditory acuity was intact and no other sign of agnosia, apraxia or aphasia was detectable. His errors on a test of sound recognition were acoustic rather than semantic. Brain CT scan showed a small lesion in the posterior part of the right temporal lobe. This case suggests that auditory sound agnosia without language disorder can ensure a lesion confined to the right hemisphere, and that the deficit is discriminative rather than associative in nature.     

Pure word deafness due to left hemisphere damage.

We report the case of a 55 year-old right-handed man who presented with a long lasting pure word deafness following left thalamic bleeding. There was no sign of aphasia. The auditory deficit was specific for language, while recognition of music and environmental sounds was normal. CT, MRI and PET examinations showed that the lesion was anatomically and functionally confined to the left cerebral hemisphere, mainly the white matter of the temporal and parietal lobes. Wernicke's area was largely preserved. It is proposed that pure word deafness was consequent to the isolation of Wernicke's area from incoming auditory information due to the interruption both of the association fibers from the right auditory area traveling across the corpus callosum and of the left auditory radiations.     

Associative visual agnosia and its related deficits: The role of the minor hemisphere in assigning meaning to visual perceptions

A patient with severe associative visual agnosia for objects and pictures could identify those objects by touch and copy them; neither naming nor visual processing difficulties could account for his deficit. He was not alexic. The CAT scan revealed bilateral infarctions: a large left parietal-occipital lesion and a smaller right occipital lesion involving underlying white matter. Evidence suggests the presence of independent pathways for meaningful representation of objects and pictures, written material, familiar faces, and, perhaps, colors. Independence of these pathways at their origin indicates the right hemisphere is important in analyzing visual material beyond the perceptual level.     

Longitudinally extensive spinal cord lesion in a case of Neuro-Beh?et disease]

A 56-year-old right-handed man with recurrent orogenital aphtoid ulcers and bilateral uveitis had presented with memory disturbance, dressing apraxia and constructional apraxia at age 53. Neuro-Beh?et disease was diagnosed based on pathergy test results and positivity for HLA-B51. Four months after azathioprine was introduced, he presented with subacute spastic paraparesis and urinary retention at age 56. Neurological examination demonstrated hyperreflexia in the lower limbs without pathological reflexes. He also showed memory disturbance, dressing apraxia and constructional apraxia. Spinal cord MRI showed a longitudinally extensive spinal cord lesion (LESCL) from C1 to Th3 with partial gadolinium enhancement from C6 to C8. Brain MRI showed moderate atrophy of the right temporal and parietal lobes without contrast enhanced lesion. There were hyperintense lesions in the pons, bilateral periventricular white matter and right parietal subcortical white matter. Cerebrospinal fluid analysis showed mild lymphocytic pleocytosis. After intravenous methylprednisolone treatment, clinical symptoms largely resolved and the abnormal intensities with contrast enhancement of the cord disappeared. However, higher cortical dysfunctions were not changed. LESCL may reflect inflammatory venous vasculitis with edema extending along the neural fibers since the lesion shows excellent responses to steroid without neurological sequelae. Differential diagnosis of neurological diseases demonstrating LESCL should include Neuro-Beh?et disease.     

Left unilateral apraxia

A 32-year-old right-handed man suffered a traffic accident with head injury, resulting in loss of spontaneity, right hemiparesis, severe aphasia, and unilateral apraxia, which was noticed on his non-paralyzed left hand. An MRI scan conducted 11 months after onset revealed a large lesion in the left frontal lobe, a small lesion in the right frontal lobe and a striking thinning of the trunk of the corpus callosum with remarkable dilatation of the lateral ventricles. An IMP-SPECT scan, performed 1 year after onset, showed a diffuse hypoperfusion extending to the left temporo-parietal area further than the MRI verified abnormal density areas. The patient's praxic abilities were precisely evaluated 1 year after onset. The performance on the object use task was characterized by content errors. For example, when using a match with his left hand, he always treated with it like a cigarette. The right hand performance of this task was clumsy due to his right hemiparesis but successful. The performance on his left hand did not improved even when the patient was given visual examples. The term "ideational apraxia" proposed by Liepmann, which was characterized by content errors, implies a conceptual deficit. Morlaas defined ideational apraxia as a agnosia of usage. Ideational apraxia has been so far investigated mainly on patients with these difficulties in both hands. On the other hand, left unilateral apraxia has been explained by callosal disconnection. Liepmann and Maas thought that a lesion of the corpus callosum would prevent the space-time engrams in the left hemisphere from reaching the right sensorimotor area necessary to carry out the skilled act with the left hand, thereby inducing apraxia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cerebral lateralization in two cases of crossed dextral aphasia with right-hemisphere arteriovenous malformation

This paper reports two cases of crossed dextral aphasia. The first patient was a 60-year-old right-handed male with no family history of sinistrality. He experienced sudden onset of left hemiplegia and loss of consciousness. A CT scan showed high-density area in the right fronto-parietal region. An angiography revealed an arteriovenous malformation (AVM) in the right parietal lobe. It was fed by a branch of the middle cerebral artery and drained through a cortical vein. Neuropsychological examination one week after the surgery showed severe defects of all language moderalities. He was alert and cooperative, but completely mute. He recognized common words by auditory and visual stimuli, but could not perform simple command. He wrote some meaningless letters when asked to write his own name. Auditory and reading comprehension gradually improved thereafter, but Broca's type of aphasia with non-fluent hesitant and effortful output was still present four months after the surgery. The second patient was a 38-year-old right-handed male. All members of this family are right-handed except for one sister who is left-handed. He suddenly suffered left hemiparesis and loss of consciousness. A CT scan disclosed a right parietal intracerebral hematoma. And an AVM which was fed by the angular artery and drained through a cortical vein was angiographically demonstrated in the same area. Postoperatively the left hemiparesis rapidly disappeared, but left homonymous hemianopsia and anomic type of aphasia still persisted. His speech was fluent and daily communication was possible in spite of circumlocutory paraphasic output.(ABSTRACT TRUNCATED AT 250 WORDS)     

Infarct in the area of the left anterior cerebral artery. II. Language disorders

Language disturbances and other neuropsychological dysfunctions were evaluated in 10 right-handed patients with left anterior cerebral artery (ACA) infarcts with CT correlation. Transcortical motor aphasia was present in 4 cases, related to involvement of the supplementary motor area (SMA) or the underlying and immediately anterior white matter. In 4 patients with sparing of the SMA but with involvement of the cingulate region, only alterations of verbal memory were found. Sensory or mixed transcortical aphasia was not observed, in any of the patients, including those in whom the supplementary sensory area (SSA) or the underlying white matter were involved, casting doubt upon the presumed receptive role in language function attributed to the SSA by some authors. Buccolingual-facial apraxia was related to subcortical lesions. A callosal disconnection syndrome was uncommon (2 patients) and no hemi-neglect was encountered, even in those cases with cingulate involvement.     

Visual and tactile agnosia

A patient presented with visual and tactile agnosia due to a spontaneous left occipito-temporal hematoma. Major memory and spatial orientation disorders were also noted, but language, gestures, auditory and olfactory perception, and interior visual imagerie were unaffected. A review of the literature since 1970 found 6 cases of an association of this type among 17 patients with visual agnosia. There appears to be no relationship between the presence of tactile agnosia and the global or partial character of the visual agnosia, the severity of memory disturbances, the presence of visuoverbal disconnection or visual imagery disorders. In contrast, these cases differed in that the lesions were more extensive and extended beyond the internal occipital regions: they were widespread in 3 cases and in the left internal occipital and parietal region in 1 case. In the patient reported in this paper there was a wide lesion of the posterior white matter of the left hemisphere.     

Motor amusia following a right temporal lobe hemorrhage--a case report

A 65-year-old female was admitted to our hospital because of left hemiparesis with sudden onset one week before. She was congenitally right-handed. She had been a teacher of Japanese string instrument (samisen) playing and been able to sing Japanese traditional songs well. A tape on which she had recorded her songs one year before the admission also proved her to be a good singer. Neurological examination on admission revealed almost normal findings except for minimal weakness in her left hand fingers. Right temporal lobe hemorrhage was revealed by CT scan. One month after the admission, she complained that she was unable to sing her songs and to play samisen as she used to do. Her intelligence was normal (WAIS VIQ116, PIQ108) and there were no abnormal findings as follows: aprosodia, aphasia, agraphia, memory disturbance, agnosia and ideational, ideomotor, constructional or limb-kinetic apraxia. She could point out her errors while singing. However, musical receptive function was slightly disturbed with tonal memory in Seashore test. When she was asked to sing a song without any instrumental support, she hummed a melody occasionally with wrong pitch, but rhythmically. After hearing a song she knew well, she reproduced it with slight improvement. With the vocal or the instrumental accompaniment, she could sing fairly well. She had some mistakes of pitch while playing a samisen. MRI was performed one year and a half after the brain hemorrhage. It displayed a thin linear of hematoma in the white matter of the right upper temporal and transverse gyrus. It was proved in our case that motor amusia with minimal musical receptive dysfunction could appear following a cerebral lesion and musical function might be independent of intelligence or verbal function.     

Alexia with agraphia produced by localized infarction in the inferior posterior region of the left temporal lobe

There have been several reports on alexia with agraphia due to hemorrhage or trauma in the inferior posterior region of the left temporal lobe since Yamadori (1982) first reported a case of cerebral hemorrhage. We presented the first case of alexia with agraphia due to a circumscribed infarct in the inferior posterior region of the left temporal lobe. A 65-year-old right-handed man had an acute onset of inability to read Japanese "kana" letters and to write any letters. He had no difficulty in speaking or understanding. Neurological examination on admission was normal except for homonymous quadrantanopia in the right upper field. Neuropsychological findings: Spontaneous speech was fluent without dysprosody. There were no disturbances in auditory understanding or in repetition. He could read Japanese "kanji" characters correctly, however, he could not read any "kana" letters. Writing was also disturbed severely even as to his address, name or telephone number. Calculation was also difficult. There were no disturbances in naming colors, no ideomotor or constructional apraxia nor visual agnosia. X-ray computed tomography (CT) scan showed a faint low density area with ring enhancement suggesting a cerebral infarct in the inferior posterior region of the left temporal lobe. Patient's hospital course was characterized by a marked improvement of alexia, especially of "kana" letters as compared with that of "kanji" characters. Dissociative improvement of alexia compared with agraphia in this case could be explained by the fact that the lesion was in close contact with the occipital lobe and that he also had pure alexia in the early stage.     

Pure Gerstmann's syndrome from a focal lesion

It is controversial whether a focal lesion can specifically induce Gerstmann's syndrome (dyscalculia, left-right disorientation, finger agnosia, and agraphia). Also, Gerstmann's tetrad has been attributed to other cerebral symptoms, particularly aphasia. We examined a patient who had all four symptoms of Gerstmann's syndrome, without other symptoms or signs, and who had a discrete left parietal lesion.     

Progressive limb-kinetic apraxia with myoclonus focal atrophy in the postcentral gyrus and the supplementary motor area]

We report a 70-year-old right handed man with a 5-year history of slowly progressive clumsiness of his left hand. A neurological examination disclosed mild rigidity and myoclonus in his left hand. He showed limb-kinetic apraxia, but neither ideational apraxia nor ideomotor apraxia was present. Aphasia and agnosia were also absent. He was thought to have the primary progressive limb-kinetic apraxia clinically. Brain CT and MRI revealed focal atrophy in the right postcentral gyrus and the supplementary motor area. A positron emission tomography (PET) study showed diffuse decrement of cerebral blood flow, predominantly in the right hemisphere. The decrease in the uptake of [18F]-Fluoro-deoxyglucose also revealed glucose hypo-metabolism, especially in the right frontal and parietal lobe. Striatal [11C]NMSP and [18F]FDOPA uptake were also reduced in an asymmetric pattern. These findings suggest that our patient is likely to have corticobasal degeneration. Transcranial magnetic stimulation using double pulse paradigm revealed a decrease in the level of cortico-cortical inhibition in the motor cortex on the affected side. Our results indicate increase in the excitability of motor cortical neurons in primary progressive limb-kinetic apraxia, likely due to a decreased excitability of cortico-cortical inhibitory mechanism as a result of focal degeneration of cortical neurons.     

Neurolinguistic analysis of the language abilities of a patient with a "double disconnection syndrome": a case of subangular alexia in the presence of mixed transcortical aphasia.

In contrast to the classic form of alexia without agraphia, subangular alexia results from a single lesion located deep in the white matter of the left parietal lobe. In the present report, a patient with subangular alexia and features of mixed transcortical aphasia is described. Neurolinguistic findings include: alexia without agraphia, paucity of spontaneous speech, moderate auditory comprehension difficulty, excellent repetition, echopraxia, colour agnosia, and naming disorder. Neurolinguistic tests revealed intact phonological organisation and grammatical filter." Our studies revealed a "double disconnection syndrome," the co-existence of two relatively rare neurobehavioural disorders. Furthermore, the studies reported here clearly show dissociations of language functions in both the visual and auditory modality, which demonstrates that the stages of language processing are separable.     

Reversed laterality of cerebral functions in a non-right-hander: neuropsychological and spect findings in a case of 'atypical' dominance.

A 54-year-old non-right-handed man with positive familial sinistrality showed a pure right hemisphere syndrome following a left hemisphere stroke. Severe right side hemineglect, transcortical motor dysprosodia, spatial dysgraphia and visuo-constructive impairments were observed. At no time were the expected left hemisphere abnormalities such as aphasia, alexia, right-left disorientation or finger agnosia noted. A left fronto-temporal subcortical lesion was documented on CT scan. A Tc-99m HM-PAO SPECT study revealed no cerebral blood flow changes in the right hemisphere while in the left hemisphere a fronto-temporo-parietal cerebral blood flow reduction was evident. This case of a complete reversed laterality of cognitive functions argues for a distinction to be made between 'anomalous' cerebral dominance and 'atypical' cerebral dominance.     

Electrophysiological correlates of associative visual agnosia lesioned in the ventral pathway

Visual agnosia has been well studied by anatomical, neuropsychological and neuroimaging studies. However, functional changes in the brain have been rarely assessed by electrophysiological methods. We carried out electrophysiological examinations on a 23-year-old man with associative visual agnosia, prosopagnosia and cerebral achromatopsia to evaluate the higher brain dysfunctions of visual recognition. Electrophysiological methods consisted of achromatic, chromatic and category-specific visual evoked potentials (CS-VEPs), and event-related potentials (ERPs) with color and motion discrimination tasks. Brain magnetic resonance imaging revealed large white matter lesions in the bilateral temporo-occipital lobes involving the lingual and fusiform gyri (V4) and inferior longitudinal fasciculi due to multiple sclerosis. Examinations including CS-VEPs demonstrated dysfunctions of face and object perception while sparing semantic word perception after primary visual cortex (V1) in the ventral pathway. ERPs showed abnormal color perception in the ventral pathway with normal motion perception in the dorsal pathway. These electrophysiological findings were consistent with lesions in the ventral pathway that were detected by clinical and neuroimaging findings. Therefore, CS-VEPs and ERPs with color and motion discrimination tasks are useful methods for assessing the functional changes of visual recognition such as visual agnosia.