Junzo Shiraishi

Conduction aphasia and arcuate fasciculus

Abstract Three patients are presented who developed conduction aphasia after a small infarction almost exclusively confined to the arcuate fasciculus. All of them were diagnosed as conduction aphasia within a week after the stroke and showed a rapid amelioration. On the basis of the 3 patients and conduction aphasics in the literature, the relation between conduction aphasia and the arcuate fasciculus is discussed.

Memory loss due to transient hypoperfusion in the medial temporal lobes including hippocampus.

ABSTRACT A typical case of transient global amnesia (TGA) was investigated with single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) with 1.5‐tesler scans. During the amnesic eposide, a marked decrease of cerebral blood flow was observed in the areas confined to the territory of the bilateral posterior cerebral arteries including the hippocampus. After the episode, cerebral blood flow returned to normal and a circumscribed lesion was detected in the middle portion of CA 1 field of the left hippocampus. The SPECT findings prove direct evidence that the medial temporal structures are involved in the establishment of new memories, as well as in process of recalling only recently acquired memories, but not in retrieval of memories acquired long ago. The MRI findings indicate that a unilateral partial damage to CA 1 sector of the hippocampus does not develop a definite memory impairment and that high‐resolution MRI study on the hippocampus is necessary in TGA patients.

Lateralization phenomenon of complex auditory hallucinations

Abstract— A case is described of a patient who developed a transient verbal hallucination, lateralized to the right ear, and fluent aphasia after a hemorrhagic infarction in the left superior temporal gyrus. On the basis of this patient and the cases in the literature showing unilateral complex auditory hallucinations, the clinical significance of the lateralization phenomenon of complex auditory hallucinations was investigated. As a result, the lateralization phenomenon of complex auditory hallucinations could be considered a significant clinical sign indicating the existence of a lesion in the superior temporal gyrus opposite the hallucination side.

Completion phenomenon in transcortical sensory aphasia

We investigated completion phenomenon for proverbs in cases demonstrating transcortical sensory aphasia due to a variety of diseases. Lack of this completion was exclusively observed in patients with focal atrophy. These patients showed a selective and consistent impairment in word comprehension without phonemic cue effects in naming. The completion phenomenon was present in patients demonstrating transcortical sensory aphasia due to other cerebral diseases. In these patients, comprehension deficits were not selective for words, or words not comprehended were inconsistent and some phonemic cue effects were observed. In a previous study, we reported that completion phenomena for multiplication tables, serial numbers and names of days were frequently noted in patients with focal atrophy. Together with the present findings, these results suggest that lack of proverb completion may be attributed to a selective, systematic and complete loss of the meaning representations for language units such as words and proverbs. In addition, pathological processes of focal atrophy with temporal predominance might selectively affect the semantic memory for language as a unit.

A case of acquired conduction aphasia in a child

ABSTRACT— A 10‐year‐old right‐handed boy showed conduction aphasia with left‐ear verbal extinction (paradoxical ipsilateral ear extinction) after removal of a arteriovenous malformation in the left parietal lobe. Buccofacial and ideomotor apraxia were not observed. Recovery from aphasia was dramatic. Postoperative computed tomography (CT) and magnetic resonance imaging scans demonstrated damage confined to the left supramarginal gyrus invading the arcuate fasciculus. Together with recently reported cases of acquired fluent aphasia in children with CT‐verified left posterior lesions, this case seems to support the current view that both fluent and nonfluent aphasia that share many similarities with the symptoms and lesion localization associated with adult cases may exist in children.

A case of slowly progressive aphasia without generalized dementia in a Japanese patient

A Japanse patient with a 4‐year history of slowly progressive aphasia without generalized dementia is described. From 1985 on, this 61‐yr‐old right‐handed dentist showed insidiously progressive deterioration in his speech and auditory comprehension, but has no memory disturbance, disorientation of space, time or persons, acalculia or other impairments in his behavior. His personality changes are unremarkable. He still treats patients at his clinic. General physical and neurological examinations were normal. CT and MRI (1.5T) scans showed widening of the left sylvian fissure and lateral ventricle without any vascular lesions. A PET scan demonstrated focal hypometabolism restricted to the left temporal lobe. The clinical course and picture of our patient corresponds well to those of slowly progressive aphasia without generalized dementia, described by Mesulam.

Auditory extinction to nonverbal and verbal stimuli.

The so‐called auditory extinction phenomenon in a verbal dichotic listening test was investigated in seven brain damaged patients from the qualitative standpoint. As the result, it became evident that the phenomenon could result from competition between verbal materials presented to both ears in at least two different levels of auditory processing i.e., sound perception and linguistic recognition. From the present study, we emphasize the following: 1) If Benders definition is followed, it is advisable to use the term extinction only for the phenomenon at the acoustic level. 2) If the use of the term extinction for the phenomenon is to be continued at the linguistic level, the presence of auditory extinction and/or obscuration to nonverbal stimuli should be noted.

Analysis of ultrasonic blood rheogram by a band pass filter.

From the Department of Neuropsychiatry, Osaka University Medical School, Fukushimaku, Osaka, Japan. Presented in part at the 4th Meeting of the Japan Society of Ultrasonics in Medicine, Osaka, November 16, 1963. * Professor and Chairman of the Department of Neuropsychiatry, Osaka University Medical School, Osaka, Japan. † Research Associate of the Department of Neuropsychiatry, Osaka University Medical School, Osaka, Japan. The ultrasonic blood rheograph has been developed by Satomura and Kanekol for the examination of the cerebral and peripheral blood flow with the use of Doppler’s effect of ultrasonic waves. This method, which can record a minute change in the resistance of peripheral veins, made it possible to investigate functional or organic changes of blood flow. Clinical application of the method to arteriosclerosis has previously been reported.2 Continuous examination of blood flow in the vein which lies deep in the tissue without surgical manipulations rendered this method clinically valuable. However, some difficulties were experienced in the recording and quantitative comparison of the ultrasonic blood rheogram in the previous experiment. This paper describes a more precise analytic method of blood flow by an additional use of a four-channel band pass filter, improvement of the method of measurement of blood flow by counting the zero-crossing number as developed by Kato and associates,3 and some results of their clinical application.

Cerebral Circulation in the Aged with Organic Dementia

一次変性痴呆型 (primary degenerative dementia type=PDD) と, 脳動脈硬化性痴呆型 (arteriosclerotic dementia type=ASD) からなる高年器質性痴呆患者34名 (平均61.2歳) につき, 阪大式老年者用知能テストを用いて痴呆の程度を軽度, 中等度および重度の3段階に分け, また臨床的に上記の2病型に鑑別, 分類した. これらの対象各症例について, 左右の内頚動脈および椎骨動脈血流を超音波ドプラ法により測定し, その流速脈波を分析, 検討してつぎの結果をえた.1) 痴呆の程度が進むにつれて内頚動脈循環血流量は減少する傾向を示した.2) 痴呆患者では, 内頚動脈血流量は右側に比し左側で有意に低下しており, それはとくに重度痴呆群, ASDで顕著であった.3) 流速脈波の波高値を, 心収縮期初期峰 (S1), 第2峰 (S2), incisura (I), 拡張期峰 (D) および拡張末期 (d) の各時期で比較すると, 痴呆の程度が進むにつれ, 内頚動脈でI, D, dにおける最高流速が低下した. また, S1における最高流速はASDに比しPDDで有意に大であった.4) 波高比D/S2およびS2/S1を指標として流速脈波パターンを比較すると, 内頚動脈では痴呆の程度がすすむにつれてD/S2値は低下した. S2/S1比はASDでは年齢相当の値であったがPDDでは若年型を示した. なお椎骨動脈血流は上記の4項目につき痴呆症例間で有意な変化は認められなかった.以上, 高年器質性痴呆患者では, 痴呆の程度にしたがい大脳半球血流量 (ことに左) がとくに心拡張期で減少することが示され, 収縮期における波高比S2/S1はPDDとASDで異なり, 両病型における脳循環動態の相違を示唆するとともに鑑別診断上の指標としても有効であろうと考えられた.

Tactile extinction to simple (elementary) and complex stimuli

ABSTRACT‐ Thirty patients with cerebrovascular disease and 85 control subjects were examined using both the classical tactile extinction test and a modified Quality Extinction Test (modified QET) in order to investigate the so‐called tactile extinction phenomenon to complex stimuli from the qualitative standpoint. As a result, 1) the patients with tactile extinction to simple (elementary) stimuli also manifested extinction to complex tactile stimuli in the modified QET; 2) there were patients who exhibited extinction only to complex tactile stimuli. Our results provide support for the concept that the so‐called tactile extinction phenomenon could result from competition between tactile stimuli presented to both hands at at least 2 different levels of tactile processing, i. e. the process of perception and the process of recognition. When discussing the phenomenon of extinction to complex tactile stimuli, therefore, one should consider these 2 forms of extinction separately.