Shunsaku Hirai

Senile Degenerative Brain Lesions and Dementia

In a study of senile degenerative lesions—including Alzheimers neurofibrillary changes, senile plaques and amyloid angiopathy—the hippocampal area of the brain was examined by thioflavine T fluorescence microscopy in 146 consecutive autopsy patients over the age of 49. The incidence and quantity of neurofibrillary changes and senile plaques rose with age, and an approximate positive correlation in quantity was noted among the three kinds of degenerative change. The quantity of neurofibrillary lesions and senile plaques was significantly different between the demented and non‐demented patients, but not between the severely and less severely demented patients. The cause of dementia was studied retrospectively, based on the extent of morphologic changes in the brain, thus classifying dementia into three types: degenerative, vascular, and mixed. Clinically, the mixed type resembled the vascular type with regard to major neurologic signs, and there was some similarity to the degenerative type with regard to mental features.

ENCEPHALOMYELOPATHY DUE TO AN ORGANIC MERCURY COMPOUND.

OUR INTEREST in the toxicity of organic metal compounds was stimulated by reports of organic tin intoxication in 19551 and the “Minamata disease,” presumably caused by organic mercury compound,2 which was reported in 1957.3 An excellent review on the clinical, histopathologic, and epidemiologic aspects of this disease has been published.4 A few reports concerning the intoxication of man by organomercury compounds indicate the cause to be the inspiration of the fumes of agricultural drugs in most cases. In 1940, Hunter and associates5 reported 4 cases of intoxication by methylmercury phosphate or nitrate. Fourteen years later, Hunter and Russell6 described detailed histopathologic findings in the brain of one of the patients in the previously reported cases. The microscopic changes in the brain were most pronounced in the occipital pole region of the cerebrum and palleocerebellum. Constriction of the visual fields may be attributed to atrophy of the area striata and, according to their statement, the ataxia could be correlated with changes in the cerebellar cortex. Brown7 reported clinical and autopsy findings in a case of phenylmercury acetate intoxication which showed a clinical picture resembling amyotrophic lateral sclerosis. Microscopic findings showed degeneration of motor cells in the anterior horn and the lateral column of the spinal cord, without changes in the brain. Kantarjians also pointed out the clinical resemblance to amyotrophic lateral sclerosis in 11 cases of definite ethylmercury ptoluene sulfonanilide intoxication. This paper is a report of 3 cases of intoxication caused by the application of a solution containing organic mercury compound for the treatment of a widespread fungus skin infection.

Posthemiplegic Shoulder-Hand Syndrome, with Special Reference to Related Cerebral Localization

Seven autopsy cases of shoulder‐hand syndrome following hemiplegia were studied with regard to cerebral localization. One of them showed an isolated brain lesion in the premotor area due to a metastasis from malignant melanoma. Four other cases with cerebral infarction and one with glioblastoma multiforme showed massive brain lesions involving the frontal and parietal lobe cortex in the area supplied by the middle cerebral artery. The seventh case showed a hemorrhagic cerebral lesion in the lentiform nucleus. The most common overlap area in 6 of the 7 cases was located in the premotor region including the anterior part of the motor region. The shoulder‐hand syndrome following hemiplegia always develops on the side contralateral to the brain lesion which might cause a unilateral longstanding autonomic dysfunction. As corroborated in a review of the relevant literature, a lesion in the premotor area appears chiefly responsible for the primary mechanism of the shoulder‐hand syndrome in post‐stroke hemiplegia.

Pure alexia in a Japanese-English bilingual: dissociation between the two languages.

Sirs: Cerebral localization of languages in bilingual speakers has received much attention. The representation of two languages in the brain has been investigated by examining patterns of language impairment in bilingual aphasics. Pure alexia is a reading disorder in patients who are able to comprehend spoken words and have no problem in writing words. They typically read words letter by letter. In traditional terms, it is seen as a disconnection syndrome in which a right visual field loss prevents direct access to information in the left hemisphere and damage to the splenium of the callosum alters interhemispheric transfer. In order to investigate whether the neural mechanism underlying reading in two languages is separate, it is appropriate to compare the reading ability of different languages in bilingual pure alexia. Of the previous reports of pure alexia in bilinguals, only a few indicated dissociation between the different languages, and none compared the two languages in the same battery [4, 5, 9]. They also have not shown the location of the lesions or discussed in detail the mechanism of the symptom. We examined a Japanese patient with pure alexia whose Japanese was more impaired than his English. A 65-year-old, right-handed Japanese man was hospitalized after sudden onset of right hemianopia, amnesia, and alexia. He was born in Japan and educated in Japanese. He started English in middle school and became fluent in speaking both languages. After graduating from university, he lived in an English-speaking country for more than 7 years. He had a history of diabetes mellitus but was otherwise healthy. In December 1997, he suddenly lost his sight in the right visual field and was referred to our hospital. He had mild hypertension, and right hemianopia with mild amnesia and pure alexia. The patient was alert and had no sensory-motor deficits except for the visual field defect. His verbal IQ was 123, performance IQ 70, and total IQ 103 on the Wechsler Adult Intelligence Scale (WAISR). On the Wechsler Memory ScaleRevised (WMSR), his verbal memory was 62, visual memory 80, general memory 72, remote memory 66, and attention 91. MRI showed a left cerebral infarction with complete posterior cerebral artery occlusion. There was total damage of the calcarin cortex; fusiform, lingual gyri; and extended infarction of the corpus callosum (Fig. 1). Although it is difficult to compare the reading ability in different languages, we tried to devise comparable tasks in both languages as follows. A detailed neuropsychological evaluation made 30 days after onset with the Western Aphasia Battery (WAB) test for Japanese showed that his spontaneous speech, auditory comprehension, repetition, and writing were perfect (Table). In contrast, he could not read any kanji (ideograms, logographic symbols of Chinese origin) or kana (phonograms, phonetic symbols for syllables). His language profile LETTER TO THE EDITORS

Clinical and epidemiological studies on hepatocerebral disease in Japan.

Publisher Summary This chapter presents clinical and epidemiological studies on hepatocerebral disease in Japan. Hepatocerebral disease is the general term to describe the clinical syndrome in which both the brain and the liver are involved with a causal relationship between the two. Hepatolenticular degeneration (H.L.D.) had been considered to be rare in Japan until the discovery of the abnormalities in copper metabolism attracted a large number of clinical investigators to the study of this disease with the aid of modern laboratory techniques, resulting in the frequent appearance of case reports in Japan. According to results with histochemical method, copper deposition in the liver gradually increased in the fetus from about the 5th month of pregnancy, reached a maximum in the 6-7th month, and gradually decreased thereafter. Ceruloplasmin was definitely low in the umbilical blood, while the maternal venous blood showed a very high level. Simultaneous determinations of serum copper in maternal blood and umbilical venous blood in 10 cases upon delivery, however, showed equally high values in both.