[A case of spongiform encephalopathy with ataxia and amyloid plaques].
CASE: A 63-year-old man was admitted to our hospital because of gait disturbance. His daughter died of the same disorder at age 29. In 1974, at age 59, the patient noticed mild recent memory disturbance and clumsiness in handwriting. In 1976, his gait was markedly unstable, but he could walk without assistance, and his speech became dysarthric. In spring, 1977, he was unable to walk without assistance. From Jan. 9, 1978, through Feb. 14, 1978, he was hospitalized in our hospital. Neurological examination revealed an ataxic gait and scanning speech. Deep tendon reflexes of the upper extremities and ankle jerks were normal, but knee jerks were absent. Pathological reflexes were not elicited. Both superficial and deep sensations were normal. He was alert and showed no overt dementia. Laboratory data including CSF, EEG and brain CT were normal except positive TPHA in serum. Thereafter, he was followed up with the diagnosis of spinocerebellar degeneration. In 1979, he developed a limb ataxia. In spring, 1980, he became very irritable and was easily excited. He gradually developed dementia and urinary incontinence. In 1981, his illness progressed to an akinetic mutism and died of pneumonia on July 19, 1981. Myoclonus and periodic synchronous discharges in EEG were not observed until his death. The brain was 1,075 g in weight after formalin fixation and the cerebrum was generally soft. The gyri showed no evidence of abnormalities or atrophy, while the cerebellum and brain stem, especially the pons, were atrophic. The arterial and venous systems showed no remarkable changes. The spinal cord was externally unremarkable. The ventricles were dilated.(ABSTRACT TRUNCATED AT 250 WORDS)