[A nosological study of a patient showing ataxia & lower motor neuron involvement].

A sporadic case of spinocerebellar degeneration with prominent involvement of the motor system has recently been encountered. A 54-year-old man without family history noticed speech disturbance at the age of 46 and weakness in his right hand the following year. The muscle weakness and atrophy were slowly progressive and made walk impossible at the age of 50, when his dysphagia increased. At the age of 54, he was admitted to our hospital when neurological findings revealed marked amyotrophy of general skeletal muscle and tongue with fasciculation. Deep tendon reflexes were decreased. Cerebellar ataxia was impossible to evaluate because of profound muscle weakness. And sensory disturbance was suspected in the distal portion of the lower extremities. CT scan revealed progressive atrophy of the brain stem and cerebellum. The patient died at the age of 54 due to CO2 narcosis. The clinical course was 8 years. A summary of the pathological findings was as follows: 1) Marked neuronal loss of the anterior horn of the spinal cord and motor cranial nerve nuclei except for oculomotor nuclei, with mild degeneration of pyramidal tract below lumbosacral level. 2) Degeneration of cerebellipetal system, spinocerebellar tract, Clarke's column and the middle root zone and cerebellifugal system, dentate nucleus, superior cerebellar peduncles, and red nucleus. 3) Mild degeneration of pontine nuclei, inferior olivary nuclei, pontine transverse fibers, the middle and inferior cerebellar peduncles, cerebellar white matter and Purkinje cells as in OPCA.(ABSTRACT TRUNCATED AT 250 WORDS)