A case of spinocerebellar ataxia in a patient initially admitted for positional vertigo

Abstract

Spinocerebellar ataxia (SCA) indicates a group of heterogeneous disorders. In Japan, approximately 60% of SCA cases consist of sporadic disorders, and the rest consist of a variety of dominant disorders. A major disorder of sporadic SCA is multiple system atrophy (MSA). MSA is a progressive neurodegenerative disease, showing parkinsonism and cerebellar, autonomic, urinary, and pyramidal dysfunction in many combinations. A 63-year-old man with short-lived bouts of positional vertigo was presented. He showed no cochlear symptom or abnormal neurological symptoms. And when he was underwent Dix-Hallpike maneuver, direction-changing torsional nystagmus was observed. Initially he was diagnosed as having benign paroxysmal positioning vertigo (BPPV). Canalith repositioning procedure (CRP) improved the patient's condition for a time, but positional vertigo and torsional nystagmus recurred soon after the CRP. An eye-tracking test and an optokinetic pattern test, undergone after 1 month from the onset, showed impaired pursuit eye movement. Drug therapy and CRP was not effective anymore. 13 months after the onset, he complained of dysarthria and rapidly showed autonomic, cerebellar ataxia, pyramidal and urinary dysfunction. Finally, he was diagnosed as having multiple system atrophy. This case indicated that the eye-tracking test and optokinetic pattern test can be useful for the primary symptoms of the initial stage of SCA.