Possible "Premotor" Multiple System Atrophy-Cerebellar Form.

We report the case of a 52-year-old Japanese man who, while he had no cerebellar ataxia or parkinsonism, was revealed to have silent cerebellar hypoperfusion/mild cerebellar atrophy and sacral autonomic disorder. His sacral autonomic disorder was urinary retention without marked prostate hyperplasia. Urodynamics-sphincter electromyography revealed detrusor hyperactivity with impaired contraction and neurogenic changes of the sphincter motor unit potentials. Although he did not have a motor disorder, these features suggested possible multiple system atrophy-cerebellar (MSA-C) form. The present case report suggests that neuroimaging helps in diagnosing "premotor" MSA-C form in situ.