Multiple System Atrophy-Cerebellar Variant With Absence of Parkinsonian Motor Features

Multiple system atrophy (MSA) is a rapidly progressive, multisystem, neurodegenerative disease characterized clinically by varying severity of Parkinsonian features, cerebellar, autonomic, and urogenital dysfunction, and corticospinal disorders. There are two subtypes of MSA - the Cerebellar and Parkinsonian types. The cerebellar subtype (MSA-C) commonly presents with gait ataxia, dysarthria, and coordination deficits; however, the absence of classical Parkinsonian features may delay diagnosis. We report the case of a 52-year-old man who presented with recurrent unexplained falls, progressive gait instability, dysarthria, and cerebellar signs without evidence of rigidity, resting tremor, or bradykinesia. The diagnosis of MSA-C was supported by neuroimaging, which showed significant pontocerebellar atrophy with the distinctive "hot cross bun" sign on MRI. Multiple conditions with similar progressive cerebellar symptoms, like spinocerebellar ataxias, Parkinson's disease, and progressive supranuclear palsy, may show overlapping manifestations. This shows the importance of thorough clinical assessment along with the distinctive neuroimaging in diagnosing MSA-C. In addition, better awareness of the clinical heterogeneity of MSA may facilitate earlier recognition and diagnosis.