Multiple System Atrophy-Cerebellar Type: A Case Report With Classic Neuroimaging Features

Background: Multiple system atrophy (MSA) is a rare progressive neurodegenerative disorder characterized by parkinsonism, cerebellar dysfunction, and autonomic failure. The cerebellar variant (MSA-C) presents predominantly with cerebellar ataxia and is often challenging to diagnose in early stages. Case Presentation: A 60-year-old male presented with a 2-year history of progressive gait instability, starting with difficulty grasping slippers and progressing to proximal muscle weakness requiring walking support. He developed postural hypotension, intentional tremor, and urinary symptoms. Examination revealed gait ataxia, horizontal nystagmus, positive cerebellar signs, and significant postural hypotension (140/90 mmHg supine to 100/60 mmHg standing). MRI brain demonstrated the pathognomonic "hot cross bun" sign in the pons with significant cerebellar atrophy. Based on clinical presentation and neuroimaging findings, a diagnosis of MSA-cerebellar type was established. Conclusion: This case highlights the importance of recognizing the classic triad of cerebellar dysfunction, autonomic failure, and characteristic neuroimaging findings in diagnosing MSA-C. Early recognition is crucial for appropriate symptomatic management and patient counseling regarding prognosis.