Video Representation of Dopamine-Responsive Multiple System Atrophy Cerebellar Type

BACKGROUND Multiple system atrophy cerebellar type (MSA-C) is a subtype of MSA that presents with predominant ataxia along with lesser signs of parkinsonism and autonomic dysfunction. Previous studies have shown benefits from carbidopa/levodopa therapy for the MSA parkinsonian subtype but few studies have focused on the MSA-C subtype. We present a video case of MSA-C that demonstrated significant improvement with carbidopa/levodopa therapy. CASE REPORT A right-handed 61-year-old man with a past medical history of chronic microvascular ischemia, mild lower extremity neuropathy, and lumbar and cervical stenosis status after decompression presented with progressive worsening gait changes over several months with acute deterioration before admission. The initial neurological workup demonstrated bilateral cogwheel rigidity; difficulty with movement initiation. including standing up from a seated position; slow saccadic eye movements; masked facies (hypomimia); right ankle clonus; bilateral upper and left lower limb ataxia; and hyperreflexia. A follow-up workup was negative for metabolic, infectious, and paraneoplastic causes, but magnetic resonance imaging demonstrated cerebellar atrophy along with a "hot cross bun sign" suggestive of probable MSA-C according to consensus criteria, and the patient was started on carbidopa-levodopa. He subsequently demonstrated improvement in key motor domains, including his cogwheel rigidity and gait testing, and was discharged shortly thereafter. CONCLUSIONS Through this case report, we highlight a significant response to L-dopa therapy beyond what is normally expected according to diagnostic criteria for MSA. MSA treatment responsiveness can vary significantly across patients, which warrants additional studies into appropriate treatment choices for patients with Parkinson's disease and MSA.