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 atax-ia along with lesser signs of parkinsonism and autonomic dysfunction. Previous studies have shown bene-fits 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 carbido-pa/levodopa therapy. A right-handed 61-year-old man with a past medical history of chronic microvascular ischemia, mild lower ex-tremity 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 neurolog-ical 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, in-fectious, 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. Through this case report, we highlight a significant response to L-dopa therapy beyond what is normally ex-pected 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.