A 38-year-old man presents with progressive gait ataxia, dysarthria, and intention tremor for 6 months. Examination reveals nystagmus and past-pointing. MRI brain shows cerebellar atrophy with preserved brainstem. Which investigation is most appropriate to confirm the underlying etiology?

See the options, answer & explanation

Sign in free to reveal the answer choices, the correct answer, the detailed explanation, and AI-powered insights for this question.