Question 41

Question:

A 36-year-old male is diagnosed with a rare trinucleotide repeat disorder. He retains full mental ability, but is experiencing progressive weakness, loss of coordination, and an unsteady gait. No other signs on physical exam are found. What is the likely diagnosis?

Correct Answer: E.  Spinocerebellar ataxia

Of each of these diseases, myotonic dystrophy and spinocerebellar ataxia are the only two that don’t present with some sort of mental deterioration. Myotonic dystrophy has significant additional signs including muscle wasting, cataracts, and heart conduction defects. Therefore, spinocerebellar ataxia is the most likely diagnosis.