4th March 2024

A 21-year-old male presents to the neurology clinic with difficulty mobilising

A 21-year-old male presents to the neurology clinic with difficulty mobilising due to a left-sided foot drop. Over the past two months, he has noticed difficulties in writing and performing tasks with his fingers due to weakness. On examination, he has a high steppage gait. Pes cavus was noted, and his distal leg muscles appear wasted. Ankle and supinator reflexes were absent. Vibration and fine touch were diminished along his upper and lower limbs distally with normal pain and temperature sensation. The cardiac examination was normal, and the ECG was unremarkable. He recalls that his mother and maternal grandfather both had difficulty walking, and his mother is now a wheelchair user due to weakness in her legs.

What is the likely underlying diagnosis?

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