21st June 2023

A 31-year-old woman came into the GP with brief, involuntary jerking of the second and third digits of the right hand for the last few months

A 31-year-old woman came into the GP with brief, involuntary jerking of the second and third digits of the right hand for the last few months. She has also lost dexterity in the right hand.

On examination, there is wasting of the flexor digitorum superficialis muscles of the second and third digits. There is a reduced sense of pain and temperature from the last two digits of the hand to the medial aspect of the arms.

She reports she was in a life-threatening road traffic accident when she was 24 years old.

Which one of the following options would be the most likely cause of the myoclonus?