Dystrophia Myotonica

I joined the neurology PACES course in TTSH in Singapore last year. One of the consultant told me that they like to show up "clinic cases" in PACES exam. One of their favourites is dystrophia myotonica that is uncommon in general practice . Remember this face for PACES!

The key features are bilateral ptosis with marked wasting of temporalis, facial muscles, sternomastoids. (no frontal balding in female)

There are features of myotonia i.e. when she shake hands there is a delay before she release her grip. Percussion myotonia is also demonstrable after tapping on the thenar eminence. Always warn them that the hit would be painful! The alternative site would be over the extensor digitorum.

Hit HARD over the thenar eminence!

This results in prolonged contraction of flexor pollicis brevis
Look for pacemaker in dystrophia myotonica patient because they are at risk for dysrythmias 2nd to cardiomyopathy. Practically, we do yearly ECG for screening purposes during follow up.

Remember the pacemaker!