Video 1 Benediction sign
The patient fails to flex the terminal phalanx of the thumb and index. There is wasting of the thenar eminence. The patient has a proximal median nerve lesion.
Video 2 Deep branch lesion of the ulnar nerve
The patient is unable to abduct the index finger on the right, and there is wasting of the first dorsal interosseous muscle.
Video 3 Dystrophia myotonica
Frontal balding, ptosis, ‘horizontal smile’, failure to bury the eye lashes, myotonia causing slowing of fist opening, and per cussion myotonia of thumb abduction.