During his one-year follow-up, no disease progression was observed except for a slight atrophy in the medial border of the left forearm, which added to the interosseal and
hypothenar muscle wasting.
CMT patients showed diminished or absent tendon reflexes (100.0%), pes cavus (85.3%), drop foot (85.3%), and claw hand (32.4%), as well as bilateral atrophy of the first dorsal interosseous muscle (85.3%), bilateral thenar muscle atrophy (58.8%),
hypothenar muscle atrophy (bilateral 47.1%, unilateral 2.9%), gastrocnemius atrophy (bilateral 47.1%, unilateral 2.9%), and anterior tibial muscle atrophy (bilateral 52.9%, unilateral 5.9%).
There was wasting of interossei, thenar and
hypothenar muscles, more marked in the left hand and clawing in both hands (fig-1).
It innervates the
hypothenar muscles, third and fourth lumbricals, dorsal and palmar interossei muscles, adductor pollicis muscle, and deep head of the flexor pollicis brevis muscle.
Variations in the motor nerve supply of the thenar and
hypothenar muscles of the hand.
voluntary muscle testing showed Grade 0 power in the thenar and
hypothenar muscles bilaterally.
In another case of ulnar nerve lesion, one could not find any denervation in
hypothenar muscles. These abnormal findings can be explained by the presence of an abnormal anastomosis of nerves in the upper extremity.
On motor examination, there was wasting of thenar and
hypothenar muscles of the right side with normal left sided examination.
The deep ulnar nerve is responsible for motor control of intrinsic hand function through innervation of the dorsal and palmar interossei, the lumbricals of fourth and fifth digits, the
hypothenar muscles (abductor, flexor and opponens digiti minimi), adductor pollicis muscle and the deep head of flexor pollicis brevis.
Atrophy of the first dorsal interosseous and
hypothenar muscles is common.
The deep branch curves around the hook of the hamate and turns radially across the interossei, supplying the
hypothenar muscles, the ulnar two lumbricals, all the interossei, and the adductor pollicis.
Hypothenar muscles include the abductor digiti minimi (abducts the 5th finger), flexor digiti minimi (flexes the little finger) and oppenens digiti minimi (opposes the fifth digit).
