Fibrillation and positive sharp waves were seen in the abductor pollicis brevis
Physical examination revealed proximal muscle weakness of the upper and lower limbs (muscle test 3/5), and weakness of the distal muscles of both hands, in the abductor pollicis brevis
, opponens pollicis, flexor pollicis and the first and second lumbricals particularly.
Bilateral median motor nerve conduction studies on the wrist-elbow segment recording from the abductor pollicis brevis
(APB) muscle, and bilateral ulnar motor nerve conduction studies on the wrist-elbow, across elbow, elbow-axilla and the axilla-erb segments recording from the abductor digiti minimi (ADM) muscle were done using superficial electrodes.
right, ms: millisecond, mV: millivolt, m/s: meter/second, APB: abductor pollicis brevis
, ADM: abductor digiti minimi, EDB: extensor digitorum brevis, AH: abductor hallucis Table 1b.