Spontaneous Activity In Abductor Digiti Minimi )Adm( As An Early Indicator Of The Irritation Of The Ulnar Nerve At The Elbow Joint

Abstract

The cubital tunnel syndrome (CuTS) is a neurological disorder that affects the ulnar nerve as it passes through the elbow joint. It may induce several physical disabilities in the affected person. The early manifestation of CuTS maybe not be well recognized clearly. The abductor digiti minimi (sometimes abductor digiti quinti, ADM) muscle is located on the ulnar side of the palm in human anatomy. The study aims to evaluate the feasibility of using the early appearance of spontaneous activity in ADM as a predictor of ulnar nerve irritation at the elbow joint. Patients and method: 67 patients were included in the study, and all of them complained of neurological manifestations. A short segment study for the ulnar nerve at the elbow joint and the Guyon`s canal was done. In addition, needle EMG was done for the ulnar innervated muscles below the level of the elbow joint, including first dorsal interossii (FDI) and abductor digiti minimi (ADM) muscles. Results: 18 of them show normal NCS of the ulnar nerve. 10 show spontaneous activity by needle EMG in the ADM only, and 9 show normal needle EMG. Conclusion: the presence of spontaneous activity in the ADM muscle may be the early signs of electrodiagnosis of cubital tunnel syndrome.