Neurophysiological Diagnosis of the Ulnar Nerve Damage at the Elbow

Damage to the ulnar nerve most frequently develops around the elbow region. Some occupations are associated with a chronic trauma to the ulnar nerve at the elbow and the resulting damage could be, under ceratin circumstances, classified as an occupational disease. Neurophysiological investigation is essential for the diagnosis of the ulnar nerve damage at the elbow. Reliable localization of the damage to the elbow region is prerequisite. Determination of the severity of the ulnar nerve damage is also important. For the purposes of obtaining an expert opinion, a standardized investigation guaranteeing comparable results from all EMG laboratories, is required. The authors discuss in detail the specific methodological parameters of a neurophysiological investigation of the ulnar nerve at the elbow. An investigational protocol is proposed that assesses the ulnar nerve in rectangular elbow flexion with the nerve stimulation at 4 cm below and 6 cm above the elbow and with registration from both, m. abductor digiti minimi and m. inteosseus dorsalis primus. Finally, the authors present the results from their own sample of patients assessed with the proposed protocol.