Electrodiagnostic Findings in 441 Patients with Ulnar Neuropathy - a Retrospective Study

Ulnar neuropathy (UN) is the second most common focal neuropathy in the upper extremities. Electrodiagnostic studies (EDx), including nerve conduction study (NCS) and electromyography (EMG), are reliable tools for the diagnosis of ulnar neuropathy. We aimed to retrospectively analyze the medical records of patients diagnosed with ulnar neuropathy in a seven-year period and report our findings.

In this retrospective study, documents of the patients whose ulnar nerve injury was confirmed through electrodiagnostic study in two departments of Physical Medicine and Rehabilitation were collected and demographic data, subjective complaints of the patient, the cause, and electrodiagnostic findings were extracted from each patient's file. The following points were specifically evaluated in the electrodiagnostic records; type of injury, location, accompanying injuries, sensory nerve action potentials (SNAP) of the fifth finger, SNAP of dorsal ulnar cutaneous nerve (DUCN), compound muscle action potential (CMAP) of abductor digiti minimi (ADM) muscle, nerve conduction velocity (NCV) across elbow, patterns of muscle involvement, and the severity of insult.

Out of 441 records, 305 (69.2%) were male and 68.1% were non-traumatic. Based on our clinical criteria, the intensity of the injury was mild in most cases. The elbow and forearm were the most involved regions in non-traumatic and traumatic cases respectively. Across elbow nerve conduction velocity showed decreased velocity in 71% of records. In non-traumatic cases, the most affected muscle was ADM (97%) and then FDI (85%).

In focal entrapments such as ulnar neuropathy, electrodiagnostic findings are very helpful in assessing location, severity, and type of injury. If a consensus is achieved for the diagnosis of UN, even retrospective studies can become valuable sources for studying UN.