The clinical, electrophysiological and prognostic heterogeneity of ulnar neuropathy at the elbow.

BACKGROUND: Ulnar nerve neuropathy is one of the most common entrapment neuropathies and is often considered to be one entity in clinical and follow-up studies.

OBJECTIVE: The aim of this study was to determine whether there is a difference in the long term outcome of patients with a severe motor conduction block (mCB) of > or =50% (50% group) in comparison with patients with an mCB of < or =20% (20% group).

METHODS: In a prospective cohort of 244 patients with ulnar neuropathy at the elbow (UNE), 16% had an mCB of > or =50%. These patients were matched with respect to surgery, age and severity of muscle weakness with patients with an mCB of < or =20%. 32 patients per group were evaluated clinically and electrophysiologically.

RESULTS: The median follow-up period was 25 months. Based on the patient's assessment, 26 (81%) patients in the 50% group and 14 (44%) patients in the 20% group had a good outcome (p = 0.005). The clinical examination showed a good outcome in 27 (84%) in the 50% group and in 13 (41%) in the 20% group (p = 0.0008).

CONCLUSION: This study showed that the prognosis of patients with focal demyelination of the ulnar nerve presenting with an mCB of > or =50% is more favourable than those without an mCB.