Peroneal mononeuropathy: predisposing factors, and clinical and neurophysiological relationships

The most common mononeuropathy in the lower extremity involves the nerve. W e retrospectively evaluated the etiological predisposing factors and clinic al-neurophysiological features of 36 patients affected by peroneal mononeur opathy (PM). In 30 patients, a clear predisposing factor was identified. PM was more frequently perioperative (11 cases), associated with axonal invol vement. Unexpectedly, PM was not only due to surgery close to the peroneal region, but was mostly associated with hip surgery and, rarely, with thorac ic-abdominal surgery. A postural predisposing factor of PM was also frequen tly observed, usually associated with a pure conduction block. Conversely, most patients with bedridden predisposing factor presented axonal involveme nt, which was rarely associated with conduction block. In 25 of 36 PM cases , a long-term follow-up lead to an improvement (12 cases) or to good recove ry (13 cases) of PM. In conclusion, our study shows that: (1) in most PM ca ses it is possible to identify a predisposing factor; (2) there is a good c orrelation between predisposing factor and neurophysiological involvement, and (3) PM usually has usually a good prognosis.