Sonographic detection of diffuse peripheral nerve enlargement in hereditary neuropathy with liability to pressure palsies.

Hereditary neuropathy with liability to pressure palsies (HNPP) is a disorder characterized by a tendency to develop focal neuropathies after trivial traumas. On teased nerve fiber studies, sausage-shaped myelin sheath swellings (tomacula) are found. We report the sonographic findings in a patient with genetically proven HNPP. We were able to demonstrate enlargement of several peripheral nerves, even nerves that were clinically unaffected. Enlargement was found not only at typical nerve entrapment sites but also outside these sites. This diffuse nerve enlargement may play an important role in the pathogenesis of entrapment neuropathies in HNPP patients. Copyright 2002 Wiley Periodicals, Inc.