Sonographic evaluation of the peripheral nerves in hereditary neuropathy with liability to pressure palsies: a case report.

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominantly inherited disorder that affects peripheral nerves by repeated focal pressure. HNPP can be diagnosed by clinical findings, electrodiagnostic studies, histopathological features, and genetic analysis. Ultrasonography is increasingly used for the diagnosis of neuromuscular diseases; however, sonographic features of HNPP have not been clearly defined. We report the sonographic findings and comparative electrodiagnostic data in a 73-year-old woman with HNPP, confirmed by genetic analysis. The cross-sectional areas of peripheral nerves were enlarged at typical nerve entrapment sites, but enlargement at non-entrapment sites was uncommon. These sonographic features may be helpful for diagnosis of HNPP when electrodiagnostic studies are suspicious of HNPP and/or gene study is not compatible.