Diagnostic value of high‐resolution sonography in common fibular neuropathy at the fibular head

In 30% of patients with common fibular ( CF ) neuropathy at the fibular head, reliable localization of the site of the lesion by means of electrodiagnostic testing is challenging. Methods We prospectively assessed proximal CF nerve cross‐sectional area ( CSA ) measurements and at the fibular head in 87 patients with CF neuropathy and 16 with a different condition. Reference values were obtained in 64 healthy volunteers. Results Patients with CF neuropathy had a significantly larger CF nerve CSA than controls and patient controls ( P < 0.0001). Sonography localized the lesion at the fibular head in 55% and just above it in 71% of patients. Assessment of the most thickened part of the CF nerve resulted in a cut‐off value of >8 mm 2 with a sensitivity of 90% ( CI 81–95%) and a specificity of 69% ( CI 58–78%). Conclusion High‐resolution sonography in addition to electrodiagnostic testing improves diagnostic reliability in CF neuropathy. Muscle Nerve , 48: 171–178, 2013