[Diagnostic nerve ultrasonography]. / Diagnostische Nervensonographie.

CLINICAL/METHODICAL ISSUE: For the diagnostics of nerve lesions an imaging method is necessary to visualize peripheral nerves and their surrounding structures for an etiological classification. STANDARD RADIOLOGICAL METHODS: Clinical neurological and electrophysiological investigations provide functional information about nerve lesions. The information provided by a standard magnetic resonance imaging (MRI) examination is inadequate for peripheral nerve diagnostics; however, MRI neurography is suitable but on the other hand a resource and time-consuming method. METHODICAL INNOVATIONS: Using ultrasonography for peripheral nerve diagnostics. PERFORMANCE: With ultrasonography reliable diagnostics of entrapment neuropathies and traumatic nerve lesions are possible. The use of ultrasonography for neuropathies shows that a differentiation between different forms is possible. ACHIEVEMENTS: Nerve ultrasonography is an established diagnostic tool. In addition to the clinical examination and clinical electrophysiology, structural information can be obtained, which results in a clear improvement in the diagnostics. Ultrasonography has become an integral part of the diagnostic work-up of peripheral nerve lesions in neurophysiological departments. PRACTICAL RECOMMENDATIONS: Nerve ultrasonography is recommended for the diagnostic work-up of peripheral nerve lesions in addition to clinical and electrophysiological investigations. It should be used in the clinical work-up of entrapment neuropathies, traumatic nerve lesions and spacy-occupying lesions of nerves.

High-resolution ultrasonography of peripheral nerves: measurements on 14 nerve segments in 56 healthy subjects and reliability assessments.

PURPOSE: The aim of this study was to assess different aspects of reliability in high-resolution ultrasonography (HRUS) of the peripheral nerves and to establish reference values for the most frequently examined nerve segments. MATERIALS AND METHODS: A nerve size parameter, the cross-sectional area (CSA) of the C5, C6 and C7 cervical roots, the median, ulnar, radial, superficial radial, peroneal, tibial, and the sural nerves was measured using HRUS at a total of 14 predefined anatomical sites in two different cohorts of healthy subjects (n = 56), and the inter-rater, intra-rater and inter-equipment reliability of measurements was assessed. RESULTS: The mean CSA of the 14 nerve segments ranged from 2 to 10 mm(2). The intra-rater, inter-rater and inter-equipment reliability was high with intraclass correlation coefficients of 0.93, 0.98, and 0.86, respectively. The CSA values showed no consistent correlation with age, height, and body weight, but males had significantly larger values than females for nerve segments on the arm after correcting for age, weight and height in multivariate analysis. CSA values did not differ when two independent cohorts were compared. CONCLUSION: Peripheral nerve ultrasonography is a reliable and reproducible diagnostic method in the hands of experienced examiners. Normal values for several upper and lower extremity nerves are provided by our study.

[Is high resolution ultrasound of the median nerve helpful before reintervention after failed carpal tunnel surgery?]. / Ist der hochauflösende Ultraschall des N. medianus vor einer Karpaltunnel-Rezidivoperation hilfreich?

A common reason for persisting or new complaints after carpal tunnel surgery is an incomplete release of the retinaculum flexorum. Traction neuropathy, a real recurrent carpal tunnel syndrome and iatrogenic nerve lesions occur less frequently. In the case of an incomplete release of the flexor retinaculum the clinical symptoms in most of the patients can be resolved with revision surgery. Electrodiagnostic testing can only support the indication for a reoperation if a preoperative examination exists but is not able to demonstrate the exact cause of a failed carpal tunnel surgery. The 4 cases presented here show that high resolution ultrasound provides valuable information in addition to electrodiagnostic testing before a reintervention.