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 Results: The mean CSA of the 14 nerve segments ranged from 2 to 10mm2. The intra-rater, interrater 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 armafter 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. healthy subjects (n = 56), and the inter-rater, intra- rater and inter-equipment reliability of measurements was assessed

Ultrasonography of MADSAM neuropathy: Focal nerve enlargements at sites of existing and resolved conduction blocks

Using the emerging technique of peripheral nerve ultrasonography, multiple focal nerve swellings corresponding to sites of existing conduction blocks have been described in demyelinating polyneuropathies. We report two cases of multifocal acquired demyelinating sensory and motor neuropathy (MADSAM). In the first, multiple focal nerve enlargements were detected by ultrasound at sites of previous conduction blocks, well after complete clinical and electrophysiological resolution. In the second case, existing proximal conduction blocks could be localized by ultrasound. Our cases highlight the importance of nerve ultrasound in identifying conduction blocks and demonstrate that ultrasonographic morphological changes may outlast functional recovery in demyelinating neuropathies. © 2012 Elsevier B.V

A nagy felbontasú ideg-ultrahangvizsgálatok jelentősége a perifériás idegek betegségeinek diagnosztikájában [The significance of high-resolution ultrasonography in the diagnosis of peripheral nerve disorders]

High resolution ultrasonography is an emerging technique for the investigation of peripheral nerves and is increasingly used worldwide in the diagnosis of peripheral nerve disorders, however, until now it is not widespread in Hungary. According to the literature this method is especially useful in entrapment neuropathies, traumatic peripheral nerve injuries, tumors of the peripheral nerves and sonographically guided interventions. Ultrasonography allows precise morphological analysis and quantitative measurements of the nerves providing useful complementary information to electrodiagnostic data. In entrapment neuropathies ultrasound shows nerve swelling mainly proximal to the sites of compression and a focal change of echotexture. On longitudinal scan, an abrupt caliber change and spindle-like swelling of the compressed nerve segment can be seen. Evaluation of the anatomical background and visualisation of the postoperative and posttraumatic changes provide useful information for planning of the therapy. Ultrasound may be of significant help in localizing the pathological nerve segment when it is at an electrophysiologically inaccessible site or when substantial secondary axonal loss precludes precise electrophysiological localization and it might even show pathological changes when nerve conduction studies are normal. Contrary to electrophysiological investigation ultrasonography might discover neurotmesis in the akute phase of traumatic nerve injuries indicating the necessity of surgical intervention. We provide a summary of the main indications and further application areas of this method

Ultrasonography of ulnar neuropathy at the elbow: Axonal involvement leads to greater nerve swelling than demyelinating nerve lesion

OBJECTIVE: To evaluate nerve size parameters measured by ultrasound in patients with ulnar neuropathy at the elbow (UNE) and to correlate them with the type of nerve lesion. METHODS: The largest cross sectional area (CSA(max)) of the ulnar nerve around the elbow and the cubital-to-humeral nerve area ratio (CHR) were measured in 50 elbows with UNE and in 87 elbows of 50 healthy subjects. CSA(max) and CHR were compared between controls and patients with predominantly demyelinative and axonal nerve involvement. Subgroups of patients with pure sensory and mixed sensorimotor axonal lesion were also compared. RESULTS: In patients with axonal nerve involvement, a significantly larger CSA(max) and CHR were found when compared to those with predominantly demyelinating nerve lesion; both groups differed significantly from healthy controls. CSA(max) values in patients with sensorimotor axonal lesion were significantly higher than in those with pure sensory axonal involvement. CONCLUSION: CSA(max) and CHR highly correlate with the type of nerve pathology in UNE, with a significantly larger nerve swelling seen in axonal lesions, as compared to demyelinating lesions. SIGNIFICANCE: In addition to helping in the localization of nerve lesion, ultrasonography may also reflect the type and degree of nerve lesion as assessed by electrophysiological means