Ultrasound of peripheral nerves in neuralgic amyotrophy

INTRODUCTION: Neuralgic amyotrophy (NA) can often be difficult to diagnose. Nerve ultrasound (US) is potentially useful, but it is operator-dependent, especially for small nerves. METHODS: Fifty-one consecutive patients with NA (mean duration 16 months) and 50 control subjects underwent US of the brachial plexus and major nerves of the upper extremity at predefined sites. We compared cross-sectional areas (CSAs) of affected and unaffected sides with controls and sides within patients. RESULTS: The median nerve and radial nerve at the level of the upper arm were enlarged on the affected sides compared with controls and the unaffected sides of patients. Enlargement was most pronounced for affected sides vs. controls (median 44%, radial 67%). DISCUSSION: NA patients showed increased CSAs, especially in the major nerves of the upper limb, even after longer disease duration. This could make US a useful adjunct in diagnosing NA. Muscle Nerve 59:55-59, 2019

Ultrasound of peripheral nerves in neuralgic amyotrophy

Contains fulltext : 203073.pdf (publisher's version ) (Closed access)INTRODUCTION: Neuralgic amyotrophy (NA) can often be difficult to diagnose. Nerve ultrasound (US) is potentially useful, but it is operator-dependent, especially for small nerves. METHODS: Fifty-one consecutive patients with NA (mean duration 16 months) and 50 control subjects underwent US of the brachial plexus and major nerves of the upper extremity at predefined sites. We compared cross-sectional areas (CSAs) of affected and unaffected sides with controls and sides within patients. RESULTS: The median nerve and radial nerve at the level of the upper arm were enlarged on the affected sides compared with controls and the unaffected sides of patients. Enlargement was most pronounced for affected sides vs. controls (median 44%, radial 67%). DISCUSSION: NA patients showed increased CSAs, especially in the major nerves of the upper limb, even after longer disease duration. This could make US a useful adjunct in diagnosing NA. Muscle Nerve 59:55-59, 2019

High-Resolution Axonal Bundle (Fascicle) Assessment and Triple-Echo Steady-State T2 Mapping of the Median Nerve at 7 T: Preliminary Experience

Objectives: The aims of this preliminary study were to determine the number of axonal bundles (fascicles) in the median nerve, using a high-resolution, proton density (PD)-turbo spin echo (TSE) fat suppression sequence, and to determine normative T2 values, measured by triple-echo steady state, of the median nerve in healthy volunteers and in patients with idiopathic carpal tunnel syndrome (CTS), at 7 T. Materials and methods: This prospective study was approved by the local ethics committee and conducted between March 2014 and January 2015. All study participants gave written informed consent. Six healthy volunteers (30 ± 12 years) and 5 patients with CTS (44 ± 16 years) were included. Measurements were performed on both wrists in all volunteers and on the affected wrist in patients (3 right, 2 left). Based on 5-point scales, 2 readers assessed image quality (1, very poor; 5, very good) and the presence of artifacts that might have a possible influence on fascicle determination (1, severe artifacts; 5, no artifacts) and counted the number of fascicles independently on the PD-TSE sequences. Furthermore, T2 values by region of interest analysis were assessed. Student t tests, a hierarchic linear model, and intraclass correlation coefficients (ICCs) were used for statistical analysis. Results: Proton density-TSE image quality and artifacts revealed a median of 5 in healthy volunteers and 4 in patients with CTS for both readers. Fascicle count of the median nerve ranged from 13 to 23 in all subjects, with an ICC of 0.87 (95% confidence interval [CI], 0.67-0.95). T2 values were significantly higher (P = 0.023) in patients (24.27 ± 0.97 milliseconds [95% CI, 22.19-26.38]) compared with healthy volunteers (21.01 ± 0.65 milliseconds [95% CI, 19.61-22.41]). The ICC for all T2 values was 0.97 (95% CI, 0.96-0.98). Conclusions: This study shows the possibility of fascicle determination of the median nerve in healthy volunteers and patients with CTS (although probably less accurately) with high-resolution 7 T magnetic resonance imaging, as well as significantly higher T2 values in patients with CTS, which seems to be associated with pathophysiological nerve changes. High-Resolution Axonal Bundle (Fascicle) Assessment and Triple-Echo Steady-State T2 Mapping of the Median Nerve at 7 T