Typical CIDP, distal variant CIDP, and anti-MAG antibody neuropathy: An ultra-high frequency ultrasound comparison of nerve structure.

To date, little is known about the usefulness of ultra-high frequency ultrasound (UHF-US, 50-70 MHz) in clinical practice for the diagnosis of dysimmune neuropathies. We present a prospective study aimed at comparing UHF-US alterations of nerves and fascicles in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), distal CIDP (d-CIDP) and anti-MAG neuropathy and their relationships with clinical and electrodiagnostic (EDX) features. 28 patients were included (twelve CIDP, 6 d-CIDP and 10 anti-MAG) and ten healthy controls. Each patient underwent neurological examination, EDX and UHF-US study of median and ulnar nerves bilaterally. UHF-US was reliable in differentiating immune neuropathies from controls when using mean and/or segmental nerve and/or fascicle cross-sectional area (CSA); furthermore, fascicle ratio (fascicle/nerve CSA) was a reliable factor for differentiating d-CIDP from other types of polyneuropathies. The fascicle CSA appears to be more increased in CIDP and its variant than in anti-MAG neuropathy. UHF-US offers information beyond simple nerve CSA and allows for a better characterization of the different forms of dysimmune neuropathies.

Focal cardiac ultrasound learning with pocked ultrasound device: A bicentric prospective blinded randomized study.

PURPOSE: Point-of-care ultrasound using a pocket-ultrasound-device (PUD) is increasing in clinical medicine but the optimal way to teach focused cardiac ultrasound is not clear. We evaluated whether teaching using a PUD or a conventional-ultrasound-device (CUD) is different when the final exam was conducted on a PUD. The primary aim was to compare the weighted total quality scale (WTQS, out of 100) obtained by participants in the two groups (CUD and PUD) on a live volunteer 2-4 weeks after their initial training. The secondary aims were to compare examination time and students' confidence levels (out of 50). METHODS: This bicentric, prospective single-blind randomized trial included undergraduate medical students. After watching a 15 min video about echocardiography views, students had a 45 min hands-on training session with a live volunteer using a PUD or a CUD. The final examination was conducted with a PUD on a live volunteer. RESULTS: Eighty-six comparable students were included, with 4 ± 1 years of medical training. In the PUD group, the mean WTQS was 65 ± 16 versus 60 ± 15 in the CUD group [p = 0.22; in multivariate analysis, OR 0.8 95% CI (0.1;1.6), p = 0.34]. The examination time was 10.0 [6.2-12.4] min in the PUD group versus 11.4 [7.3-13.2] in the CUD group (p = 0.39), while the confidence level was 27.9 ± 7.7 in the PUD group versus 27.4 ± 7.2 in the CUD group (p = 0.76). CONCLUSION: There was no difference between teaching echocardiographic views using a PUD as compared to a CUD on the PUD image quality, exam time, or confidence level of students.

Ultra-high-frequency ultrasound imaging of sural nerve: A comparative study with nerve biopsy in progressive neuropathies.

INTRODUCTION: Nerve ultrasound has been used increasingly in clinical practice as a complementary test for diagnostic assessment of neuropathies, but nerve biopsy remains invaluable in certain cases. The aim of this study was to compare ultra-high-frequency ultrasound (UHF-US) to histologic findings in progressive polyneuropathies. METHODS: Ten patients with severe, progressive neuropathies underwent ultrasound evaluation of the sural nerve before nerve biopsy. Ultrasound data were compared with histologic results in a retrospective manner. RESULTS: Sural nerves were easily identified on UHF-US. Nerve hyperechogenicity correlated with inflammatory infiltrates on biopsy. Nerve fascicles could be identified and measured on ultrasound in the majority of patients. DISCUSSION: Hyperechogenicity on UHF-US may be a marker of nerve inflammation in neuropathies. Furthermore, the UHF-US probe allows for evaluation of sensory nerves in spite of their small size, providing valuable information on their size and on their internal structure.