PURPOSE: This study aims to assess the precision of ultrasound in identifying upper limb peripheral nerves by comparing ultrasonographic findings with direct human cadaveric dissection.
METHOD: Fourteen fresh-frozen upper limb specimens were examined in February 2023. Ultrasound assessments were performed by two experienced musculoskeletal radiologists using three linear probes (15 MHz, 24 MHz, and a 22 MHz hockey stick probe). Seven peripheral nerves were identified and marked using dye injections. Subsequent dissections were conducted under loupe magnification by hand surgeons.
RESULT: The recurrent motor branch of the median nerve exhibited the lowest discrepancy (mean 1.014 ± 1.459 mm) and the highest accuracy (64.29% of specimens). The greatest discrepancy was observed in the branch of the musculocutaneous nerve to the brachialis (mean 5.114 ± 3.758 mm). The interrater correlation coefficient (ICC) varied across nerve sites, ranging from - 6.298 to 0.795, with the highest ICC observed in the superficial branch of the ulnar nerve (0.795, 0.066).
CONCLUSION: These findings suggest that ultrasound is a valid and effective tool for identifying peripheral nerve branches in the upper limb, particularly for superficial nerves. Improved accuracy in ultrasound-guided nerve identification may enhance surgical precision and reduce complications in nerve-related procedures.
METHODS: We prospectively recruited 17 GBS patients and 17 age and gender-matched controls. Serial studies of their nerve conduction parameters and nerve ultrasound, documenting the cross-sectional areas (CSA), were performed at admission and repeated at several time points throughout disease course.
RESULTS: Serial nerve ultrasound revealed significantly enlarged CSA in median, ulnar and sural nerves within the first 3 weeks of disease onset. Longitudinal evaluation revealed an improvement in the nerve CSA with time, reaching significance in the ulnar and sural nerves after 12 weeks. There was no significant difference between the demyelinating and axonal subtypes. There was also no significant correlation found between nerve CSA and neurophysiological parameters or changes in nerve CSA and muscle strength.
CONCLUSION: In GBS, serial studies of peripheral nerve ultrasound CSA are helpful to detect a gradual improvement in the nerve size.
SIGNIFICANCE: Serial nerve ultrasound studies could serve as a useful tool in demonstrating nerve recovery in GBS.
Materials and Methods: One hundred healthy adults' nerves were assessed, using standardized techniques. Individuals were grouped into age groups. Gender differences were assessed.
Results: Of the 100 volunteers, 49 were female and 51 were male. Their mean age was 39.8 years. Findings showed statistically significant prolongation of median distal motor latency (DML) and F-wave latency with age and reduction of median, ulnar, and sural sensory amplitudes as age increased. Gender differences showed consistent difference in the normal values for median, ulnar, and peroneal DMLs and respective F-wave latencies, which were significantly shorter in females. Sensory amplitudes of tested upper extremity nerves were significantly lower in males. Comparing with available data, our findings are similar to the Saudi population but significantly different from the American and multiethnic Malaysian populations. Pakistani individuals generally have significantly higher amplitudes and faster conduction velocities with similarities to South Asian studies.
Conclusions: We recommend normative NCS parameters for commonly tested nerves for the Pakistani population, using standardized techniques to ensure highest quality testing and outcomes.