Longitudinal Sliding of the Median Nerve in Patients with Carpal Tunnel Syndrome

Abstract

In nerve compression syndromes restricted nerve sliding may lead to increased strain, possibly contributing to symptoms. Ultrasound was used to examine longitudinal median nerve sliding in 17 carpal tunnel syndrome patients and 19 controls during metacarpophalangeal joint movement. Longitudinal movement in the forearm averaged 2.62 mm in controls and was not significantly reduced in carpal tunnel syndrome (CTS) patients (mean=2.20 mm). In contrast, CTS patients had a 40% reduction in transverse nerve movement at the wrist on the most, compared to least, affected side and nerve areas were enlarged by 34%. Normal longitudinal sliding in the patients indicates that nerve strain is not increased and will not contribute to symptoms.

High‐resolution ultrasound analysis of subsynovial connective tissue in human cadaver carpal tunnel

“…1 Speckle tracking of ultrasound images has been employed to assess longitudinal sliding of the median nerve. 15,28 Color Doppler ultrasound has been used successfully for measurements of flexor tendon excursion. 29 We used spectral Doppler to measure the relative velocities of the tendon and SSCT because of its ability to identify anatomical structures interrogated by the scan plane in motion and, at the same time, to steer the beam and place the Doppler gate at the desired location in the tendon or SSCT.…”

“…Erel and colleagues 15 used ultrasound to examine longitudinal median nerve sliding in patients with CTS and compared the results to controls. They used a custom frame-by frame cross-correlation algorithm and took advantage of the relatively wide cross-section of the median nerve to track its motion.…”

“…As the tunnel size and shape is uncommonly altered, increased pressure is assumed to result from a change in volume or material properties of the contents of the tunnel, 8,9 of which the most likely is the SSCT, which is known to be fibrotic in patients with CTS. 8,[10][11][12] Ultrasound imaging has been described to detect pathologies such as thickening of the flexor tendons 13 and transverse carpal ligament, 14 shape and echogenicity alterations, restricted median nerve sliding in the carpal tunnel, 15,16 synovial proliferation, soft-tissue infection and joint effusion, tissue calcification and tumors, 17 persistent median artery, 18 tendinous and ligamentous injuries and swelling of the median nerve in the proximal part of the carpal tunnel, and flattening of the median nerve in the distal part of the carpal tunnel. 6,14,[19][20][21] High-resolution ultrasonography with approximately 7 MHz transducers is suitable for assessment of dynamic changes in the tunnel.…”

Transverse Movement of the Median Nerve in the Carpal Tunnel during Wrist and Finger Motion in Patients with Carpal Tunnel Syndrome

“…Additionally, the transverse displacements of the nerve and the tendons within the carpal tunnel have been evaluated during wrist or finger motion (Nakamichi and Tachibana 1992;Erel et al 2003). Some studies by transverse ultrasound have shown that the median nerve moves palmarly in active finger flexion, and gets compressed between the transverse carpal ligament (TCL) and the flexor tendons in healthy subjects and in patients with CTS (Yoshii et al 2009; van Doesburg et al 2012;Wang et al 2014a).…”

Ultasonographic indicators of carpal tunnel syndrome demonstrate reversibility following carpal tunnel release

“…In healthy individuals, Nakamichi reported transverse sliding motion of 1.75 mm inside the carpal tunnel during passive index finger movements, but only 0.3 mm in patients with CTS [7]. Erel used ultrasonography examination to measure median nerve movement at the wrist during passive movements performed with 4 fingers [11]. They observed movement of approximately 1.5 mm in healthy individuals and a smaller value in patients with CTS.…”