Shearwave Elastography in the Differentiation of Carpal Tunnel Syndrome Severity.

BACKGROUND: There is emerging evidence that ultrasound elastography may provide additional diagnostic information in peripheral neuropathies.

OBJECTIVE: To investigate the use of ultrasound elastography to evaluate median nerve stiffness in patients with carpal tunnel syndrome (CTS), as well as the relationship between the elastographic stiffness and electrophysiological severity.

DESIGN: Case control study.

SETTING: Tertiary hospital outpatient neurophysiology clinic.

PARTICIPANTS: Twenty eight patients (47 wrists) with CTS and 25 control patients (25 wrists).

INTERVENTIONS: None.

MAIN OUTCOME MEAURES: Ultrasound parameters (median nerve cross-sectional area [CSA] at carpal tunnel, ratio of median nerve CSA at carpal tunnel and forearm), shearwave elastography parameter (median nerve stiffness), and electrophysiological severity of carpal tunnel syndrome.

RESULTS: In patients with CTS, median nerve stiffness by ultrasound elastography was increased between the different severity groups (control 83.5 ± 24.8, EDx negative CTS 84.2 ± 46.4, mild 117.7 ± 79.3, moderate 144.0 ± 71.1, severe 196.6 ± 48.4). The control versus moderate and severe subgroup was statistically significant.

CONCLUSIONS: In total, this study has demonstrated that ultrasound elastography was able to discriminate the severity of CTS whereas conventional ultrasound parameters did not.