Sonography of Carpal Tunnel Syndrome According to Pathophysiologic Type: Conduction Block Versus Axonal Degeneration

Abstract

The cross-sectional area and wrist-to-forearm ratio were associated with the pathophysiologic type of carpal tunnel syndrome, with larger nerve swellings seen in patients with axonal degeneration compared with those with demyelinating lesions. In addition to helping in the localization of the nerve lesion, sonography may indicate the type of nerve lesion.

Ultrasound, Clinical, and Electrophysiological Findings in Persistent Carpal Tunnel Syndrome

“…The ultrasound evaluation revealed in the majority of the cases disturbed echogenicity of the median nerve. The increased incidence of echogenicity changes in our group is in line with previous literature reports . In our opinion, changes in echogenicity of the nerve are mainly considered to be the result of edema, intraneuronal inflammation, and fibrosis.…”

“…The increased incidence of echogenicity changes in our group is in line with previous literature reports. 13,14 In our opinion, changes in echogenicity of the nerve are mainly considered to be the result of edema, intraneuronal inflammation, and fibrosis. Furthermore, 16/18 patients demonstrated a pathological WFR, while 12/18 cases showed CSA enlargement at the distal wrist crease.…”

Use of Multiple Ultrasonographic Parameters in Confirmation of Carpal Tunnel Syndrome

“…In other words, instead of following the "1 subject 5 1 hand" approach, we observed wrists as independent entities. This approach is relatively common in neurology 8,12,[27][28][29][30][31][32]35,38 as well as in other specialties. [39][40][41] On the basis of such references and our everyday clinical experience with patients who have CTS, we decided to use data on all available wrists instead of omitting valuable information by choosing only 1 wrist per patient.…”

Reduction in median nerve cross-sectional area at the forearm correlates with axon loss in carpal tunnel syndrome

“…However, slightly in contradiction with our findings, a negative correlation between wCSA and motor unit number estimation of the APB muscle in CTS patients was found in a previous study ( Bayrak et al, 2007 ). Moreover, in another study, a negative correlation was found between the WFR and the distal sensory nerve action potential amplitude (stimulated at the palm and registered at the third digit), which was considered to represent axon loss ( Moon et al, 2017 ). The mentioned finding of Moon et al might correspond to our finding that the WFR is greater when axon loss evident in patients with moderate CTS.…”