Study of Wrist Ratio and Wrist-to-Palm Index Radio in Individuals Suffering from Carpal Tunnel Syndrome

Ann Indian Acad Neurol. 2019 Apr-Jun;22(2):159-163. doi: 10.4103/aian.AIAN_343_18.


Background: Carpal tunnel syndrome (CTS) is the commonest median nerve entrapment neuropathy, with preponderance in females.

Aims and objective: The aim of the present study was to find out wrist ratio (WR) and wrist/palm ratio (WPR) in clinically diagnosed patients of CTS.

Methodology: One hundred individuals (fifty patients of CTS and fifty as control group) aged between 30 and 50 years were recruited for the study. Early confirmation of clinically suspected patients of CTS was done by performing electrodiagnostic tests of median and ulnar nerves. Motor and sensory conduction velocities, distal motor and sensory latencies, and F-wave latencies were performed in the recruited volunteers.

Results: The values for mean wrist ratio in control groups were 0.694, 0.703 respectively, and in patients with carpal tunnel syndrome, it was 0.704 and 0.719 respectively in moderate and severe type. The mean wrist to palm ratio (WPR) in control group was 0.371, while in patients with CTS, it was 0.374, 0.382, 0.387, and 0.401 based on progression of severity. Both were statistically significant for the last two groups (wrist to index finger [WIF] >4.4 m/s, moderate, and WIF nonrecordable, severe). Statistically significant (P < 0.001) decrease of motor conduction velocities for median nerve was seen in the CTS group as compared to control group. Statistically significant (P < 0.001) increase in distal motor and sensory latencies was observed for both median and ulnar nerves in CTS group with more increase in distal motor latency than sensory latency. Increase in F-wave latencies of both nerves was seen in CTS group.

Conclusion: The study results confirm selective slowing of sensory and motor conduction within wrist-to-palm segment in patients of CTS. Both WR and WPR have a progressive correlation with the severity of CTS, but statistically significant changes were seen in the groups with moderate and severe CTS. Thus, WR/WPR can act as one of the essential parameters in the diagnosis of CTS with moderate-to-severe CTS.

Keywords: Carpal tunnel; distal latencies; electrophysiological diagnosis; nerve entrapments; wrist ratio.