# Multiple Electrophysiological Evaluation of Carpal Tunnel Syndrome

## TL;DR

This study identifies a highly sensitive and specific electrophysiological method for diagnosing mild carpal tunnel syndrome by comparing median and ulnar nerve conduction.

## Contribution

The study introduces a novel electrophysiological technique with high sensitivity for detecting very mild carpal tunnel syndrome.

## Key findings

- All tested EDX techniques showed high specificity (>96.3%) and positive predictive value (>95.2%) for CTS diagnosis.
- Comparing median and ulnar distal sensory latencies in fingers 2 and 4 achieved 98.1% sensitivity.
- Comparing median and ulnar nerve conduction in the same hand is the most reliable method for very mild CTS.

## Abstract

To investigate a high-sensitivity electrodiagnostic (EDX) combination for diagnosing mild carpal tunnel syndrome (CTS).

A total of 68 healthy controls (HCs, 136 hands) and 91 adult patients (CTSs, 162 hands) clinically diagnosed with CTS were enrolled. All patients accepted EDXs, including the sensory ganglia segment method of the median and ulnar nerves, and motor nerve conduction of the median and ulnar nerves. We examined the electrophysiological results and compared the sensitivity and specificity of various sensory nerve detection methods for the median nerve between the two groups.

The electrophysiological results of the CTSs were significantly different from those of HCs. All EDX techniques selected showed high specificity (>96.3%), positive predictive value (>95.2%), and large area under the curve (0.922 as the smallest) for the diagnosis of CTSs. A comparison of the median distal sensory latencies with the ulnar distal sensory latencies in fingers 2 and 4 showed a high sensitivity of 98.1%. Comparison of the nerve conduction study between the median and ulnar nerves in the same hand is the most reliable EDX technique for diagnosing very mild CTS because of its high sensitivity and specificity.

If clinical CTS patients exhibit normal median motor distal latency or sensory nerve conduction velocity across the wrist, a comparison of median and ulnar nerve conduction through the wrist, including M-U and M-U ringdiff, is recommended.