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Updated: Jul 5, 2026

Screening of Axonal Degeneration in Carpal Tunnel Syndrome Using Ultrasonography and Nerve Conduction Studies
Published on: January 11, 2019
Sensory distribution indicates severity of median nerve damage in carpal tunnel syndrome
E P Wilder-Smith1, E S Ng, Y H Chan
1Neurology, Yong Loo Lin School of Medicine, National University, 5 Lower Kent Ridge Road, Singapore, Singapore. mdcwse@nus.edu.sg
Objective:
Sensory symptoms within the median nerve distribution are a primary clinical diagnostic criterion for the diagnosis of carpal tunnel syndrome (CTS). However, the distribution of the sensory symptoms in CTS varies from patient to patient. This study identifies the clinical and electrophysiological findings that correlate with the distribution of sensory symptoms in an Asian population with CTS.
Methods:
In a prospective study of 105 patients with electrophysiologically confirmed CTS, clinical and educational data were correlated with sensory symptom distribution.
Results:
Median nerve distribution was strongly associated with more severe nerve conduction abnormality, male gender, and relief by movement. Patients with a complete median sensory distribution had more electrophysiological abnormality than those with an incomplete median distribution. Extra-median distribution was associated with the least nerve conduction abnormality. Educational qualification, age, symptom duration and body mass index were not associated with the pattern of sensory symptoms.
Conclusions:
In carpal tunnel syndrome, sensory symptom distribution is strongly dependant on the degree of electrophysiological median nerve damage. Median nerve sensory distribution is associated with severe nerve damage.
Significance:
This study provides clinicians with a simple clinical rule for assigning the degree of median nerve damage in patients with CTS based on sensory distribution patterns.
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