Recommended diagnostic tests for evaluating median nerve compression in suspected carpal tunnel syndrome (CTS) primarily include nerve conduction studies (NCS). NCS assess the speed and strength of electrical impulses along the median nerve across the carpal tunnel, helping to confirm impaired conduction, quantify severity, and establish a baseline for recovery assessment NICE CKS.
These studies also assist in excluding other neurological conditions such as polyneuropathy or radiculopathy NICE CKS. However, NCS have moderate sensitivity and specificity and a low positive predictive value; some patients may benefit from surgery despite normal NCS results NICE CKS.
Clinical provocative maneuvers (e.g., Phalen’s test, Tinel’s sign) are commonly used in initial assessment but have variable diagnostic accuracy. A recent systematic review and meta-analysis found that while these tests can support diagnosis, their sensitivity and specificity vary, and they should not be solely relied upon for definitive diagnosis Dabbagh et al. 2023.
Therefore, clinical assessment combined with NCS remains the cornerstone of diagnosis. In cases of diagnostic uncertainty or atypical presentations, referral for specialist assessment and further electrophysiological testing is recommended NICE CKS.
Additional investigations to exclude other causes of neuropathy (e.g., blood tests for vitamin B12, thyroid function) may be considered if symptoms are atypical or there is suspicion of broader neurological disease NICE NG127.
Key References
- CKS - Carpal tunnel syndrome
- NG127 - Suspected neurological conditions: recognition and referral
- NG211 - Rehabilitation after traumatic injury
- (Padua et al., 2016): Carpal tunnel syndrome: clinical features, diagnosis, and management.
- (Zuniga and Keir, 2019): Diagnostic and Research Techniques in Carpal Tunnel Syndrome.
- (Dabbagh et al., 2023): Diagnostic Test Accuracy of Provocative Maneuvers for the Diagnosis of Carpal Tunnel Syndrome: A Systematic Review and Meta-Analysis.