A 35-year-old patient presents with numbness and tingling sensations in the

A 35-year-old patient presenting with numbness and tingling in the distribution of the median nerve indicates compression of the median nerve as it passes through the carpal tunnel at the wrist. The carpal tunnel is a narrow passage formed by the carpal bones dorsally and the transverse carpal ligament (flexor retinaculum) volarly, through which the median nerve and flexor tendons travel. Compression within this tunnel leads to ischemia and impaired conduction of the median nerve, producing symptoms such as paraesthesia, numbness, and sometimes weakness in the thumb, index, middle fingers, and the radial half of the ring finger, consistent with carpal tunnel syndrome (CTS) NICE CKS.

On examination, specific tests such as Tinel's sign (tapping over the median nerve at the wrist), Phalen’s test (wrist flexion provocation), and Durkan's compression test support the diagnosis by reproducing symptoms in the median nerve territory NICE CKS.

While the carpal tunnel and transverse carpal ligament are the anatomical structures implicated in median nerve compression, rare cases show that space-occupying lesions within or adjacent to the flexor tendon sheath, such as ganglion cysts, can also compress the median nerve at this level, causing similar median nerve neuropathies NICE CKS Alsharif et al. 2026. Surgical exploration in such cases confirms median nerve compression beneath the transverse carpal ligament within the carpal tunnel, highlighting this anatomical structure as the primary site of compression in typical CTS.