The motor supply to the muscles involved come from segments of C8 and T1. Such a widespread lesion, however, would be unlikely to have such limited symptoms. Carpal tunnel syndrome is caused by a compression of the median nerve . This can be due to the inflammation of the common flexor tendon sheath after strain and overexertion. Fluid retention, as seen in pregnancy and hormonal imbalances, can also cause compression of the nerve.
Patients often feel an increase in symptoms at night due to venous stasis.
Venous stasis contributes to the compression of the nerve. Although this patient recovered with rest and physical therapy, some patients do not improve with conservative treatment and opt for surgery. Surgery can decompress the median nerve . Structures superficial to the flexor retinaculum, however, can be endangered. This includes the superficial palmar vascular arch formed by the superficial branch of the ulnar artery and superficial branch of the radial artery , the palmar cutaneous branches of the median and ulnar nerves and the recurrent motor branch of the median nerve .