The carpal tunnel is a passage located in the frontal aspect of the wrist formed between the bones of the wrist and a retinaculum (fibrous band) that extends from right to the left side of the wrist. The tunnel provides a passageway for tendons of the muscles in the frontal aspect of the forearm and the median nerve.
The compression of the median nerve within this tunnel is known as carpal tunnel syndrome. This occurs following the swelling of any of the tendons within this narrow tunnel. Most times the precipitating cause is not known and there are countless associated risk factors.
Carpal tunnel syndrome results in numbness/tingling sensation in the palmar aspect of the thumb, index, middle and outer half of the ring fingers (including the nail beds), inability to make a fist due to the weakness of some of the muscles of the thumb.
Treatment is by physical therapy, use of corticosteroid, splinting and surgery. Acupuncture is another therapeutic option with the advantage of being less invasive as compared to surgery but its mode of action and efficacy were not known.
Therefore, a study was conducted to unravel these. 80 patients with carpal tunnel syndrome were treated with electro-acupuncture. This therapy was provided in 16 sessions over 8 weeks. The symptoms and the functions of the median nerve were then assessed and patients were followed up for 3months.
Acupuncture intervention reduced symptoms and improved the functions of the median nerve. The mode of action was detected to be due to changes in the primary somatosensory cortex in the brain following treatment.
Maeda Y, Kim H, Kettner N, Kim J, Cina S, Malatesta C, Gerber J, McManus C, Ong-Sutherland R, Mezzacappa P, Libby A, Mawla I, Morse LR, Kaptchuk TJ, Audette J, Napadow V. Rewiring the primary somatosensory cortex in carpal tunnel syndrome with acupuncture. Brain. 2017 Apr 1;140(4):914-927. doi: 10.1093/brain/awx015.