The Double Crush Phenomenon - Carpal Tunnel Syndrome
Pain resulting from compromise of neural structures (neuropathic pain) is common in various regions of the body. It is often thought to be associated with excessive tension or compression on a nerve leading to ischemia (loss of blood flow). One of the most familiar syndromes associated with neuropathic pain is carpal tunnel syndrome (CTS). In this case, the median nerve is thought to be compromised at the carpal tunnel of the wrist.
What many people are not told is that there is a concept referred to as the double crush phenomenon. The double crush phenomenon occurs when nerve is compromised in one area along its path; it then is more likely to demonstrate symptoms somewhere else. In the example of CTS and the median nerve, there are numerous areas where the median nerve could run into problems including the neck, inter-scalene triangle, near the first rib, under the pectoralis minor, under the pronator teres muscle and at the carpal tunnel. When these areas are addressed, through conservative care including Active Release Technique (ART), the carpal tunnel symptoms (usually found in the thumb, index and middle fingers) often disappear.
So, before rushing to surgery for neuropathic pain, make sure the symptoms are examined by a practitioner who can check the entire nerve’s path. All too often we see patients who have surgeries like a carpal tunnel release and continue to have symptoms, while individuals who only underwent conservative care had complete resolution at long-term follow-ups.
Manual Physical Therapy Versus Surgery for Carpal Tunnel Syndrome: A Randomized Parallel-Group Trial. Randomized Controlled Trial. Fernández-de-Las Peñas C, et al. J Pain. 2015.