Recently you’ve begun to feel numbness, tingling, and occasional burning pain in your hand, and your co-worker proclaims, “Oh no, you have carpal tunnel syndrome!” If that indeed is true, don’t feel like you’ve been struck with a bit of bad luck, as carpal tunnel syndrome (CTS) is an extremely common entrapment neuropathy. A study by the University of Manchester estimates that CTS effects 1% to 3% of the general population. A nerve, called the median nerve, runs from your neck (nerve roots C6-T1) throughout your arm and all the way down into your hand.
The median nerve provides both sensory and motor functions to the upper extremity. Compression of the median nerve by the transverse carpal ligament in the carpal tunnel is what causes the common symptoms of tingling, numbness, and/or pain in the hand. These symptoms may be constant or intermittent, and pain could also potentially radiate up into the forearm as well.
Entrapment neuropathies, like CTS, compromise the neurovascular microcirculation of the nerve itself. Much like compressing a water hose or “kinking” it, any form of compression or excessive pressure on a nerve decreases its available blood supply and hinders its ability to properly function. Nerves and the brain, in particular, demand an extremely high amount of blood.
The brain and the spinal cord makes up only 2% of our body mass, yet they consume almost 20% of our circulating blood!
Improper neural circulation and nutrition to the median nerve underlies the cause of symptoms associated with CTS.
The clinical signs and symptoms associated with CTS are very specific, and care must be taken to differentiate CTS from a host of other neurological disorders that can present in the hand and forearm. The best way to do this, of course, would be to see your local physical therapist! Ideally, try to look for a PT who is a certified hand specialist (C.H.T.). A physical therapist can easily differentiate among other common neurological disorders, such as cervical radiculopathy, pronator syndrome, ulnar tunnel syndrome, or Wartenberg’s syndrome, just to name a few.
For a quick self-diagnosis, ensure that your symptoms in the hand are within the cutaneous distribution of the median nerve shown below: the palmar surface and fingertips of the thumb, index, middle, and radial half of the ring fingers.
Additional symptoms on the backside of the hand, or in the pinky finger, can indicate other pathologies, such as cervical radiculopathy or ulnar tunnel syndrome. If symptoms consistently radiate from the forearm into the hand, it can possibly be a sign of similar median nerve pathology, but with a nerve entrapment at a different location higher up near your elbow called pronator syndrome.
Now if you’re still with me, and you’ve self-diagnosed yourself with CTS, there are a host of conservative treatment options that can help alleviate your symptoms. All of the following interventions aim to improve circulation and/or relieve pressure off of the median nerve.
Pressure within the carpal tunnel is lowest when the wrist is held in a neutral (0°) wrist position, while wrist flexion and extension increase pressure. As discussed earlier, when pressure increases, circulation to the nerve decreases and causes pain. An easy fix to maintaining lower levels of pressure in the carpal tunnel is to use a wrist splint. These can be worn both during the day and at night, although it is not apparent in the literature that the addition of daytime wearing of splints further improves symptoms or function. A wrist splint also helps limit excessive hand movements, which is often associated with an aggravation of symptoms.
Exercises that help to promote movement of the tendons in the carpal tunnel as well as the median nerve itself are recommended for patients with mild to moderate CTS. Research has shown that light to moderate wrist and finger movement exercises can actually decrease carpal tunnel pressures, in part by facilitating venous return or edema dispersion in the median nerve. However, these exercises should only be implemented once symptoms regress or subside.
Modalities that promote healing and increased circulation, such as heat, therapeutic ultrasound, and laser have all demonstrated success in treating CTS. Heat induces vasodilation, increasing local circulation and flushing out “toxic by-products” to decrease pain. Therapeutic ultrasound increases cell wall permeability and proliferates the healing processes. Laser encourages more proficient oxygen uptake by cells. All in all, these therapeutic modalities aim to improve nerve function and decrease your symptoms.
See your local physical therapist and give these conservative treatment interventions a shot first before electing for any surgical options, like a carpal tunnel release!