What is carpal tunnel syndrome?
Carpal tunnel syndrome is a common medical condition that occurs when the median nerve is squeezed or compressed as it travels through the wrist. The syndrome is characterized by pain in the hand, numbness, and tingling in the distribution of the median nerve. These sensations may be felt in the thumb, index finger, middle finger, and the radial side of the ring finger. The painful feelings may result in a reduction in grip strength and hand function.
What causes carpal tunnel syndrome?
The pathophysiology of CTS involves a combination of mechanical trauma, increased pressure, and ischemic damage to the median nerve within the carpal tunnel. In carpal tunnel syndrome, dramatic changes of pressure may lead to changes in fluid pressure, which is commonly experienced during wrist flexion and extension. Repetitive wrist movements become a risk factor for carpal tunnel syndrome. Consequently, demyelination of the median nerve can occur when exposed to automatic frequent forces. The development of carpal tunnel syndrome occurs in three phases.
Stages of carpal tunnel syndrome:
- First stage: patient would wake up feeling numbness or swelling on the hand. Pain may be felt from the wrist to the shoulder, with tingling on the hands and fingers, also known as brachialgia paresthetica nocturna.
- Second stage: occurrence of symptoms experienced in the first stage, specifically when the individual engages in repetitive activity involving the hand or wrist. Additionally, patients may also report clumsiness when using their hands to grip objects
- Third stage: carpal tunnel syndrome development appears when there is hypotrophy or atrophy of the thenar eminence. The occurrence of this stage also entails the ability to engage in any sensory symptoms by the patients.
Diagnostic tests for carpal tunnel syndrome
- Phalen’s maneuvre: a patient flexes the wrist to 90 degrees, and the test is positive if the flexing produces symptoms along with the distribution of the median nerve
- Tinel’s sign: positive result when tapping over the along the carpal tunnel produces symptoms in the median nerve distribution
Differential diagnosis
- Other median nerve entrapment syndromes
- Pronator teres syndrome
- Anterior interosseous nerve syndrome
- Injury of nerve digitales in the palm
- Cervicobrachial syndrome
Treatment/management
There are many ways that we can treatment carpal tunnel syndrome such as exogenous heat, laser therapy, ultrasound therapy, magnotherapy, iontophoresis, acupuncture, shockwave therapy, immobilisation, and kinesiotherapy. However, these methods are either extremely expensive or impractical for the individual. Therefore, exercise has been looked at as a form of treatment for carpal tunnel syndrome. More specifically, exercise-based therapy and neurodynamic therapy have been directly compared to each other in their effectiveness. A randomized parallel-group clinical trial found that both exercise-based and neurodynamic therapy being effective. However, neurodynamic therapy is more effective as it combines nerve-specific mobilisation with home exercise. As a result, patients have been found able to avoid surgery after receiving neurodynamic or exercise-based therapy. These therapies have been found to be effective in decreasing pain and improving function in patients with carpal tunnel syndrome. These outcomes may be explained by neurodynamic providing a desensitization effect where the pain threshold is decreased when combined with home exercise that improve nerve and joint mobility. Additionally, exercises that target median nerve movement have been shown to increase nerve excursion without straining it.
References
Genova, A., Dix, O., Saefan, A., Thakur, M., & Hassan, A. (2020). Carpal tunnel syndrome: a review of literature. Cureus, 12(3). https://doi.org/10.7759/cureus.7333
Hamzeh, H., Madi, M., Alghwiri, A. A., & Hawamdeh, Z. (2020). The long-term effect of neurodynamics vs exercise therapy on pain and function in people with carpal tunnel syndrome: A randomized parallel-group clinical trial. Journal of Hand Therapy. https://doi.org/10.1016/j.jht.2020.07.005
Schick C.W., Kaplan F.T.D. (2017) Differential Diagnosis of Carpal Tunnel Syndrome. In: Duncan S., Kakinoki R. (eds) Carpal Tunnel Syndrome and Related Median Neuropathies. Springer, Cham. https://doi.org/10.1007/978-3-319-57010-5_5
Society of Physiotherapy (2017). Exercise advice: carpal tunnel syndrome. Retrieved from https://www.csp.org.uk/public-patient/rehabilitation-exercises/carpal-tunnel-syndrome
Zaralieva, A., Georgiev, G. P., Karabinov, V., Iliev, A., & Aleksiev, A. (2020). Physical therapy and rehabilitation approaches in patients with carpal tunnel syndrome. Cureus, 12(3). https://doi.org/10.7759/cureus.7171