Etiology of Carpal Tunnel Syndrome
Carpal tunnel syndrome results from compression of the median nerve as it travels through the carpal tunnel at the wrist, caused by a combination of mechanical pressure, anatomical factors, and underlying systemic conditions. 1
Primary Mechanism
The fundamental pathophysiology involves:
- Mechanical compression of the median nerve within the confined space of the carpal tunnel 1
- Increased pressure within the carpal tunnel leading to ischemic damage to the nerve 2
- Combination of mechanical trauma and vascular compromise 2
Anatomical and Structural Factors
Several anatomical variations predispose individuals to CTS:
- Congenital smaller carpal tunnel increases susceptibility to median nerve compression 3
- Bifid median nerve or persistent median artery as anatomic variants 4
- Enlargement and flattening of the median nerve with bowing of the flexor retinaculum 4
- Space-occupying lesions within the carpal tunnel 4
- Tendon pathology such as tenosynovitis 4
Systemic and Medical Conditions
Bilateral CTS may be an early sign of systemic conditions or amyloidosis, particularly cardiac amyloidosis when occurring without rheumatoid arthritis or known trauma 4, 5. Other associated conditions include:
- Diabetes mellitus 6
- Hypothyroidism 6
- Rheumatoid arthritis 2
- Obesity 2, 6
- Pregnancy 2, 6
- Acromegaly 6
- Hemodialysis 6
Occupational and Environmental Factors
- Repetitive strain and monotonous wrist activity contribute to CTS development 1, 2
- Use of vibratory objects during work tasks 2
- Repetitive wrist movements in occupational settings 3
Genetic Predisposition
- Genetic heredity plays a role in CTS susceptibility 2
- Variations in genes encoding proteins involved in extracellular matrix remodeling, inflammation, and nerve function have been linked to increased CTS risk 3
Important Clinical Caveat
While many cases have identifiable risk factors, idiopathic CTS remains the most typical diagnosis for patients presenting with characteristic symptoms 2. The interaction between biological, genetic, environmental, and occupational factors with structural elements determines individual susceptibility 3.