Last updated on:November 29th, 2020
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Pain and paresthesia
The pain of carpal tunnel syndrome is most commonly felt in the palmar surface of the thumb, index, and middle fingers. However, the whole hand can be affected. The pain can also radiate to the elbow or shoulder. This can often start off worse in the evenings and progress to affect the patient during the daytime as well.
The underlying cause is compression of the median nerve as it passes through the narrowed carpal tunnel.
Pain and paresthesia may improve when shaking the affected hand. This is thought to be due to transient relief of median nerve compression.
Loss of motor function
Adduction and opposition of the thumb can be affected. This leads to difficulty in grasping objects firmly and tasks requiring fine motor control (e.g., picking up a needle or buttoning a shirt). This is because injury to the median nerve leads to weakness and clumsiness of the hand.
Workplace exposure to activities requiring prolonged wrist flexion or extension, overuse of flexor muscles, or exposure to vibration is a risk factor for CTS. This type of exposure can be seen in manual workers employed in construction, logging, manufacturing, or certain service industries; and in artisans.
Extrinsic and intrinsic risk factors
Extrinsic risk factors include obesity, hypothyroidism, pregnancy, menopause, renal failure, oral contraceptive use, and congestive heart failure. These conditions affect the body's fluid regulation, and can increase the fluid volume within the carpal tunnel.
Intrinsic risk factors refer to tumors and similar pathologies that increase the pressure on the median nerve by taking up space within the carpal tunnel.