How to detect carpal tunnel syndrome?
Do you think you are suffering from carpal tunnel syndrome?
i. One of the diagnostic maneuvers is Phalen’s maneuver. This involves bringing the wrist into forced flexion at 90 degrees and maintaining that position for a period of one minute. The maneuver can be made more efficient by raising the arm stretched over the head, keeping the wrist flexed. The appearance of tingling at the tip of the forefinger or middle finger or wrist pain is strongly suggestive of carpal tunnel syndrome especially if it occurs with both hands. The maneuver can be performed for both hands at the same time.
ii. Another test is to lightly strike the path of the median nerve along the area of the carpal tunnel with two fingers of the other hand. This percussing will often cause the sensation of an electric shock or abnormal pain. This is Tinel’s sign.
iii. A third test consists of applying slight pressure with two fingers or the thumb of the other hand, again on the path of the median nerve two to three centimeters above the carpal tunnel, ie at the forearm. This pressure test will evoke numbness or tingling in the fingers after about twenty seconds. This is the Durkan test.
iv. It is also useful to compare the quality of the perception of touch at the extremity of the index finger and the middle finger to that of the tip (pulp) of the little finger since the latter is innervated by another nerve called the ulnar nerve. This sensitivity test can be done by delicately touching the pulp of the fingers with a cotton swab. If perception of the cotton swab is different in the pulp of the index finger or of the middle finger compared to that of the little finger or auricular, it is important to suspect an already very advanced attack of the median nerve, and thus probably carpal tunnel syndrome that is more severe and therefore more urgent to deal with. This loss of sensitivity can become permanent and disabling.
i. Electromyogram (EMG):
Electromyography and measurement of nerve conduction velocities are very useful and informative. These are tests that evaluate the function and performance of the nerve rather than an imaging test that visualizes the nerve.
ii. The nerve can be described as a large electrical cable that contains hundreds of wires and cords (nerve fiber fascicles). Compression of the nerve will compromise the vasculature and oxygenation of the axons and these then start to function abnormally. The conduction velocity, or in other words, the speed at which the nerve impulses circulate through the nerve fibers, diminishes in a measurable manner. The test gives essential information on the degree of progress of the pathology and therefore on the prognosis of the recovery.
iii. It is very important to know that this test may be a false negative in the presence of symptomatic carpal tunnel syndrome in less advanced cases. False reassurance and treatment delays may result if the physician or patient is unaware of the limitations of this test.
Ultrasound is an examination that can be suggested to identify and evaluate the nerve and its condition. In cases of nerve compression, the nerve thickness will often be increased just above the compression zone. We can observe a dilation of the nerve just before the place where it is stuck, much like a garden hose that is blocked in one place. Ultrasound can detect this dilation and even measure the dimensions of the nerve. This ultrasound examination can also identify the presence of an anomaly (such as an abnormal muscle) or a mass in the canal, such as a tumor, cyst, or vascular dilatation.
Severity of your Carpal Tunnel Syndrome
Carpal tunnel syndrome is classified into three stages according to the severity of the symptoms.
i. Stage 1 is characterized by numbness, pain and tingling that occurs mainly during the night and can be relieved by shaking the hand. The affected hands are often characterized by stiffness in the morning.
ii. Stage 2 is characterized by symptoms that also occur during the day, with prolonged positions or repetitive hand movement. Weakness often develops, and it becomes common to drop things.
iii. Stage 3 is the most severe and is characterized by atrophy or irreversible weakening of the muscles stimulated by the median nerve. Tingling may no longer be present due to severe nerve injury.