Introduction:
The Tinel’s sign, which was initially known as the Hoffman-Tinel sign, was defined by physiologist Paul Hoffmann and neurologist Jules Tinel in 1915. They described the sign as a “pins and needle feeling” experienced on tapping on the skin over an injured nerve proximally. The “pins and needle feeling” may be experienced even in the areas distributed by the nerve that may lie away from the origin of the injured nerve.
What Is Tinel’s Sign?
The Tinel’s sign is the tingling or pricking sensation which is experienced when tapped along the skin over an affected nerve. The Tinel’s sign is the result of a non-invasive test performed by a doctor that is used to detect nerve abnormalities. A tingling sensation elicited even on light banging over the affected nerve indicates a positive Tinel’s sign. The Tinel’s sign is now commonly used as an indicator of peripheral nerve compression or damage. Peripheral nerves are the nerves that are present outside the brain and spinal cord.
When Is Tinel’s Sign Tested?
The Tinel’s sign is tested by a healthcare provider in persons who are suspicious of having nerve damage, irritation, or compression at a particular site.
What Are the Symptoms of Nerve Damage?
The symptoms experienced by persons having nerve compression or damage are as follows:
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Pain in the wrist and hand.
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Numbness.
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Weakness of the affected region.
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Pain that may radiate to the forearm, shoulder, and elbow.
What Nerve Problems Does Tinel’s Sign Indicate?
Generally, Tinel’s sign is considered an indication of nerve damage. The common nerve problems associated with Tinel’s sign are as follows:
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Carpal Tunnel Syndrome: Carpal tunnel syndrome is a disorder characterized by pain, weakness, numbness, and tingling sensation in the hand and wrist. The carpal tunnel is a narrow pathway consisting of ligaments and bones at the base (palm side) of the hand, which is the house for the median nerve and tendons that help in bending fingers. This condition is caused due to the excess pressure exerted on the median nerve at the wrist. The median nerve is one of the major nerves of the hand that runs from the forearm into the palm. This nerve is responsible for providing sensation to the thumb, index finger, middle finger, and half of the ring finger.
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Tarsal Tunnel Syndrome: Tarsal tunnel syndrome is characterized by pain, numbness, and tingling sensation in the foot. The tarsal tunnel is a pathway located inside the ankle and is composed of ankle bones and ligaments that stretch along the foot. Several nerves, blood vessels, and tendons that provide flexibility and movement to the foot pass through the tarsal tunnel. Tarsal tunnel syndrome is caused due to the compression of the tibial nerve, which travels through the tarsal tunnel.
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Cubital Tunnel Syndrome: Cubital tunnel syndrome is characterized by a tingling sensation or numbness in the ring and small fingers, forearm pain, and hand weakness. The cubital tunnel is a pathway that is made up of bones, ligaments, and muscles on the inside of the elbow. Cubital tunnel syndrome is caused due to the compression or injury of the ulnar nerve that runs from the neck passing through the cubital tunnel and ending in the fingers.
How Is Tinel’s Sign Tested?
The doctor takes a full history of the symptoms experienced by the person, which may include numbness, tingling sensation, pain, and weakness of the area around the affected nerve. After taking the detailed history of the patient, the doctor conducts a physical examination which includes testing for the tinel’s sign. The tinel’s sign is tested by the doctor by tapping lightly on the area over the affected nerve using a fingertip or a reflex hammer. The doctor then asks the patient to describe the sensation experienced while tapping over the affected nerve.
What Do Tinel’s Sign Test Results Indicate?
If a tingling or pricking sensation is experienced along the affected nerve area that radiates through the areas supplied by the nerve, it is considered a positive Tinel’s test result which indicates damage to the corresponding nerve. The nerve damage may be caused due to the following factors:
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Over usage of the part (hand, foot) supplied by the respective nerve.
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Thyroid disorders.
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Pregnancy.
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Diabetes.
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Tumor or cyst.
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Broken bones that compress the nerve.
When the patient does not experience any tingling sensation on tapping the nerve, it is considered a normal test result which indicates that the nerve is not affected. The normal test result is also known as a negative Tinel sign. However, a negative Tinel sign does not always indicate that the nerve is normal. A negative Tinel’s sign may also indicate that the nerve is not regrowing after an injury.
What Is the Clinical Significance of Tinel’s Test?
The Tinel’s sign is a test that helps doctors to diagnose nerve entrapments or nerve regrowth following an injury. Even though Tinel’s sign testing is a valid method of testing nerve damage clinically, thorough patient history and other clinical evaluation methods are necessary to confirm the diagnosis. Since Tinel’s sign test is not an accurate method to diagnose nerve damage, a few other tests may also be conducted. They are as follows:
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Phalen test.
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Nerve conduction velocity test.
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Magnetic resonance imaging (MRI).
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Ultrasound.
What Are the Limitations of Tinel’s Sign?
The result of the Tinel’s sign test may vary depending upon the amount of pressure applied to the affected area. If the tapping of the doctor is too hard or sharp, even a normal person who does not have nerve damage may experience a tingling sensation. Tinel’s sign is also not effective in all cases. In some carpal tunnel syndrome cases, other nerves in the affected area may grow. Hence when the doctor checks for the Tinel’s sign to diagnose nerve regrowth, the other nerves in the area could be mistaken.
Conclusion:
The Tinel’s sign is an old test that has been used by doctors as a part of physical examination for a long time. However, this test has limitations which might give a normal result even if the patient has a nerve injury. Hence other tests may be done to confirm the diagnosis. Even though this test has limitations, Tinel’s sign test is used as a method to make a rapid diagnosis of nerve damage or compression. Hence any nerve damage-related symptoms should be reported to the doctor for a prompt diagnosis and the right treatment options, which would help the patient to lead a normal life without any discomfort.
