Historical Overview1
- 1915: Paul Hoffman (1884-1962), a German physiologist, described a sensation of “tingling” or “pins and needles” that could be elicited when an injured nerve was tapped and attributed the sign to nerve regeneration.
- 1915: Jules Tinel (1879-1952), a French neurologist, described a “tingling sensation” or “formication sign” after slight percussion of a nerve trunk after injury to which he attributed the sensation to the presence of growing axons.
Description1-6
- When the area over a nerve is lightly tapped, the patient may feel a tingling sensation or “pins and needles” in the area served by it. Tinel’s sign may be elicited when a mass is compressing a nerve. A variety of non-malignant and malignant masses can cause Tinel’s sign to be elicited, including but not limited to, neurilemmomas (Schwannomas) that compresses the median nerve at the wrist, the radial or ulnar nerves, the anterior interosseous nerve, the muscle-cutaneous nerve, and the digital nerves. Tinel’s sign can also be elicited by the presence of a ganglion cyst, and such cases affecting the median nerve in the carpal tunnel and the radial and ulnar nerves have been reported.
- Where Tinel’s sign appears depends on which nerve is compressed and where it is compressed:
- Median nerve at the carpal tunnel: thumb, index and middle finger
- Radial nerve at the wrist: radial, back side of the hand
- Superficial radial nerve in the forearm: pain or dysesthesias on the dorsal radial forearm radiating to the thumb and index finger (with variations in distribution owing to differences in anatomical phenotypes
- Ulnar nerve at the wrist: numbness and tingling in the little finger and along the outside of the ring finger
- Ulnar nerve at the elbow: tingling in the forearm, ulnar-palmar side of the wrist and hand, and in little finger and the ring finger
Pathophysiology
- Due to nerve compression
- On a cellular level, the sign may be caused by a hyper-excitable membrane.
Instructions1,7
- When a palpable mass is present, the nerve is often tapped at this site.
- For suspected compression of the median nerve in the carpal tunnel, tap over it as it passes through this tunnel in the wrist.
- For suspected compression of ulnar nerve in the cubital tunnel, tap over the nerve in the cubital tunnel in the elbow.
- For suspected compression of the superficial radial nerve, Tinel’s sign can be elicited by tapping over the course of the nerve.
- The intensity of the tapping should be enough to cause the expected response while avoiding direct mechanical stimulation of the nerve.
Variations8
- Single-finger strike: striking the load cell with the dominant middle finger only
- Double-finger strike: striking the load cell with the dominant index and middle finger together
- Preload: preloading with the non-dominant thumb and then striking the thumb with the dominant middle finger
Related Signs and Tests
- Related signs and tests will depend on which nerve is compressed, and where it is compressed.
- Imaging is often used in patients with a suspected (or palpable) mass. The modality that is most informative depends on the type of mass:
- For ganglion cysts, plain X-rays are, if needed, often sufficient
- MRI is often used for more suspicious masses
Diagnostic Performance Characteristics
- Whether Tinel’s sign can be elicited due to the presence of a mass partly depends on the location and size of the mass. Because these vary in clinical practice, it is difficult to derive a quantitative estimate of the diagnostic performance of this sign that is clinically relevant. One study2 of 234 solitary neurilemmomas found that Tinel’s sign was present in 81% of patients.
