Tinel's sign

Tinel's sign
Transverse section across the wrist and digits. (The median nerve is the yellow dot near the center. The carpal tunnel is not labeled, but the circular structure surrounding the median nerve is visible.)
Classification and external resources
Specialty	neurology
ICD-10	G56.0
ICD-9-CM	354.0
OMIM	115430
DiseasesDB	2156
MedlinePlus	000433
eMedicine	orthoped/455 pmr/21 emerg/83 radio/135
MeSH	D002349
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Tinel's sign is a way to detect irritated nerves. It is performed by lightly tapping (percussing) over the nerve to elicit a sensation of tingling or "pins and needles" in the distribution of the nerve. It takes its name from French neurologist Jules Tinel (1879–1952).

For example, in carpal tunnel syndrome where the median nerve is compressed at the wrist, Tinel's sign is often "positive" causing tingling in the thumb, index, middle finger and the radial half of the fourth digit. Tinel's sign is sometimes referred to as "distal tingling on percussion" or DTP. This distal sign of regeneration can be expected during different stage of somatosensory recovery.

Although most frequently associated with carpal tunnel syndrome, Tinel's sign is a generalized term, and can also be positive in tarsal tunnel syndrome, or in ulnar nerve impingement at the wrist (Guyon's canal syndrome), where it affects the other (ulnar) half of the fourth digit and the fifth digit.

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