Tinel's sign

Clinical sign elicited by percussing a superficial peripheral nerve, producing distal paresthesias (tingling, pins and needles) in its sensory distribution, indicating focal nerve irritation, compression neuropathy, or axonal regeneration at or distal to the lesion site. Common causes of positive Tinel's sign are carpal/cubital/tarsal tunnel syndrome, fracture compressing a nerve, crushing nerve injury, diabetes, hypothyroidism, rheumatoid arthritis, pregnancy, and compressing tumor (lipoma, ganglion cysts).