What is Tinel sign?

What is Tinel Sign?

Tinel sign is a clinical test where tapping or percussion over a nerve produces a tingling sensation (paresthesias) that radiates distally along the distribution of that nerve, indicating either nerve compression or nerve regeneration after injury. 1

Historical Context and Nomenclature

• The sign was originally described by Paul Hoffman, though it is commonly named after Jules Tinel, a French neurologist who described it in 1915 2, 3
• The more accurate term is the "Hoffman-Tinel sign," though it is most commonly referred to simply as "Tinel sign" in clinical practice 2

Clinical Mechanism and Interpretation

• The sign reflects increased sensitivity of compressed or regenerating nerve fibers 1
• A positive Tinel sign indicates the presence of nerve pathology but does NOT necessarily predict complete functional recovery - it only signals the progress of nerve regeneration, which is a common misconception 1
• The tingling sensation occurs because percussion mechanically stimulates the affected nerve fibers 1

Primary Clinical Applications

Compression Neuropathies

• Most commonly used in the diagnosis of carpal tunnel syndrome, where tapping over the median nerve at the wrist produces tingling in the thumb, index, middle, and radial half of the ring finger 1, 2
• Also utilized in diagnosing cubital tunnel syndrome and other peripheral nerve compression syndromes 2
• In carpal tunnel syndrome specifically, Tinel sign shows significant correlation with motor and sensory nerve conduction velocity abnormalities, particularly when distal motor and sensory latencies exceed 4.5 ms 4

Evaluation of Nerve Regeneration

• Used to track the progress of peripheral nerve healing after injury 1, 2
• The advancing point of Tinel sign along a nerve's course can indicate the leading edge of regenerating axons 1

Diagnostic Limitations and Caveats

• The diagnostic value of Tinel sign remains controversial and should not be used in isolation 1, 5
• In one study of carpal tunnel syndrome, Tinel sign was positive in 63% of patients with electrophysiologically confirmed disease, but was also positive in 45% of control patients without the condition 5
• This high false-positive rate means the sign has limited diagnostic value when used alone in individual patients 5
• Tinel sign should always be interpreted in conjunction with other clinical findings, patient symptoms, and electrodiagnostic studies 5, 4

Proper Clinical Use

• The test is performed by gently tapping or percussing over the suspected site of nerve compression or injury 1
• A positive test produces tingling, pins-and-needles sensation, or electric shock-like paresthesias radiating into the nerve's distribution 1
• Despite its limitations, Tinel sign remains an important component of the physical examination for peripheral neuropathies when used appropriately as part of a comprehensive evaluation 2