TINEL'S SIGN FOR CARPAL TUNNEL SYNDROME (CTS) Another test, next to the Phalen's test to test for CTS, is the Tinel's sign. The idea behind the Tinel sign -which is a test that is generally used in suspected peripheral nerve pathology - is that tapping elicits paresthesia (tingling, needles) as the nerve is rendered mechanosensitive due to prolonged pressure and resulting ischemia. This is due to the fact that the Sodium-Potassium pump cannot work properly without oxygen, which is why the nerve'