**Question:** Tinels sign is seen in -

A. Tarsal Tunnel Syndrome
B. Carpal Tunnel Syndrome
C. Peroneal Nerve Palsy
D. Radial Nerve Palsy

**Core Concept:** Tinels sign is a clinical test used to evaluate peripheral nerve entrapment syndromes. It is named after Dr. Giovanni Battista Tinel, a renowned Italian physician who first described this test in 1906.

**Why the Correct Answer is Right:** Tinels sign is positive in conditions that involve compression or irritation of peripheral nerves. In this case, the correct answer is **B. Carpal Tunnel Syndrome**.

Carpal Tunnel Syndrome is caused by compression of the median nerve at the wrist, resulting from the narrowing of the carpal tunnel, a bony and fibrous structure containing the median nerve, ulnar nerve, and tendons of flexor muscles. Tinels sign is elicited by tapping or palpating the region of the affected nerve, in this case, the wrist. This test is positive when the patient experiences a paresthesia or numbness in the distribution of the median nerve (typically the thenar eminence) upon palpation or tapping over the affected region.

**Why Each Wrong Option is Incorrect:**

A. Tarsal Tunnel Syndrome is caused by compression of the tibial nerve in the ankle, not the wrist. The tibial nerve does not pass through the tarsal tunnel, which is why this option is incorrect.

C. Peroneal Nerve Palsy is caused by compression of the peroneal nerve, not the radial nerve. The peroneal nerve is responsible for the dorsiflexion of the ankle and eversion of the foot, while the radial nerve is involved in abduction and supination of the forearm. This option is incorrect due to the incorrectly identified nerve.

D. Radial Nerve Palsy is caused by compression of the radial nerve, not the median nerve. The radial nerve controls the flexion and supination of the forearm and hand, while the median nerve is responsible for the flexion of the thumb and fingers. This option is incorrect due to the incorrectly identified nerve.

**Clinical Pearl:** Tinels sign is a useful clinical examination tool in identifying peripheral nerve entrapment syndromes. However, it should be interpreted in conjunction with other clinical findings and imaging studies to confirm the diagnosis. A positive Tinels sign alone is not sufficient for a definitive diagnosis.