What it is
Peripheral nerves can be compressed or irritated at specific anatomical "tunnels" or bottlenecks as they travel from the spine to the extremities. These entrapment syndromes differ from radiculopathy, which originates at the spine.
Common examples include:
- Carpal tunnel syndrome — median nerve compressed at the wrist. The most common peripheral nerve entrapment.
- Cubital tunnel syndrome — ulnar nerve compressed at the medial elbow, causing numbness in the ring and small finger and inner forearm.
- Peroneal nerve entrapment — at the fibular head, causing foot drop and numbness over the dorsal foot.
- Meralgia paresthetica — lateral femoral cutaneous nerve compressed at the inguinal ligament, producing outer thigh numbness and burning.
Distinguishing entrapment from cervical radiculopathy
Symptoms of peripheral nerve entrapment can overlap significantly with cervical or lumbar radiculopathy. Electrodiagnostic studies (nerve conduction study and EMG) are an important tool for localizing the problem and distinguishing spine-level from peripheral nerve-level pathology. A correct diagnosis prevents operating on the wrong site.
Surgical treatment
When conservative measures fail and symptoms are significantly impairing function — or when there is evidence of motor nerve damage — surgical release is often straightforward and highly effective. Carpal tunnel release, ulnar nerve transposition, and peroneal nerve decompression are among the more reliable operations in peripheral neurosurgery, with high rates of symptom improvement in appropriately selected patients.