Nerve entrapment syndromes occur when peripheral nerves in the arms or legs are compressed in narrow anatomical passages, causing numbness, pain and weakness. The most common examples are carpal tunnel syndrome and ulnar nerve entrapment.
What is nerve entrapment?
Peripheral nerves leave the spinal cord and run into the arms and legs, passing through narrow passages surrounded by bone, ligament and muscle. Prolonged pressure on a nerve in these passages disrupts its blood supply, causing numbness, tingling, pain and, over time, muscle weakness.
The most common nerve entrapments are:
- Carpal tunnel syndrome: Compression of the median nerve at the wrist
- Cubital tunnel syndrome: Compression of the ulnar nerve at the elbow
- Guyon's canal syndrome: Compression of the ulnar nerve at the wrist
- Tarsal tunnel syndrome and peroneal nerve entrapment in the leg
Risk factors
- Work involving repetitive wrist, hand or elbow movements
- Diabetes, thyroid disease and rheumatoid arthritis
- Pregnancy and fluid retention
- Previous fractures and joint deformities
Diagnosis
Diagnosis is based on the pattern of symptoms and examination findings. Electromyography (EMG) shows the location and severity of the compression. Ultrasound and MRI can help in some cases. It is important to distinguish it from conditions with similar symptoms, such as a cervical disc herniation.
Treatment Approach
In mild cases, resting splints, activity modification, medication and, in suitable patients, injections are used. If symptoms persist, muscle wasting or weakness develops, or EMG shows significant nerve damage, surgical decompression to release the nerve is recommended. These operations are usually short, and patients are generally discharged the same day.