• Clinical science

Ulnar nerve entrapment (Ulnar nerve palsy…)

Summary

Ulnar nerve entrapment occurs when the ulnar nerve is compressed, typically at the elbow or the wrist. Compression at the elbow is called cubital tunnel syndrome; compression at the wrist it is referred to as Guyon's canal syndrome or ulnar tunnel syndrome. The compression causes paresthesias, numbness, and/or pain in the ulnar nerve distribution. Depending on the site of compression, the patient may experience weakness in certain hand muscles. Ulnar entrapment neuropathy may be suspected based on clinical symptoms and signs, but it must be confirmed by electromyography (EMG). Conservative treatment involves NSAIDs, behavior modification, and bracing. Severe, persistent, or worsening symptoms require surgical decompression.

Basic anatomy

References:[1]

Etiology

The ulnar nerve is most commonly compressed at or near the cubital tunnel of the elbow and Guyon canal of the wrist.

References:[1]

Clinical features

Proximal as well as distal lesions lead to claw hand deformity!

References:[2][1]

Diagnostics

  • EMG: main confirmatory diagnostic test; it identifies the level of nerve compression.
  • Ultrasound and MRI: used to support the EMG findings and to detect possible causes of compression (e.g., space-occupying lesions)

References:[1]

Treatment

  • Conservative therapy
    • Analgesia (e.g., NSAIDs)
    • Modify behavior (i.e., avoid prolonged resting on or repeated flexion of elbow)
    • Bracing at night
  • Surgical decompression if clinical features are severe, persistent (lasting more than 6–12 weeks), or progressively worsen despite conservative therapy.

References:[1]

last updated 10/18/2019
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