Nerve Examination and Treatment for Carpal Tunnel Syndrome
For patients with suspected carpal tunnel syndrome, the recommended nerve examination should include clinical evaluation combined with electrophysiologic studies, with ultrasound being highly sensitive and specific for measuring median nerve cross-sectional area to confirm diagnosis. 1
Diagnostic Approach
Clinical Examination
- Evaluate for pain, paresthesia, and weakness in the distribution of the median nerve (palmar aspect of thumb, index and middle fingers, and radial half of ring finger) 2
- Perform provocative maneuvers to aid diagnosis: 3
- Phalen test (wrist flexion)
- Tinel sign (percussion over median nerve)
- Median nerve compression test
Key Diagnostic Findings
- Hypalgesia in the median nerve territory (strongest diagnostic indicator with likelihood ratio 3.1) 3
- Classic or probable hand diagram results showing median nerve distribution symptoms (likelihood ratio 2.4) 3
- Weak thumb abduction strength (likelihood ratio 1.8) 3
- Thenar atrophy is a late finding but highly specific for CTS 4
Confirmatory Testing
- Electrodiagnostic studies (nerve conduction studies and electromyography) should be used to: 1, 4
- Confirm diagnosis in atypical cases
- Exclude other causes
- Gauge severity for surgical prognosis
- Ultrasound is recommended as first-line imaging to measure median nerve size and identify potential causes of symptoms 1, 5
- MRI without contrast may be appropriate in selected circumstances but is not routinely indicated 1
Treatment Algorithm
Mild to Moderate Carpal Tunnel Syndrome
- Initial conservative treatment options include: 4, 2
- Wrist splinting (neutral position is more effective than extension splint)
- Night-only splinting is as effective as continuous wear
- Local corticosteroid injections (provide greater symptom improvement than splinting at 6 weeks)
- Physical therapy, therapeutic ultrasound, and yoga may be beneficial
Severe Carpal Tunnel Syndrome
- Surgical decompression is the most effective treatment for: 1, 4
- Patients with severe symptoms
- Those with objective weakness or sensory deficits
- Cases not responding to conservative treatment after 4-6 months
- Both open carpal tunnel release and endoscopic techniques are equally effective for symptom relief 1, 4
- Endoscopic repair allows patients to return to work approximately one week earlier than open repair 2
Ineffective Treatments
- Over-the-counter analgesics including NSAIDs and acetaminophen have not shown benefit 4
- Diuretics and vitamin B6 supplementation are not effective therapies 2