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Carpal tunnel syndrome — the surgical angle
Pressure on the median nerve in the carpal tunnel causes night-time tingling in the thumb, index, middle and half of the ring finger; a night splint and a steroid injection suit mild cases, and surgical release suits atrophy, constant numbness or failed conservative care.
Why it matters in the exam
The classic stem describes a middle-aged woman, sometimes pregnant, with diabetes or hypothyroidism, who wakes at night with a tingling hand and shakes it for relief. On examination the Phalen test — wrist flexion — and a Tinel sign over the tunnel reproduce the symptoms, and the direct compression test over the tunnel (Durkan) is particularly sensitive. In advanced cases there is weakness and wasting of the thenar muscles. An important point in the differential: sensation in the palm itself (over the thenar eminence) is preserved in carpal tunnel syndrome, because the palmar sensory branch leaves before the tunnel; numbness of the palm suggests a more proximal compression of the nerve or a neck problem. C6 radiculopathy must also be distinguished, with neck pain and reflex changes. Other risk factors: rheumatoid arthritis, acromegaly, amyloidosis, dialysis and work with vibrating tools. Nerve conduction studies confirm the diagnosis and grade severity, and are advised before surgery. In pregnancy symptoms usually settle after delivery, so a splint is used. Surgery, release of the transverse carpal ligament by an open or endoscopic approach, is highly effective; sensory recovery is quick, whereas long-standing wasting may not fully recover.
Key points
- Night tingling in the thumb, index, middle and half of the ring finger.
- Phalen, Tinel and direct compression; palm sensation is preserved.
- Risk factors: pregnancy, diabetes, hypothyroidism and rheumatoid arthritis.
- Mild — splint and injection; severe with wasting — surgical release.
- Nerve conduction studies confirm and grade severity before surgery.
Summary table
| Severity | Findings | Tests | Treatment |
|---|---|---|---|
| Mild | Intermittent night tingling, normal examination between episodes | Clinical diagnosis, nerve conduction as needed | Night splint in neutral, avoid prolonged flexion |
| Moderate | Daytime tingling too, positive Phalen and Tinel tests | Nerve conduction studies | Splint and steroid injection; surgery if symptoms recur |
| Severe | Constant numbness, thenar weakness and wasting | Nerve conduction and EMG | Prompt surgical release |
| In pregnancy | Night tingling in the third trimester | Clinical diagnosis | Splint; usually settles after delivery |
| With palm numbness | Numbness over the thenar eminence | Nerve conduction, neck examination | Look for proximal compression or radiculopathy |
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Sources
- AAOS Clinical Practice Guideline, 2016 (updated 2024) — Management of Carpal Tunnel Syndrome
- Green's Operative Hand Surgery, 8th ed. (2022) — Compression Neuropathies
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.