Median Nerve Symptoms After Forearm Laceration
A 29-year-old chef sustained a glass laceration to the volar distal forearm 5 weeks ago, repaired primarily without documented nerve exploration. He now reports numbness in the thumb, index and middle fingers, worse at night, and drops small objects. Two-point discrimination is 7 mm in the index finger versus 4 mm on the unaffected side; thumb abduction strength is reduced. Tinel sign is positive over the distal forearm scar and reproduces his finger tingling. Wrist flexion does not clearly worsen symptoms. Scar is adherent to underlying tissue. He wants to know if this is just scar tightness that stretching will fix.
1. Differentiate scar-related restriction from a nerve lesion and state what the findings suggest about the likely structure involved.
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This is not simply scar tightness.
Reasoning:
- Distal median-innervated sensory distribution (thumb, index, middle) with nocturnal symptoms and reduced 2PD (7 mm) indicates median nerve involvement, not isolated scar restriction.
- Positive Tinel over the distal forearm scar reproducing tingling localizes the problem to the nerve at/near the laceration site-consistent with either a partial nerve injury or neuroma-in-continuity, and/or compression from adherent scar.
- Thumb abduction weakness supports a motor component (recurrent median branch/median nerve).
- The absence of clear wrist-flexion provocation makes carpal tunnel syndrome less likely as the primary driver; the Tinel location points proximally to the forearm.
Because nerve exploration was not documented at injury, a surgical/nerve review is warranted rather than assuming a soft-tissue problem amenable to stretching alone. Aggressive stretching over an adherent scar with a positive Tinel risks further nerve irritation.
2. Outline your assessment and management priorities over the next 4 weeks, including when you would escalate.
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Assessment priorities: serial sensory mapping (2PD, light touch), Tinel tracking (does it advance distally-regenerating-or stay fixed/enlarge), motor testing (thumb abduction, thenar bulk), scar mobility/adherence, and functional grip/dexterity.
Management (4 weeks):
- Scar management: gentle scar mobilisation and desensitisation, avoiding direct compression over the Tinel point; silicone if indicated.
- Nerve gliding: gentle, symptom-guided median nerve glides-stop if tingling is reproduced or lingers.
- Protective sensory education and dexterity retraining.
- Night symptoms: discuss with referring team; nocturnal paresthesia may warrant medical review.
Escalation triggers: worsening or non-improving 2PD, enlarging or non-advancing Tinel, progressive weakness/atrophy, or persistent night waking. These warrant prompt referral back to the surgeon/hand team for nerve assessment (e.g., nerve conduction studies or exploration). Document baseline and re-measure at 4 weeks to make the escalation decision objective.