Ascertaining the Role of Acetyl-L-Carnitine in Carpal Tunnel Syndrome – A Randomised Controlled Trial

Abstract

Background: Carpal tunnel syndrome is the most common entrapment neuropathy with variable responses to conservative therapy, and Acetyl-L-Carnitine’s putative neuroprotective and analgesic actions warrant evaluation as an adjunctive treatment.

Objectives: To determine the efficacy of Acetyl-L-Carnitine on neuroprotection, neuropathic symptoms, and hand function in carpal tunnel syndrome; and to study recurrence of symptoms in CTS patients on standard treatment.

Methods: We conducted a single-centre, prospective, open-label randomized trial at a neurology outpatient clinic, enrolling adults (18–65 years) with idiopathic CTS (N=80) and allocating them to standard care alone or Acetyl-L-Carnitine 500 mg three times daily for 12 weeks plus standard care. Outcomes (BCTQ-SSS/FSS, DN4) were assessed at baseline, 4, 12, and 20 weeks; median-nerve NCS were performed at baseline and 12 weeks.

Results: Both groups were similar at baseline (age 45.5 vs 47.3 years; p=0.210; female-predominant). Over 12 weeks, electrophysiology improved in both arms but more with ALCAR, notably in sensory metrics: sensory nerve conduction velocity rose 41.12→44.49 m/s (Δ+3.37) vs 40.12→41.78 m/s (Δ+1.66), and sensory distal latency fell 3.77→3.26 ms vs 3.68→3.29 ms; distal motor latency decreased more with ALCAR (−5.84% vs −4.04%; p=0.012). The best discriminator was % increase in sensory conduction velocity (AUC 0.775, 95% CI 0.675–0.875). Patient-reported outcomes favored ALCAR from 4 weeks onward: BCTQ-SSS 20.02 vs 26.00 (p<0.001) at 4 weeks and 16.20 vs 23.63 (p<0.001) at 12 weeks; BCTQ-FSS and DN4 showed parallel advantages, persisting to 20 weeks. Adverse events were mostly nausea (40%) and vomiting (40%); weight gain and hair fall occurred in 10% each.

Conclusion: Adjunctive Acetyl-L-Carnitine (500 mg three times daily for 12 weeks) significantly improved neuropathic pain, hand function, and sensory nerve conduction in mild–moderate carpal tunnel syndrome versus standard care, with partial symptom return after discontinuation.