title: Acetyl-L-carnitine (ALCAR) to enhance nerve regeneration in carpal tunnel syndrome: study protocol for a randomized, placebo-controlled trial.
abstract: BACKGROUND
  Carpal tunnel syndrome (CTS) is the most common form of peripheral nerve injury, affecting approximately 3 % of the population. While surgery is effective in mild and moderate cases, nerve and functional recovery are often not complete in severe cases. Therefore, there is a need for adjuvant methods to improve nerve regeneration in those cases. Acetyl-L-carnitine (ALCAR) is involved in lipid transport, vital for mitochondrial function. Although it has been shown to be effective in various forms of neuropathies, it has not been used in traumatic or compressive peripheral nerve injury.
  
  
  METHODS
  In this pilot study we will utilize a double-blind, randomized, placebo-controlled design. Inclusion criteria will include adult patients with severe CTS. This will be confirmed by nerve conduction studies and motor unit number estimation (MUNE). Only those with severe motor unit loss in the thenar muscles (2 standard deviations [SD] below the mean for the age group) will be included. Eligible patients will be randomized to receive 3,000 mg/day of ALCAR orally or placebo following carpal tunnel release surgery for 2 months. The primary outcome will be MUNE with supplementary secondary outcome measures that include: 1) two-point discrimination; 2) Semmes-Weinstein monofilaments for pressure sensitivity; 3) cold and pain threshold for small fiber function; 4) Boston self-assessment Carpal Tunnel Questionnaire and 5) Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire for symptom severity; and 6) Purdue Pegboard Test for hand functional performance. To follow post treatment recovery and monitor safety, patients will be seen at 3 months, 6 months and 1 year. The outcome measures will be analyzed using two-way ANOVA, with treatment assignment and time points being the independent factors. If significant associations are detected, a post hoc analysis will be completed. We aim to recruit ten patients into each of the two groups. Data from this pilot will provide the basis for power calculation for a full-scale trial.
  
  
  CONCLUSIONS
  ALCAR is a physiologic peptide crucial for fatty acid transport. ALCAR has been shown to be effective in neuroprotection in the central nervous system and increase peripheral nerve regeneration. This has been applied clinically to various systemic peripheral neuropathies including diabetic neuropathy, antiretroviral toxic neuropathy, and chemotherapy-induced peripheral neuropathy. While animal evidence exists for the benefit of ALCAR in compression neuropathy, there have been no human studies to date. This trial will represent the first use of ALCAR in peripheral nerve injury/compression neuropathy.
  
  
  BACKGROUND
  NCT02141035 ; 20 April 2015.
authors.affiliation: Walter Mackenzie Centre, University of Alberta Hospital, 8440 112 St, Edmonton, AB, T6G 2B7, Canada.
authors.forename: Matthew W T
authors.initials: MW
authors.lastname: Curran
authors.affiliation: 2D3 Walter Mackenzie Centre, University of Alberta, 8440 112 St, Edmonton, AB, T6G 2B7, Canada.
authors.forename: Jaret
authors.initials: J
authors.lastname: Olson
authors.affiliation: 303 Coronation Plaza East Tower, Edmonton, AB, T5M 3Z7, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Morhart
authors.affiliation: Women and Children's Health Research Institute, 4-081 Edmonton Clinic Health Academy, University of Alberta, 11405 - 87 Ave NW, Edmonton, AB, T6G 1C9, Canada.
authors.forename: Dory
authors.initials: D
authors.lastname: Sample
authors.affiliation: 5-005 Katz Group Centre, University of Alberta, Edmonton, AB, T6G 2E1, Canada. ming.chan@ualberta.ca.
authors.forename: K Ming
authors.initials: KM
authors.lastname: Chan
mesh_terms: D000108:Acetylcarnitine / Q000009:adverse effects / Q000627:therapeutic use*; D000416:Alberta; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology / Q000601:surgery; D002985:Clinical Protocols; D003131:Combined Modality Therapy; D004185:Disability Evaluation; D004311:Double-Blind Method; D006801:Humans; D009416:Nerve Regeneration / Q000187:drug effects*; D009460:Neurologic Examination; D019637:Orthopedic Procedures; D010147:Pain Measurement; D010865:Pilot Projects; D020127:Recovery of Function; D012107:Research Design; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000108:Acetylcarnitine
keywords: Acetyl-L-carnitine; Carpal tunnel syndrome; Motor unit number estimation; Nerve regeneration; Peripheral nerve injury