Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 78

Abstract

Introduction: Acetyl‐L‐Carnitine (ALC) is a safe and well‐tolerated drug in the treatment of peripheral neuropathy in HIV infected patients. Its efficacy is focused on its role in modulating TNF‐alpha expression and on the restoration of endogenous acetylcarnitine. Peripheral nervous system is frequently involved during HIV infection and distal sensitive polyneuropathy is one of the most common neurological complications (up to 30% of AIDS patients). Etiology is still unknown. One of the pathogenetic hypotheses is the role of proinflammatory cytokines (TNF‐alpha) in causing neuropathic pain. Method: Twenty HIV‐ positive patients affected by neuropathic pain with EMG‐evidence of axonal alterations were enrolled; we excluded patients with mini‐mental test score < 24, acute CMV infection, chronic demyelinating neuropathies. All patients were treated with ALC at the dose of 1 gram t.i.d. for 4 weeks. A visual analogue scale (VAS) was used to evaluate characteristics of patient's pain before, during, and after treatment. EMG and neurographic assessment was performed before and after treatment. To evaluate changes in VAS score we used non‐parametric Friedman's test (F). Wilcoxon's test (W) was performed to timing the appearance of pain improvement, and to evaluate neurophysiological data. Results: The changes in VAS score were statistically significant during ALC treatment (mean score: before 6.7 ± 2.1 – after treatment 5.0 ± 2.1)(F = P < 0.001). The appearance of therapeutic effect was reached during the first week (W = P < 0.03) and during the fourth week (W = P < 0.05) of treatment. Analysis of neurophysiological data showed a statistically significant improvement of peroneal nerve motor parameters: reduced motor distal latency (W = P < 0.02), increased amplitude of the compound motor action potential at distal (W = P < 0.02) and proximal (W = P < 0.05) site of stimulation. Conclusions: Our data show the efficacy of ALC in the treatment of neuropathic pain, confirming previous results. Moreover, the analgesic effects appear during the first week of treatment according with pre‐clinical data in different experimental models of pain. Among mechanisms for ALC efficacy in patients with HIV‐related polyneuropathy, there is a neurotrophic effect as evidenced from patch‐skin biopsy evaluation.