Short-term trials with the antioxidant thioctic acid (TA) appear to improve neuropathic symptoms in diabetic patients, but the long-term response remains to be established. Therefore, Type 1 and Type 2 diabetic patients with symptomatic polyneuropathy were randomly assigned to three treatment regimens: (1) 2 x 600(mg of TA (TA 1200), (2) 600)mg of TA plus placebo (PLA) (TA 600) or (3) placebo and placebo (PLA). A trometamol salt solution of TA of 1200 or 600 mg or PLA was intravenously administered once daily for five consecutive days before enrolling the patients in the oral treatment phase. The study was prospective, PLA-controlled, randomized, double-blind and conducted for two years. Severity of diabetic neuropathy was assessed by the Neuropathy Disability Score (NDS) and electrophysiological attributes of the sural (sensory nerve conduction velocity (SNCV), sensory nerve action potential (SNAP)) and the tibial (motor nerve conduction velocity (MNCV), motor nerve distal latency (MNDL)) nerve. Statistical analysis was performed after independent reviewers excluded all patients with highly variable data allowing a final analysis of 65 patients (TA 1200: n = 18, TA 600: n = 27; PLA: n = 20). At baseline no significant differences were noted between the groups regarding the demographic variables and peripheral nerve function parameters for these 65 patients. Statistically significant changes after 24 months between TA and PLA were observed (mean +/- SD) for sural SNCV: +3.8 +/- 4.2 m/s in TA 1200, +3.0+/-3.0m/s in TA 600, -0.1+/-4.8m/s in PLA (p < 0.05 for TA 1200 and TA 600 vs. PLA); sural SNAP: +0.6+/-2.5 microV in TA 1200, +0.3+/-1.4 microV in TA 600, -0.7 +/- 1.5 microV in PLA (p = 0.076 for TA 1200 vs. PLA and p < 0.05 for TA 600 vs. PLA), and in tibial MNCV: +/- 1.2 +/- 3.8 m/s in TA 1200, -0.3 +/- 5.2 m/s in TA 600, 1.5 +/- 2.9 m/s in PLA (p < 0.05 for TA 1200 vs. PLA). No significant differences between the groups after 24 months were noted regarding the tibial MNDL and the NDS. We conclude that in a subgroup of patients after exclusion of patients with excessive test variability throughout the trial, TA appeared to have a beneficial effect on several attributes of nerve conduction.

These findings suggest that treatment with ALA using a well-tolerated oral dose of 800 mg/day for 4 months may slightly improve CAN in NIDDM patients.

Botulinum neurotoxins (BoNTs) are the primary treatment for focal dystonias such as blepharospasm. Several different BoNT products are available in various countries. Given the variability in manufacturing, formulation, and unit doses of BoNTs, it is important to compare the profiles of products from different manufacturers. This double-blind, randomised, parallel-group pilot study compared the efficacy and safety of the BoNT type A product Xeomin® from Merz to BOTOX® from Allergan. Subjects (n = 65) were randomly assigned to receive one or the other BoNTA in a 1:1 proportion at a dose equal to that of their most recent treatment (≥20 U/eye). Symptoms were assessed on the Blepharospasm Disability Index (BSDI), Jankovic Rating Scale (JRS), and Patient Global Assessment (PGA) scale at 4 and 8 weeks. Both BoNTA products reduced scores on the BSDI and JRS (no statistically significant difference, tendency toward greater improvements with BOTOX® than Xeomin® at 4 and 8 weeks). A post hoc analysis showed a significantly greater number of BOTOX® treated patients reaching a responder threshold of 4 points on the total BSDI score and 0.67 points on the BSDI mean item score. No significant differences between products were noted in PGA and adverse events at the doses used in this study.

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Botulinum toxin has long been known for its paralytic effects on the human voluntary musculature via inhibition of acetylcholine release at neuromuscular junctions. Its original clinical use for the treatment of strabismus has expanded significantly to include neurological conditions related to muscle hyperactivity and/or spasticity (e.g., dystonia, spasticity, tics, tremor, dysphonia). Recently, botulinum toxin has been shown to impact autonomic disorders by acting at acceptors on glands and smooth muscle, and consequently it has been used in the management of a number of other conditions including hypersecretory disorders, pain syndromes, detrusor sphinchter dyssenergia or overactivity and gastointestinal smooth muscle/sphincter spasm; it may also reduce pain in patients for whom it is used to treat these and other primary conditions. This article will review the pharmacology and formulations of botulinum toxins as well as data from clinical trials demonstrating their efficacy for numerous conditions based on their effects on cholinergic synapses outside the motor nervous system.