N-Acetylcysteine for Neuroprotection in Parkinson's Disease

Study Summary

The overall objective of this developmental/exploratory study is to use noninvasive proton magnetic resonance spectroscopy (1H MRS) to assess (a) whether brain levels of the antioxidant glutathione (GSH) are decreased in vivo, as has been found in postmortem brain, in 30 patients with Parkinson's disease (PD) compared to matched controls; (b) whether GSH levels in PD brain increase significantly following 30 days of daily supplementation with 1800mg or 3600mg of N-acetylcysteine (NAC) compared to placebo and to baseline, and (c) whether any such increases in brain GSH would be dose-dependent and be associated with a change in the participants' oxidative stress profiles. In addition, a clinical assessment battery, including quantitative tests of motor function, will be performed to investigate potential associations between the NAC intervention, brain GSH levels, oxidative stress markers, and clinical presentation. If successful, this study will represent the first objective documentation of whether there is a GSH deficit in living PD brain that dietary NAC supplementation can mitigate, thereby providing a compelling justification for investigating such neuroprotective strategies in larger controlled clinical trials.

Primary Outcome

In vivo brain GSH measured with 1H MRS in the unmedicated patients with idiopathic PD and in sex- and age-matched healthy controls prior to and following 4 weeks supplementation with either placebo, 1800mg/day or 3600 mg/day of NAC. Striatal and occipital cortex glutathione levels as measured in vivo by 1H MRS at baseline and following 4 weeks of treatment with placebo, 1800mg NAC/day and 3600mg NAC/day. The area under the GSH spectral peak was obtained by frequency-domain fitting of the GSH re

Interventions

• DRUG Placebo
• DRUG N-acetylcysteine