Evidence for long-term neurotoxicity associated with methamphetamine abuse -: A 1H MRS study

Objective: To determine whether proton MRS (H-1 MRS) can detect long-term metabolite abnormalities in abstinent methamphetamine users. Background: Methamphetamine is toxic to dopaminergic and serotonergic neurons in rodents; however, little data are available on the toxic effects of methamphetamine on the human brain. Methods: H-1 MRS was performed in 26 abstinent methamphetamine abusers with a history of methamphetamine dependence (median total cumulative lifetime exposure, 3,640 g; median recency of last methamphetamine use, 4.25 months) and 24 healthy subjects without a history of drug abuse. Cerebral metabolite concentrations on H-1 MRS were measured in the frontal cortex, frontal white matter, and basal ganglia. Results: The concentration of N-acetylaspartate ([NA]), a neuronal marker, was reduced significantly (-5 to -6%) in the basal ganglia and frontal white matter of methamphetamine users compared with control subjects. The frontal white matter [NA] correlated inversely with the logarithm of the lifetime methamphetamine use. The methamphetamine users also showed significantly reduced total creatine in the basal ganglia (-8%), and increased choline-containing compounds ([CHO], +13%) and myo-inositol ([MI], +11%) in the frontal grey matter. Conclusions: The reduced [NA] on H-1 MRS provides evidence for long-term neuronal damage in abstinent methamphetamine users.