Elevated myo-inositol in gray matter of recently detoxified but not long-term abstinent alcoholics: A preliminary MR spectroscopy study

Background: Individuals in short-term abstinence from chronic alcohol consu mption commonly have neuropsychological impairments with parallel abnormali ties in brain structure. Stable, long-term sobriety often results in improv ements in both brain structure and function, although the mechanisms underl ying these changes are currently not well understood. Methods: To investigate further the neurobiological underpinnings of alcoho l-associated brain abnormalities in short-term and long-term abstinence fro m alcohol, proton magnetic resonance spectroscopy (echo time, 35 msec; repe tition time, 1.5 sec) was used to assay metabolites in the anterior centrum semiovale, anterior cingulate gyrus, and right thalamus of two groups of n on-Korsakoff alcoholic men, at different stages of abstinence, compared wit h a control group of alcohol-nonabusing men. Absolute concentrations of N-a cetylaspartate, choline, myo-inositol, and creatine were measured in four r ecently detoxified alcoholics (mean age, 48.7 years; median abstinence, 41. 5 days), five long-term abstinent alcoholics (mean age, 45.1 years; median abstinence, 1.7 years), and five nonalcoholic controls (mean age, 45.0 year s). Results: Although there were no between-group differences in concentrations of N-acetylaspartate, choline, or creatine, recently detoxified alcoholics had significantly higher myo-inositol in the thalamus, compared with contr ols and long-term abstinent alcoholics, and significantly higher myo-inosit ol in the anterior cingulate gyrus, compared with the controls. Conclusions: Elevations in myo-inositol in recently detoxified alcoholics a re compatible with an acute alcohol cytotoxicity model. myo-Inositol is ele vated in hyperosmolar states such as hypernatremia, renal failure, and diab etes; alcohol-induced hyperosmolarity may trigger accumulation of myo-inosi tol to stabilize the intracellular environment. Increases in myo-inositol m ay also reflect proliferation or activation of glia. The reduction of myo-i nositol to control group levels in long-term abstinent alcoholics may refle ct osmolar stability in abstinent alcoholics and/or a reduction in glial ce ll activation.