MRS study of the effects of minocycline on markers of neuronal and microglial integrity in ALS

Objective

Magnetic resonance spectroscopy (MRS) allows to monitor brain metabolites noninvasively in amyotrophic lateral sclerosis (ALS). The objective of this study was to use MRS to monitor the effect of minocycline treatment (200 mg/day) over a short period (6 weeks) on the brain metabolites in the precentral gyrus and brainstem in newly diagnosed ALS patients.

Methods

Ten ALS patients (not on riluzole treatment) were recruited and submitted to single-voxel proton MRS longitudinal examinations (1) before minocycline treatment, (2) 3 weeks and (3) 6 weeks after initiation of treatment.

Results

Results did not show the expected decrease of N-acetylaspartate/creatine (NAA/Cr) in the precentral gyrus, and an increased NAA/Cr ratio in the brainstem suggested neuronal recovery. The myo-inositol (mI)/Cr ratio was unchanged in the precentral gyrus, but increased in the brainstem, indicating a glial reaction.

Conclusions

MRS results suggest that minocycline treatment could be beneficial in the early stages of ALS.