[Proton MR spectroscopy studies of the brain in ALS patients]

Nuclear magnetic resonance spectroscopy (MRS) has an ability to measure brain metabolites noninvasively in vivo. The content of N-acetyl-aspartate (NAA) is used as a biochemical marker of neuronal integrity and viability. In amyotrophic lateral sclerosis (ALS) patients the degeneration and neuronal loss of motor cortex was reported. The presence of these changes can lead to the decrease of NAA. The aim of this study was to evaluate the neurochemical status of motor cortex (by using 1H-MRS) in 11 patients with clinically definite or probable forms of ALS (according to the El Escorial criteria). These data were compared with MRS results from 4 healthy controls. The mean NAA/(Cr + PCr) values were decreased by 19% (p < 0.05) when compared with controls. In 4 ALS patients the NAA/(Cr + PCr) ratio was decreased by 31% (p < 0.05) and these patients had rapidly progressing disease. In other 7 ALS patients, we found that NAA/(Cr + PCr) was decreased by 10% (p < 0.05) and they showed less advanced neurological symptoms. 1H-MRS of the motor cortex can be a new diagnostic tool in ALS and it might help to monitor the progress of the disease.