The overall long term goal of this project is to establish whether in vivo measurement of neuronal dysfunction in the human brain with proton Magnetic Resonance Spectroscopy (1H MRS) could assist in confirming the clinical diagnosis of ALS, especially in the early stages of the disease. In addition, proton spectroscopy may contribute to an understanding of ALS pathogenesis, because metabolites implicated in the disease process can be detected (i.e. glutamate). The following metabolites will be monitored using short echo time 1H MRS in patients with ALS and healthy controls: glutamate (GLU), an amino acid that functions as a neurotransmitter, and N-acetyl aspartate (NAA), a marker to neurons. In the previous studies of ALS via MRS (one report on increase Glu, several reports on decrease of NAA), the major technical limitation was the spectral overlap between NAA and Glu region at low field. This proposed project would use higher magnetic fields (e.g. 4T) and spectral editing techniques that will facilitate spectral interpretation of metabolites, especially Glu. The hypothesis that Glu is elevated in motor cortex region of the brain in ALS patients will be tested and the possibility of using Glu elevation as a surrogate marker of ALS will be investigated.