title: Estimation of brainstem neuronal loss in amyotrophic lateral sclerosis with in vivo proton magnetic resonance spectroscopy.
abstract: In vivo proton magnetic resonance spectroscopy (MRS) may be used to quantify brainstem neuronal degeneration in ALS because of the neuronal localization of N-acetylaspartate and N-acetylaspartylglutamate, together termed NA, which are estimated with this technique. We measured the ratio of NA to creatine/phosphocreatine (NA/Cr) with proton MRS at 3.0 tesla (T) in a 4.3-cm3 volume in the pons and upper medulla of 12 ALS patients and 17 age-matched control subjects. Brainstem NA/Cr was reduced in ALS versus control subjects (mean +/- SD: 1.57 +/- 0.20 versus 1.95 +/- 0.14; p < 0.0001). Patients with severe spasticity or prominent bulbar weakness had the lowest NA/Cr ratios; those with predominantly lower motor neuron limb weakness had near-normal ratios. We conclude that proton MRS may quantify region-specific neuronal dysfunction in ALS.
authors.affiliation: Department of Neurology, University of Arizona, Tucson 85724, USA.
authors.forename: V A
authors.initials: VA
authors.lastname: Cwik
authors.forename: C C
authors.initials: CC
authors.lastname: Hanstock
authors.forename: P S
authors.initials: PS
authors.lastname: Allen
authors.forename: W R
authors.initials: WR
authors.lastname: Martin
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000473:pathology*; D001933:Brain Stem / Q000473:pathology*; D016923:Cell Death; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000473:pathology*; D011522:Protons
chemical_list: D011522:Protons