Influence of ratio between N-acetylaspartat (NAA) and myoinositol brain tissue metabolites as well as ratio beween myoinositol and kreatinine on the therapy efficacy in children with epilepsy has been studied by authors. The obtained results allowed detecting the derangement in one section of cerebral metabolism, recovery of which on the background of effective antiepileptic treatment finds its reflection in ratio between N-acetylaspartat (NAA) and myoinositol and between myoinositol and kreatinine.
We aimed to test whether in vivo levels of magnetic resonance spectroscopy (MRS) metabolites myo-inositol (mI), N-acetylaspartate (NAA), and choline are abnormal already during preclinical Alzheimer disease (AD), relating these changes to amyloid or tau pathology, and functional connectivity.
In this cross-sectional multicenter study (a subset of the prospective Swedish BioFINDER study), we included 4 groups, representing the different stages of predementia AD: (1) cognitively healthy elderly with normal CSF ß-amyloid 42 (Aß42), (2) cognitively healthy elderly with abnormal CSF Aß42, (3) patients with subjective cognitive decline and abnormal CSF Aß42, (4) patients with mild cognitive decline and abnormal CSF Aß42 (Ntotal = 352). Spectroscopic markers measured in the posterior cingulate/precuneus were considered alongside known disease biomarkers: CSF Aß42, phosphorylated tau, total tau, [(18)F]-flutemetamol PET, f-MRI, and the genetic risk factor APOE.
Amyloid-positive cognitively healthy participants showed a significant increase in mI/creatine and mI/NAA levels compared to amyloid-negative healthy elderly (p
We present here a combination of time-domain signal analysis procedures for quantification of human brain in vivo 1H NMR spectroscopy (MRS) data. The method is based on a separate removal of a residual water resonance followed by a frequency-selective time-domain line-shape fitting analysis of metabolite signals. Calculation of absolute metabolite concentrations was based on the internal water concentration as a reference. The estimated average metabolite concentrations acquired from six regions of normal human brain with a single-voxel spin-echo technique for the N-acetylaspartate, creatine, and choline-containing compounds were 11.4 +/- 1.0, 6.5 +/- 0.5, and 1.7 +/- 0.2 mumol kg-1 wet weight, respectively. The time-domain analyses of in vivo 1H MRS data from different brain regions with their specific characteristics demonstrate a case in which the use of frequency-domain methods pose serious difficulties.