Non-invasive detection of hippocampal sclerosis: correlation between metabolite alterations detected by (1)H-MRS and neuropathology

NMR Biomed. 2008 Jul;21(6):545-52. doi: 10.1002/nbm.1222.

Abstract

We assessed (1)H-MRS as a screening tool for detection of hippocampal sclerosis in patients with temporal lobe epilepsy (TLE). (1)H-MRS was carried out in the hippocampus of 23 patients with unilateral TLE. Metabolite alterations detected by (1)H-MRS correlated with degree of segmental neuronal cell loss and amount of astrogliosis. Positive correlation was found between total N-Acetylaspartate (tNAA) reduction and neuronal density in hippocampal CA1 (P < 0.001), CA3 (P = 0.015), and CA4 subfields (P = 0.031) and the dentate gyrus (P = 0.006). Neuronal cell loss in CA1 turned out to be the most predictive and only significant variable for tNAA reduction (P = 0.027). The association between myo-inositol (m-Ins) and astroglial glial fibrillary acidic protein (GFAP) expression revealed significantly increased m-Ins concentrations associated with diffuse astrogliosis (m-Ins = 6.4 +/- 1.1 institutional units) compared with gliosis restricted to isolated sectors of the hippocampus (i.e. hilus) (m-Ins = 5.2 +/- 1.2 institutional units) (P = 0.039). A negative correlation was found between m-Ins and neuronal loss in the CA4 subfield of the hippocampus (P = 0.028). Our results support (1)H-MRS as a suitable non-invasive method for preoperative identification of hippocampal sclerosis in patients with TLE. The extent of tNAA reduction correlates with hippocampal neuronal cell density. Furthermore, m-Ins is associated with the extent of hippocampal astrogliosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aspartic Acid / analogs & derivatives*
  • Aspartic Acid / analysis
  • Biomarkers / analysis
  • Child
  • Child, Preschool
  • Epilepsy, Temporal Lobe / diagnosis*
  • Epilepsy, Temporal Lobe / metabolism*
  • Female
  • Hippocampus / metabolism*
  • Hippocampus / pathology
  • Humans
  • Infant
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Middle Aged
  • Protons
  • Reproducibility of Results
  • Sclerosis / diagnosis*
  • Sclerosis / metabolism*
  • Sensitivity and Specificity
  • Statistics as Topic
  • Tissue Distribution

Substances

  • Biomarkers
  • Protons
  • Aspartic Acid
  • N-acetylaspartate