A mechanism of rapidly reversible cerebral ventricular enlargement independent of tissue atrophy

Neuropsychopharmacology. 2013 May;38(6):1121-9. doi: 10.1038/npp.2013.11. Epub 2013 Jan 10.

Abstract

Ventricular enlargement, a common in vivo marker of aging, disease, and insult, is presumed to reflect atrophy of surrounding brain regions. Pathological mechanisms underlying ventricular enlargement, however, are likely specific to the condition under investigation. Here, multimodal imaging, incorporating structural magnetic resonance imaging (MRI), MR spectroscopy (MRS), and diffusion weighted imaging (DWI), was used in rats exposed to binge ethanol (EtOH) to provide insight into a mechanism of reversible ventricular enlargement. During intoxication, MRI revealed expansion of ventricles, but volume changes in dorsal or ventral hippocampi, caudate-putamen, or thalamus were not detectible. MRS of whole-brain parenchyma showed decreases in N-acetylasparate (NAA) and tissue water T2, and increases in choline-containing compounds (Cho). DWI showed decreased diffusivity selective to the thalamus. All MR parameters returned to baseline with 7 days of recovery. Rapid recovery of ventricular volume and the absence of detectable tissue volume reductions in brain regions adjacent to ventricles argue against atrophy as a mechanism of ventricular expansion. Decreased tissue water T2 and decreased thalamic diffusivity suggest lower tissue water content and a role for both NAA and Cho, as osmolytes is proposed. Together, these data support a model of fluid redistribution during acute EtOH intoxication and recovery to account for rapid ventricular volume changes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Atrophy / chemically induced
  • Atrophy / pathology
  • Cerebral Ventricles / drug effects
  • Cerebral Ventricles / pathology*
  • Cerebral Ventricles / physiology
  • Ethanol / administration & dosage
  • Ethanol / toxicity*
  • Magnetic Resonance Imaging / methods
  • Magnetic Resonance Spectroscopy / methods
  • Male
  • Rats
  • Rats, Wistar
  • Time Factors
  • Tissue Distribution / drug effects
  • Tissue Distribution / physiology

Substances

  • Ethanol