Decrease in cortical benzodiazepine receptors in symptomatic patients with leukoaraiosis: a positron emission tomography study.

Abstract

BACKGROUND AND PURPOSE:

[11C]flumazenil (FMZ), a ligand that selectively binds to the central benzodiazepine receptor in the neuronal membrane, is useful for evaluating neuronal viability in a positron emission tomography (PET) scan. Using this ligand, we investigated whether there was a correlation between neuronal integrity in various brain structures and dementia in patients with leukoaraiosis.

METHODS:

Twelve patients with extensive leukoaraiosis on magnetic resonance imaging were divided into groups of patients with or without dementia. Based on a 2-compartment, 2-parameter model that included metabolite-corrected arterial input and PET-measured cerebral radioactivity, the distribution volume of FMZ (FMZ-V(d)) was calculated in various regions of interest by nonlinear curve fitting. Additionally, tracer kinetic analysis was applied for voxel-by-voxel quantification of FMZ-V(d), and data analysis was performed by statistical parametric mapping.

RESULTS:

The presence of dementia was associated with a reduced FMZ-V(d) in widespread areas of the cerebral cortex, including the bilateral frontopolar and frontal/insular areas, the left temporo-occipital border areas, and the left marginal cortical areas.

CONCLUSIONS:

Differences in neuronal integrity in the cerebral cortex might determine whether patients with leukoaraiosis become symptomatic or not.

• Authors: M Ihara, H Tomimoto, K Ishizu, T Mukai, H Yoshida, N Sawamoto, M Inoue, T Doi, K Hashikawa, J Konishi, H Shibasaki, H Fukuyama
• Journal: Stroke (Stroke) Vol. 35 Issue 4 Pg. 942-7 (Apr 2004) ISSN: 1524-4628 [Electronic] United States
• PMID: 15001785 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Ligands
• Radioactive Tracers
• Receptors, GABA-A
• Flumazenil

Topics

• Aged
• Cerebral Cortex (diagnostic imaging, metabolism, pathology)
• Cerebrovascular Circulation
• Dementia, Vascular (diagnosis, diagnostic imaging, metabolism)
• Female
• Flumazenil (metabolism)
• Humans
• Ligands
• Magnetic Resonance Imaging
• Male
• Oxygen Consumption
• Radioactive Tracers
• Receptors, GABA-A (metabolism)
• Tomography, Emission-Computed