Comparison of regional cerebral blood flow in two subsets of subcortical ischemic vascular dementia: statistical parametric mapping analysis of SPECT.

BACKGROUND: The brain imaging criteria for subcortical ischemic vascular dementia (SIVD), as proposed by Erkinjuntti, incorporated two clinical entities, the lacunar state and Binswanger's disease. However it has not been proven whether these two subtypes of SIVD have common pathophysiological features. This study investigated the changes of regional cerebral blood flow (CBF) in the two subsets of SIVD to establish whether these two subtypes could be incorporated into the same group for the purpose of conducting clinical trials.
METHODS: Twelve SIVD patients with predominant white matter lesions, 13 patients with predominant lacunar infarctions and 17 controls were evaluated. Single photon emission computed tomography (SPECT) was performed to measure the regional CBF, and statistical parametric mapping (SPM) was applied to the analysis of the SPECT data.
RESULTS: The normalized CBF (nCBF) in the bilateral thalami, the anterior cingulate gyri, the superior temporal gyri, the caudate heads and the left parahippocampal gyrus was significantly decreased in the SIVD patients compared to the controls. This pattern of nCBF reduction was same in both the two subtypes of SIVD patients.
CONCLUSION: Our study suggests that the two subsets of SIVD may have a common nCBF abnormality, and Erkinjuntti's criteria offer a solution for researchers to identify the more homogeneous group of vascular dementia patients.