Regional cerebral blood flow in Alzheimer’s disease: Comparison between short and long-term donepezil therapy

Abstract

Relative rCBF significantly increased in the short-term donepezil therapy, while following the long-term therapy, rCBF decreased to the pre-treatment level.

SPECT-Identified Neuroanatomical Predictor of the Cognitive Effects of Donepezil Treatment in Patients with Alzheimer’s Disease

“…Among such AD patients, while some may have remained stable, others may have transiently responded to donepezil therapy, with the cognitive level returning at 24 weeks after the start of donepezil therapy. Furthermore, in terms of the long-term (1 year) effects of donepezil, several previous studies [7,9,10] have reported a difference in the rCBF patterns between the stable and nonstable groups. Unfortunately, under our study design, we could not predict either the very short-or long-term effects of donepezil therapy in AD patients.…”

“…However, a recent study by Yoshida et al [8] reported that clinical improvement as assessed by ADAS-cog with donepezil therapy was the greatest after 3 months' therapy; they also suggested that after 3 months the clinical effect gradually decreased to the pretreatment level. Several SPECT studies have demonstrated significant increases in the rCBF of the frontal lobe after 1 month's [8] or 3 months' [7] donepezil treatment. Therefore, the rCBF in areas containing cholinergic neuronal pathways may increase during the early stages of treatment.…”

“…For example, the rCBF increased in the frontal lobes of AD patients who were treated with donepezil for short periods (less than 3 months) [6][7][8] . On the other hand, studies on the long-term effects of donepezil treatment (from 10 to 15 months) in patients with AD have indicated that while the rCBF in the frontal lobe either remained stable or increased in the responder groups, the nonresponder groups exhibited reduced rCBF patterns [9,10] .…”

“…Although a few studies [7,11] comparing relative rCBF to absolute rCBF suggested that relative rCBF should be used to evaluate rCBF changes after treatment because absolute rCBF showed smaller changes than relative rCBF [7] . In addition, it is important to note that there is a difference between the region of interest (ROI) analysis [4,7,8,10] , which utilizes a reference area, and statistical parametric mapping (SPM) [9,11] , carried out on a voxel-by-voxel basis. While ROI analysis increases the effect of statistical artifacts such as type I errors, SPM analysis may produce type II errors.…”

Comparison of Alzheimer’s disease with vascular dementia and non-dementia using specific voxel-based Z score maps

“…The fi nding of cerebral hypoperfusion in the bilateral posterior cingulate gyri, precunei, and inferior parietal cortex of the brain using positron emission tomography (PET) and single-photon emission computed tomography (SPECT), and the application of statistical images have been established as early diagnostic tools of AD [6][7][8][9][10]. The effectiveness of the SPECT response to drug treatment and diagnosis at the stage prior to clinical diagnosis of AD have also been reported [1,11,12]. Matsuda 1 3 interest (VOI) in the posterior cingulate gyri, precunei, and inferior parietal cortex using easy Z score imaging system (eZIS) and developed a program (specifi c VOI analysis) that automatically fi gured out the following indicators: severity, extent, and ratio [13].…”