SPECT-identified neuroanatomical predictor of the cognitive effects of donepezil treatment in patients with Alzheimer's disease

Background/Objective: We attempted to determine whether the pretreatment regional cerebral blood flow (rCBF) might predict cognitive changes in response to donepezil treatment, as assessed in terms of the Alzheimer Disease Assessment Scale cognitive subscale (ADAS-cog), and in relation to the severity of subcortical hyperintensities (SH). Method: Forty-one patients with Alzheimer's disease (AD) were treated with donepezil at baseline. All the patients underwent a single photon emission computed tomography examination before donepezil therapy. They also completed the ADAS-cog at baseline and after 24 weeks of donepezil therapy. SH were assessed semiquantitatively using a recently developed visual rating scale. We analyzed the correlation between the baseline rCBF and changes in the ADAS-cog score using statistical parametric mapping, including the severity of the SH as a covariate. Results: Lower pretreatment rCBF levels in the right orbitofrontal cortex (OFC) predicted a better improvement in the ADAS-cog score in response to donepezil therapy. The severity of SH did not appear to influence this correlation. Conclusions: This effect may reflect the choline acetyltransferase activity associated with the OFC. The presence of SH did not appear to influence the effect of donepezil therapy on the cognitive function as assessed by ADAS-cog.