Association of Temporolimbic Volumes with TreatmentResponse to Antipsychotic Medication for Delusion inPatients with Alzheimer’s Disease

Abstract

Objective: This study investigated the association between gray matter volume and thetreatment response to antipsychotic medication in patients with Alzheimer’s disease (AD). Methods: We included 26 AD patients with delusions from the Memory Impairment Centerof the Pusan National University Hospital in South Korea. All participants underwent base line brain magnetic resonance imaging and took risperidone as an antipsychotic medica tion for 6 weeks. Gray matter volumes were measured using voxel-based morphometryat baseline. Treatment response with respect to delusional symptoms was defined as thechange in delusion item scores in the Korean version of the Neuropsychiatry Inventory(K-NPI), from baseline to 6 weeks later. A voxel-based multiple linear regression modelintegrated with statistical parametric mapping was used to investigate the associationbetween gray matter volume and treatment response after controlling for covariates. Results: The treatment response was significantly positively correlated with gray mattervolume in the temporal lobe (both the fusiform gyri and the left superior and inferior tem poral gyri) and the limbic system (the left parahippocampal gyrus and left amygdala) aftercontrolling for age, sex, education level, total intracranial volume, risperidone dosage,baseline Korean version of the Mini-Mental Status Examination scores, and baseline K-NPIscores for the delusion and non-delusion domains (P 100 voxels). Conclusion: Our findings suggest that specific gray matter volumes, including those ofthe temporal region and the limbic system, may affect treatment response to antipsy chotic medication in terms of delusional symptoms in patients with AD.