The effects of small vessel disease and amyloid burden on neuropsychiatric symptoms: A study among patients with subcortical vascular cognitive impairments

Neuropsychiatric symptoms (NPS) affect the quality of life of patients with dementia and increase the burden on caregivers. We aimed to evaluate how small vessel disease (SVD) such as lacunae or white matter hyperintensities (WMH), and amyloid burden affect NPS. We recruited 127 patients with subcortical vascular cognitive impairment who were assessed with brain magnetic resonance imaging, Pittsburgh compound-B (PiB) positron emission tomography and the neuropsychiatric inventory (NPI). To explore the association between lacunae, WMH, or PiB retention ratio and NPS, we performed multivariate regression analysis after controlling for possible confounders. Each additional lacuna, especially in the frontal region, was associated with higher odds of depression, apathy, aberrant motor behavior, nighttime behavior, appetite changes, and higher score of total NPI; larger WMH volume, especially in the frontal region, was associated with higher odds of apathy and higher score of total NPI. Furthermore, for the effects of lacunae or WMH on total NPI score we set Clinical Dementia Rating Sum of Boxes as the mediator. Greater PiB retention ratio was associated with higher odds of delusions and irritability. The SVD and amyloid pathologies did not show interactive effects on NPS. Our findings suggested that SVD and amyloid burden independently affected specific NPS.