Deep cerebral microbleeds are associated with poor cholinesterase inhibitor treatment response in people with Alzheimer disease

Objectives: Cholinesterase inhibitors (ChEIs) are the most effective treatment for Alzheimer disease (AD), but the response to treatment varies. Vascular lesions are associated with the pathogenesis of AD, and cerebral microbleeds (CMBs) are an indicator of hemorrhagic vascular pathology, which can be detected through susceptibility-weighted magnetic resonance imaging (SWMRI). This study investigated the association between CMBs and ChEI treatment response in patients with AD. Patients and Methods: We reviewed the medical records of 112 Taiwanese people with mild to moderate AD and at least 2 years of ChEI treatment between 2009 and 2016. Their baseline CMBs were quantified using the Microbleed Anatomical Rating Scale on SWMRI. Cognitive function of the patients was assessed using the Mini–Mental State Examination (MMSE) and Cognitive Abilities Screening Instrument (CASI). Student t test and multivariable logistic regression were used to analyze the association between cognitive decline and CMBs. Results: The mean age of the study population was 76.0 ± 8.0 years. In total, 79 out of 112 patients were women. The presence of deep, but not lobar CMBs at baseline was associated with a significant cognitive decline according to the MMSE and CASI, particularly in long-term memory, attention, orientation, mental manipulation, and verbal fluency. Among deep CMBs, those in the basal ganglia and thalamus were significantly associated with cognitive decline. Conclusions: Deep CMBs, particularly those in the basal ganglia and thalamus, but not lobar CMBs, are associated with poor response to ChEI treatment in people with AD. This can serve as a biomarker for predicting ChEI treatment response.