Asymptomatic spontaneous cerebral emboli predict cognitive and functional decline in dementia.

Background: Spontaneous cerebral emboli (SCE) are frequent in Alzheimer's disease (AD) and vascular dementia (VaD). We investigated the effect of SCE on the rates of cognitive and functional decline in AD and VaD.
Methods: One hundred thirty-two patients with dementia (74 AD, National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association [NINCDS/ADRDA] criteria; 58 VaD, National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences [NINDS/AIREN] criteria) underwent 1-hour transcranial Doppler for detection of SCE (mean [SD] age 75.5 (7.4) years; 46% female). Neuropsychological tests (Mini-Mental State Examination [MMSE], Alzheimer's Disease Assessment Scale-Cognitive subscale [ADAS-Cog], and Neuropsychiatric Inventory [NPI]) and assessment of activities of daily living (Interview for Deterioration in Daily Living Activities in Dementia [IDDD]) were performed initially and 6 months later. SCE positive (SCE+ve, n = 47) and SCE negative (SCE-ve, n = 85) patients were compared using repeated measures analyses of variance (ANOVAs) adjusted for age, gender, and cardiovascular risk factors.
Results: SCE+ve patients with dementia, both AD and VaD, suffered a more rapid decline in cognitive functioning over 6 months (ADAS-cog, mean increase 7.1 for SCE+ve compared with 3.3 for SCE-ve, p = .006) and activities of daily living (IDDD, mean increase 24.4 for SCE+ve compared with 10.8 for SCE-ve, p = .014).
Conclusions: Asymptomatic SCE are associated with an accelerated cognitive and functional decline in dementia. SCE may be a potentially treatable cause of disease progression in dementia.