Silent stroke: not listened to rather than silent.

ABSTRACT

BACKGROUND AND PURPOSE: The prevalence of silent brain infarcts varies from 8% to 28% in the general elderly population. Silent brain infarcts are associated with increased risk of subsequent stroke and cognitive dysfunction. By definition, silent strokes lack clinically overt stroke-like symptoms and fail to come to clinical attention; however, impaired recall of symptoms may be a potential confounder. Our aim is to report a series of patients with incidentally detected acute and subacute strokes and examine whether they were truly asymptomatic. METHODS: Subjects included in this study were drawn from ongoing dementia research studies at the Memory Ageing and Cognition Center, in which all participants underwent a cranial MRI. Incidental hyperintense lesions on diffusion-weighted imaging with corresponding apparent diffusion coefficient defects indicative of acute/subacute silent stroke were identified. Clinical data for individuals with incidental hyperintense lesions on diffusion-weighted imaging were collated. RESULTS: Six of 649 subjects had incidental hyperintense lesions on diffusion-weighted imaging; on retrospective questioning, 3 recalled symptoms temporally correlated with MRI lesions, which had been reported to but ignored by family members. Two subjects had focal neurological signs. A majority of the subjects with incidental hyperintense lesions on diffusion-weighted imaging had significant cognitive impairment. CONCLUSIONS: A significant number of strokes may be "silent" due to lack of awareness of stroke-like symptoms in the elderly and their families. Enhanced stroke prevention education strategies are needed for the elderly population and, in particular, for their families.