Stroke

14 Jun After Hemorrhagic Stroke, Patients at High Risk of Early and Delayed Dementia

MedicalResearch.com Interview with: [caption id="attachment_25101" align="alignleft" width="137"] Dr. Alessandro Biffi[/caption] Alessandro Biffi, MD Behavioral Neurology and Neuropsychiatry Departments of Neurology and Psychiatry Massachusetts General Hospital / Harvard Medical School MedicalResearch.com: What is the background for this study? Dr. Biffi: Intracerebral Hemorrhage (ICH) is the most severe form of stroke. It is a form of hemorrhagic (i.e. bleeding) stroke that accounts for ~ 15% of all acute cerebrovascular conditions, affecting ~ 70,000 Americans every year. However, because of its severity it is responsible for almost half of all stroke-related disability worldwide. Survivors of ICH are at very high risk for cognitive impairment (up to and including dementia) following the acute cerebral bleeding event. However, we possess very limited understanding of the time dynamics and risk factors for post-ICH dementia. In particular, prior to our study it was unclear whether the acute cerebral injury due to ICH would be the only mechanism potentially responsible for subsequent development of dementia. This question is motivated by prior observations suggesting that Intracerebral Hemorrhage represents the acute manifestation of cerebral small vessel disease, a progressive degenerative disorder of small caliber arteries of the central nervous system. There exist two major subtypes of small vessel disease: 1) cerebral amyloid angiopathy, caused by the deposition of a toxic protein product, beta-amyloid, in the blood vessels (in a process similar to the formation of beta-amyloid plaques that cause Alzheimer's disease); 2) arteriolosclerosis, caused by long-standing elevated blood pressure. ICH survivors have been previously shown to harbor very severe small vessel disease, which has been linked to dementia in patients without cerebral bleeding. Our hypothesis was that early-onset dementia (occurring in the first 6 months after ICH) is a manifestation of the acute neurological damage associated with cerebral bleeding, whereas delayed onset dementia (developing beyond 6 months from the acute ICH event) is associated with known markers of small vessel disease, including imaging findings on CT/MRI and genetic markers (such as the APOE gene).