Sarah Pendlebury, from John Radcliffe Hospital (Oxford, United Kingdom), and colleagues analyzed 30 previously completed studies involving 7,511 people and published between 1950 and mid-year 2009.  Reporting that “10% of patients had dementia before first stroke, 10% developed new dementia soon after first stroke, and more than a third had dementia after recurrent stroke,” the researchers comment that “first, there is a clear relationship between having multiple strokes and the risk of dementia; and secondly, the data suggest that the presence of complications after stroke [which may include high blood pressure, low oxygen saturation, cardiac events, and seizures] also increase the risk of developing dementia.”