Vascular dementia Vascular dementia is the second most common type of dementia, responsible for about 17% of cases. Diseased or damaged blood vessels mean that the blood supply to parts of the brain is reduced. This causes death of brain cells, leading to problems with memory, thinking and reasoning. Symptoms will vary according to the area of the brain affected, but may include memory loss and difficulties with language or problem-solving. Vascular dementia may be caused by a stroke, but not all strokes cause dementia. This will depend on the severity of the stroke and the part of the brain that is affected. A stroke patient is at risk of further strokes, which will also increase the risk of dementia. Another cause may be diseases of small blood vessels deep inside the brain. This is known as subcortical vascular dementia. At least 10% of people with dementia are diagnosed with both Alzheimer’s disease and vascular disease.