Investigational treatment for vascular cognitive impairment

Cognitive impairment of any severity associated with cerebrovascular damage is defined as vascular cognitive impairment as proposed by O'Brien. This is a heterogeneous syndrome with many subtypes, the most prevalent being vascular cognitive impairment without dementia. Neuropathological studies confirm that cerebrovascular disease and Alzheimer's disease frequently coexist. Diagnosis depends on criteria for dementia and vascular pathologies. Brain imaging is an important diagnostic tool. Although there is no approved intervention specifically for vascular cognitive impairment, general treatments (such as antiplatelet and antihypertensives) aimed at the prevention and management of stroke are used. Evidence from randomised, placebo-controlled studies of cholinesterase inhibitors for vascular dementia suggests that there may be beneficial effects for cognitive function, and clinical global impression is more favourable for the cholinesterase inhibitors compared with placebo. The effect of memantine also seems to be modest and similar to the effect that is demonstrated in patients with Alzheimer's disease. The accumulated evidence is not as comprehensive as that which exists for Alzheimer's disease. The cholinesterase inhibitors and memantine have not been extensively studied in vascular cognitive impairment without dementia. For the purposes of this review, the authors focus on interventions that have been evaluated by randomised controlled trials.