Does pre-existing cognitive impairment no-dementia influence the outcome of patients treated by intravenous thrombolysis for cerebral ischaemia?

摘要

Approximately 10% of patients with a first-ever stroke and 30% with a recurrent stroke have pre-existing dementia, and many others have cognitive impairment no-dementia (CIND). A recent trial and an updated meta-analysis showed that rt-PA is also beneficial after 80?years of age. Cognitive impairment being frequent in elderly subjects, more patients eligible for rt-PA will have prestroke cognitive impairment. They often have an underlying brain pathology associated with an increased bleeding risk: brain microbleeds and leukoaraiosis are frequent and usually associated with cerebral amyloid angiopathy in Alzheimer's disease or hypertensive microangiopathy in vascular dementia. They are also less likely to recover because of pre-existing brain lesions, impaired brain plasticity and possibly higher sensitivity to the neurotoxic effects of rt-PA. Three studies evaluated the influence of pre-existing dementia on outcome after thrombolysis. They provided conflicting results, that is, a tendency towards increased in-hospital mortality and symptomatic haemorrhagic transformation (sHT), increased in-hospital mortality without increase in sHT4 and no significant difference in outcome. However, they did not take into account important predictors of outcome such as baseline stroke severity and did not evaluate the proportion of independent survivors at 3?months. Moreover, they did not take into account CIND.