"stroke" é uma patologia aguda que afecta a irrigação de partes do cérebro (veja, por favor, as definiçoes mais abaixo) e que pode ser isquémico ou hemorrágico. Em terminologia não técnica é denominado "brain attack".
Enfarte é "heart atack" ou "myocardial infarction"

Em textos com carácter não muito técnico poderá usar "derrame cerebral" (razão pela qual vou também concordar com a resposta do Roberto)


A stroke is sometimes called a "brain attack." A stroke can injure the brain like a heart attack can injure the heart. Stroke is the result of cerebrovascular disease—disease of the blood vessels in the brain
http://www.wrongdiagnosis.com/medical/stroke.htm

stroke s. a condition with sudden onset caused by acute vascular lesions of the brain, such as infarction from hemorrhage, embolism, or thrombosis, or rupturing aneurysm. It may be marked by any of a variety of symptoms reflecting the focus of infarction or hemorrhage, including hemiparesis, vertigo, numbness, aphasia, and dysarthria; it is often followed by permanent neurologic damage. Called also cerebrovascular accident http://www.mercksource.com/pp/us/cns/cns_hl_dorlands.jspzQzp...

Cerebrovascular disease; CVA; Cerebral infarction; Cerebral hemorrhage; Ischemic stroke; Stroke - ischemic
Definition Return to top

A stroke is an interruption of the blood supply to any part of the brain. A stroke is sometimes called a "brain attack.
"http://www.nlm.nih.gov/medlineplus/ency/article/000726.htm

A sudden, nonconvulsive loss of neurologic function due to an ischemic or hemorrhagic intracranial vascular event. In general, cerebrovascular accidents are classified by anatomic location in the brain, vascular distribution, etiology, age of the affected individual, and hemorrhagic vs. nonhemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)
http://www.medical-conditions.org/?q=Stroke

stroke
<neurology> A condition due to the lack of oxygen to the brain which may lead to reversible or irreversible paralysis. http://cancerweb.ncl.ac.uk/cgi-bin/omd?stroke

stroke - acidente vascular cerebral; qualquer evento clínico agudo relacionado a comprometimento da circulação cerebral. Sin. apoplexy, brain attack
Stedman Medical dictionary

www.oboulo.com/enfermagem-1-trabalho.html
PDAMED - ACIDENTE CEREBROVASCULAR - Dicionário Digital de Termos Médicos. ... devido a um evento vascular intracraniano isquêmico ou hemorrágico. ...
www.pdamed.com.br/diciomed/pdamed_0001_0083.php