Editing Transient ischemic attack (section)

==Cause==
The most common underlying pathology leading to TIA and stroke is a cardiac condition called [[atrial fibrillation]], where poor coordination of heart contraction may lead to a formation of a clot in the atrial chamber that can become dislodged and travel to a [[Cerebral arteries|cerebral artery]].<ref name=":11" /><ref name=":10" /> Unlike in [[stroke]], the blood flow can become restored prior to [[infarction]] which leads to the resolution of neurologic symptoms.<ref name=NBK459143/><ref name=":11" /> Another common culprit of TIA is an [[Atheroma|atherosclerotic plaque]] located in the [[common carotid artery]], typically by the bifurcation between the internal and external carotids, that becomes an embolism to the brain vasculature similar to the clot in the prior example.<ref name=":11" /><ref name=":10" /> A portion of the plaque can become dislodged and lead to embolic pathology in the cerebral vessels.<ref name=":11">{{cite book | vauthors = Smith WS, Johnston SC, Hemphill III JC |chapter=Cerebrovascular Diseases |chapter-url=https://accessmedicine.mhmedical.com/content.aspx?bookid=2129&sectionid=192531947 | veditors = Jameson JL, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscalzo J |year=2019 |title=Harrison's Principles of Internal Medicine |publisher=McGraw-Hill Education |edition=20th }}</ref>

In-situ [[thrombosis]], an obstruction that forms directly in the cerebral vasculature unlike the remote embolism previously mentioned, is another vascular occurrence with possible presentation as TIA.<ref name=":11" /> Also, [[Carotid artery stenosis|carotid stenosis]] secondary to atherosclerosis narrowing the diameter of the lumen and thus limiting blood flow is another common cause of TIA.<ref name=":11" /> Individuals with carotid stenosis may present with TIA symptoms, thus labeled symptomatic, while others may not experience symptoms and be asymptomatic.<ref name=NBK459143/><ref name=":11" /><ref name=":10" />

===Risk factors===
Risk factors associated with TIA are categorized as modifiable or non-modifiable. Non-modifiable risk factors include age greater than 55, sex, family history, genetics, and race/ethnicity.<ref name=":11" /><ref name=":14" /> Modifiable risk factors include cigarette [[smoking]], [[hypertension]] (elevated blood pressure), [[Diabetes mellitus|diabetes]], [[hyperlipidemia]], level of [[carotid artery stenosis]] (asymptomatic or symptomatic) and activity level.<ref name=":11" /><ref name=":10">{{cite book |doi=10.1159/000448302 |chapter=Stroke Mechanisms |title=Intracranial Atherosclerosis: Pathophysiology, Diagnosis and Treatment |series=Frontiers of Neurology and Neuroscience |year=2017 | vauthors = Wong KS, Caplan LR, Kim JS |volume=40 |pages=58–71 |pmid=27960181 |isbn=978-3-318-02758-7 }}</ref><ref name=":14">{{cite journal | vauthors = Boehme AK, Esenwa C, Elkind MS | title = Stroke Risk Factors, Genetics, and Prevention | journal = Circulation Research | volume = 120 | issue = 3 | pages = 472–495 | date = February 2017 | pmid = 28154098 | pmc = 5321635 | doi = 10.1161/CIRCRESAHA.116.308398 }}</ref> The modifiable risk factors are commonly targeted in treatment options to attempt to minimize risk of TIA and stroke.<ref name=pmid19423857/><ref name=":11" /><ref name=":10" />