Transient ischemic attack

Transient ischemic attack
Hariadhi · CC BY-SA 4.0 · source
Name	Transient ischemic attack
Field	Neurology
Symptoms	Sudden focal neurological deficits
Complications	Stroke

Transient ischemic attack is a brief episode of focal neurological dysfunction caused by transient cerebral ischemia without acute infarction. It presents with sudden onset of deficits such as weakness, speech disturbance, or visual loss and often precedes ischemic stroke. Evaluation and rapid management in emergency and stroke systems of care aim to identify etiology and reduce short-term stroke risk.

Introduction

A transient ischemic attack typically lasts minutes to less than 24 hours and historically has been defined by symptom duration rather than imaging. Modern practice emphasizes tissue-based criteria using neuroimaging, vascular evaluation, and cardiac assessment to distinguish transient ischemia from completed infarction. Acute care pathways, stroke centers, and guidelines from organizations such as the World Health Organization, American Heart Association, European Stroke Organisation, National Institutes of Health, and Centers for Disease Control and Prevention influence triage and secondary prevention strategies worldwide.

Signs and symptoms

Presentation often mirrors focal deficits seen in hemispheric or brainstem infarction: sudden unilateral weakness or numbness, aphasia, dysarthria, hemianopia, diplopia, ataxia, or vertigo. Symptoms may mimic transient global amnesia, seizure, migraine with aura, or syncope, requiring differentiation by history and examination. Clinical scales and rapid assessment tools used in emergency medicine and prehospital systems include protocols influenced by entities like American College of Emergency Physicians, Royal College of Physicians, European Resuscitation Council, World Stroke Organization, and regional stroke networks. Observation units, telemedicine platforms linked to institutions such as Massachusetts General Hospital, Mayo Clinic, Johns Hopkins Hospital, and Cleveland Clinic support acute assessment.

Causes and risk factors

Common mechanisms involve embolic or hemodynamic transient reduction of cerebral blood flow from sources including atherosclerotic carotid stenosis, cardiac emboli, small vessel disease, or hypercoagulable states. Specific etiologies reference pathology encountered in settings associated with Atherosclerosis Research Unit, cardiac conditions like atrial fibrillation seen in cohorts from Framingham Heart Study and thromboembolic phenomena described in studies from International Stroke Trial investigators. Risk factors overlap with vascular disease populations studied by World Health Organization MONICA Project, including hypertension, diabetes mellitus cohorts from UK Prospective Diabetes Study, smoking prevalence tracked by Global Burden of Disease Study, dyslipidemia profiles from the Framingham Heart Study, and age-related risks characterized in longitudinal studies at Cardiovascular Health Study.

Diagnosis

Diagnosis integrates neuroimaging, vascular imaging, cardiac evaluation, and laboratory testing to identify stroke mimics and underlying cause. Noncontrast computed tomography and diffusion-weighted magnetic resonance imaging protocols derived from trials at National Institutes of Health Stroke Scale centers and imaging consortia (e.g., Stroke Imaging Research) help detect acute infarction. Vascular studies include carotid duplex ultrasound, computed tomography angiography practiced in stroke centers like Royal Melbourne Hospital and Guy's and St Thomas' NHS Foundation Trust, and magnetic resonance angiography. Cardiac monitoring for paroxysmal atrial fibrillation uses technologies and studies from EMBRACE trial investigators and devices produced by companies linked with cardiology units at St Bartholomew's Hospital and Mount Sinai Hospital. Laboratory evaluation for coagulation disorders, inflammatory markers, and metabolic contributors follows protocols influenced by research groups such as European Atherosclerosis Society and American College of Cardiology.

Management and treatment

Immediate management focuses on rapid risk stratification, antithrombotic therapy, and addressing modifiable risk factors to prevent stroke. Short-term antiplatelet strategies reflect evidence from trials conducted by groups including Oxford Vascular Study, TOAST investigators, and interventions studied in multicenter trials associated with NINDS. In cardioembolic sources, anticoagulation strategies follow guidance informed by landmark randomized trials and professional societies like European Society of Cardiology and American College of Cardiology. Revascularization for symptomatic carotid stenosis references outcomes reported by investigators at NASCET and ACST trials. Secondary prevention includes blood pressure control, lipid-lowering therapy with statins evaluated in studies supported by the Cholesterol Treatment Trialists' Collaboration, smoking cessation programs modeled by public health initiatives such as WHO Framework Convention on Tobacco Control, and lifestyle interventions as promoted by the Global Hearts Initiative.

Prognosis and complications

Short-term risk after a transient ischemic attack is concentrated in the first hours to days, with early stroke risk quantified in cohort studies like Oxford Vascular Study and registries maintained by the Get With The Guidelines-Stroke program. Long-term outcomes depend on etiology, comorbidities, adherence to secondary prevention, and access to stroke care infrastructures exemplified by comprehensive stroke centers such as Royal Prince Alfred Hospital and Toronto Western Hospital. Complications include progression to ischemic stroke, recurrent transient ischemic attacks, cognitive decline observed in longitudinal cohorts including Whitehall Study and Rotterdam Study, and functional disability requiring rehabilitation resources coordinated by institutions like Rehabilitation Institute of Chicago.

Category:Neurology