Neurology · Cerebrovascular Disease
The facts most likely to be tested
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A Transient Ischemic Attack (TIA) is defined as a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia without acute infarction on neuroimaging.
The ABCD2 score is the validated clinical tool used to stratify the risk of stroke within 2, 7, and 90 days following a TIA.
Carotid endarterectomy (CEA) is indicated for patients with a TIA and ipsilateral carotid artery stenosis of 70% to 99%.
MRI with Diffusion-Weighted Imaging (DWI) is the preferred diagnostic modality to exclude acute ischemic stroke and identify tissue-based evidence of infarction.
Antiplatelet therapy with aspirin or clopidogrel is the standard of care for secondary prevention in non-cardioembolic TIA.
Atrial fibrillation must be ruled out in all TIA patients using prolonged cardiac rhythm monitoring to determine if anticoagulation is required.
Amaurosis fugax, described as a painless, transient monocular vision loss resembling a "curtain coming down," is a classic presentation of ipsilateral carotid artery disease.
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A 68-year-old male with a history of hypertension and hyperlipidemia presents to the emergency department after experiencing a sudden episode of right-sided hemiparesis and expressive aphasia. The symptoms resolved completely within 45 minutes. Physical examination reveals a carotid bruit on the left side. An MRI of the brain shows no evidence of acute infarction, and an ECG shows normal sinus rhythm.
What is the most appropriate next step in the management of this patient's carotid artery?
Carotid duplex ultrasonography
The patient experienced a TIA, and the presence of a carotid bruit necessitates immediate evaluation for carotid artery stenosis using duplex ultrasonography to determine if surgical intervention is indicated.
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Etiology / Epidemiology
Caused by temporary focal cerebral ischemia without infarction. Hypertension is the single most significant modifiable risk factor.
Clinical Manifestations
Sudden onset of transient focal neurological deficits (typically <1 hour) that fully resolve without acute infarction on imaging. Amaurosis fugax is a classic retinal presentation.
Diagnosis
MRI brain is the gold standard to rule out infarction. Carotid duplex ultrasound is required to evaluate for stenosis.
Treatment
Aspirin is the first-line antiplatelet. Do not administer thrombolytics for TIA.
Prognosis
High risk of stroke within 48 hours post-TIA. Use ABCD2 score to risk-stratify for hospitalization.
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Epidemiology & Etiology
TIA is a clinical diagnosis defined by transient neurological dysfunction caused by focal ischemia. Major risk factors include hypertension, atrial fibrillation, diabetes mellitus, and hyperlipidemia. It serves as a critical warning sign for impending ischemic stroke.
Pertinent Anatomy
Symptoms depend on the vascular territory: Carotid distribution leads to unilateral weakness or amaurosis fugax. Vertebrobasilar involvement presents with vertigo, ataxia, or diplopia.
Pathophysiology
Transient interruption of blood flow occurs via microemboli (often from carotid plaque or cardiac source) or low-flow states. Unlike stroke, the duration is insufficient to cause permanent neuronal necrosis. Resolution occurs when the embolus lyses or collateral circulation restores perfusion.
Clinical Manifestations
Patients present with sudden focal deficits such as hemiparesis, aphasia, or sensory loss. Amaurosis fugax (transient monocular vision loss) suggests ipsilateral carotid disease. Red flags include symptoms lasting >1 hour or evidence of infarction on imaging, which reclassifies the event as a stroke.
Diagnosis
The MRI brain (specifically diffusion-weighted imaging) is the gold standard to exclude acute infarction. Carotid duplex ultrasound or CTA head/neck is mandatory to assess for >70% stenosis. The ABCD2 score (Age, BP, Clinical features, Duration, Diabetes) helps determine the necessity for inpatient admission.
Treatment
Initiate Aspirin (or clopidogrel) immediately to prevent recurrence. Do not use thrombolytics (e.g., tPA) as there is no tissue to salvage. Patients with symptomatic carotid stenosis >70% require carotid endarterectomy (CEA). Manage underlying risk factors with statins and aggressive blood pressure control.
Prognosis
The risk of stroke is highest within the first 48 hours to 7 days. Patients with an ABCD2 score ≥4 should be admitted for urgent workup. Long-term management focuses on antiplatelet therapy and lifestyle modification.
Differential Diagnosis
Hypoglycemia: check fingerstick glucose to rule out neuroglycopenia
Complex Migraine: look for a positive visual aura or headache progression
Seizure: look for post-ictal state or rhythmic motor activity
Bell's Palsy: isolated facial nerve palsy without other focal deficits
Conversion Disorder: symptoms inconsistent with known vascular territories