Stroke and TIA

• Stroke symptoms last ≥24 hours
• Stroke results in permanent neurologic deficits
• Stroke can be due to hemorrhage (20%) or ischemia (80%)
• Stroke with no known cause is called cryptogenic
• Stroke spares the upper 1/3 of the face
• TIA symptoms last <24 hours
• TIA symptoms resolve completely
• TIA can only be due to ischemia (emboli or thrombus) – because hemorrhage would take >24 hours to resolve
• TIA does not spare the upper 1/3 of the face

Artery localization

The artery affected in stroke or TIA can be localized based on the symptoms.

Anterior Cerebral Artery (ACA)

• Mainly lower extremity weakness
• Urinary incontinence
• Personality changes or psychiatric symptoms

Middle Cerebral Artery (MCA)

• Mainly upper extremity weakness
• Aphasia
• Apraxia/ neglect
• Eyes deviate toward lesion
• Contralateral homonymous hemianopsia with macular sparing

Posterior Cerebral Artery (PCA)

• prosopagnosia – can’t recognize faces

Vertebrobasilar Artery

• Vertigo
• Nausea and vomiting
• loss of consciousness (“drop attack”)
• Vertical nystagmus
• Dysarthria and dystonia
• Sensory changes in face and scalp
• Ataxia
• Bilateral findings

Posterior Inferior Cerebellar Artery (PICA)

• ipsilateral face
• contralateral body
• vertigo
• Horner syndrome

Ophthalmic Artery

• Amaurosis fugax

Lacunar Infarct

• Hemiparesis
• Sensory deficits
• Parkinsonian signs
• No cortical deficits
• Ataxia
• Possible bulbar signs

Almost 1 in 4 ischemic strokes occur deep within the brain – internal capsule, basal ganglia, thalamus – due to occlusion of small perforating blood vessels, which originate from the MCA.

Brainstem

The symptoms differ based on the tracts or structures in the brainstem that are affected. There are specific brainstem syndromes that important to recongnize.

Stroke Management

Stroke Etiology

Most strokes (about 80%) are due to ischemia – either due to emboli or thrombosis. The rest (about 20%) are due to hemorrhage – either intracerebral or subarachnoid. Part of stroke and TIA management is to determine the underlying cause or etiology. Thrombi can be the result of atherosclerosis or vasculitis. Emboli can be due to atrial fibrillation, heart valve disease, endocarditis, atrial septal defects, or cervical artery dissection.

One of the most common causes of stroke is atrial fibrillation (responsible for about 1 in 7 strokes).

Tests to determine the etiology of a stroke or TIA

• Echocardiogram
• Carotid Doppler/ Duplex
• EKG and Holter monitor
• LAB tests
  • ESR
  • VDRL or RPR
  • ANA
  • dsDNA
  • Protein C, ProteinS, Factor V Leiden mutation

Resources and Further Reading

• CDC on AFib – here
• Heart Valve Disease – Heartandstroke.ca link here