Stroke

Scott E. Kasner, M.D.
University of Pennsylvania School of Medicine

Lewis B. Morgenstern, M.D.
University of Michigan Medical School

Definition/Key Clinical Features
Differential Diagnosis
Best Tests
Best Therapy
Best References

Definition/Key Clinical Features

• A sudden neurologic deficit caused by either ischemia (80%) or hemorrhage (20%)
• Acute ischemic stroke produces varied signs and symptoms, depending on the location of the occlusion
  • Anterior cerebral artery (ACA): contralateral leg weakness
  • Middle cerebral artery (MCA): contralateral hemiparesis and hemisensory deficit (face + arm > leg); aphasia (dominant hemisphere) or neglect (nondominant hemisphere); contralateral visual-field defect; deviation of gaze; dysarthria; and other cortical symptoms
  • Posterior cerebral artery (PCA): occipital infarction and contralateral visual-field loss; contralateral hemiparesis; behavioral changes
  • Vertebral arteries or basilar artery: crossed facial sensory and body motor signs; diplopia; facial numbness and weakness; vertigo; nausea and vomiting; tinnitus; hearing loss; ataxia; gait abnormality; hemiparesis; dysphagia; and dysarthria
  • Penetrating vessels: pure motor hemiparesis, pure sensory stroke, clumsy hand–dysarthria syndrome, or ataxic hemiparesis
• Hemorrhagic stroke
  • Subarachnoid (5%)
    • Severe headache
    • Rapid onset
    • Photophobia
    • Stiff neck
    • Decreased level of consciousness
    • Focal neurologic signs
  • Intracerebral (intraparenchymal) (15%)
    • Severe headache
    • Focal neurologic signs (resembles ischemic stroke)
• Transient ischemic attack (TIA): sudden vascular-related focal neurologic deficit that resolves completely and lasts < 24 hr, generally < 1 hr; a herald of ischemic stroke and an opportunity to intervene

Differential Diagnosis

• Drugs or other toxins
• Seizure
• Metabolic derangements
• Migraine
• Brain tumor
• Intracranial hemorrhage
• Psychiatric disease

Best Tests

• Noncontrast CT to distinguish ischemic stroke from hemorrhagic stroke
• To localize lesion and evaluate blood vessels in ischemic stroke
  • Brain MRI
  • Angiography
  • CT-angiography (CT-A)
  • Magnetic resonance angiography (MRA)
  • Carotid duplex ultrasound
  • Transcranial Doppler ultrasound
• Cardiac evaluation of ischemic strokes
  • Cardiac history and examination
  • Electrocardiogram
  • Transthoracic echocardiogram (TTE) or transesophageal echocardiogram (TEE)
• Laboratory tests
  • Fasting lipids within 48 hours of symptom onset
  • Homocysteine level
  • Complete blood count
  • Prothrombin time
  • Partial thromboplastin time
  • Chemistry panel

Best Therapy

• Aspirin (160 to 325 mg daily) administered within 48 hr of stroke onset; aspirin should be withheld for at least 24 hr after administration of thrombolytics
• Intravenous recombinant tissue plasminogen activator (rt-PA) as soon as possible after onset of symptoms
  • Indications
    • Firm clinical diagnosis of potentially disabling stroke
    • Onset of symptoms or last time seen normal < 3 hr ago
  • Absolute contraindications
    • Onset > 3 hr ago or patient not seen normal within previous 3 hr
    • Intracranial mass lesion or hemorrhage on noncontrast head CT
    • Previous stroke or serious head trauma within previous 3 mo
    • Any history of intracranial hemorrhage
    • Current use of anticoagulants with PT > 15 sec or use of heparin within the past 48 hr
    • Platelets < 100,000/mm³
    • Presenting symptoms suggestive of subarachnoid hemorrhage (worst headache of patient's life)
    • Blood pressure > 185/110 mm Hg unless minimal doses of a smooth-acting I.V. agent such as labetalol were sufficient to lower below this range
    • Previously known cerebral aneurysm or arteriovenous malformation
  • Relative contraindications
    • Glucose < 50 or > 400 mg/dl
    • Seizure at stroke onset
    • Major surgery within 14 days
    • Arterial puncture at a noncompressible site or lumbar puncture within 1 wk
    • Rapidly improving symptoms suggestive of TIA
    • GI or GU hemorrhage within 21 days
  • Dose: 0.9 mg/kg (maximum dose, 90 mg) infused over 1 hour, with 10% of the total dose infused over the first minute; if treatment with rt-PA is suspected of inducing intracranial hemorrhage, the infusion should be suspended

• Supportive medical management
  • Maintain respiratory function, using intubation and mechanical ventilation if necessary; maintain oxygen saturation above 95%
  • Maintain adequate blood pressure; avoid rapid lowering of blood pressure; antihypertensive therapy is indicated before and during thrombolysis with rt-PA, when infarction converts to hemorrhage, and in patients with myocardial ischemia, aortic dissection, or hypertensive encephalopathy
  • Maintain normal fluid volume
  • Maintain normal body temperature with antipyretics or cooling blankets
  • Maintain normal blood glucose levels
  • Surgical decompression to relieve intracranial pressure in acute cerebellar stroke
  • Begin early prophylaxis for deep vein thrombosis with heparin (5,000 units S.C. q. 12 hr); if heparin is contraindicated (e.g., patients with acute hemorrhage), use pneumatic compression stockings
  • Prevent aspiration pneumonia
  • Early physical therapy, occupational therapy, and speech therapy
• Reduce risk factors for ischemic stroke prevention: control hypertension, tobacco use, hyperlipidemia, diabetes, excessive alcohol consumption, elevated homocysteine levels, infection, and inflammation; encourage exercise
• Management of risk of cardioembolism
  • Oral anticoagulation for patients at high risk for cardioembolism, including those with atrial fibrillation, mechanical prosthetic valves, severe dilated cardiomyopathy, intracardiac thrombus, and/or akinetic ventricular segments
    • Warfarin: contraindicated in pregnancy, poor compliance, alcohol abuse, and risk of falling; dose: adjusted to international normalized ratio (INR) between 2.0 and 3.0 for most patients
    • Ximelagatran: efficacy similar to that of warfarin in patients with atrial fibrillation and deep vein thromboembolism
  • Aspirin or other antiplatelet agents for patients at lower risk of cardioembolism or with contraindication to warfarin
  • Antibiotics for treatment of endocarditis
• Manage carotid artery disease by carotid endarterectomy or carotid angioplasty and stenting
• Antiplatelet treatment to prevent ischemic stroke
  • Aspirin (50–325 mg/day): can cause gastritis, peptic ulcer disease
  • Ticlopidine: reduces risk of stroke by 21%, compared with aspirin; may cause significant neutropenia and thrombocytopenia and requires complete blood count monitoring every 2 wk for the first 3 mo; can cause diarrhea and rash
    • Dose: 250 mg b.i.d.
    • Cost/mo: $86
  • Clopidogrel: reduces risk of major vascular events by 7.3%, compared with aspirin, though not specifically stroke; causes a lower frequency of neutropenia than ticlopidine; can cause rash, diarrhea, and, rarely, thrombotic thrombocytopenic purpura
    • Dose: 75 mg daily
    • Cost/mo: $115
  • Dipyridamole (extended-release) + aspirin: reduces risk of stroke by 23%, compared with aspirin alone; side effect: headache
    • Dose: 25 mg aspirin + 200 mg extended-release dipyridamole b.i.d.
    • Cost/mo: $115

• Surgical evacuation of hematoma
• Ventricular drainage for hydrocephalus
• Sedation with propofol to control intracranial pressure (ICP), with ICP monitor; with or without neuromuscular blockade
• Osmotic diuretics before hematoma evacuation
  • Mannitol load, 0.5–1.0 g/kg I.V.; maintenance dose, 0.25–1.0 g q. 6 hr; titrate to keep serum osmolality 300–310 mOsm/kg H₂O
• Hyperventilation: titrate to keep Pco₂ at 30–35 mm Hg; wean slowly
• Further supportive care as for ischemic stroke

• Surgical clipping or endovascular coiling within 72 hr of onset; before clipping or coiling, patients are kept mildly sedated in a quiet room and given stool softeners to reduce the risk of rebleeding
• After clipping, daily transcranial Doppler examinations to monitor vasospasm
• At first sign of vasospasm, begin hypertensive, hypervolemic, and hemodilution therapy to maximize cerebral blood flow, but only in patients with secured (clipped or coiled) aneurysms
• Anticonvulsants at first sign of seizure
• Blood pressure should be gently, not drastically, controlled
• Emergency CT scan in case of change in mental status to look for hydrocephalus, which can be treated with ventricular drainage
• Begin nimodipine on the first day and continue for 21 days
• Patients should be well hydrated, and blood pressure should be slightly high

• Dissection of the internal carotid artery and vertebral artery: may follow head and neck trauma or occur spontaneously
  • Clinical features: neck pain, headache, Horner syndrome, TIA or ischemic stroke, and tinnitus or audible bruits
  • Diagnosis: conventional angiography (gold standard) shows string sign, tapered stenosis or occlusion, dissecting aneurysm, intimal flap, distal pouch formation, and an underlying arteriopathy; CT-A, MRI, or MRA may be used
  • Treatment: early antithrombotic therapy with heparin or, if contraindicated, aspirin; continue until serial imaging demonstrates recana

Best References

Adams HP, et al: Stroke 34:1056, 2003

Albers GW, et al: Stroke 30:2502, 1999

Broderick JP, et al: Stroke 30:905, 1999

Coull BM, et al: Stroke 33:1934, 2002

November 2004


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