Acute Stroke Management

Introduction to Stroke

• Stroke is a leading cause of disability, cognitive impairment, and death in the United States, affecting approximately 800,000 people per year.
• It accounts for 1.7% of national health expenditures, with an estimated U.S. cost of $71.5 billion in 2012.
• Appropriate use of IV t-PA can reduce long-term costs.

Definition of Stroke

• The World Health Organization (WHO) defined stroke in 1970 as a cerebral dysfn of vascular origin lasting >24 hours or leading to death.
• New definition incorporates clinical and tissue criteria, including CNS infarction, silent CNS infarction, and transient ischemic attack (TIA).
• The American Heart Association (AHA) and American Stroke Association (ASA) updated the definition of stroke in 2013.

Types of Stroke

• Ischemic stroke (85%): clot occluding an artery, leading to cerebral infarction.
• Intracerebral hemorrhage (10%): bleeding into the brain.
• Subarachnoid hemorrhage (5%): bleeding around the brain.

Stroke Scales

• National Institute of Health Stroke Scale (NIHSS): a 13-item scoring system, 7-minute exam, integrating neurologic exam components, with a maximum score of 42.
• Scores greater than 15-20 indicate a more severe stroke.

Etiology of Ischemic Strokes

• Large vessel thrombotic: atherosclerosis, vasculitis, and hypocoagulable states.
• Large vessel embolic: cardiac or aortic sources.
• Small vessel (lacunar): lipohyalinosis, atherosclerosis, and amyloid angiopathy.

Cortical Signs

• Right gaze preference: indicates a left large vessel stroke.
• Neglect: indicates a right large vessel stroke.
• Aphasia: a language disorder, often associated with left large vessel stroke.

Large Vessel Stroke Syndromes

• Middle cerebral artery (MCA): arm>leg weakness, language deficits.
• Anterior cerebral artery (ACA): leg>arm weakness, cognitive deficits.
• Posterior cerebral artery (PCA): hemianopia, visual field defects.
• Cerebellum: ataxia, dysmetria.

Aphasia

• Broca's aphasia: expressive aphasia, left posterior inferior frontal gyrus.
• Wernicke's aphasia: receptive aphasia, posterior part of the superior temporal gyrus.

Determining the Location

• Large vessel: cortical signs.
• Small vessel: no cortical signs.
• Posterior circulation: crossed signs, cranial nerve findings.
• Watershed: watershed pattern, signs of hypoperfusion.

Etiology of Stroke

• Small vessel (lacunes): lipohyalinosis, atherosclerosis, and amyloid angiopathy.
• Large vessel: atherosclerosis, vasculitis, and hypocoagulable states.

Acute Management

• Ensure clear airway and good ventilation.
• Nurse in slight head-up tilt (0-45-90 degrees).
• Continuous monitoring of neurological deficit for deterioration.
• Continuous cardiac monitoring.
• Do not feed orally if patient is unconscious or drowsy.
• DVT prophylaxis.
• Do not treat hypertension except in specific cases.

Imaging

• CT scan: superior for showing IVH and ICH.
• MRI: superior for showing underlying structural lesions.

Multimodal Imaging

• Multimodal CT: perfusion CT, CT angiogram (CTA).
• Multimodal MRI: diffusion-weighted imaging (DWI), perfusion-weighted imaging (PWI).

Thrombolysis

• Tissue plasminogen activator (tPA): a "clot buster" that increases the chance of good recovery.
• IV tPA window: 3 hours.
• IA tPA window: 4.5 hours.

Mechanical Thrombolysis

• Often used in adjunct with tPA.
• MERCI (Mechanical Embolus Removal in Cerebral Ischemia) Retrieval System.
• PENUMBRA system aspirates the clot.

Blood Pressure Management

• The goal is to maintain cerebral perfusion.
• BP management is critical in ischemic stroke.
• Lower BP goals in hemorrhagic stroke.

Hypertension - Ischemic Stroke

• Labetalol, Enalapril, Nitroglycerine, and Nitroprusside can be used to manage hypertension.
• AVOID NIFEDIPINE.### Fever and Stroke Outcome
• Fevers > 37.5 C that persist for > 24 hrs are correlated with ventricular extension and are found in 83% of patients with poor outcomes

Therapeutic Hypothermia

• Hypothermia reduces ischemia in animal models of stroke
• Current efforts are focused on translating this to patients with ischemic stroke
• Technical issues surrounding the timing and method for inducing hypothermia, and the deleterious effect of re-warming, remain unresolved
• Hypothermia can be combined with thrombolysis

Trophic Factors and Cell-Based Therapies

• These approaches aim to promote repair and recovery
• They can be divided into two categories: trophic factor treatments (e.g. growth factors like NDF) and cell-based therapies (e.g. neural stem cells)
• These approaches have met with variable degrees of success in animal models
• More work is needed to translate these promising results into effective stroke therapies

Supportive Care

• Secure airway using basic and advanced methods
• Protect C-spine
• Assure oxygenation and ventilation
• Maximize perfusion using IV fluids
• Monitor blood pressures in both arms and treat carefully
• Normalize temperature and glucose levels
• Treat seizures if they occur
• Reevaluate patient condition regularly

This quiz covers the medical management of acute stroke, including etiology, physical exam, and acute management of ischemic and hemorrhagic strokes. Review stroke facts and objectives.