Stroke and Neurological Disorders Quiz

Management of Patients with Cerebrovascular Disorders: Stroke

• Stroke, also known as a cerebrovascular accident (CVA) or cerebral infarction, is the third leading cause of death in the United States.
• A stroke is a medical emergency needing immediate attention.
• Stroke is characterized by the sudden loss of oxygen-rich blood circulation to an area of the brain, causing nerve cell death and loss of neurological function.
• Stroke can lead to serious long-term disability or even death.
• Stroke is either ischemic (80-85% of cases) or hemorrhagic (15-20% of cases).

Stroke Types

• Ischemic Stroke: Caused by blockage of blood flow to an area of the brain, often due to a thrombus (blood clot) or embolus (traveling clot).
  • Large artery thrombosis (atherosclerosis)
  • Small penetrating artery thrombosis (lacunar)
  • Cardiogenic embolism
  • Cryptogenic (unknown cause)
  • Other (drug use)
• Hemorrhagic Stroke: Caused by bleeding into the brain.
  • Intracerebral hemorrhage: Bleeding within the brain tissue, often caused by high blood pressure, head injury, or blood disorders.
  • Subarachnoid hemorrhage: Bleeding into the subarachnoid space, often caused by aneurysm rupture.

Risk Factors

• Nonmodifiable: Age (over 55, though younger adults can be affected), male gender, African American descent, Hispanics & Asian ethnicity
• Modifiable: Hypertension, cardiovascular disease (arterial anomalies, atrial fibrillation, valvular disease), elevated cholesterol, obesity, diabetes, smoking, drug & alcohol abuse, oral contraceptive use, sedentary lifestyle, previous TIA

Clinical Approach to Stroke

• Ischemic stroke is further categorized by:
  • Thrombotic
    • Large-vessel
    • Small-vessel
    • Cardiac
  • Embolic
    • Arterial
• Hemorrhagic stroke is further categorized by:
  • Intracranial
  • Subarachnoid

Ischemic Stroke

• Causes: Large artery thrombosis due to atherosclerosis, small penetrating artery thrombosis/lacunar (25%), cardiogenic embolism (20%), cryptogenic (30%), and other (5%).
• Main Presenting Symptom: Numbness or weakness of the face, arm, or leg, especially on one side of the body.

Hemorrhagic Stroke

• Causes: Intracerebral hemorrhage (often caused by high blood pressure), subarachnoid hemorrhage (often caused by ruptured aneurysm).
• Main Presenting Symptom: Exploding headache, decreased level of consciousness

Pathophysiology of Ischemic Stroke

• Disruption of blood supply to the artery by obstruction (thrombus or embolus) causes infarction of brain tissue.
• Results in temporary or permanent loss of movement, thought, memory, speech, or sensation.
• The penumbra is an area of minimally perfused cells surrounding the dead cells where intervention is often effective.

Time Lost is Brain Lost

• Around 1.9 million neurons are lost per minute during ischemia.
• Reperfusion must occur within 3-4.5 hours (therapeutic window) for effective intervention.
• The goal is to salvage the ischemic penumbra and reduce ischemia time.

6 Most Common Manifestations of Ischemic Stroke

• Numbness or weakness of face, arm, or leg.
• Trouble speaking or understanding speech.
• Difficulty in walking, dizziness, or loss of balance.
• Confusion or change in mental status.
• Visual disturbances.
• Sudden, severe headache.

Stroke Assessment: NIH Stroke Scale

• Used by healthcare providers to assess stroke severity.
• Measures neurological function through questions and physical/mental tests.
• Scores a person's level of alertness and ability to communicate and perform simple movements.
• Scoring ranges from 0-42.

Acute Ischemic Stroke Syndromes - Classification by Artery Involved

• Anterior cerebral artery: Motor and/or sensory deficit (leg > face, arm), grasp, sucking reflexes, abulia, paratonic rigidity, gait apraxia.
• Middle cerebral artery: Aphasia, motor and sensory deficit (face, arm > leg > foot).
• Posterior cerebral artery: Homonymous hemianopia, alexia without agraphia, visual impairments, sensory loss.
• Penetrating vessels: Pure motor hemiparesis, pure sensory deficit, etc.
• Vertebrobasilar: Crossed sensory deficits.

Transient Ischemic Attack (TIA)

• Transient ischemic attacks (TIAs) precede nearly 15% of ischemic strokes.
• Characterized by temporary ischemic cerebral neurologic deficits that last for few minutes to hours (less than 24 hours).
• Equivalent to brain angina; temporary disturbance in blood flow that reverses before infarction.
• No structural damage or evidence of infarction.

Hemorrhagic Stroke Pathophysiology

• Bleeding into brain tissue, ventricles or subarachnoid space.
• Disrupts normal brain metabolism.
• Increased intracranial pressure (ICP) from the sudden entry of blood.
• Secondary ischemia of the brain due to reduced perfusion pressure.

Types of Hemorrhagic Stroke

• Intracerebral hemorrhage (ICH): Bleeding within the brain tissue.
• Subarachnoid hemorrhage (SAH): Bleeding into the subarachnoid space (between the arachnoid and pia mater).

Intracranial Aneurysm

• Dilation of a cerebral artery wall.
• Often occurs at bifurcations of large arteries (Circle of Willis).
• Can be due to atherosclerosis, congenital defects, or hypertension.
• Affected arteries include internal carotids, anterior cerebrals, anterior communicatings, posterior communicatings, and posterior cerebrals.

Arteriovenous Malformations (AVMs)

• Abnormal tangle of arteries and veins in the brain, lacking a capillary bed.
• Leads to dilation of arteries and veins, risking rupture.
• Common cause of hemorrhagic strokes, especially in young people.

Hemorrhagic Stroke Manifestations

• Similar to ischemic stroke symptoms, often with a severe sudden headache (exploding headache), nausea, vomiting, hypertension, seizures sudden changes in level of consciousness (LOC)

Assessment and Diagnostic Findings

• CT scan: To establish the type of stroke, size and location of hematoma, presence/absence of ventricular blood and hydrocephalus.
• Cerebral angiography: Confirms the diagnosis of intracranial aneurysm or arteriovenous malformation (AVM).
• Lumbar puncture: Confirms subarachnoid hemorrhage if CT is negative and intracranial pressure (ICP) isn't elevated.

Hemorrhagic Stroke Complications

• Cerebral hypoxia and decreased blood flow.
• Rebleeding or hematoma expansion.
• Increased ICP.
• Seizures.
• Cerebral vasospasm.

Increased Intracranial Pressure (ICP) Management

• Mannitol osmotic diuretic is often administered.

Stroke Hypertension Management

• Systolic BP may be lowered to prevent hematoma enlargement, using antihypertensive medications (Labetalol, Nicardipine, Nitroprusside, or Hydralazine).
• Close hemodynamic monitoring is essential to avoid precipitous drops in BP, which can lead to ischemia.

Medical Stroke Management

• Goals are to allow brain recovery from initial insult, minimize rebleeding risk, and prevent/treat complications.
• Management may include bed rest with sedation to prevent agitation and stress, and vasospasm management.

Treatment for Complications

• Seizures are treated with antiseizure drugs (Phenytoin).
• Hyperglycemia is managed to maintain normal blood sugar levels.
• Acetaminophen or other analgesics can be administered to manage head and neck pain.
• Cooling blankets may be used to manage fever.

Surgical Management

• In many cases, initial intracerebral hemorrhages are not surgically treated.
• Surgical evacuation by craniotomy may be necessary for patients with worsening neurologic examination, increasing ICP or signs of brain stem compression.

Rehabilitation

• Multidisciplinary team approach including physical therapists, occupational therapists, speech therapists, and dieticians.