A Cerebral Vascular Accident (CVA), commonly known as a stroke, is a medical emergency that occurs when blood flow to a part of the brain is interrupted or reduced. This interruption prevents brain tissue from getting oxygen and nutrients, causing brain cells to die rapidly. A stroke can cause lasting brain damage, long-term disability, or even death. Recognizing the signs and symptoms of a stroke and acting quickly is crucial for minimizing brain damage and improving outcomes.

Types of Stroke

Strokes are broadly classified into two main types:

1. Ischemic Stroke: This is the most common type, accounting for about 87% of all strokes. It occurs when a blood vessel supplying blood to the brain is blocked, usually by a blood clot.

2. Hemorrhagic Stroke: This type occurs when a blood vessel in the brain ruptures or leaks, causing bleeding into the surrounding brain tissue.

Ischemic Stroke

Ischemic strokes are caused by a blockage in an artery that supplies blood to the brain. The blockage can be due to:

• Thrombotic Stroke: A blood clot (thrombus) forms in an artery within the brain, often in arteries already narrowed by atherosclerosis (hardening and narrowing of the arteries due to plaque buildup).

• Embolic Stroke: A blood clot or other debris (embolus) forms elsewhere in the body (often in the heart or large arteries in the neck) and travels through the bloodstream to the brain, where it lodges in a smaller artery and blocks blood flow. Atrial fibrillation is a common cause of cardioembolic stroke.

Transient Ischemic Attack (TIA): Sometimes called a “mini-stroke,” a TIA is caused by a temporary blockage of blood flow to the brain. Symptoms are similar to a stroke but are brief, typically lasting only a few minutes to an hour, and resolve completely. TIAs are a warning sign of increased risk for a full stroke and require urgent medical evaluation.

Hemorrhagic Stroke

Hemorrhagic strokes occur when a blood vessel in the brain bursts or leaks. This causes bleeding into the brain tissue (intracerebral hemorrhage) or into the space around the brain (subarachnoid hemorrhage).

• Intracerebral Hemorrhage: Bleeding occurs within the brain tissue itself. This is often caused by high blood pressure that weakens and ruptures small arteries. Other causes include arteriovenous malformations (AVMs), aneurysms, trauma, and anticoagulant use.

• Subarachnoid Hemorrhage: Bleeding occurs in the subarachnoid space, the space between the brain and the membranes covering it. The most common cause is a ruptured aneurysm (a weakened, bulging spot on an artery wall). AVMs can also cause SAH. This type of stroke often causes a sudden, severe headache described as the “worst headache of my life.”

Risk Factors for Stroke

Many factors can increase a person’s risk of having a stroke. Some risk factors can be controlled or modified, while others cannot.

Modifiable Risk Factors:

• High Blood Pressure (Hypertension) – the most significant risk factor.

• High Cholesterol.

• Diabetes Mellitus.

• Smoking (including exposure to secondhand smoke).

• Heart Disease (e.g., Atrial Fibrillation, heart failure, coronary artery disease).

• Obesity.

• Physical Inactivity.

• Unhealthy Diet.

• Excessive Alcohol Consumption.

• Use of certain drugs (e.g., cocaine, methamphetamine).

Non-Modifiable Risk Factors:

• Age (risk increases with age).

• Family History of Stroke.

• Race/Ethnicity (African Americans have a higher risk).

• Sex (men have a slightly higher risk than women, but women have more strokes overall and are more likely to die from them).

• Previous Stroke or TIA.

• Presence of an Aneurysm or AVM.

Pathophysiology

The pathophysiology of stroke involves the consequences of interrupted blood flow to the brain.

Ischemic Stroke:

When an artery is blocked, the brain tissue downstream from the blockage is deprived of oxygen and glucose. Brain cells are highly sensitive to this deprivation and begin to die within minutes (infarction). There is a central area of dead tissue (infarct core) surrounded by an area of potentially salvageable tissue called the ischemic penumbra. The goal of acute stroke treatment is to restore blood flow to the penumbra to prevent further damage. Lack of oxygen leads to a cascade of events including energy failure, accumulation of toxic metabolites, and cell death.

Hemorrhagic Stroke:

When a blood vessel ruptures, blood spills into the brain tissue or surrounding space. This bleeding causes damage through several mechanisms:

• Direct Tissue Compression and Damage: The accumulating blood clot puts pressure on surrounding brain tissue, damaging cells and disrupting function.

• Increased Intracranial Pressure (ICP): The volume of blood adds to the contents within the skull, increasing ICP. High ICP can reduce blood flow to healthy brain tissue and cause herniation (shifting of brain tissue), which is life-threatening.

• Vasospasm: In subarachnoid hemorrhage, blood in the subarachnoid space can irritate blood vessels, causing them to constrict (vasospasm). Vasospasm can further reduce blood flow to the brain and cause delayed ischemic injury.

• Excitotoxicity and Inflammation: The presence of blood and breakdown products in the brain triggers inflammatory responses and the release of chemicals that are toxic to neurons.

Diagnosis and Investigations

Prompt and accurate diagnosis is essential to determine the type of stroke and guide treatment. This involves a combination of clinical assessment and various investigations.

• Medical History and Physical Examination: Gathering information about the onset and nature of symptoms, risk factors, and performing a neurological examination to assess the extent of neurological deficits.

Investigations

Various diagnostic tests are performed to confirm a stroke, determine its type (ischemic or hemorrhagic), locate the affected area, identify the cause, and assess for complications.

• Brain Imaging: This is the most critical diagnostic step in the acute setting to differentiate between ischemic and hemorrhagic stroke, which dictates immediate treatment.

  • CT Scan of the Brain: Often the first imaging test performed due to its speed and availability. It is excellent at quickly identifying bleeding (hemorrhagic stroke), which appears bright white. While it may not immediately show the full extent of ischemic damage, it is crucial for ruling out hemorrhage before administering clot-busting medications (tPA).

  • MRI of the Brain: More sensitive than CT for detecting early ischemic changes and can help determine the age of an ischemic stroke. Specific MRI sequences (like diffusion-weighted imaging – DWI) can detect areas of acute infarction within minutes of stroke onset. MRI is also valuable for identifying smaller strokes or lesions in areas difficult to visualize with CT.

• Vascular Imaging: These tests visualize the blood vessels supplying the brain to identify blockages, narrowings, aneurysms, or malformations.

  • CT Angiography (CTA): Uses intravenous contrast dye and CT scanning to create detailed images of the arteries in the brain and neck. It can show blockages or narrowings that may be causing an ischemic stroke.

  • MR Angiography (MRA): Similar to CTA but uses MRI technology. It also visualizes blood vessels in the brain and neck without using ionizing radiation (though contrast may still be used).

  • Cerebral Angiography: An invasive procedure considered the “gold standard” for visualizing cerebral blood vessels. A catheter is inserted into an artery (usually in the groin) and guided to the brain vessels, and contrast dye is injected while X-rays are taken. It provides very detailed images and can identify aneurysms, AVMs, and severe narrowings. It can also be used for therapeutic interventions (like mechanical thrombectomy).

• Blood Tests: Several blood tests are performed to assess the patient’s overall health, identify potential stroke risk factors, and rule out other conditions that mimic stroke.

  • Complete Blood Count (CBC): To check for infection, anemia, or abnormalities in platelets that could affect clotting.

  • Blood Chemistry: Includes tests for electrolytes, kidney function (BUN, creatinine), liver function, and blood glucose. High or low blood glucose can cause stroke-like symptoms.

  • Coagulation Studies (PT/INR, PTT): Measure how quickly blood clots. This is essential if the patient is on anticoagulant medications or if a bleeding disorder is suspected, particularly before administering tPA.

  • Lipid Profile: Measures cholesterol and triglyceride levels, which are significant risk factors for atherosclerosis.

  • Cardiac Markers: Tests like Troponin are done to rule out a heart attack, which can sometimes occur concurrently with or contribute to a stroke.

• Electrocardiogram (ECG): Records the electrical activity of the heart. It is performed to check for heart rhythm abnormalities, particularly atrial fibrillation, which is a major cause of embolic stroke.

• Echocardiogram: An ultrasound of the heart. It is used to visualize the heart’s structure and function and to look for potential sources of blood clots that could travel to the brain (emboli), such as clots in the heart chambers or valve problems.

• Carotid Ultrasound: An ultrasound of the carotid arteries in the neck. These large arteries supply blood to the brain, and narrowing (stenosis) due to atherosclerosis in these vessels is a common cause of ischemic stroke. Ultrasound can assess the degree of narrowing.

Management

Acute stroke management is time-sensitive and aims to restore blood flow (in ischemic stroke), control bleeding (in hemorrhagic stroke), minimize brain damage, and prevent complications.

Acute Management of Ischemic Stroke:

• Thrombolytic Therapy (tPA – tissue plasminogen activator): This “clot-busting” medication can dissolve the blood clot causing the stroke. It is only effective if given intravenously within a narrow time window after symptom onset (typically 4.5 hours, but criteria vary) and after hemorrhagic stroke has been ruled out by CT scan.

• Mechanical Thrombectomy: A procedure where a catheter is threaded through blood vessels to the blocked artery in the brain, and the clot is physically removed using a stent retriever or aspiration device. This is often used for large artery blockages and can be performed within a longer time window than tPA (up to 24 hours in selected patients).

• Anticoagulants and Antiplatelets: Medications like aspirin, clopidogrel, or anticoagulants may be used after the acute phase to prevent future clots, depending on the cause of the stroke.

• Blood Pressure Management: Carefully managing blood pressure is important. In acute ischemic stroke, blood pressure may be allowed to be slightly elevated to maintain blood flow to the penumbra, but very high pressures are treated.

Acute Management of Hemorrhagic Stroke:

• Blood Pressure Control: Aggressive control of high blood pressure is critical to stop the bleeding and prevent further rupture.

• Reversal of Anticoagulation: If the patient is on anticoagulant medications, efforts are made to reverse their effects.

• Surgery: May be needed to stop the bleeding, remove the blood clot, repair a ruptured aneurysm (clipping or coiling), or repair an AVM.

• Management of Increased ICP: Measures to lower ICP may include head elevation, osmotic diuretics, or CSF drainage.

General Management for Both Types of Stroke:

• Monitoring: Close monitoring of neurological status, vital signs, cardiac rhythm, oxygen saturation, and blood glucose.

• Airway and Breathing Support: Ensuring a patent airway and providing oxygen or mechanical ventilation if needed.

• Fluid and Electrolyte Management: Maintaining adequate hydration and correcting imbalances.

• Fever Control: Treating fever, as it can worsen brain injury.

• Blood Glucose Control: Managing hyperglycemia and hypoglycemia.

• Prevention of Complications: Preventing aspiration (difficulty swallowing is common), deep vein thrombosis (DVT) and pulmonary embolism (PE), pressure ulcers, infections (pneumonia, urinary tract infections), and falls.

• Early Rehabilitation: Starting rehabilitation as soon as the patient is medically stable to help recover lost function.

Complications of Stroke

Stroke can lead to a wide range of complications, both in the immediate period after the stroke and in the long term. These complications can significantly impact a patient’s recovery and quality of life.

• Increased Intracranial Pressure (ICP): Brain swelling (edema) or bleeding can increase pressure inside the skull, which can further damage brain tissue and lead to herniation.

• Neurological Deficits: These are the most common long-term complications and vary depending on the area of the brain affected. They can include:

  • Motor Deficits: Weakness or paralysis (hemiparesis/hemiplegia), problems with coordination and balance.

  • Sensory Deficits: Numbness, tingling, or loss of sensation.

  • Communication Problems: Difficulty speaking (dysarthria) or difficulty with language comprehension or expression (aphasia).

  • Swallowing Difficulties (Dysphagia): Impaired ability to swallow, increasing the risk of aspiration.

  • Cognitive Impairment: Problems with memory, attention, concentration, problem-solving, and executive functions.

  • Visual Disturbances: Loss of vision, double vision, or neglect of one side of space.

• Aspiration Pneumonia: Due to dysphagia, food or liquids can enter the airways and lungs, leading to infection.

• Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE): Immobility after stroke increases the risk of blood clots forming in the legs (DVT), which can break off and travel to the lungs (PE), a life-threatening condition.

• Pressure Ulcers: Reduced mobility and sensation increase the risk of skin breakdown.

• Infections: Patients are at increased risk for urinary tract infections (UTIs) and pneumonia.

• Falls: Weakness, balance problems, and cognitive deficits increase the risk of falls.

• Pain: Patients may experience pain related to spasticity, joint problems, or central post-stroke pain syndrome (neuropathic pain).

• Emotional Changes: Depression, anxiety, frustration, and emotional lability (uncontrolled laughing or crying) are common after stroke.

• Spasticity and Contractures: Increased muscle tone (spasticity) can lead to joint stiffness and contractures (permanent shortening of muscles and tendons).

• Hydrocephalus: In some cases, particularly after hemorrhagic stroke, there can be a buildup of CSF in the brain’s ventricles.

• Seizures: Can occur in the acute phase or later as a long-term complication.

• Recurrence of Stroke: Patients who have had one stroke are at higher risk of having another.

Nursing Management

Nursing care for stroke patients is complex and requires specialized knowledge and skills.

• Rapid Assessment and Recognition: Be able to recognize the signs and symptoms of stroke quickly (using FAST) and initiate the stroke protocol in your facility.

• Neurological Monitoring: Frequent neurological assessments are essential, including level of consciousness (GCS), pupillary response, motor and sensory function, speech, and cranial nerve assessment. Report any changes immediately.

• Vital Sign Monitoring: Monitor blood pressure closely according to protocol, heart rate and rhythm, respiratory rate, temperature, and oxygen saturation.

• Airway and Respiratory Management: Assess airway patency and respiratory status. Elevate the head of the bed. Provide oxygen as ordered. Assess swallowing ability and implement aspiration precautions (NPO until swallow screen/evaluation, thickened liquids, proper positioning during feeding).

• Medication Administration: Administer medications as prescribed, including tPA (if applicable), antihypertensives, antiplatelets, anticoagulants, seizure medications, etc. Monitor for side effects and effectiveness. For tPA, follow strict protocols for administration and monitoring for bleeding.

• Fluid and Electrolyte Management: Monitor I&O, assess hydration status, and administer IV fluids as ordered.

• Blood Glucose Monitoring and Management: Monitor blood glucose levels and administer insulin or other medications as needed.

• Skin Care: Implement a turning schedule to prevent pressure ulcers, especially in patients with mobility deficits. Keep skin clean and dry.

• Bowel and Bladder Management: Assess bowel and bladder function. Patients may experience incontinence or retention. Implement a bowel and bladder program as needed.

• Mobility and Positioning: Assist with turning and positioning to prevent contractures and promote circulation. Encourage early mobilization as tolerated and ordered by the physician.

• Safety: Implement fall precautions. Orient the patient to their surroundings if they are confused. Provide a safe environment.

• Communication: Assess communication deficits (aphasia, dysarthria) and use strategies to facilitate communication (e.g., pictures, communication boards, speaking slowly and clearly).

• Emotional Support: Stroke can be a frightening experience. Provide emotional support to the patient and family.

• Patient and Family Education: Educate about stroke risk factors, signs and symptoms (FAST), the importance of seeking immediate medical attention, the treatment plan, medications, rehabilitation, and lifestyle modifications to prevent future strokes.

• Collaboration: Work closely with the interdisciplinary team, including physicians, physical therapists, occupational therapists, speech therapists, dietitians, and social workers, to provide comprehensive care and plan for discharge and rehabilitation.