Stroke – Causes, Symptoms, Treatments

What is a Stroke?

A stroke is a serious medical condition that happens when the blood supply to part of the brain is cut off. Strokes are a medical emergency and urgent treatment is essential. The sooner a person receives treatment for a stroke, the less damage is likely to happen.

There are two main types of strokes:

• Ischemic stroke: This is the most common type of stroke, accounting for about 87% of all strokes. It occurs when a blood clot blocks an artery that supplies blood to the brain. When the blood supply is cut off, brain cells start to die.
• Hemorrhagic stroke:This type of stroke occurs when a blood vessel in the brain bursts (ruptures) and bleeds. The leaked blood puts too much pressure on brain cells, which damages them. Hemorrhagic strokes are less common than ischemic strokes, accounting for about 13% of all strokes.

Strokes are very prevalent around the world. Globally, over 12.2 million new strokes occur each year according to the World Stroke Organization. That means someone has a stroke somewhere in the world every 25 seconds.  Around 795,000 people experience a stroke in the United States annually according to the Centers for Disease Control and Prevention(CDC). This translates to roughly one stroke every 40 seconds and a stroke death every 4 minutes.

What are the Long Term Effects of Strokes on Survivors?

Strokes leave a lasting impact on survivors and the long-term effects can vary greatly depending on the severity and location of the brain damage.

One of the most common challenges after a stroke is physical impairment. This can manifest as weakness or paralysis on one side of the body, making it difficult to walk, maintain balance, and perform everyday activities. Daily tasks like dressing, bathing, and eating may require assistance or adaptation.

Another significant consequence is difficulty with speech and language, also known as aphasia. Stroke survivors may struggle to find the right words, speak fluently, or understand what others are saying. Reading, writing, and even basic communication can become frustrating challenges.

Cognitive problems are another frequent long-term effect. Memory loss, especially short-term memory, can make it difficult to remember instructions, follow routines, or learn new things. Difficulty concentrating, focusing, and problem-solving can significantly impact a person’s ability to manage daily life and return to work.

The emotional toll of a stroke can be substantial. Anxiety, depression, and emotional swings are common reactions to the physical and cognitive limitations caused by the stroke. Feelings of frustration, helplessness, and isolation can significantly affect a survivor’s well-being.

Pain and sensory changes are other potential long-term effects. Stroke survivors may experience numbness, tingling, or even persistent pain in the area of the body affected by the stroke. This discomfort can make it difficult to sleep, move around, and engage in daily activities.

Fatigue is another frequent complaint after a stroke. Many survivors experience an ongoing tiredness that can limit their energy levels and participation in activities they once enjoyed. This fatigue can be caused by the stroke itself, by medications, or by emotional stress.

The severity of these long-term effects depends on the extent of brain damage caused by the stroke. A larger area of affected brain tissue typically leads to more pronounced and widespread problems.

The location of the stroke also plays a critical role. Different parts of the brain control different functions. So, the specific challenges a survivor faces will depend on which area of the brain was injured. For instance, damage to the left hemisphere can affect a person’s ability to speak, understand language, read, write, and perform math calculations. In contrast, damage to the right hemisphere can cause problems with spatial awareness, coordination, and neglect, a condition where a person becomes unaware of or inattentive to one side of their body. Strokes affecting the cerebellum can lead to issues with balance, coordination, and movement, while strokes in the brainstem, which controls vital functions like breathing and heart rate, can be very serious and life-threatening.

What Factors Increase the Risk of a Stroke? 

Stroke risk factors can be broadly categorized into modifiable and non-modifiable factors. Modifiable factors are those we can influence through lifestyle changes and medical interventions, while non-modifiable factors are inherent characteristics we cannot change.

Modifiable Risk Factors:

• High Blood Pressure: This is the single biggest risk factor for stroke. Chronically high blood pressure damages blood vessel walls, making them more susceptible to blockage by fatty deposits (atherosclerosis) and blood clots. Over time, uncontrolled high blood pressure weakens and hardens the arteries, narrowing the passage for blood flow to the brain. If a clot forms in a narrowed artery or a weakened vessel bursts, it can cut off blood supply to a part of the brain, leading to a stroke.
  
• High Cholesterol: Similar to high blood pressure, high cholesterol levels contribute to atherosclerotic plaque buildup in arteries. This plaque is a sticky substance made up of fat, cholesterol, and other cellular debris. As plaque accumulates on the artery walls, it narrows the passage for blood flow. If a blood clot forms within this narrowed passage or if a piece of plaque breaks loose and travels to a smaller artery, it can block blood flow to the brain and cause a stroke.
  
• Diabetes: Diabetes disrupts how the body regulates blood sugar, leading to damage of blood vessels throughout the body, including those supplying the brain. Chronically high blood sugar levels can damage the inner lining of blood vessels, making them more prone to inflammation and narrowing. This can increase the formation of blood clots and further restrict blood flow to the brain, raising stroke risk.
  
• Smoking: Smoking damages blood vessels in several ways. It reduces the good cholesterol (HDL) levels that help remove plaque from arteries and increases the bad cholesterol (LDL) that contributes to plaque buildup. Smoking also makes blood more likely to clot and can damage the lining of the arteries, making them more susceptible to inflammation. All these effects significantly increase the risk of stroke.
  
• Physical Inactivity: Lack of exercise weakens the heart and contributes to high blood pressure, obesity, and high cholesterol, all of which elevate stroke risk. Regular physical activity strengthens the heart, improves blood flow, and helps maintain a healthy weight. It can also improve blood sugar control in people with diabetes.
  
• Unhealthy Diet: A diet high in saturated fats, trans fats, sodium, and low in fruits, vegetables, and whole grains promotes high blood pressure, obesity, and diabetes, all risk factors for stroke. A healthy diet rich in fruits, vegetables, whole grains, and lean protein can help lower blood pressure, maintain a healthy weight, and improve blood sugar control, reducing stroke risk.
  
• Obesity: Excess weight puts a strain on the heart and circulatory system, increasing blood pressure and the risk of blood clots. Obesity is often linked to unhealthy diet, physical inactivity, and insulin resistance, all of which contribute to a higher risk of stroke.
  
• Excessive Alcohol Consumption: Heavy alcohol consumption can raise blood pressure, damage the heart, and increase stroke risk. Over time, excessive alcohol intake can weaken the heart muscle and increase blood pressure. It can also interfere with the body’s ability to regulate blood sugar and increase the risk of blood clots.
  
• Sleep Apnea: This sleep disorder disrupts breathing patterns, leading to oxygen deprivation and increased blood pressure, both of which contribute to stroke risk. Sleep apnea causes pauses in breathing during sleep, which can lead to drops in blood oxygen levels. The body responds by raising blood pressure to keep oxygen flowing throughout the body. These repeated fluctuations in blood pressure can damage blood vessels and increase stroke risk.

Non-Modifiable Risk Factors:

• Age: Stroke risk increases with age as blood vessels naturally weaken and harden over time. As we age, our arteries become less elastic and more prone to atherosclerosis. This narrowing of the arteries can significantly increase the risk of stroke.
  
• Family History: Having a close relative (parent, sibling) with a history of stroke increases your own risk. This may be due to genetics or shared lifestyle habits. Certain genes may increase susceptibility to stroke, and families may share similar lifestyle habits that contribute to stroke risk factors like high blood pressure, high cholesterol, and obesity.
  
• Race and Ethnicity: African Americans, Hispanics, and Asian Americans have a higher risk of stroke compared to Caucasians. The reasons for these racial and ethnic disparities are complex and likely involve a combination of genetic factors, socioeconomic conditions, and access to healthcare.
  
• Sex: Men are generally more prone to strokes than women, although women’s risk increases after menopause. The protective effect of estrogen before menopause is likely a contributing factor. However, after menopause, women’s risk of stroke increases and becomes roughly equal to men’s risk.

Recognizing the Signs of a Stroke

Recognizing the signs of a stroke promptly is crucial because a stroke is a medical emergency where brain cells are being deprived of oxygen and nutrients. The sooner a stroke is diagnosed and treated, the less brain damage is likely to occur. Every minute counts when it comes to stroke treatment, and early intervention can significantly improve a person’s chances of a full recovery or minimize long-term disability.

The FAST acronym is a helpful tool to remember the key warning signs of stroke and act quickly. Here’s how it works:

• F – Face Drooping: Does one side of the face droop or become numb? Ask the person to smile. If one side of the face appears uneven, it could be a sign of stroke.
• A – Arm Weakness: Is one arm weak or numb? Ask the person to raise both arms. Does one arm drift downward while the other remains up? Weakness or numbness on one side of the body is a common stroke symptom.
• S – Speech Difficulty: Is speech slurred or difficult to understand? Ask the person to repeat a simple phrase. If their speech is garbled or they are unable to speak, it could be a sign of stroke.
• T – Time to Call 911: If you observe any of these signs, don’t hesitate! Call emergency services immediately. Even if the symptoms seem minor or go away, seeking immediate medical attention is critical.

What are Transient Ischemic Attacks (TIAs)?

A transient ischemic attack (TIA), often referred to as a “mini-stroke,” is a temporary blockage of blood flow to part of the brain. It’s similar to a stroke but differs in the crucial aspect of duration. Unlike strokes, TIAs cause symptoms that typically last for a short period, usually just a few minutes, and rarely persist for longer than 24 hours. Thankfully, these temporary blockages don’t cause permanent brain damage.

However, TIAs are crucial warning signs not to be ignored. Both strokes and TIAs share a similar underlying cause – a temporary or permanent blockage of blood flow to the brain. In a TIA, the blockage is brief, allowing blood flow to resume and preventing lasting damage. However, the presence of a blockage, even temporary, indicates an increased risk of a more severe blockage happening again in the future, potentially leading to a full stroke.

The risk factors for TIAs are very similar to those for strokes. These include high blood pressure, high cholesterol, diabetes, smoking, obesity, and unhealthy diet. The presence of these risk factors puts an individual at an increased risk of experiencing both TIAs and strokes.

While TIAs don’t cause permanent brain damage, they can sometimes leave subtle changes detectable on brain imaging tests. These changes, although not causing current symptoms, can indicate a vulnerability in the brain that makes a stroke more likely.

Experiencing a TIA is a wake-up call to take immediate action. It’s essential to seek medical attention right away to identify the underlying cause of the blockage and take steps to reduce the risk of a full-blown stroke.

Preventative Measures

There are two main approaches to reducing stroke risk: lifestyle changes and medical interventions. By adopting healthy habits and working with your doctor to manage any underlying health conditions, you can significantly lower your chances of experiencing a stroke.

Lifestyle Changes:

• Healthy Diet: A balanced diet rich in fruits, vegetables, and whole grains is essential. Limiting saturated and trans fats, sodium, and added sugars can help control blood pressure and cholesterol, both major stroke risk factors.
  
• Regular Exercise: Aim for at least 150 minutes of moderate-intensity exercise or 75 minutes of vigorous-intensity exercise per week. Physical activity strengthens the heart, improves blood flow, and helps maintain a healthy weight, all of which contribute to stroke prevention.
  
• Maintain a Healthy Weight: Obesity puts a strain on the circulatory system and increases blood pressure. Losing weight and reaching a healthy body mass index (BMI) can significantly reduce stroke risk.
  
• Smoking Cessation: Smoking damages blood vessels and increases blood clot formation. Quitting smoking is one of the most significant steps you can take to lower your stroke risk.
  
• Moderate Alcohol Consumption: Excessive alcohol consumption can raise blood pressure and damage the heart. Limiting alcohol intake can help reduce stroke risk.
  
• Stress Management: Chronic stress can elevate blood pressure. Techniques like meditation, yoga, or deep breathing exercises can help manage stress and improve overall cardiovascular health.
  
• Sleep Hygiene: Getting enough quality sleep is important for overall health, including stroke prevention. Aim for 7-8 hours of sleep per night and practice good sleep hygiene habits.

Medical Interventions:

• Blood Pressure Control: High blood pressure is the single biggest risk factor for stroke. Medications like diuretics, ACE inhibitors, or angiotensin receptor blockers can effectively control blood pressure and significantly reduce stroke risk.
  
• Cholesterol Management: Medications like statins can help lower LDL (bad) cholesterol and raise HDL (good) cholesterol, reducing the buildup of plaque in arteries and lowering stroke risk.
  
• Diabetes Management: If you have diabetes, it’s crucial to maintain good blood sugar control through medication, diet, and exercise. This can help prevent damage to blood vessels and reduce stroke risk.
  
• Blood Thinners: For certain individuals with a high risk of blood clots, medications like aspirin or blood thinners might be prescribed to help prevent clot formation and stroke.
  
• Carotid Endarterectomy: In some cases, if a major artery supplying blood to the brain is severely narrowed due to plaque buildup, a surgical procedure called a carotid endarterectomy might be recommended. This surgery removes the plaque, improving blood flow to the brain and reducing stroke risk.

How These Strategies Reduce Stroke Risk:

These lifestyle changes and medical interventions work in various ways to prevent stroke:

• Lowering Blood Pressure: By following a healthy diet, exercising regularly, and taking medications if needed, you can effectively control blood pressure. This reduces the force exerted on blood vessel walls, making them less prone to damage and rupture.
  
• Improving Blood Flow: Exercise and maintaining a healthy weight promote good circulation throughout the body, including the brain. This ensures adequate blood flow to the brain and reduces the risk of blockages.
  
• Managing Cholesterol: By lowering bad cholesterol and increasing good cholesterol levels, you can prevent the buildup of plaque in arteries that can narrow the passage and potentially block blood flow to the brain.
  
• Preventing Blood Clots: Lifestyle changes like quitting smoking and medical interventions with blood thinners can help prevent blood clots from forming in the arteries, reducing the risk of stroke caused by a blockage.
  
• Addressing Underlying Conditions: Medical interventions like medication management for diabetes can help control blood sugar levels and prevent damage to blood vessels, lowering stroke risk.

How are Strokes Diagnosed?

A stroke diagnosis is a critical step in determining the best course of treatment and maximizing a patient’s chances of recovery. Doctors typically employ a two-part approach to diagnose a stroke. The first part involves gathering detailed information about the patient’s medical history and conducting a thorough physical examination. The second part relies on medical imaging tests to visualize the brain and pinpoint any damage.

The medical history portion of the diagnosis focuses on understanding the patient’s experience with the stroke. The doctor will inquire about when the symptoms began, how long they have lasted, and their severity. This information helps establish a timeline for the stroke and gauge the potential extent of brain damage. Additionally, the doctor will ask about any pre-existing medical conditions the patient might have, such as high blood pressure, diabetes, or a family history of stroke. These factors can significantly increase the risk of stroke and are crucial for the doctor to consider during diagnosis.

Following the medical history, a physical examination assesses the patient’s neurological function. This examination involves testing the patient’s muscle strength, coordination, reflexes, speech, and vision. By evaluating these functions, the doctor can identify any impairments caused by the stroke and determine the affected area of the brain. For instance, weakness on one side of the body might indicate damage to the brain region controlling movement on the opposite side.

Once the doctor has gathered a comprehensive medical history and performed a physical examination, they will likely order imaging tests to confirm a stroke diagnosis and determine the specific type. These tests provide valuable visual data about the brain and blood vessels.

A common and non-invasive imaging test used for stroke diagnosis is a computerized tomography (CT) scan. This technology utilizes X-rays to create detailed cross-sectional images of the brain. A CT scan can reveal signs of bleeding in the brain, which is indicative of a hemorrhagic stroke. Conversely, it can also show a lack of blood flow, which is a sign of an ischemic stroke, the more common type of stroke. Moreover, a CT scan can be helpful in ruling out other conditions that might mimic stroke symptoms.

Another imaging test used for stroke diagnosis is magnetic resonance imaging (MRI). An MRI scan employs strong magnetic fields and radio waves to generate detailed pictures of the brain and blood vessels. While MRI scans are more expensive and time-consuming than CT scans, they offer superior image clarity, especially for detecting ischemic strokes within the first few hours of their occurrence. Additionally, MRI scans can help identify complications like swelling or damage to brain tissue.

In some cases, depending on the initial assessment by the doctor, additional tests might be necessary to evaluate the underlying cause of the stroke or assess potential complications. These tests could include an electrocardiogram (ECG) to measure heart rhythm and identify any abnormalities that might have contributed to the stroke, a carotid ultrasound to examine the carotid arteries in the neck for blockages that could increase stroke risk, or blood tests to check for risk factors like high cholesterol, diabetes, or blood clotting abnormalities.

How are Strokes Treated? 

Stroke treatment strategies depend on the specific type of stroke – ischemic (caused by a blood clot) or hemorrhagic (caused by bleeding in the brain). Here’s a breakdown of the main approaches:

Ischemic Stroke Treatments:

Thrombolytic Therapy (Clot Busters) are the gold standard treatment for ischemic stroke within a specific time window (usually up to 4.5 hours). Clot-busting medications are administered intravenously to dissolve blood clots and restore blood flow to the affected brain area. Early administration is critical as these medications can significantly improve recovery outcomes and minimize brain damage.

Mechanical Thrombectomy is a minimally invasive procedure that is often used in conjunction with clot-busting medications or for strokes outside the time window for thrombolytic therapy. A thin catheter is inserted through an artery in the groin and navigated to the blocked blood vessel in the brain. A tiny device is then used to grab and remove the clot, restoring blood flow.

Hemorrhagic Stroke Treatments:

Since high blood pressure can worsen bleeding in the brain, medications are administered to bring blood pressure down to a safe range. This helps prevent further bleeding and reduce pressure on the brain tissue.

In some cases, surgery might be necessary to remove the source of bleeding or relieve pressure on the brain. This could involve procedures to clip a ruptured aneurysm (a weak spot in a blood vessel) or remove a hematoma (a collection of clotted blood).

General Supportive Care:

Stroke can deprive brain cells of oxygen. Oxygen therapy may be administered to increase oxygen levels in the blood and improve brain function. 

Intravenous fluids and electrolytes are administered to maintain hydration and balance essential minerals in the body, which is crucial for overall health and brain recovery. 

Stroke patients are at increased risk of infections, so preventive measures like maintaining a clean environment and using antibiotics when necessary are important. 

Once a stroke is stabilized, rehabilitation plays a vital role in recovery. This may include physical therapy to improve mobility and coordination, occupational therapy to regain daily living skills, and speech therapy to address any communication difficulties.

What Medications are Most Often Prescribed for Stroke Survivors?

Medications prescribed for stroke survivors depend on the type of stroke they experienced (ischemic or hemorrhagic) and their individual medical needs. However, some common medications are often used to manage stroke risk factors and prevent future strokes. Here’s a breakdown of some of the most frequently prescribed medications:

Medications to Prevent Blood Clots:

• Antiplatelet Drugs: These medications, like aspirin or clopidogrel (Plavix), help prevent blood platelets from sticking together and forming clots. This can be particularly important for ischemic stroke survivors to reduce the risk of another clot blocking blood flow to the brain.
  
• Anticoagulants: These medications, like warfarin (Coumadin), dabigatran (Pradaxa), or rivaroxaban (Xarelto), are stronger blood thinners compared to antiplatelet drugs. They work by inhibiting different clotting factors in the blood, making it less likely for clots to form. Anticoagulants might be prescribed for certain stroke survivors, especially those with a high risk of blood clots due to conditions like atrial fibrillation (irregular heartbeat).
  

Medications to Control Blood Pressure:

• Antihypertensives: High blood pressure is a major risk factor for stroke. Medications from various classes, like diuretics, ACE inhibitors, or angiotensin receptor blockers, are used to lower blood pressure and prevent future strokes.
  • Diuretics: These medications help the kidneys remove excess fluid from the body, which can help lower blood pressure. (Examples: hydrochlorothiazide (HCTZ), chlorthalidone)
  • ACE Inhibitors: These medications work by relaxing blood vessels, allowing blood to flow more easily and lowering blood pressure. (Examples: lisinopril (Zestril), ramipril (Altace))
  • Angiotensin Receptor Blockers (ARBs): These medications block the hormone angiotensin II, which causes blood vessels to narrow. This helps relax blood vessels and lower blood pressure. (Examples: losartan (Cozaar), valsartan (Diovan))

Medications to Manage Cholesterol:

• Statins: These medications like atorvastatin (Lipitor) or rosuvastatin (Crestor) help lower LDL (“bad”) cholesterol and raise HDL (“good”) cholesterol. This reduces the buildup of plaque in arteries, which can narrow blood vessels and increase stroke risk. Statins are often prescribed for stroke survivors with high cholesterol levels. Examples: atorvastatin (Lipitor), rosuvastatin (Crestor).

Other Medications:

• Antidepressants: Stroke can sometimes lead to depression. Medications like selective serotonin reuptake inhibitors (SSRIs) can help regulate mood and improve emotional well-being after a stroke. Examples: fluoxetine (Prozac), sertraline (Zoloft), escitalopram (Lexapro).
  
• Anticonvulsants: If a stroke affects certain areas of the brain, it can increase the risk of seizures. Anticonvulsant medications can help prevent or control seizures after a stroke. Examples: carbamazepine (Tegretol), lamotrigine (Lamictal), levetiracetam (Keppra)