A Neurosurgeon's Guide to Stroke Symptoms, Treatment, and Prevention (2023)

Stroke is an abrupt interruption of constant blood flow to the brain that results in loss of neurological function. The interruption of blood flow can be caused by an obstruction, leading to the most common ischemic stroke, or by bleeding in the brain, leading to the most fatal hemorrhagic stroke. Ischemic stroke accounts for about 87% of all stroke cases. Stroke often occurs with little or no warning, and the results can be devastating.

It is crucial that adequate blood flow and oxygen are restored to the brain as soon as possible. Without oxygen and important nutrients, the affected brain cells are damaged or die within minutes. Once brain cells die, they normally do not regenerate and devastating damage can occur, sometimes resulting in physical, cognitive and mental impairments.

ischemic stroke

• Thrombotic (cerebral thrombosis)It is the most common type of ischemic stroke. A blood clot forms inside a diseased or damaged artery in the brain as a result of atherosclerosis (cholesterol-containing deposits called plaques) obstructing blood flow.
• Embolism (cerebral embolism)It occurs when a clot or small piece of plaque formed in one of the arteries leading to the brain or heart is pushed by the bloodstream and lodges in the narrower brain arteries. The blood supply is cut off from the brain due to the clogged vessel.

Transient ischemic attack (TIA)

This is a warning sign of a possible future stroke and is treated as a neurological emergency. Common temporary symptoms include difficulty speaking or understanding others, loss of or blurred vision in one eye, and loss of strength or numbness in an arm or leg. These symptoms usually go away in less than 10 to 20 minutes and almost always within an hour. Even if all symptoms go away, it is very important that anyone experiencing these symptoms call 911 and immediately be evaluated by a qualified physician.

hemorrhagic attack

• subarachnoid hemorrhageIt is bleeding that occurs in the space between the surface of the brain and the skull. A common cause of a subarachnoid hemorrhagic stroke is a ruptured brain aneurysm, an area where a blood vessel in the brain weakens, resulting in a bulge or swelling of part of the vessel wall; or rupture of an arteriovenous malformation (AVM), an abnormal, malformed tangle of blood vessels (arteries and veins) with an innate propensity to bleed.

• Hemorragia intracerebralis bleeding that occurs within brain tissue. Many intracerebral hemorrhages are due to changes in the arteries caused by long-term hypertension. Other possible causes can be delineated through testing.

stroke statistics

• Stroke is the third leading cause of death in the US.
• Statistics indicate that approximately 135,592 people in the US died of cerebrovascular disease in 2007.
• Of all strokes, 87% are ischemic, 10% are intracerebral hemorrhages, and 3% are subarachnoid hemorrhages.
• Although the incidence has increased, there has been a steady decline in death rates since 2002.
• Of the more than 795,000 people affected each year, about 610,000 are first attacks and 185,000 are recurrent.
• About 25% of people who recover from their first stroke will have another stroke within five years.
• Stroke is a leading cause of severe long-term disability, with an estimated 5.4 million stroke survivors currently living.
• In 2010, stroke cost an estimated $73.7 billion in direct and indirect costs in the US alone.

Source: American Heart Association (AHA), Heart Disease and Stroke Statistics, 2010 Update.

Risk factors

Although they are more common in older adults, strokes can occur at any age. Understanding the factors that increase stroke risk and recognizing the symptoms can help you prevent a stroke. Getting an early diagnosis and treatment can improve your chances of a full recovery.

Controllable or treatable risk factors for stroke include:

• Smoking: You can lower your risk by stopping smoking. Your risk may increase further if you use some forms of oral contraceptives and smoke. There is recent evidence that prolonged exposure to secondhand smoke may increase the risk of stroke.

• High blood pressure: Blood pressure of 140/90 mm Hg or higher is the most important risk factor for stroke. It usually has no specific symptoms or early warning signs. That's why it's important to check your blood pressure regularly. Blood pressure control is crucial for stroke prevention.

• Carotid or other arterial disease: The carotid arteries in the neck supply blood to the brain. A carotid artery narrowed by fatty deposits from atherosclerosis can become blocked by a blood clot. The carotid arteries are treated by neurosurgeons with carotid endarterectomy, a procedure in which an incision is made in the neck and plaque is removed from the artery; or carotid artery angioplasty and stenting, an endovascular procedure that does not require a surgical incision in the neck.

• History of TIAs: About 30% of strokes are preceded by one or more TIAs that can occur days, weeks or even months before a stroke.

• Diabetes: it is essential to control blood sugar levels, blood pressure and cholesterol levels. Diabetes, especially when left untreated, puts you at greater risk for stroke and has many other serious health implications.

• High blood cholesterol: A high total blood cholesterol level (240 mg/dL or higher) is a major risk factor for heart disease, which increases the risk of stroke. Recent studies show that high levels of LDL (bad) cholesterol (more than 100 mg/dL) and triglycerides (blood fats, 150 mg/dL or more) increase the risk of stroke in people with previous coronary artery disease, stroke ischemic stroke or TIA. Low levels (less than 40 mg/dL) of HDL (good) cholesterol can also increase the risk of stroke. You can often improve your cholesterol levels by cutting salt and saturated fat in your diet. However, some people inherit genes associated with high cholesterol levels. While they may be able to eat well and exercise, they may still have high cholesterol and need to take medication to control it.

• Sedentary lifestyle and obesity: Sedentary lifestyle, obesity or both can increase the risk of high blood pressure, high cholesterol, diabetes, heart disease and stroke. Getting 30 minutes of moderate exercise five days a week can help reduce your risk of stroke. Consult your physician before beginning any exercise program if you have a medical condition or are inactive.

• Recent research shows evidence that people taking hormone replacement therapy (HRT) have a 29% higher overall risk of stroke, particularly ischemic stroke.

Uncontrollable risk factors include:

• Age: People of all ages, including children, experience strokes. But the older you are, the greater your risk of stroke.

• Gender: Stroke is more common in men than in women. In most age groups, more men than women will have a stroke in any given year. However, women account for more than half of all stroke deaths. Pregnant women are at greater risk of stroke. Some research has indicated that women may experience and interpret stroke symptoms differently than men, causing them to delay seeking care and contributing to higher stroke mortality rates.

• Heredity and race: You are at greater risk of stroke if a parent, grandparent, sister, or brother has had a stroke. African Americans have more than twice the risk of stroke compared to Caucasians, in part related to the prevalence of hypertension. Hispanics are also at an increased risk of stroke.

• Previous stroke or heart attack: If you've had a stroke, you're at a much higher risk of having another one. If you've had a heart attack, you're also at a higher risk of having a stroke.

stroke symptoms

The range and severity of early stroke symptoms vary considerably but share the common feature of being sudden. Warning signs can include some or all of the following symptoms:

• Seas, nausea or vomiting
• unusually severe headache
• Confusion, disorientation, or memory loss
• Numbness, weakness in an arm, leg or face, especially on one side
• abnormal or slurred speech
• Difficulty in understanding
• Vision loss or difficulty seeing
• Loss of balance, coordination or ability to walk
• It is especially important to note that many strokes can cause a completely painless loss of neurological function, leading to possible hesitation in calling 911 or visiting an emergency room.

stroke effects

The effects of a stroke depend mainly on the location of the obstruction and the extent of brain tissue affected. One side of the brain controls the opposite side of the body, so a stroke that affects the right side will cause neurological complications on the left side of the body. A blow to the right side can result in the following:

• Paralysis of the left side of the body.
• Vision problems
• Quick, curious, or purposeless behavior.
• Memory loss

A stroke on the left side can result in the following:

• Paralysis of the right side of the body.
• speech/language problems
• Slow and cautious behavior.
• Memory loss

stroke treatment

Rehabilitation after a stroke can involve several medical specialists; but the early diagnosis of a stroke, its treatment or its prevention, can be done by a neurosurgeon. A quick and accurate diagnosis of the type of stroke and the exact location of its damage are essential for successful treatment. Technical advances such as digital imaging, microcatheters and other neurointerventional technologies, the use of the operating microscope (microsurgery) and the surgical laser have made it possible to treat stroke problems that were inoperable just a few years ago.

Ischemic stroke treatment

Ischemic stroke is treated by removing the blockage and restoring blood flow to the brain. The only drug approved by the US Food and Drug Administration (FDA) for ischemic stroke is tissue plasminogen activator (tPA), which must be given within three hours of the onset of symptoms to work best. Unfortunately, only 3 to 5 percent of stroke sufferers make it to the hospital in time to be considered for this treatment, and the actual use of tPA is considerably lower. This medication carries an increased risk of intracranial bleeding and is not used for hemorrhagic stroke.

Emergency surgical treatment of stroke: neurointerventional procedures

Microcatheter-based stroke surgery may involve the use of a small microcatheter, which is inserted through a larger guide catheter that is inserted into the groin through a small incision. A microguide is used to guide the microcatheter to the blockage site in the brain. Thrombolytic medication such as tPA can be administered directly into the occluded thrombus. This type of treatment, which administers thrombolytic drugs intra-arterially, is more specific than IV (intravenous) tPA and therefore may require significantly lower drug doses. The deadline for implementing this type of intervention is also significantly (twice) longer than that of the IV TPA. Generally, only Stroke Comprehensive Care Centers offer this type of treatment.

Clot Recovery Devices

The Merci Retriever, approved in 2004 by the FDA, is a corkscrew-shaped device used to help remove blood clots from the arteries of stroke patients. A small incision is made in the patient's groin, where a small catheter is inserted until it reaches the arteries of the neck. In the neck, a small catheter is guided inside the larger catheter through the arteries to the brain, until it reaches the brain clot. A straight wire inside the small catheter protrudes beyond the clot and automatically curls into a corkscrew. Pulled back into the clot, the corkscrew spins and grabs the clot. A balloon is inflated in the artery in the neck, cutting off blood flow so the device can safely remove the clot from the brain. The clot is removed through the catheter with a syringe.

The Penumbra is also a microcatheter-based system device, which works using a suction principle. It was approved by the FDA in 2008.

Stentiever devices are the latest generation of stroke embolectomy devices. They are still under investigation, but they work by breaking the occlusive clot, combined with aspiration or extraction.

medical prevention

Medications used to help prevent stroke in high-risk patients (especially those who have had a previous TIA or ischemic stroke) fall into two main categories: anticoagulants and antiplatelet agents.

Anticoagulants thin the blood and prevent clotting. Heparin works quickly and is given intravenously or subcutaneously (under the skin) while the patient is in the hospital. The slower-acting warfarin can be taken by mouth and is used over a longer period of time. Because these medications affect the blood's ability to clot, they require careful monitoring by a doctor.

Antiplatelet drugs prevent platelet aggregation. Platelets are specialized cells in the blood that start a healing process. Large numbers of platelets clump together to form a clot, which can sometimes block an artery or rupture, travel through the bloodstream and block a smaller artery. Antiplatelet drugs make platelets less sticky and less likely to clot, which reduces the risk of ischemic stroke in patients who have had a previous TIA or ischemic stroke.

Preventive Surgical Procedures

Carotid endarterectomy surgery (Carotid edarterectomy, CEA)

Patients will receive general or local anesthesia prior to surgery. In this procedure, the neurosurgeon makes an incision in the carotid artery in the neck and removes the plaque with a dissection tool. Plaque removal is accomplished by widening the passage, which helps restore normal blood flow. The artery will be repaired with sutures or a graft. The entire procedure usually takes about two hours. You may experience pain near the neck incision and some difficulty swallowing for the first few days after surgery. Most patients can go home after a day or two and return to work usually within a month. Patients should avoid driving and limit physical activity for a few weeks after surgery.

There are potential complications with carotid endarterectomy surgery, as with any type of surgery. There is a 1-3 percent risk of stroke after surgery. Another rather rare complication is re-blockage of the carotid artery, called restenosis. This can happen later, especially in cigarette smokers. Numbness in the face or tongue caused by temporary nerve damage is a possibility, but a rare one. This usually goes away in less than a month and in most cases does not require any treatment.

Carotid angioplasty and stent placement

An alternative and newer form of treatment, carotid angioplasty and stent (CAS), shows promise in patients who may be at high risk to undergo surgery. Carotid stenting is a neurointerventional procedure in which a tiny, thin metal mesh tube is placed inside the carotid artery to increase blood flow blocked by plaques. Access is via a small incision in the groin (0.5 cm), but no incision is made in the neck. The stent is inserted after a procedure called angioplasty, in which the doctor inserts a balloon-tipped catheter into the blocked artery. The balloon is inflated and pressed against the plaque, flattening it and reopening the artery. The stent acts as a scaffold to prevent the artery from collapsing or closing again after the procedure is complete.

There are several potential complications of endovascular treatment. The most serious risk of carotid stent implantation is an embolism caused by a ruptured plaque particle dislodged from the site. This can block an artery in the brain and cause a stroke. These risks are minimized by using small filters called embolic protection devices in conjunction with angioplasty and stenting. There is also a small risk of stroke due to a loose piece of plaque or a blood clot blocking an artery during or immediately after surgery. The risks are outweighed by the advantages of a shorter occlusion time (10 seconds, compared to 30 minutes for endarterectomy), shorter anesthesia, and a smaller leg incision.

Hyperperfusion, or the sudden increase in blood flow through a previously blocked carotid artery and into the arteries of the brain, can cause a hemorrhagic stroke. Other complications include restenosis and short periods of reduced blood pressure and heart rate that can be medically managed. These risks are similar for CEA and CAS.

Hemorrhagic stroke treatment

Hemorrhagic stroke usually requires surgery to relieve the intracranial (inside the skull) pressure caused by the bleeding. Surgical treatment of hemorrhagic stroke caused by an aneurysm or defective blood vessel can prevent further strokes. Surgery may be done to seal off the defective blood vessel and redirect blood flow to other vessels that supply blood to the same region of the brain.

For a patient with a ruptured brain aneurysm, surgical removal of the aneurysm is just the beginning. Recovery from intensive care for the next 10 to 14 days is the rule of thumb, during which time a multitude of complications related to subarachnoid hemorrhage (SAH) can and do occur. Sometime during this time (usually immediately after surgery is completed), a cerebral angiogram or surrogate study is performed to document that the aneurysm has been removed. The first two to five days after SAH pose the greatest threat of cerebral edema; at this point, special measures (both medical and surgical) are used to lessen the swelling's effect on intracranial pressure. Toward the end of this initial period, the period of risk of late-onset cerebral vasospasm begins and lasts for most of the next 14 days. Progressive infections, such as pneumonia, are common, and hydrocephalus may occur.

Surgery/Cutting

Before surgery, the exact location of the subarachnoid hemorrhage or aneurysm is identified using cerebral angiography. An operation is performed to "cut out" the aneurysm by performing a craniotomy (surgical opening of the skull) and isolating the aneurysm from the normal bloodstream. In addition, a craniectomy, a surgical procedure in which a part of the skull is removed and left temporarily, may be performed to help alleviate the increased intracranial pressure.

One or more small spring-loaded titanium clips are placed at the base of the aneurysm, allowing it to deflate. The size and shape of the clips are selected based on the size and location of the aneurysm. Clips are permanent, stay in place and generally provide long-lasting healing for the patient. Angiography is used to confirm the exclusion of the aneurysm from the cerebral circulation and the preservation of normal blood flow in the brain.

Endovascular treatment (neurointerventional)

Neurointervention procedures for cerebral aneurysm share the advantages of not making an incision in the skull and an anesthesia time that is often much shorter than that of craniotomy and microsurgical clipping.

In endovascular microcoil embolization, a needle is placed into the femoral artery of the leg and a small catheter is inserted. Using X-ray guidance, the catheter is advanced through the body's arterial system into one of the four blood vessels that supply the brain. A smaller microcatheter is inserted into the aneurysm and, once correctly positioned, a thin wire filament or "coil" is threaded into the aneurysm. The flexible platinum coil is designed to adapt to the shape of the aneurysm. Additional coils are inserted into the aneurysm to close the aneurysm from the inside. This impedes blood flow to the aneurysm, causing a clot to form inside.

Balloon Assisted Coil uses a small balloon catheter to help hold the coil in place. While this has been shown in several studies to increase risks, continued innovations in this relatively new technology have helped to improve its effectiveness. The stent-spring combination uses a small flexible cylindrical mesh tube that provides a scaffold for the coil. Intracranial stents and other innovations are relatively new, and endovascular technology is constantly evolving. These add-ons allow consideration of coil placement for cerebral aneurysms that may not be optimally shaped for conventional coil placement.

stroke rehabilitation

Recovery and rehabilitation are among the most important aspects of stroke care. As a general rule, most strokes are associated with some recovery, the degree of which is variable. In some cases, undamaged areas of the brain can perform functions that were lost when the stroke occurred. Rehabilitation includes physiotherapy, speech therapy and occupational therapy. This type of recovery is measured in months to years.

• Physical therapy involves the use of exercise and other physical means (eg, massage, heat) and can help patients regain the use of their arms and legs and prevent muscle stiffness in patients with permanent paralysis.
• Speech therapy can help patients regain their ability to speak.
• Occupational therapy can help patients regain independent function and relearn basic skills (eg, dressing, preparing a meal, and bathing).

conclusion

Modern treatments for ischemic and hemorrhagic stroke have reached an advanced state of development in the modern era of digital and device technology. Neurointerventional treatments allow for surgical procedures on the brain without the need to surgically open the skull and provide excellent treatment alternatives for all forms of stroke and cerebrovascular disease. These advances are timely and come in an era where the incidence of stroke is increasing as the population ages.

AANS does not endorse any treatment, procedure, product or physician mentioned in these patient information sheets. This information is provided as an educational service and is not intended to serve as medical advice. Anyone seeking specific neurosurgical advice or assistance should consult their neurosurgeon or search for one in their area through the AANS Find a Board-certified Neurosurgeon online tool.