Understanding Different Types Of Strokes And Their Varied Impacts

Strokes are medical emergencies that occur when there is a sudden disruption to the blood and oxygen supply to the brain. There are two main types of strokes: ischemic strokes and hemorrhagic strokes. Ischemic strokes are caused by a blockage in a blood vessel, while hemorrhagic strokes are caused by bleeding in or around the brain. Ischemic strokes account for about 87% of all strokes, while hemorrhagic strokes account for about 13%. Both types of strokes can have severe and life-threatening complications, so it is crucial to seek immediate medical attention if you or someone you know is exhibiting stroke symptoms.

Ischemic strokes (account for 87% of all strokes)

There are two main types of stroke: ischemic strokes and hemorrhagic strokes. Ischemic strokes are the most common type, accounting for about 87% of all stroke cases. They occur when a blood vessel supplying blood to the brain is blocked or clogged, which can be caused by a blood clot or a buildup of fatty substances called plaque. This blockage impairs blood flow to the brain, causing brain cells and tissues to begin dying within minutes due to a lack of oxygen and nutrients.

Ischemic strokes are further divided into two groups: thrombotic strokes and embolic strokes. Thrombotic strokes are caused by a blood clot that develops in the blood vessels inside the brain, typically in older people with high cholesterol, atherosclerosis, or diabetes. Embolic strokes, on the other hand, are caused by a blood clot or plaque debris that forms elsewhere in the body and then travels to one of the blood vessels in the brain through the bloodstream. Embolic strokes often result from heart disease or heart surgery and occur rapidly without warning signs.

The symptoms of ischemic strokes are typical of strokes in general and include weakness or numbness of the face, arms, or legs, especially on one side of the body. Other symptoms include confusion or difficulty speaking or understanding, problems with vision, dizziness or problems with balance and coordination, loss of consciousness or seizures, and severe headaches with no apparent cause.

The urgent treatment for ischemic strokes is clot removal, which can be achieved through medication or mechanical treatments. Medication with tissue plasminogen activator (known as alteplase) can be administered through an IV to dissolve the clot and improve blood flow to the affected area of the brain. Mechanical treatments, such as mechanical thrombectomy, involve using a wire-cage device called a stent retriever to remove the clot.

Hemorrhagic strokes (account for 13% of all strokes)

A hemorrhagic stroke is a type of stroke that accounts for about 13% of all stroke cases. It occurs when a weakened blood vessel, often due to high blood pressure, ruptures and bleeds into the brain or the surrounding area. This results in a loss of blood flow to the brain, leading to severe complications and even death.

There are two main types of hemorrhagic strokes: intracerebral hemorrhage and subarachnoid hemorrhage. An intracerebral hemorrhage occurs when there is bleeding directly into the brain tissue, often caused by high blood pressure. This type of stroke is associated with severe morbidity and high mortality, and early diagnosis and treatment are crucial due to the rapid progression of the hemorrhage.

On the other hand, a subarachnoid hemorrhage occurs when bleeding happens in the subarachnoid space, which is the area between the brain and the membranes covering it. This type of stroke is often due to an aneurysm or an arteriovenous malformation (AVM). An aneurysm is a weakened, ballooned area on an artery wall that has a high risk of rupturing. An AVM, on the other hand, is a congenital disorder characterised by a tangled web of arteries and veins that bypasses normal brain tissue.

The symptoms of a hemorrhagic stroke include a sudden and severe headache, loss of balance or coordination, weakness or numbness in the arms or legs, loss of speech or difficulty understanding speech, confusion or loss of alertness, and loss of consciousness. It is important to seek immediate medical attention if any of these symptoms are present, as prompt treatment can prevent life-threatening complications and reduce the risk of permanent brain damage.

Treatment options for hemorrhagic strokes include interventional radiology and neurosurgical procedures such as surgical clipping and coil embolization, which aim to stop the bleeding and reduce pressure in the brain. Additionally, medications may be given to reduce swelling, prevent seizures, and manage pain. The goal of treatment is to prevent life-threatening complications, reduce disability, and help the patient regain as much normal functioning as possible through rehabilitation.

Transient ischemic attacks (TIAs) or mini-strokes

Transient ischemic attacks (TIAs), often called "mini-strokes", are temporary blockages of blood flow to the brain. They are caused by a temporary clot, and the symptoms usually last less than five minutes, though they can last up to 24 hours. TIAs are a type of ischemic stroke, which occur when a blood vessel supplying blood to the brain is obstructed. Ischemic strokes are the most common type of stroke, accounting for about 87% of all cases in the US.

The symptoms of a TIA are similar to those of a stroke and can include:

• Weakness, numbness, or paralysis on one side of the body
• Slurred speech or difficulty understanding others
• Blindness in one or both eyes
• Severe headaches with no apparent cause
• Loss of consciousness or seizure
• Dizziness or problems with balance or coordination

TIAs are considered a "warning stroke", indicating a possible full-blown stroke in the near future. They are a medical emergency and should not be ignored. If you experience any symptoms of a TIA, seek immediate medical attention, even if the symptoms go away. Up to 20% of people who have a TIA will have a stroke within 90 days, and half of those strokes occur within the first two days after a TIA.

TIAs can be diagnosed through a combination of methods, including a medical history, physical and neurological exams, and imaging scans such as CT scans and MRIs. Treatment options may include catheter-based procedures, medications, and blood thinners to prevent blood clots and lower the risk of a future stroke.

Cryptogenic strokes

A cryptogenic stroke is a stroke of unknown cause. Doctors and scientists can make educated guesses about what causes them, but there is no universally accepted definition of what constitutes a cryptogenic stroke. It is estimated that about 1 in 3 ischemic strokes are cryptogenic, and they account for 30-40% of ischemic stroke patients. Cryptogenic strokes are more prevalent in African Americans and Hispanics, who are two times and 46% more likely, respectively, to experience this type of stroke.

The symptoms of a cryptogenic stroke are the same as those of any other stroke and include:

• Weakness in the face, leg, or arm, especially if this weakness affects only one side of the body
• Vision difficulties, which could affect one or both eyes
• Dizziness, lack of coordination, or lack of balance
• Confusion, problems with speaking, or problems with understanding
• Severe headache, seemingly without a cause

While the cause of a cryptogenic stroke may be uncertain, it is believed that most have an ischemic origin, meaning they develop due to a blockage in a blood vessel that reduces blood flow to the brain. Some possible causes of cryptogenic strokes include:

• Patent foramen ovale (a hole that develops between the left and right upper chambers of the heart)
• Atrial fibrillation (an atypical heart rhythm)
• A fatty buildup of plaque inside the aorta
• A disposition to form blood clots
• Infection, cancer, or a tear in an artery wall

The diagnosis of cryptogenic stroke remains a subject of scientific debate, and treating these strokes can be complicated since doctors cannot be certain of their ischemic origin. However, there is evidence that anticoagulants are a useful form of treatment, particularly in preventing a second stroke.

Brainstem strokes

Symptoms of a brainstem stroke may include hearing and vision problems, problems with balance, a feeling of spinning when still, and problems with chewing, swallowing, and speaking. Diagnosis involves a physical exam, blood tests, and brain imaging. Emergency medical attention is required, and treatment options include medication, embolectomy, and vertebrobasilar angioplasty and stenting.

The faster blood flow can be restored after a brainstem stroke, the better the chances for recovery. Early intervention has been shown to dramatically reduce morbidity and mortality associated with brainstem strokes. Rehabilitation may be needed to regain lost skills through physical, occupational, speech, and psychological therapy.

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