Understanding Acute Stroke Patients: A Comprehensive Guide

Acute stroke is a cerebrovascular accident, or brain attack, that occurs when there is a blockage in a blood vessel, resulting in a restricted blood supply to the brain. This is known as an ischemic stroke, which accounts for about 87% of all strokes. The remaining 13% are hemorrhagic strokes, which occur when a blood vessel ruptures, causing blood to leak into the intracranial cavity.

The symptoms of an acute stroke include the abrupt onset of hemiparesis, monoparesis, or quadriparesis, hemisensory deficits, visual disturbances, vertigo, and a sudden decrease in the level of consciousness. It is important to note that the presence of these symptoms does not always indicate a stroke, and other conditions such as seizures, migraines, or hypoglycemia can mimic the effects of a stroke.

The diagnosis of an acute stroke is time-sensitive, as the potential for achieving a complete neurological recovery decreases with every minute of untreated stroke. Therefore, prompt evaluation and management are crucial. Neuroimaging techniques such as non-contrast computed tomography (CT) and magnetic resonance imaging (MRI) play a vital role in differentiating between ischemic and hemorrhagic strokes and guiding treatment decisions.

Ischemic stroke

An ischemic stroke is a medical emergency and the most common type of stroke, accounting for about 87% of all strokes. It occurs when a blood vessel supplying blood to the brain is blocked or obstructed, often by a blood clot, which can form in the heart, large arteries in the upper chest or neck, or another location in the circulatory system. This blockage causes brain cells to begin dying within minutes due to interrupted blood flow. Ischemic strokes can also be caused by stenosis, or the narrowing of an artery, which may be due to atherosclerosis, a disease where plaque builds up inside arteries.

The main cause of ischemic stroke is atherosclerosis, which can lead to two types of obstruction: cerebral thrombosis and cerebral embolism. Cerebral thrombosis occurs when a thrombus (blood clot) develops at the site of fatty plaque within a blood vessel supplying blood to the brain. Cerebral embolism happens when a blood clot forms elsewhere in the circulatory system and then travels through the brain's blood vessels until it reaches vessels too small to let it pass. An irregular heartbeat called atrial fibrillation is a significant cause of embolism.

Urgent treatment for ischemic stroke focuses on clot removal, which can be achieved through medication and mechanical treatments. Medication with drugs like tissue plasminogen activator (tPA) can dissolve the clot and improve blood flow, but it must be administered promptly to be effective. Mechanical treatments like mechanical thrombectomy use a wire-cage device called a stent retriever to remove the clot directly.

The "time is brain" concept is crucial in ischemic stroke treatment, emphasizing the importance of prompt evaluation and management to prevent irreversible brain damage.

Intracerebral hemorrhage

Intracerebral haemorrhage (ICH) is a subtype of stroke, a devastating condition whereby a blood clot is formed within the brain parenchyma, with or without blood extension into the ventricles. ICH is a life-threatening type of stroke and is the second most common cause of stroke, comprising 10-30% of all strokes. It is associated with high morbidity and mortality and is the most deadly type of stroke.

ICH can be divided into primary and secondary bleeds. Primary bleeds account for 85% of all ICH and are related to chronic hypertension or amyloid angiopathy. Secondary haemorrhage is caused by bleeding diathesis, vascular malformations, neoplasms, haemorrhagic conversion of an ischaemic stroke, and drug abuse.

The risk factors for ICH include non-modifiable factors such as non-white ethnicity, older age, familial apolipoprotein syndromes, and being male. Modifiable risk factors include uncontrolled or untreated hypertension, and abuse of drugs such as alcohol, nicotine, and cocaine.

ICH is often diagnosed using a non-contrast CT head, which remains the gold-standard imaging modality. CT Angiography (CTA) of the intracranial vessels may also be used to help identify vascular pathology that may be the cause of the ICH.

ICH treatment ranges from medical therapy to open surgery to actively evacuate the haematoma. Treatment focuses on stopping the bleeding, removing the blood clot, and relieving the pressure on the brain. Non-surgical treatments include clotting factor administration, blood pressure control, and intracranial pressure (ICP) control. Surgical treatments include craniotomy and stereotactic clot aspiration.

Subarachnoid hemorrhage

An acute stroke patient is someone who is experiencing a sudden loss of brain function due to a disruption in the blood supply to the brain. One cause of acute stroke is a subarachnoid hemorrhage, which is a life-threatening condition that requires immediate medical attention.

The most common symptom of subarachnoid hemorrhage is an extremely severe headache, described as the worst headache pain one has ever experienced. This is often followed by a loss of consciousness, which can be brief or prolonged. Other symptoms include confusion, trouble concentrating, and sensitivity to light. It is important to note that these symptoms may be indicative of other health problems, so medical care should be sought immediately if any of these symptoms are present.

The diagnosis of subarachnoid hemorrhage involves several tests, including a CT scan, MRI scan, angiogram, and spinal tap. Treatment focuses on stopping the bleeding and preventing rebleeding to reduce the risk of long-term brain damage. Medicines may be administered, and surgery may be required to place a small clip or stent on the blood vessel to stop the bleeding. Endovascular coiling is another treatment option, which involves inserting a catheter into an artery in the leg and guiding it to the bleeding artery in the head.

The outlook for subarachnoid hemorrhage depends on the speed of controlling the bleeding. Complications can include swelling in the brain (hydrocephalus), irritation, and damage to other blood vessels, leading to reduced blood flow and potential for additional strokes. These complications can result in lifelong brain damage, paralysis, or a coma. Therefore, it is crucial to seek emergency medical care if any signs or symptoms of subarachnoid hemorrhage are present.

Thrombotic strokes

The blood clot that triggers a thrombotic stroke typically forms inside an artery that has been narrowed by atherosclerosis. Atherosclerosis is a condition in which fatty deposits (plaques) accumulate inside blood vessels, restricting blood flow. Thrombotic strokes can affect both large and small arteries in the brain. When large arteries are blocked, a greater portion of the brain is affected, often resulting in more severe disabilities. On the other hand, thrombotic strokes in small arteries are usually lacunar strokes, which have minimal symptoms as only a small part of the brain is impacted.

The symptoms of a thrombotic stroke depend on the area of the brain affected, as different areas control different functions such as movement, sight, speech, balance, and coordination. Some possible symptoms include:

• Dizziness or confusion
• Weakness or paralysis on one side of the body
• Sudden, severe numbness in any part of the body
• Visual disturbances, including sudden loss of vision
• Difficulty walking, including staggering or veering
• Coordination problems in the arms and hands
• Slurred speech or inability to speak

Embolic strokes

Emboli can form from air bubbles, fat globules, or plaque from an artery wall. They can also result from atrial fibrillation (AFib), a type of irregular heart rhythm. When the heart doesn’t beat effectively, it can cause blood to pool and clot. AFib is the most common cause of embolic strokes.

Emboli may result in large vessel occlusion and cause severe strokes. Such patients may benefit from mechanical thrombectomy, which can be done within the first 6 hours of a stroke and up to 24 hours for selected patients.

The standard treatment for acute stroke within the first 4.5 hours remains IV thrombolysis with recombinant tissue plasminogen activator (tPA) in patients with no contraindication, regardless of the underlying etiology.

To prevent future embolic strokes, surgeons can perform a procedure called a carotid endarterectomy, which involves opening arteries that have been narrowed by plaque. Doctors may also use stents to keep an artery open.

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