Chapter 14: Cerebrovascular diseases Flashcards
What is cerebrovascular disease and which 2 types are there?
- Cerebrovascular disease = a collection of symptoms caused by interruption of the blood supply, called cerebral stroke.
- There are two types:
1. Embolic infarction.
2. Intracerebral hemmorrhage.
What is an intracerebral hemorrhagge?
- Intracerebral hemorrhage = brain hemorrhage resulting from a ruptured blood vessel.
What is an infarction?
- Infarction = death of tissue due to lach of oxygen.
What is an ischemia?
- Ischemia = abscence of blood flow, and doesn’t have to invovle tissue death.
What are the symptoms of a stroke?
- Depending on the location of the stroke, specific functions are lost laterally in the limbs, which may include a loss of:
- Sensation,
- Strength,
- Coordination,
- And control.
- Asymmetric sagging of the mouth may also occur, causing speech difficulties.
- Patients with infarction usually remain conscious.
- Patients with cerebral hemorrhage often lose consciousness.
How are the 2 types of strokes distinguished and diagnosed and treated?
- In the acute phase, the diagnosis of the stroke is made by a CT or a MRI and they can distinguish between an infarction or a hemorrhage.
- Patients are usually treated by a multidisciplinary team in a stroke unit.
What is the epidemiology of strokes?
- Each year, around 17 million people suffer their 1st stroke, with infarctions having a higher incidence that hemorrhages.
- It’s estimated that the number will increase with 40% between 2005 and 2025, because the population gets older and age is a risk factor of strokes.
- Strokes are the second leading death of people above 60 years old, but this varies drastically between countries.
- Thanks to better care, the death rate is falling, which means more people are living with the aftermath of strokes.
What are the causes of infarctions?
- Embolisms.
- Stenosis.
- Perfusion.
What are embolisms and which 2 causes are there?
- Embolisms = a cause of infarction in which an artery in the brain is blocked because of blood clots, air bubbles or fat.
- There are 2 causes of embolisms:
1. Thrombi
2. Calcification fragments in the wall of the blood vessels.
What are Thrombi?
- Thrombi = blood clots that form within blood vessels. They consists of coherent mass of platelets, fibrin, and other cellular components that may obstruct blood flow.
What does calcification fragments in the wall of blood vessels mean?
- Calcification fragments in the wall of blood vessels = the accumulation of calcium within the walls of blood vessels.
- Over time, calcium deposits can accumulate and harden within the vessel walls, leading to the formation of calcification fragments.
- These fragments can contribute to the narrowing and stiffening of blood vessels, potentially impairing blood flow.
What is stenosis and how is it caused?
- Stenosis = refers to the narrowing or constriction of a body passage or opening.
- In the context of blood vessels, stenosis occurs when there is a narrowing of the artery or vein, reducing the flow of blood through the vessel.
- This narrowing can be caused by various factors such as plaque buildup, inflammation, or abnormal tissue growth.
What is perfusion?
- Perfusion = insufficient blood supply.
Which arteries are affected in infarctions?
- The middle cerebral artery is affected in 80% of the cases.
- The posterior cerebral artery is affected in 5% to 10% of the cases.
- The anterior cerebral artery is affected 0.6% to 3% of the cases.
What is thrombolysis and when is it performed?
- Thromnolysis = a treatment of infarction, in which a drug is injected into the bloodstream to disperse the blood clot.
- It is performed when the infarction is detected in time.
What are the terms when the neurological symptoms of an infarction disappear within 24 hours?
- The terms for when symptoms disappear within 24 hours are:
- Transient ischemic attack (TIA),
- Or transient neurological attack (TNA).
- These usually last less than 30 min and include temporary loss of function and persistent but subtle cognitive impairment(s).
What risk factors of infarctions are there?
- Of people who experienced a TIA, 30% will have a stroke within the next 5 years.
- Age.
- Atherosclerosis (caused by smoking, obesity, etc.).
- Heart disease.
What is the main goal in the treatment of brain hemorrhages?
- The main goal is to maintain important functions and prevent another bleed.
- Sometimes surgery helps to reduce the pressure built up in the brain.
What is the highest risk factor of brain hemorrhage?
- The highest risk factor of brain hemorrhage is high blood pressure.
What are the different types of brain hemorrhages?
- The different types of brain hemorrhages are:
- Intracerebral hemorrhage.
- Subarachnoid hemorrhage (SAH).
What is an intracerebral hemorrhage?
- Intracerebral hemorrhage (ICH) = a type of stroke characterized by bleeding within the brain tissue itself. It occurs when a blood vessel ruptures and released blood in the surrounding brain area(‘s), causing localized damage and compression of brain structures.
What subtypes of intracerebral hemorrhages are there and what do they mean?
- Subtypes of intracerebral hemorrhages are:
1. Lobar hemorrhage = bleeding that is localized in one or more of the cerebral lobes and is caused by amyloid antipathy.
- Hemorrhage infarction = blockage and leakage of an artery.
- Hematoma = the accumulation of blood caused by trauma.
What does amyloid antipathy mean?
- Amyloid antipathy = a degenerative cerebrovascular disease in which is characterized by the accumulation of amyloid protein in the walls of the blood vessels in the brain.
What are common causes of cerebral hemorrhage?
- Common causes are:
- High blood pressure,
- Arteriovenous malformation,
- Inflammation of the vessel wall,
- Coagulopathy,
- And brain tumor.
What is an subarachnoid hemorrhage (SAH)?
- Subarachnoid hemorrhage (SAH) = a type of brain hemorrhage, in which the bleeding occurs in the arachnoid space (between the meninges), causing sudden headache, followed by stiffness of the head.
- This type of stroke occurs in 5% of the cases.
- It is usually caused by the rupture of an aneurysm.
- Surgery is usually required to close the leak.
- 2/3 of patients with SAH suffer significant loss of function and cognitive impairment.
What are the differences between the effects of infarction and hemorrhage and when are these differences most obvious?
- The differences between the effects of infarction and hemorrhage are most obvious shortly after the stroke.
- Brain hemorrhages:
- Causes immediate damage due to the increasing pressure. - - Because a larger portion of the brain is affected and the increased blood pressure causes loss of consciousness.
- This results in that normal function often can be restored when the brain pressure in lowered.
- Infarction:
- Affects specific cognitive functions based on its location and can also cause (temporary) damage to remote brain regions (diaschisis) at secondary level.
- This is why patients with an infarct usually suffer from marked cognitive impairment and cannot recover as quickly as patients with a hemorrhage.
What is the percentage of stroke patients that experience memory impairments?
- 13% to 15% of patients suffer from memory impairments in the first week after the stroke.
- 11% to 31% of patients suffer from memory impairments 1 year after the stroke.
When does memory loss frequently occur after a stroke?
- Memory loss frequently occurs after a stroke in the middle cerebral artery when the medial temporal lobe (hippocampus) is affected.
- But it can also appear following a stroke in other areas.
On what is the impact of a stroke on memory loss dependent on?
- The impact of a stroke on memory loss is dependent on the:
- Nature,
- Extent,
- And location of the stroke.
What is the hemispheric involvement on memory loss after a stroke?
- Damage in the left hemisphere or bilateral damage is more apparent in memory loss.
- Memory problems especially occur when the left hemisphere is damage.
- This also applies to modality-specific problems, such as visual memory.
- Damage in the right hemisphere has less impact on memory.
- When nonverbal memory is impaired, the right medial temporal lobe, thalamus, mamillary body, or basal frontal lobe is often affected.
What kind of amnesia is more common after a stroke?
- Anterograde amnesia (forgetting new things) is in most patients effected after stroke.
- Reterograde amnesia is less common, but can occur after damage to the non-medial parts of the temporal lobe.
What happens to the declarative and procedural memory after a stroke?
- Especially declarative memory is affected after a stroke.
- Procedural memory often remains unaffected, but can occur after damage in the basal ganglia.
What is the percentage of impaired attention processes in patients after a stroke?
- About 40% of the patients experience impaired attention processes after a stroke.
What kind of distinction can be made in attention processes and which brain areas are involved in these processes?
- Basic attentional processes = related to basic functions, such as falling asleep, and to multitasking.
- Impaired basic attentional processing: difficulty in doing more things at once.
- Originates in the subcortical networks. - Complex attentional processes = related to directing, distributing and sustaining attention, which involve limited attention time and easy distraction.
- Impaired complex attentional processing: difficulty in doing things for a longer time period.
- Originates in the parietal lobe, temporal lobe and prefrontal cortex.
When does impaired attention becomes particularly apparent and what plays a role in this?
- Impaired attention becomes particularly apparent under time pressure and a declaration in the speed of information processing plays an important role in this.