Neurological Diseases and Disorders

Question 1

What is Cerebrovascular Disease?

Answer 1

A stroke - occurs when part of the brain is deprived of blood.
Blood vessels carry oxygen and nutrients to the brain and can become blocked or burst.

Question 2

What are the two causes (types of stroke) of cerebrovascular disease?

Answer 2

1. Ischemic strokes: clogged blood vessel

2. Hemorrhagic strokes: ruptured blood vessel

Question 3

Which is more common, ischemic strokes or hemorrhagic strokes?

Answer 3

Ischemic strokes are more common (around 80%), while on about 20% of strokes are hemorrhagic.

Question 4

What are the two types of ischemic strokes?

Answer 4

1. Thrombotic: A clot forms locally, usually at a site of arteriosclerosis.
2. Embolic: A blood clot forms at another part in the circulatory system and travels through the bloodstream until it reaches a part of the vessel in the brain that is too narrow for it to pass.

Question 5

What does arteriosclerosis mean?

Answer 5

Arteriosclerosis is characterized by abnormal thickening and hardening of the arterial walls due to deposits (e.g., fatty substances and cholesterol) in the inner lining of an artery.
It causes narrowing of the arteries.

Question 6

What are the three vascular territories?

Answer 6

Anterior Cerebral Artery
Middle Cerebral Artery
Posterior Cerebral Artery

Question 7

What motor deficit might you expect given severe narrowing of the left carotid artery?

Answer 7

The left carotid artery feeds both the anterior cerebral artery and the middle cerebral artery.
If the carotid artery is partially occluded, the flow into both the anterior and the middle cerebral arteries will be reduced. Consequently, the brain region between them will be affected.
If you consider where on the motor homunculus the anterior and middle cerebral arteries meet, you will see that deprivation of blood to that area fits with the symptom of arm weakness.

Question 8

Hemorrhagic strokes are a result of ruptured blood vessels, there are two main types of weakened blood vessels, these are:

Answer 8

Aneurysm: An abnormal bulge in a blood vessel due to weakening of the vessel wall. If left untreated, the aneurysm may continue to weaken until it ruptures and bleeds into the brain. Arteriovenous malformation (AVM): A congenital disorder characterized by a cluster of abnormal connections between arteries and veins. These abnormal vessels can rupture, causing bleeding into the brain.

Question 9

What is a Transient Ischemic Attack (TIA)?

Answer 9

A minor stroke. In a TIA, conditions indicative of an ischemic stroke are present and the typical stroke warning signs develop. However, the obstruction (blood clot) occurs for a short time and tends to resolve itself through normal mechanisms.

Question 10

Do TIAs need treatment?

Answer 10

Even though the symptoms disappear after a short time, TIAs are strong indicators of a potential major stroke. Steps should be taken immediately to prevent a major stroke.

Question 11

How long do TIAs typically last and is functional recovery expected after a TIA?

Answer 11

A transient ischemic attack is classically defined as a neurological deficit lasting less than 24 hours and caused by temporary brain ischemia, but the typical duration of a transient ischemic attack is less than 10 minutes.
Improved imaging technology suggests that ischemic deficits lasting more than about 10 minutes probably produce at least some permanent cell death in the involved region of the brain.
Despite the appearance of a small infarct on an MRI scan, complete functional recovery can sometimes occur within 1 day.

Question 12

How is a stroke diagnosed?

Answer 12

Imaging brain tissue can reveal the location and extent of tissue damage; Computed Tomography or Magnetic Resonance Imaging.
Imaging the blood vessels of the brain can reveal abnormalities in the blood vessels; Angiography

Question 13

What are the three main cerebral arteries?

Answer 13

Anterior Cerebral Artery; Middle Cerebral Artery; Posterior Cerebral artery

Question 14

How does the location of a stroke along an artery affect the damage to the brain?

Answer 14

Occlusion at the origin of one of the main arteries can cause destruction of the entire territory; while more distal occlusion of one of the branches can cause destruction in part of the territory.

Question 15

Regarding motor function, which part of the body is most likely to be adversely affected by an ACA stroke?

Answer 15

Because the ACA supplies the leg area of motor cortex, ACA strokes are commonly associated with leg weakness or paralysis.

Question 16

In lecture, what was the damage caused in the example of a Posterior Cerebral Artery Stroke?

Answer 16

Damage to the visual cortex caused blindness to the contralesional hemifield and damage to the hippocampus caused memory problems.

Question 17

What difference in appearance is there when looking at CT scans of new strokes vs. old strokes?

Answer 17

More dense materials appear more white and less dense materials appear more black.
Older strokes appear darker because the cells have been cleared, leaving a CSF-filled hole.

Question 18

How are dead or degenerating brain cells cleared up?

Answer 18

Microglia devour and remove debris left by dead or degenerating brain cells.

Question 19

Would you expect to see an increase or decrease in neurogenesis after a stroke?

Answer 19

Post-stroke, neurogenesis increases for a short time.

Question 20

What is a brain tumour?

Answer 20

A brain tumour is a lump caused by uncontrolled growth of brain cells.

Question 21

What is the main type of brain tumour?

Answer 21

Most brain tumours develop from glial cells, and are called gliomas.

Question 22

What does it mean when brain tumours are malignant or benign?

Answer 22

A tumour can either be malignant (cancerous) or benign.

In the brain, both malignant and benign tumours can be harmful because they increase pressure in the skull.

Question 23

What is epilepsy?

Answer 23

Epilepsy is a neurological condition characterized by excessive and abnormally patterned activity in the brain.
People can experience unwanted brain activity as a one-off, people with epilepsy have recurring abnormal brain activity.
The primary symptom is seizures.

Question 24

What are seizures?

Answer 24

Seizures are epileptic events and having seizures is the defining characteristic of epilepsy.
Seizures vary from a momentary disruption of the senses, to short periods of unconsciousness or staring spells, to convulsions caused by a brief electrical disturbance in the brain.

Question 25

How would you confirm seizure activity?

Answer 25

Electroencephalography (EEG) is used to confirm seizure activity; during a seizure, the EEG profile shows a distinctive spike and wave pattern.

Question 26

An EEG example in class showed a patient with generalised epilepsy, how did this appear?

Answer 26

The distinctive spike and wave pattern occurred at electrode sites across the scalp.

Question 27

Describe the two types of seizures.

Answer 27

Generalized seizures involve the whole brain.

Partial seizures start in one part of the brain and may stay in that part or may spread.

Question 28

What are the causes of epilepsy?

Answer 28

Epilepsy can be caused by anything that affects the brain, including tumours and strokes. Sometimes epilepsy is inherited. Sometimes children have seizures during development and they grow out of it - due to rapid development of the brain.

Question 29

What are some seizure precipitants?

Answer 29

Stress
Lack of sleep
Illness
Hormones – many women report that their seizures are linked to their menstrual cycle
Patterns of light – for some photosensitive people
Alcohol

Question 30

What are epilepsy treatment options?

Answer 30

Medication: antiepileptics or anticonvulsants. In reality there tends to be many side effects.
Surgery (for intractable seizure activity); when it cannot be managed by drugs. Involves cutting out some of the tissue where the seizure activity is occurring.

Question 31

What are watershed zones and how do they relate to strokes?

Answer 31

Watershed locations are those border-zone regions in the brain supplied by the major cerebral arteries where blood supply is decreased. Watershed strokes are a concern because they comprise approximately 10% of all ischemic stroke cases.

Question 32

What could be caused by arteriosclerosis?

Answer 32

An Ischemic Thrombotic stroke.
Ischemic meaning it’s caused by a block instead of a burst.
Thrombotic meaning that the clot formed locally.