brain damage guided notes

Question 1

Differentiate between the two broad types of strokes: cerebral haemorrhage and cerebral ischemia

Answer 1

Stroke’ is a sudden-onset cerebrovascular
accident (CVA) resulting in brain damage

cerebral haemorrhage = A rupture of a blood vessel leading to
bleeding within the brain (e.g., burst
aneurysm)

cerebral ischemia = blood supply disruption caused by
* Thrombosis (at formation thrombus blocks artery)
* Embolism (traveling thrombus lodges in narrower
artery)
* Arteriosclerosis (thickening of blood vessel walls)
* Sudden drop in blood pressure

Question 2

Describe the sequence of damage associated with ischaemic stroke

Answer 2

does not develop immediately (couple of days)
– affects some neurons more than others (e.g.,
hippocampus)
– different mechanisms for different brain structures
– involves brain’s own neurotransmitters (!)

Question 3

Define and explain contusions and differentiate between coup and contrecoup injuries

Answer 3

Contusions are closed head injuries that involve damage to the cerebral circulatory system, which produces internal hemorrhaging

When an external force is applied to the body, such as a blunt blow, it can cause blood vessels underneath the skin or within the tissues to rupture. This leads to the leakage of blood into the surrounding area, resulting in discoloration, swelling, and pain.

coup = primary impact e.g.
A coup injury refers to damage that occurs at the site of impact. For example, if a person’s head strikes a hard surface, such as in a fall or a direct blow, the brain may hit the inner side of the skull at that point, causing injury.

contrecoup = occurs on the opposite side of the brain from the site of impact. When the head suddenly stops or changes direction, the brain can rebound within the skull, leading to injury on the side opposite the initial impact.

Question 4

Define concussion and briefly outline long term consequences of repeated impact forces (i.e. CTE)

Answer 4

disturbance of consciousness but no evidence
of structural damage (e.g., no contusion).
– lack of evident structural damage does not
mean concussion is benign (e.g., CTE)

consequences = linked to increased risk of alzheimers, parkinsons and chrontic traumatic encephalopathy

Question 5

Differentiate between the different types of brain tumours

Answer 5

A tumour (neoplasm) = independently growing
cell mass without any physiological function
* Types of tumours:
* Meningiomas: ≈ 20% of tumours; grow between
meninges; encapsulated (within own membrane),
usually benign
* Infiltrating tumours: Most tumours are infiltrating.
Grow diffusely through surrounding tissue, typically
malignant, difficult to remove or destroy
* Metastatic tumours: ≈ 10% of brain tumours;
originate elsewhere, usually lungs, skin, breast
tissue

Question 6

Explain the difference between apoptosis and necrosis

Answer 6

Triggers internal reactions that lead to cell death
(apoptosis)

Apoptosis is a programmed and controlled form of cell death, characterized by specific changes in cell morphology, lack of inflammation, and efficient clearance of dead cells. It occurs naturally during development and tissue homeostasis.

Necrosis, on the other hand, is an uncontrolled and accidental form of cell death caused by external factors such as injury or toxins. It involves rapid cell swelling, membrane rupture, inflammation, and inefficient clearance of cellular debris.

Question 7

Explain what is known about recovery of function after CNS damage + classification of severely

Answer 7

Poorly understood
* Difficulty to differentiate between
compensation and true recovery (e.g.,
improvements due to reduction in brain
swelling after injury)

mild: less than 30 min of loss of consciousness and less than 24 hours of post traumatic amnesia (13-15)

moderate: beween 30 mins and 24 hours loss of consciousness and 1-7 days of post traumatic amnesia (9-12)

severe: loss of consciousness for 24 ours or more and 7 days + of post traumatic amesia (3-8)