CNS

Question 1

SOL

Answer 1

Space occupying lesion

can either lead to atrophy or herniation of brain

Question 2

Brain herniation

Answer 2

Displacement of brain tissue from one compartment to another in response to increased ICP

Question 3

List some neurodegenerative disease

Answer 3

Multiple sclerosis - autoimmune
Dementia - vascular and alzheimer
Parkinson’s disease
Huntington’s disease (genetics)

Question 4

Intracranial Tumours

Answer 4

Meningioma - benign (dangerous/life-threatening but has good prognosis)
Gliomas - malignant
Glioblastoma - malignant, originates from astrocytoma
Medullablastoma and neuroblastoma - childhood cancer and poor prognosis

Question 5

Stroke

Answer 5

sudden disturbance in CNS function due to vascular disease
Stoke - ischaemic vs haemorrhagic 
Embolic > thrombotic 
Aneurysms rupture
Liquefactive necrosis 
Clinical presentation: 
	- Sensory loss
	- Contralateral hemiplegia 
	- Global aphasia - cannot speak

Question 6

Oedema in the CNS

Answer 6

abnormal accumulation of fluid in cerebral parenchyma –> increase in cerebral volume

Question 7

consequences of ICP

Answer 7

Papilloedema
- Swelling & compression of optic nerve
Nausea & vomiting
- Pressure on vomiting centres in pons & medulla
Headache
- Pressure on pain receptors around intracranial blood vessels & in the dura mater

Epilepsy
Systemic Fx
Altered levels of consciousness (Drowsy  Deep Coma)
Death

Question 8

How does ageing impact the CNS?

Answer 8

• atherosclerosis
• metastatic cancer (breast and adenocarcinoma) increases incidence in age
• degenerative disease increase with age
• primary cancers incidence increase with age

Question 9

How does the CSF differ in pyogenic (acute bacterial) meningitis versus viral meningitis?

Answer 9

Acute bacterial - bacteria is extracellular, strong inflammatory, csf is pussy and cloudy, High protein
Low glucose

Viral - no changes, looks normal, slight rise in protein, normal glucose, may cause thickening of meningeal layers

Question 10

How do microbes enter the CNS?

Answer 10

1. Through arterial blood supply
   
   2. Direct extension from local sites of infection
   3. Direct trauma - e.g. Surgical intervention
2. Peripheral nervous system

Question 11

What determines whether a SOL causes atrophy or herniation, give some examples?

Answer 11

Accumulate slowly - atrophy

Herniation - rapid

SOL examples - abscess, tumours and hydrocephalus

Question 12

epidural hematoma

Answer 12

• Arterial - fast
• Skull and dura
  
  • Ruptured meningeal artery
  • Trauma
  • Rapid rise ICP

Question 13

subdural hematoma

Answer 13

venous 
	- Dura and arachnoid
	- Ruptured bridging veins 
	- Blunt trauma 
	- Mild, non-specific symptoms 
Gradual and chronic

Question 14

What is the purpose of myelin & an example of a demyelinating disease that affects the CNS?

Answer 14

Purpose - insulates the nerve
demyelination -
slow nerve impulse, lost signal

Question 15

subarachnoid hematoma

Answer 15

• Can be due to stroke and hypertension
  
  • Arachnoid and pia, surface of the brain
  • Ruptured cerebral vessels at base of brain
  • Traumatic contusion of brain or stroke
    High mortality

Question 16

Explain main chronic conditions atherosclerosis of the carotid and cerebral arteries can cause

Answer 16

- slow
decrease blood supply to brain
atrophy of brain
vascular dementia
subdural hematoma

Question 17

Explain main acute conditions atherosclerosis of the carotid and cerebral arteries can cause

Answer 17

• happens suddenly
• stroke due to thrombus or embolus
• weakens walls of vessels –> aneurysm –> haemorrhagic stroke –> hematoma and raised ICP