CNS patho

Question 1

what are the 4 reasons for increased ICP

Answer 1

1. cerebovascular disease
2. intracranial haemorrage (blood leaking out)
3. CNS tumour
4. CNS infection

Question 2

what determines ICP

Answer 2

mean CSF pressure

Question 3

what is the normal range for ICP

Answer 3

7-15 mmHg (supine)

Question 4

which cranial nerve is most succeptible to increased ICP

Answer 4

CN6

Question 5

communicating vs non communicating hydrocephalus

Answer 5

communicating:
1. impaired CSF resorption
2. increased CSF production

non-communicating: (usually due to localised lesions)
1. obstruction in CSF flow

Question 6

what does this picture show

Answer 6

arnold chiari malformation
= displacement of brain tissue into foramen magnum
= stenosis of cerebral aqueduct

Question 7

what are the 3 cerebal herniations due to increased ICP

Answer 7

1. subfalcine herniation
2. uncal herniation
3. tonsillar herniation

Question 8

what is subfacline herniation

Question 9

what are the 5 risk factors for cardiovascular disease?

Answer 9

1. hypertension
2. diabeties mets
3. hyperlipedmia
4. smoking
5. A fib

Question 10

mechanism of action of MG

Answer 10

AChRAb (acetylcholine receptor antibodies) produced in MG patients [AChRab is a subset of IgG]
= AChRAb bind to AchR (acetylcholine receptors)
= ACh (acetylcholine) in the synaptic cleft cannot bind to the AChR anymore
= free floating ACh gets broken down by AChE (acetylcholinesterase)
= to treat myasthenia gravis, need acetylcholinesterase inhibitors (pyridostigmine)
= CANNOT give too much, if not ACh will NOT be broken down
= excessive ACh over stimulates muscarinic receptors (M3)
= excessive parasympathetic effects, leading to cholinergic toxicity
1. Increased glandular secretions = increase secretion in lungs = lungs fill with water and cannot breathe
2. Smooth muscle contraction = twitching = seizure
3. Bradycardia
4. Miosis
5. Diarrhoea
= cholinergic toxicity

Question 11

what are the cranial nerves for
1. pupillary
2. corneal
3. gag reflex

Answer 11

pupillary: 2,3
corneal: V1, 7
gag: 9, 10

Question 12

what does accommodation mean in terms of the visual pathway?

Answer 12

pre rectal nucleus changes lens thickness

Question 13

where is the primary visual cortex located?

Answer 13

in te occipital lobe

Question 14

what is temporal artheritis + what are the symptoms

Answer 14

inflammation of medium - large arteries (esp. carotid artery and superficial temporal artery)
= macrophage fusion
= giant cell formation
= granulomatous inflammation in the tunica media
= narrowing of lumen
= decrease blood flow and perfusion
= ischemia

symptoms:
1. jaw claudiaction
2. new onset headaches in elderly over 50
3. visual field defects (if untreated will result in blindness)

treatment: corticosteriods asap

Question 15

what is a thunderclap headache associated with?

Answer 15

subarachnoid haemorrage (cresent shaped)

Question 16

what are the top 4 causes of a thunderclap headache 1

Answer 16

1. SAH
2. dural venous sinus embolism
3. reversible cerebal vasoconstriction syndrome
4. carotid/ vetebral artery dissection