Neuro exams - Parkinson's, Epilepsy and Glaucomo

Question 1

What is the pathophysiology of parkinson’s disease?

Answer 1

o Loss of Dopaminergic Neurones from the pars compacta of the Substantia Nigra in the midbrain that project to the striatum of the basal ganglia.

Question 2

GIve main treatment for Parkinson’s and five adjuvants

Answer 2

Levodopa (L-DOPA)
o	Dopamine receptor agonists
o	MAOI Type B inhibitors
o	COMT inhibitors
o	Anticholinergics
o	Amantadine

Question 3

When is L-dopa used?

Answer 3

Immediate precursor of dopamine and is able to penetrate the BBB to replenish the dopamine lost in the neostriatum

Question 4

Give four of the main ADRs of L-dopa

Answer 4

 Nausea and vomiting
 Hallucinations, delusions (schizophrenia)
 Cardiovascular effects (hypotension)
 Dyskinesia

Question 5

What does L-dopa have to be given with in order to prevent its breakdown?

Answer 5

Periperhal DOPA dexcarboxylase inhibitor

Question 6

What kind of drugs can cause parkinson’s like symptoms?

Answer 6

Anti-psychotic drugs

Question 7

Why do you need to give a large dose of L-dopa?

Answer 7

Large amount of peripheral breakdown

Question 8

What is the mechanism of dopamine receptor agonists?

Answer 8

Agonist for D2 receptors

Question 9

What are some ADRs for dopamine receptor agonists?

Answer 9

 Sedation, hallucination, confusion
 Nausea
 Hypotension
 Psychiatric symptoms

Question 10

What do monoamine oxidase type B inhibitors do?

Answer 10

selectively inhibits the MAOB enzyme in the brain that is normally responsible for the breakdown of dopamine. By inhibiting breakdown, the dose of L-DOPA is prolonged.

Question 11

What are three ADRs for MAOIs

Answer 11

Hypertension
Sympathetic response
Psychiatric symptoms

Question 12

What do COMT I inhibitors do?

Answer 12

 Inhibits the enzyme COMT, which degrades L-dopa in the periphery. No therapeutic effect alone.
 Potentiates effects of L-dopa

Question 13

Give three ADRs of COMT

Answer 13

 Nausea and Vomiting
 Abdominal pain
 Diarrhoea

Question 14

How do anti-cholinergics work in parkinsons?

Answer 14

 Antagonists at the muscarinic receptors that mediate striatal cholinergic excitation
 Acetylcholine -> Antagonistic effect on dopamine
 Main action in treatment of Parkinson’s disease is to reduce excessive striatal cholinergic activity

Question 15

Give two ADRs of anti-cholinergics

Answer 15

 CNS effects – Mild memory loss, acute confusional states

 Dry mouth and blurred vision (less common)

Question 16

What does amantadine do?

Answer 16

 Stimulates neuronal dopamine release and inhibition of its reuptake
 Additional muscarinic blocking actions

Question 17

Give three ADRs of amantadine?

Answer 17

 Anorexia
 Nausea
 Hallucinations

Question 18

What is the treatment in myasthenia gravis?

Answer 18

Acetylcholinesterase inhibitors

Question 19

CRANIAL NERVES What do acetylcholinesterase inhibitors do?

Answer 19

Prevent breakdown of Ach in synaptic cleft

Question 20

What is the major ADR of acetylcholinesterase inhibitors

Answer 20

Muscarinic side-effects

SSLUDGE syndrome

Question 21

What is another treatment for myasthenia gravis?

Answer 21

Plasmaphoresis

Removes AchR antibodies and gives short term improvement

Question 22

What drug should not be given in Myasthenia gravis?

Answer 22

ACE inhibitor

• Myasthenic crisis
• Cholinergic crisis

Question 23

What is SSLUDGE syndrome?

Answer 23

Salivation 
Sweating
Lacrimation
Urinary incontinence 
Diarrhoea
GI upset 
Emesis

Question 24

What is the mechanism of action for lamotrigine?

Answer 24

 Prolongs VGSC inactivation state

Question 25

Give some DDIs for lamotrigine

Answer 25

 Adjunct therapy with other anti-epileptic drugs
 Oral Contraceptives reduce Lamotrigine plasma levels
 Valproate increases Lamotrigine plasma levels (protein binding)

Question 26

Give some ADRs for lamotrigine

Answer 26

Dizziness, ataxia, drowsiness

Question 27

What is the mechanism of action of sodium valproate?

Answer 27

 Weak inhibition of GABA inactivation enzymes   GABAA
 Weak stimulus of GABA synthesising enzymes   GABA A
 Weak VGSC blocker and Weak Ca2+ channel blocker   Discharge

Question 28

Give three ADRs for sodium valproate

Answer 28

Ataxia, tremor, weight gain

Question 29

What is a big DDI for sodium valproate?

Answer 29

Displaces other AED (lamotrigine and phenytoin), increasing concentration

Question 30

When is carbamezapine used?

Answer 30

Status epilepticus/second line in others

Question 31

What is mech of action of carbamezapine?

Answer 31

Voltage gated sodium channel blocker

Question 32

Give a couple of adverse drug reactions of carbamezapine?

Answer 32

Dizziness, drowsiness

Hyponatraemia

Question 33

What is the major cause of DDIs in carbamezapine treatment?

Answer 33

CYP450 Enzyme inducer

PCBRAS

Question 34

Why should phenytoin dose be carefully monitered?

Answer 34

Non-linear, can reach toxic doses quickly

Question 35

What can cause horner’s syndrome?

Answer 35

Apical Lung Tumour

Lower brachial plexus injury