Lecture 26

Question 1

L-Dopa

Answer 1

Decrease in dopamine neurons= decrease in dopamine = decrease in post-synaptic pathways. You cannot give a patient dopamine as it cannot cross BBB but, L-Dopa can. L-dopa is precursor and taken up by dopamine neurons in the brain by a.a transporter. Once there, it becomes dopamine through dopa decarboxylase where it is stored and released when needed. Most effective treatment, manages motor symptoms temporarily. Doesn’t stop progression.

Question 2

AADC inhibitor

Answer 2

regulates rate that L dopa becomes dopamine in periphery to increase [L-Dopa] in CNS. AADC doesn’t cross BBB

Question 3

COMPT inhibitor

Answer 3

also decreases peripheral metabolism of L-DOPA, this time acting on different pathway (can be taken with AADC)

Question 4

Dopamine receptor agonists

Answer 4

directly stimulate post-synaptic dopamine receptors. Alone for mild symptoms or with L-Dopa. Not suitable for people with cognitive disorders as it increases impulsive disorders.

Question 5

MAOB inhibitors

Answer 5

slow central metabolism of L-Dopa in synaptic cleft allowing it to stay in synaptic cleft for longer, increasing likelihood of interaction with postsynaptic dopamine recepors.

Question 6

Adjustment to L-Dopa

Answer 6

When patients first start L-Dopa, can feel nausea, postural hypotension but body adapts to it. Can lead to dyskinesia from chronic administration therefore, combination of drugs. As dopamine neurons die = decrease efficacy of L-Dopa.

Question 7

Anticholinergics

Answer 7

Drugs that antagonise muscarinic receptors on post-synaptic neurons dampening their activity in the striatum. Interneurons become overactive in PD as they lose normal inhibition by dopamine. Reliable.

Question 8

Deep brain stimulations

Answer 8

Surgical where permanent electrical stimulator implanted in subthalamic nuclei to decrease AP in area. Increase in motor symptoms esp. tremors. But, it is not a cure and benefits may be transient. Not suitable for all patients. For young and well (no comorbidities).

Question 9

Patient-carer engagement

Answer 9

Exercise: stimulates dopamine release

nutrition/sleep

education: understand disease and burden

Recognition: seek motor and non-motor symptom support

controlling comorbidities.