Term
| What is decreased in Parkinson's? |
|
Definition
| dopaminergic neurons in the substantia nigra |
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|
Term
| Describe the disrupted flow of info through the basal ganglia in Parkinson's. |
|
Definition
The direct pathway is inhibited
The indirect pathway is activated
Result - decreased movement |
|
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Term
| What are the broad types of treatments for Parkinson's? |
|
Definition
1. Drugs that increase dopamine levels
2. Drugs that are dopamine receptor agonists
3. Acetylcholine receptor antagonists |
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Term
|
Definition
| a biosynthetic precursor to dopamine |
|
|
Term
| L-dopa (can/cannot) cross the BBB. |
|
Definition
|
|
Term
| What converts L-dopa into dopamine? |
|
Definition
| l-amino acid decarboxylase (LAAD) |
|
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Term
| What are some adverse effects of L-dopa? |
|
Definition
nausea
orthostatic hypotension
cardiac arrythmias
(due to increased catecholamines in peripheral tissues) |
|
|
Term
|
Definition
- an analog of l-dopa
- it inhibits LAAD from converting l-dopa to dopamine
- |
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|
Term
| Peripherally administered dopamine (can/cannot) cross the BBB. |
|
Definition
|
|
Term
|
Definition
It is a COMT inhibitor.
It prevents the conversion of L-dopa to 3-OMD, which competes with l-dopa to cross the BBB |
|
|
Term
| What are the longterm effects of L-dopa? |
|
Definition
dyskinesia & involuntary movements
psychotic effects |
|
|
Term
| Why do dopamine receptors cause nausea and vomiting? |
|
Definition
| Because they stimulate dopamine receptors in the vomiting centre of the medulla. |
|
|
Term
| What are two types of MOA-B inhibitors? |
|
Definition
| Selegiline and rasagiline |
|
|
Term
| MOA-B inhibitors inhibit the oxidation of dopamine into ____ |
|
Definition
dihydroxyphenlacetic acid
DOPAC |
|
|
Term
| Who is selegiline best suited for? |
|
Definition
| young patients or those with mild parkinson's disease |
|
|
Term
| What does selegiline get metabolized into? |
|
Definition
amphetmine and methamphetamine
which cause anxiety and insomnia |
|
|
Term
| What would happen if you administered a non-selective MOA inhibitor while a patient was taking L-dopa? |
|
Definition
| They may have a life-threatening hypertensive crisis |
|
|
Term
| What is neuroleptic malignant syndrome? |
|
Definition
A potentially life-threatening condition characterized by rigidity, confusion and hyperthermia
it is caused if there's abrupt withdrawal of l-dopa or other dopaminergic meds. |
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Term
| What are some peripheral adverse effects of antimuscarinics? |
|
Definition
dry mouth
urinary retention
constipation
blurred vision |
|
|
Term
|
Definition
increased tone, DTR & clonus
velocity dependent
asymmetric about the joints |
|
|
Term
| Describe the monosynaptic muscle stretch reflex arc |
|
Definition
1. Muscle spindle is stimulated
2. Ia afferents synapse on motor neurons
3. they synapse on UMN which projects to the muscle causing it to contract |
|
|
Term
| How are spinal reflexes suppressed? |
|
Definition
| pyramidal UMN from the cortex suppress spinal reflexes by activating inhibitory interneurons in the spinal cord |
|
|
Term
| How does spasticity occur? |
|
Definition
| damage to UMN that inhibit the reflex --> hyperreflexia |
|
|
Term
| Baclofen - type, action, what it treats, effects |
|
Definition
GABAb agonist
Increases spinal inhibition of motor neurone
CP, MS, Stroke
Sedation and weakness |
|
|
Term
| Tizanidine - type, action, what it treats, side effects |
|
Definition
alpha 2 adrenoreceptor agonist
increases inhibition of spinal cord motor neurone
MS, ALS, stroke
sedation, weakness and hypotension |
|
|
Term
| Dantrolene - type, action, what it's used for, side effects |
|
Definition
RyR1 Ca2+ channel antagonists in the sarcoplasmic reticulum of skeletal muscles
Reduces actin-myosin interaction, weakens skeletal msucl contraction
used for drug induced hyperthermia + CP, spinal cord injury and MS
side effect: weakness |
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