Exam #02 - Parkinson's Disease Flashcards
Name the region of the brain containing (4) substructures (striatum, globus pallidus, subthalamic nucleus, and substantia nigra)
Basal ganglia
This condition is characterized by the inability to initiate movement even though patient is cognitive and really does want to move?
Akinesia
This condition is characterized by involuntary movements that patient is unable to control? This is typically a result of long term use of what drug?
Dyskinesia
from long term use of Levodopa
PD is a neurologic disorder of muscle movements characterized by what (4) conditions?
- tremor
- muscle rigidity or stiffness of limbs and trunk
- bradykinesia/akinesia
- postural and gait abnormalities & impaired balance
DA (via D2 receptors) causes inhibition of movement. PD is characterized by loss of dopaminergic neurons so there is less DA which means there is less activation of direct pathway and less inhibition of indirect pathway resulting in decreased movement (hypokinesia)
Loss of dopaminergic neurons in what part of the brain is the primary cause of PD symptoms?
Loss of dopaminergic neurons in the substantia nigra pars compacta (SNc) – in the basal ganglia
All of the following are known to cause loss of dopaminergic neurons and contribute towards developing PD, except:
A. MPTP B. Rotenone & Paraquat C. Mn2+ D. Genetic mutations E. All of the above contribute towards developing PD
(E)
All contribute to developing PD
MPTP is a contaminate in synthetic heroin and Rotenone & Paraquat are pesticides
True or False - genetic mutations in proteins can lead to mitochondrial dysfunction, oxidative stress, and abnormal degradation of misfolded proteins that all result in neurodegeneration
True - and neurodegeneration leads to PD
True or False - PD is a progressive disease and by the time symptoms are observed, 70-80% of dopaminergic neurons have been lost
True
All of the following are true regarding basal ganglia cicuitry, except:
A. In an individual with normal dopamineurgic neurons, dopamine activates the direct pathway (via D1 receptors) and inhibits indirect pathway (via D2 receptors)
B. Activating the direct pathway increases excitatory thalamic input to cortex
C. Inhibiting the indirect pathway decreases excitatory thalamic input to cortex
D. A patient with PD will have less activation of direct pathway and more inhibition of indirect pathway
E. All of the above are true
(D)
Patients with PD will have a loss of dopamine leading to less activation of direct pathway and LESS inhibition of indirect pathway which results in decrease in movement (bradykinesia)
The indirect pathway is all about STOPPING movement. If there is less inhibition of this pathway, there will be a STRONGER signal for stopping movement.
Name (4) MOA used in the pharmacological treatment of PD to restore dopaminergic function and the class of drugs used in each?
- increase DA synthesis - Levodopa
- increase activity at DA receptors - DA agonists
- inhibit DA metabolism - MAO-B inhibitors & COMT inhibitors
- restore balance of DA and ACh - anticholinergics
All of the following about Levodopa are true, except:
A. Carbidopa increases the amount of Levodopa available for conversion in the brain
B. Effectiveness decreases with long term treatment
C. Carbidopa is able to cross the BBB
D. In the brain, Levodopa is converted to DA by DOPA decarboxylase (DDC) enzyme
E. All the above are true
(C)
Carbidopa exhibits its effects of preventing conversion of Levodopa to DA in the peripheral nervous system. It CANNOT cross the BBB.
All of the following statements is/are true, except:
A. Nausea, emesis, postural hypotension, mood changes, and sleep disturbances are all common AE of Levodopa
B. Development of dyskinesia is common with long-term Levodopa treatment of PD
C. Muscarinic antagonists are NOT effective for bradykinesia
D. Muscarinic antagonists can be used in advanced PD for tremor
E. Haloperidol is an effective treatment for Hungtington’s disease
(D)
Muscarinic antagonists (anti-cholinergics) can only be used in MILD PD to control tremor caused by excessive, unopposed ACh
Benztropine (Cogentin ®)
Trihexyphenidyl (Artane ®)
What are the (3) trade names for Carbidopa/L-DOPA combinations?
- Sinemet ®
- Sinemet CR ®
- Parcopa ®
All of the following are DA agonists, except:
A. Requip XL B. Pergolide C. Selegiline D. Only C E. Both B & C
(D)
Roprinirole (Requip ®, Requip XL®) and Pergolide are both DA agonists
Selegiline is MAO-B inhibitor
All of the following are correctly matched, except:
A. Bromocriptine - DA agonist B. Mirapex ER - DA agonist C. Tolcapone - COMT inhibitor D. Cogentin - anticholinergic E. All of the above are correct
(E) all are correctly matched
Bromocriptine - DA agonist
Pramipexole (Mirapex ER ®) - DA agonist
Tolcapone - COMT inhibitor
Benztropine (Cogentin ®) - anticholinergic