OnlineMedEd: Neurology - Tremor Flashcards
Parkinson’s is caused by loss of neurons in the _______________.
substantia nigra
D2 receptors are inhibitory or excitatory?
Inhibitory (“inhibiTWOry”)
Explain how acetylcholine receptors are the “brakes”.
Acetylcholine receptors stimulate the GABAergic neurons that inhibit the thalamus.
Thus, giving anticholinergics to a person with hypokinesia releases the brakes and promotes movement.
_____________ converts dopamine to DOPA-C.
MAO-B
List the four cardinal signs and symptoms of Parkinson’s.
- Bradykinesia
- Resting tremor
- Cogwheel rigidity
- Gait and postural instability
Even though MRIs can show degeneration of the substantia nigra, ____________ should not be used to diagnose Parkinson’s.
imaging
Benztropine should only be used in _________________.
young patients with mild disease (basically just the resting tremor)
Why does carbidopa not inhibit the conversion of levodopa in the brain?
Carbidopa cannot pass the blood-brain barrier.
Go through the algorithm for choosing Parkinson’s drugs.
- Is the patient functional and younger than 70? Choose dopamine agonists like ropinirole or pramipexole.
- Is the patient nonfunctional and older than 70? Choose levodopa/carbidopa.
Only add adjuncts like selegiline, tolcapone, or entacapone when levodopa/carbidopa fail.
What demographic has the most incidence of essential tremor?
Middle-aged men
Describe the pattern of essential tremor.
- Not present at rest
- Occurs with intentional movement
- Worsens with difficult poses
How are essential tremors different from intention tremors?
Essential tremors are constant throughout a movement, while intention tremors worsen as the movement progresses.
Think of the nose-to-finger test: an ET will be the same throughout, while an IT will get worse as the person gets closer to the finger.
How are intention tremors treated?
Nothing helps because they are due to cerebellar destruction.
How might you hear chorea described?
“Purposeless ballistic movements”
