Medical Management of PD Flashcards
Medical Management Strategies for PD
Replace Dopamine
Block Acetylcholine
Dopamine Replacement Therapy
Sinemet: L-Dopa/Carbidopa
Amantadine
Dopamine agonists
Enzyme inhibitors
Anticholinergics and what does it affect
Block Ach
Effective for tremor only
S/E: confusion, ↓ memory, halluncinations, dry mouth, constipation, urinary retention, orthostasis
What do we have to be aware of with dopamine medication and working with our pts
their on and off times - they can make a chart
Dopamine is given with
carbidopa
Inhibits the release of L-Dopa in the peripheral tissue and ↑ its release into the brain
↓ the total amount of L-Dopa needed, cutting down on side effects
The combination is called Sinemet
Sinemet function
Limits bradykinesia, rigidity & tremor
Does not treat motor planning deficits, postural instability, or non-motor sx
Over time therapeutic window gets smaller and toxic window gets bigger
S/E: Dyskinesia, dystonia, on/off motor fluctuations
50-60% of pts on L-Dopa will have motor complications w/in 5 years
Dopamine agonists
Bromocriptine (Parlodel) and Pergolide (Permax)
When Dopamine agonists are added to Sinemet
it can ↓ clinical fluctuations
Dopaminergic Drugs work by
Boosting output of remaining substantia nigra cells
Neuroprotective Drugs:
MAOs
PD
MAOs work by
Monoamine Oxidase Inhibitors (MAOs)
Neuronal degradation can be controlled w/ anti-oxidants which control the synthesis & elimination of free radicals
Free radicals damage cells by stealing an electron from another cell to stabilize itself, thereby damaging the other cells
Hypothesis:
In PD, there is ↑ production or ↓ defense against free radicals in the SN, accelerating cell death
Selegiline (Eldepryl) is a type of and does
MAO
Inhibits the enzyme that breaks down dopamine
Limits free radical production during dopamine metabolism
May rescue damaged but viable dopaminergic neurons
Early use may ↓ the need for Sinemet early in the course of the disease
Anticholinergic Drugs work by, and drug ex
Improves sx of PD by restoring the balance of acetylcholine and dopamine
Parsidol, Cogentin, Akinetin, Artane
Used less frequently than others
More useful early in the disease when tremor is the most prominent problem
4 types of anticholinergic drugs
Parsidol, Cogentin, Akinetin, Artane
Amantadine is what type of drug and what does it do
Has dopaminergic and anticholinergic properties
Stimulates the release of dopamine from surviving presynaptic terminals in the striatum
Affects rigidity and bradykinesia, but not tremor
(for movement dependent)
Problems with Medical Management: Sinemet can cause
Dyskinesia Orthostatic hypotension Behavioral signs Confusion Hallucinations Paranoia Psychosis
Problems with Medical Management: On/Off phenomenon
Short duration therapeutic response followed by rapid decline in symptomatic relief
Due in fact that PD medications are toxic to the receptor site
Grows more dramatic over time
“On” time becomes shorter, with “off” time having dyskinesia or severe bradykinesia
“Narrowing therapeutic window”
“Wearing Off” Phenomenon
PT attempted ideally during “on” times
Do all patients respond to Sinemet
Not all patients respond to Sinemet
1/3 respond for a lifetime
1/3 for 3-5 years
1/3 for 5-7 years
What can help treat Hypertonia
Botox injections
Have been used in cases where the PD & dystonia have led to severe equinovarus or claw deformities
Effects are temporary!
What is done if the medications are not very effective
Surgical Approaches
- Ventrolateral thalamotomy
- Pallidotomy
- Intracranial Electrical Stimulation
What is a Ventrolateral thalamotomy
Ventrolateral thalamotomy
Used for patients that have severe unilateral tremor which is refractory to medical treatment
(B) thalamotomy has been tried for patients with (B) tremor, but this resulted in severe speech deficits
What is a Pallidotomy
Scarring of the globus pallidus
Has been useful against bradykinesia and tremor
Intracranial Electrical Stimulation is
Experimental use of low level stimulators with promising results
More and more positive results are being published about Deep Brain Stimulation (DBS)
What is Deep Brain Stimulation
Surgical placement of electrode into brain regions that control movement
Allows electrical stimulation to the area of altered brain activity
Normalizes pattern of electrical activity w/in specific brain motor circuits
Specific brain sites chose for specific problems
DBS on one side of brain mainly affects symptoms on the opposite side of the body – can have bilateral DBS if sx on both sides
