Lec 34 Parkinsons Flashcards
What are the 4 cardinal motor signs of parkinsons?
- bradykinesia [slowness]
- tremor
- rigidity
- postural instability
–> must have brady + at least one of the other 3 to make diagnosis
parkinsons TRAPS your body = Tremor [at rest] [cogwheel] Rigidity Akinesia [or bradykinesia], Postural instability Shuffling gate
What are the 4 premotor signs of parkinsons?
- hyposmia
- constipation
- anxiety/depression
- REM sleep behavior disorder
How does parkinsons usually present?
- unilateral onset with persistent asymmetry [good and bad side]
- rest tremor [as opposed to postural or kinetic]
- excellent response to levodopa for > 5 yrs –> later development levodopa-induced dyskinesias
- clinical course >= 10 yrs
What is dementia with lewy bodies?
- disease looks like parkinsons
- presents with: visual hallucination, significant cognitive impairment, confusion, motor features of parkinsons: shuffling gait, stiff movement
How do you distinguish parkinson’s from other diseases?
must demonstrate response to L-Dopa
What are signs of bradykinesia?
- slowed rapid alternating movements
- dragging/shuffling gate
- small handwriting that trails off
- decreased facial movement
- difficulty swallowing
What are signs of postural instability?
- loss of postural reflexes
- pull test > 2 steps
- does not respond to L Dopa
What is the pathophysiology of parkinsons?
- loss of dopamine [DA] neurons in the substantia nigra pars compacta
- causes overactive indirect pathway [subthalamic nuclei, substantia nigra reticulata, and globus pallidus]
- causes decreased excitatory input from thalamus to cortex
- associated with Lewy bodies [of alpha synuclein]
What are some presentations that might make you think its in atypical parkinsons-like disease rather than true Parkinsons?
- postural instability early in presentation of disease [PSP]
- early dementia [lewy body disease]
- early failure of vertical gaze
- early autonomic dysfunction
- cerebellar or brainstem atrophy
- lack of resting tremor
If you suspect parkinsons what else should you consider?
- stroke, tumor in basal ganglia
- normal pressure hydrocephalus
- toxins, drugs
- wilsons disease
What is multiple system atrophy?
- disease that looks a lot like parkinsons
3 types
- MSA-P = parkinsonian MSA due to striatal nigral degeneration
- MSA-C = cerebellar MSA due to olivopontocerebellar atrophy
- MSA-A = autonomic MSA = shy-drager syndrome
signs:
- early autonomic dysfunction
- symetrical parkinsonism with more rapid progression
may respond to Ldopa
What is progressive supranuclear palsy [PSP]?
- parkinsons-like disease
- called the “toppling disease”
- have early postural instability with falls
- symmetric onset parkinsonian symptoms, axial rigidiy without tremor
- supranuclear gaze plasy, square wave jerkcs
- no response to Ldopa
What is coritcobasal syndrome?
- like PSP
- rapid progression parkinsonism without tremor
- cortical involvement: agraphesthesia [problems writing], aphasia
- early subcortical dementia
What are secondary parkinsonisms?
- tremor/bradykinesia/gate disorders
- can be due to any pharma derangement of dopamine system or structural lesion of substantia nigra
What are lewy bodies?
- eosinophilic inclusion in neuron
- made of alpha synuclein
- hallmark of PD as well as lewy body dementia and some others
- classic site = found in substantia nigra
What is L-dopa?
- prodrug of dopamine
- crosses BBB
- greatest efficacy + fewest side effects of any antiparkinson drug
- causes dyskinesia
What is carbidopa?
- peripheral dopa-decarboxylase inhibitor
- does not cross BBB
- administered with levodopa to inhibit peripheral conversion of levodopa and minimize side effects [N/V]
What are characteristics of dopamine agonists? examples?
- less effective than L-dopa for treating parkinsons
- do not cause dyskinesias
- side effects: sleep attacks, impulse control disorders
ex. pramipexole, ropinirole, apomorphine
What are characteristics of amantadine?
- anti-viral drug
- has mild dopamine agonist properties
- helpful in treating tremor
- used to treat ldopa-induced dyskinesias
- side effects: constipation, leg edema, hallucinatons
What are MAO inhibitors? examples?
- inhibit monamine oxidase that metabolizes dopamine
- can be used alone in early disease or later as adjunctive with L-dopa
ex. selegiline, rasagiline
What are COMT inhibitors? example?
- inhibit catechol-o-methyl transferase [COMT] that breaks down dopamine
- administered with Ldopa to prolong its effects
- ex. entacapone
What is mech of anticholinergics in parkinsons? example?
- help treat tremor and dystonia in PD
- have significant side effects, poorly tolerated in elderly
- ex. trihexyphenidyl
How is botulinum toxin used to treat parkinsons?
- prevents release of vesicles of ACh and other NT
- give IM injections to relieve dystonia [involuntary movement]
- inject into parotid/submandular saliva glands to improve sialorrhea [drooling]
What is deep brain stimulation?
- place pacemaker in subthalamic nuclei [STN] or globus pallidus
- improve tremor, dyskinesias, wearing off of meds
- don’t give to pts with significant cognitive impairment or poor response to levodopa
