FN: Parkinsons Disease Flashcards
Epidemiology
Mean onset 65yrs
2% prevalence
Pathophysiology
Destruction of dopaminergic neurones in pars compacta
of substantia nigra.
β-amyloid plaques
Neurofibrillary tangles: hyperphosphorlated tau
Features: TRAPPS PD
Asymmetric onset: side of onset remains worst
Tremor: ↑ by stress, ↓ by sleep
Rigidity: lead-pipe, cog-wheel
Akinesia: slow initiation, difficulty ̄c repetitive movement,
micrographia, monotonous voice, mask-like face
Postural instability: stooped gait ̄c festination
Postural hypotension: + other autonomic dysfunction
Sleep disorders: insomnia, EDS, OSA, RBD
Psychosis: esp. visual hallucinations
Depression / Dementia / Drug SEs
Sleep Disorder
Affects ~90% of PD pts. Insomnia + frequent waking → EDS Inability to turn Restless legs Early morning dystonia (drugs wearing off) Nocturia OSA REM Behavioural sleep Disorder Loss of muscle atonia during REM sleep Violent enactment of dreams Da SEs: insomnia, drowsiness, EDS
Autonomic Dysfunction
Combined effects of drugs and neurodegeneration
Postural hypotension
Constipation
Hypersalivation → dribbling (↓ ability to swallow saliva)
Urgency, frequency, Nocturia
ED
Hyperhidrosis
L-DOPA SEs: DOPAMINE
Dyskinesia On-Off phenomena = Motor fluctuations Psychosis ABP↓ Mouth dryness Insomnia N/V EDS (excessive daytime sleepiness)
Motor Fluctuations
End-of-dose: deterioration as dose wears off ̄c
progressively shorter benefit.
On-Off effect: unpredictable fluctuations in motor
performance unrelated to timing of dose.
Ix
DaTSCAN
Mx
MDT: neurologist, PD nurse, physio, OT, social worker, GP and carers
Assess disability
e.g. UPDRS: Unified Parkinson’s Disease Rating Scale
Physiotherapy: postural exercises Depression screening
Mx for young onset ± biologically fit
Young onset ± biologically fit
- Da agonists: ropinirole, pramipexole
- MOA-B inhibitors: rasagiline, selegiline 3. L-DOPA: co-careldopa or co-beneldopa
Biologically frail ± comorbidities Mx
- L-DOPA
2. MOA-B inhibitors
Other therapies
COMT inhibitor Apomorphine Amantiine Atypical antipyschotices SSRIs
COMt inhibitor
tolcapone, entacapone
Lessen end-of-dose effect
Apomorphine:
potent Da agonist
SC rescue pen for sudden “off” freezing
Amantidine:
weak Da agonist
Rx of drug-induced dyskinesias
