Parkinson's disease Flashcards
What?
Idiopathic syndrome of parkinsonism
Progressive neurodegenerative disorder
Caused by degeneration of dopaminergic neurons in substantia nigra
Other causes of parkinsonism
Drug-induced Progressive supranuclear palsy Multiple system atrophy Post-encephalitis Dementia pugilistica (secondary to chronic head trauma eg boxing) Toxins: carbon monoxide, MPTP
Drugs causing parkinsonism
Note: quicker onset and bilateral
Phenothiazines: e.g. chlorpromazine, prochlorperazine
Butyrophenones: haloperidol, droperidol
Metoclopramide
Epidemiology and risk factors
Mean age diagnosis 65 M>F Increasing age Pesticide exposure (???born in spring)
Cardinal triad
Tremor
Increased tone (cogwheel rigidity)
Bradykinesia/hypokinesia
Tremor characteristics
Worse at rest
Pill-rolling
Brought out with distractability
NOTE: Essential tremor = symptomatic postural and action tremor of arms and head
Bradykinesia characteristics
Slow to initiate movements
Slow, low amplitude excursions in repetetive actions (reduced blink rate, monotonous hypophonic speech, micrographia)
Gait: Reduced arm swing, festinance (shuffling, flexed trunk), freezing at obstacles/doors
Hypomimesis (expressionless face)
Presentation
Asymmetrical Bradykinesia plus one or more of: rest tremor, postural instability, rigidity Other: Poor decoding of emotional content of speech Poor executive function REM sleep disorders Reduced sense of smell Constipation Visual hallucinations Frequency/urgency Dribbling saliva Depression/dementia
Examination
Walk, including turn
Upper limb motor exam - ITPRC
Also: reduced amplitude, distraction for rigidity and tremor
Referral
Urgently, without treatment if PD suspected
Should be seen w/in 6 weeks if mild
Within 2 weeks if later disease/more complex problems
Investigations
Diagnosis is clinical. Investigations are to exclude other causes of parkinsonism
CT/MRI: if fail to respond to L-dopa for 12 weeks; MRI to exclude rare secondary causes (supratentorial tumours, normal pressure hydrocephalus) and extensive subcortical vascular pathology
DaTscan
Conservative management
MDT: parkinson’s specialist nurses, physiotherapist, OT, SALT
Refer early (before treatment)
Regular access to specialist care (every 6-12 months)
Good communication between primary and secondary care
Regular assessment of disability (patient self-reporting and objective rating of motor symptoms - Unified PD rating scale)
Consider common non-motor symptoms - sleep disturbance, cognition, depression, psychosis
Education
Nursing assessment
Carer support and involve carers as much as possible
Health and social care assessment
Patient should inform DVLA and insurers
Drug treatments
No universal first choice drug
Choice depends on balance of improving motor disability (better with levodopa) vs risk of motor complications (more common in younger people) and neuropsych complications (more common in older/cog impaired patients, more common with agonists)
Options: monoamineoxidase B inhibitors, dopamine receptor agonists, levodopa, amantidine or an anticholinergic
Dopamine agonists
Pramipexole, ropinirole, roitigotine
Recommended as initial treatment in younger patients - fewer dyskinesia and motor fluctuations than levodopa
Can be used in early disease
Less effective than levodopa - LD eventually required
Adverse effects (N+V) more common and severe than LD
Can be added to LD to improve motor flucations/reduce LD dose but increased dopaminergic AEs and dyskinesia
Non-ergot derived preferred (pramipexole and ropinirole)
Ergot-derived - NOT first line (fibrotic reactions) (bromocriptine, cabergoline, lisuride, pergolide) - must check renal function, ESR and CXR
SE: impulse control disorders, excessive daytime somnolence, hallucinations in older people, nasal congestion, N+V, postural hypotension
Levodopa
Given combined with dopa-decarboxylase inhibitor - prevents peripheral conversion to dopamine. Sinemet and madopar most common
Well tolerated, acute AEs rare and mild
Longer-term: motor complications (dyskinesias), “on-off” (dyskinesias to immobility in a few mins) effect, dry mouth, anorexia/weight loss, palpitations, postural hypotension, psychosis, drowsiness
Reduced effectiveness with time (2 years)
