pathophysiology of Parkinson’s disease
- dopamine deficiency in substantia nigra
- Lewy bodies found in dopaminergic cells which die
- Lewy bodies have α-synuclein
- this destruction disturbs the motor balance of basal ganglia
general symptoms/signs of Parkinson’s disease
TRAPPS PD Tremor Rigidity Akinesia Postural instability Postural hypotension Sleep disorders Psychosis Depression/Dementia/Drug side effects
features of Parkinson’s Disease tremor
↑ by stress, ↓ by sleep
features of Parkinson’s Disease rigidity
lead-pipe
cog-wheel
features of Parkinson’s Disease akinesia
slow initiation, difficulty with repetitive movement,
micrographia,
monotonous voice,
mask-like face
features of Parkinson’s Disease postural instability
stooped gait with festination
features of Parkinson’s Disease postural hypotension
+ other autonomic dysfunction
features of Parkinson’s Disease sleep disorders
affects 90% of PD pts.
insomniaexcessive daytime sleepiness (due to insomnia +frequent waking)
obstructive sleep apnoea
REM sleep behaviour disorder (loss of muscle atonia during REM sleep, violent enactment of dreams)
features of Parkinson’s Disease psychosis
visual hallucinations
features of Parkinson’s Disease autonomic dysfunction
- Combined effects of drugs and neurodegeneration
- Postural hypotension
- Constipation
- Hypersalivation → dribbling (↓ ability to swallow saliva)
- Urgency, frequency, Nocturia- Erectile dysfunction
- Hyperhidrosis
acronym for side effects of L-DOPA
DOPAMINE
- Dyskinesia
- On-Off phenomena = Motor fluctuations
- Psychosis
- ABP↓
- Mouth dryness
- Insomnia
- N/V
- EDS (excessive daytime sleepiness)
investigations for Parkinson’s disease
DaTSCAN
general management of Parkinson’s disease
- 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
medical management of Parkinson’s disease in young onset + biologically fit
- Da agonists: ropinirole, pramipexole
- MAO-B inhibitors: rasagiline, selegiline
- L-DOPA: co-careldopa or co-beneldopa
medical management of Parkinson’s disease in biologically frail + comorbidities
- L-DOPA2.
2. MOA-B inhibitors
other drug therapies for Parkinson’s disease
- COMT inhibitor
- Apomorphine
- Amantidine
- Atypical antipsychotics
- SSRIs:
surgical management of Parkinson’s disease
- interrupt basal ganglia
- deep brain stimulation
Examples of COMT inhibitors
tolcapone, entacapone
Use of apomorphone
- potent Da agonist
- SC rescue pen for sudden “off” freezing
Use of amantidine
- weak Da agonist
- Rx of drug-induced dyskinesias
Use of quetiapine
atypical antipsychotic
Rx of PD induced psychosis
SSRIs use in PD
citalopram, sertraline
- Rx PD induced Depression
DatScan use
PD is a clinical dx
But differentiating between dystonia and Essential tremor is done using DatScan
Which drug is given with L-dopa and why
dopa-decarboxylase (DDC) to prevent peripheral conversion of to dopamine
