Parkinson's Disease Flashcards
Define Parkinson’s disease
Neurodegenerative disease due to a severe loss in dopaminergic neurones in the substantia nigra
Define Parkinsonism
symptoms of Parkinson’s either in other diseases (Lewy body dementia) or as S/E of medication (DA antagonist)
What is Parkinson plus syndrome
Group of neurodegenerative diseases with Parkinsonism and additional features (not in idiopathic PD)
MSA - multiple system atrophy (Parkinson’s + autonomic systemic changes)
CBD - cortical bulbar degeneration (Parkinson’s + they believe to have an additional moving limb)
PSP - progressive supranucleic palsy (Parkinson’s + supranuclear gait palsy - impaired gaze, balance, dysarthria) - ophthalmoplegia
What is the aetiology of Parkinson’s disease
Usually idiopathic
Substantia nigra degeneration → dopamine deficiency in striatum → motor symptoms
Considered sporadic, although there are rare autosomal dominant and recessive forms
Genetic variants: SNCA, Parkin, PINK-1, DJ-1, TERM2, MHFTR, LRRK2
What are the risk factors for Parkinson’s disease
Increasing age
Male sex
History diet of familial PD in younger-onset disease
Mutation in gene encoding glucocerebrosidase
MPTP exposure
Chronic exposure to metals (manganese, iron)
Additional genetic risk factors
Head trauma
Geographic influence
Toxin exposure e.g. insecticides
Occupation as teacher, healthcare provider, construction worker, carpenter or cleaner
What are the symptoms of Parkinson’s disease
Cardinal symptoms:
→ Resting tremor (4-6Hz)
→ Rigidity (“Lead pipe”)
→ Bradykinesia
→ Postural instability
Other:
Masked facies/hypomimic face
Hypophonia
Hypokinetic dysarthria
Micrographia
Shuffling gait
Stooped posture
Conjugated gaze disorder
Fatigue
Constipation
Depression, anxiety
Dementia
REM sleep disorder: very active in sleep, vivid dreams
What is the UK PDS Brain Bank Criteria for PD
- Bradykinesia + one other cardinal symptom
- Exclusion criteria e.g. repeated strokes/head injury, antipsychotic use, encephalitis, more than one affected relative, neurological features
- supportive criteria (3 or more) e.g. unilateral, excellent response to levodopa, resting tremor
What are the signs of Parkinson’s disease on examination
Cogwheel rigidity
Shuffling gait, especially when turning a corner
Reduced arm swing
“Pill rolling” tremor
Masked facies (hypomimic face) - look at blinking
Hypophonia (reduced volume of voice)
Hypokinetic dysarthria
Micrographia
Stooped posture
Conjugated gaze disorder
What investigations should be done for Parkinson’s disease
Clinical diagnosis
+ dopaminergic agent trial
MRI brain:
- Normal in most patients
- Age-related changes e.g. small vessel disease acceptable
- Advanced disease - cortical atrophy, dorsolateral nigra hyperintensity
PET: Reduced basal ganglia pre-synaptic dopamine uptake
What is the management for Parkinson’s disease
Bio
First line: levodopa + carbidopa (DOPA-decarboxylase inhibitor)
Dyskinesia/motor fluctuations → dopamine agonists, MAO-B inhibitors or COMT inhibitors as an adjunct
Hallucinations: (1) review medication (2) quetiapine (3) clozapine
Dementia: cholinesterase inhibitors
Drooling: (1) SALT (2) glycopyrronium bromide (3) botulinum toxin A
Advanced disease: Deep brain stimulation: intermittent apomorphine injection and/or continuous SC apomorphine infusion
Social
Physiotherapy referral: assessment, education, advice
Alexander technique for balance or motor function problems
Occupational therapy
SALT (communications, swallowing, saliva)
Dietician referral
What are the side effects of levodopa
Increase risk of impulse control disorders: compulsive gambling, hypersexuality, binge eating, shopping
Nausea
Orthostatic hypotension
Excessive sleepiness → Consider modafinil to treat excessive daytime sleepiness
Hallucinations
Dyskinesias
Restless leg syndrome → consider clonazepam or melatonin
REM sleep disorder → consider clonazepam or melatonin
Nocturnal akinesia → consider levodopa or oral dopamine agonists
