Parkinson's disease (N) Flashcards
(45 cards)
Define Parkinson’s disease.
Degeneration of dopaminergic neurons in basal ganglia, from substantia nigra to striatum
What is the pathophysiology of Parkinson’s disease?
Degeneration of dopaminergic neurons from substantia nigra to striatum, due to mitochondrial DNA dysfunction
What demographics is Parkinson’s disease more common in? (2)
- M>F
- mean age of onset: 65y
What is parkinsonism (Parkinson’s disease)?
Triad of resting tremor, hypertonia and bradykinesia + additional clinical features
What are some different causes of parkinsonism?
- drug-induced (typically bilateral)
- Lewy-Body dementia
- progressive supranuclear palsy (Steel-Richardson)
- multisystem atrophy
What are some drug-induced causes of parkinsonism? (2)
- antipsychotics e.g. haloperidol
- metoclopramide
How do we manage tremor in drug-induced parkinsonism?
Procyclidine
What are the symptoms of Lewy-Body dementia (parkinsonism)? (3)
- memory loss
- visual hallucinations
- parkinsonism
What are the symptoms of progressive supranuclear palsy (Steel-Richardson)? (5)
- postural instability (falls)
- impaired vertical gaze AKA vertical gaze palsy (difficulty reading or descending stairs)
- cognitive impairment
- parkinsonism
- poor response to levodopa
What are the symptoms of multisystem atrophy (parkinsonism)?
Autonomic features like postural hypotension, incontinence and impotence
Poor response to levodopa
What conditions showing parkinsonism have poor response to levodopa?
Progressive supranuclear palsy (Steel-Richardson syndrome) & multisystem atrophy
What is sporadic/idiopathic Parkinson’s disease?
Most common, unknown aetiology, may be related to environmental toxins or oxidative stress
What can cause secondary Parkinson’s disease? (6)
- neuroleptic therapy (e.g. for schizophrenia)
- vascular insults (e.g. in basal ganglia)
- MPTP toxin from illicit drug contamination
- repeated head injury
- manganese or copper toxicity (Wilson’s disease)
- HIV
What are main clinical features of Parkinson’s disease? (4)
- bradykinesia - slowness of movements, shuffling gait, slow-turning
- resting tremor
- rigidity - lead pipe, cogwheel
- postural instability - imbalance or falling, festination and shuffling gait
Describe the resting tremor in Parkinson’s disease. (4)
- asymmetrical onset
- improves with voluntary movement
- typically ‘pill-rolling’ (thumb and index finger)
- 4-6Hz
Describe the rigidity seen in Parkinson’s disease.
- lead pipe rigidity of muscle tone
- superimposed tremor –> cogwheel rigidity
- rigidity enhanced by distraction
Describe gait in Parkinson’s disease. (5)
- shuffling
- stooped
- small-stepped
- reduced arm swing
- difficulty initiating walking
What are some other symptoms of Parkinson’s disease? (6)
- fatigue
- constipation
- depression
- anxiety
- insomnia
- hypomimia (reduced facial expressions)
Why can Parkinson’s disease lead to postural hypotension?
Due to autonomic failure
What are some risk factors for Parkinson’s disease? (5)
- increasing age
- Hx familial Parkinson’s disease in younger-onset disease
- mutation in gene encoding glucocerebrosidase
- MPTP exposure
- drug-induced (antipsychotics, metoclopramide)
How is a diagnosis of Parkinson’s disease primarily made?
Clinical diagnosis - Hx alongside presenting features
Revised Unified Parkinson’s Disease Rating Scale (MDS-UPDRS)
What are some investigations that can be done for Parkinson’s disease? (3)
- dopaminergic agent (levodopa) trial - improvement in Sx
- single photon emission computed tomography (SPECT)
- dopamine transporter scintigraphy - reduction in striatum and putamen
What are some differential diagnoses for Parkinson’s disease? (8)
- essential tremor (asymmetry, bradykinesia and rigidity uncommon)
- normal pressure hydrocephalus
- parkinsonism
- drug-induced parkinsonism
- Lewy-body dementia
- progressive supranuclear palsy (Steel-Richardson)
- multisystem atrophy
- Alzheimer’s disease with parkinsonism
What feature is not common in Parkinson’s disease?
Diplopia not common in Parkinson’s disease and may suggest an alternative cause of parkinsonism e.g. progressive supranuclear palsy