14. Parkinson's Disease Flashcards
(28 cards)
What is the pathophysiology of Parkinson’s Disease?
Loss of pigmented dopaminergic neurons in the substantia nigra
What system is used to stage Parkinson’s Disease?
Braak staging
What parts of the brain does the substantia nigra project to?
Striatum: caudate and putamen
What are the causes of Parkinson’s disease?
Idiopathic
Toxins and drugs
Head trauma
Genetic
What are the cardinal symptoms of Parkinson’s disease?
Tremor
Bradykinesia
Rigidity
Postural instability
Describe the tremor present in Parkinson’s disease
Unilateral ‘pill rolling’
Rapid, present at rest
Increased with anxiety
What is bradykinesia?
Slowness of movement
Difficulty initiating tasks or carrying out sequential tasks
Reduced amplitude of movement eg. small handwriting
Rapid fatigue of repetitive movement
what are the features of rigidity seen in Parkinson’s?
Increased resistance of relaxed muscles to passive stretch: ‘clasp knife and pin wheel’
What are the signs of postural instability in Parkinson’s disease?
Shuffling gait with poor arm swing
Turning ‘en bloc’
Leaning forward
What are the other motor symptoms of Parkinson’s disease?
Painful involuntary muscle contractions (dystonia) Hypomimia (reduced facial expression) Drooling Hypophonia Freezing
What are the mental symptoms of Parkinson’s?
Depression
Lack of impulse control and visiospatial difficulty
Sleep disturbance, vivid dreams, hallucinations
What are the miscellaneous symptoms of Parkinson’s?
Orthostatic hypotension Anosmia Seborrhoeic dermatitis (fungal infection of the face) Urinary incontinence and constipation Weight loss, anhidrosis, sexual dysfunction
How is a diagnosis of Parkinson’s made?
Clinical
MRI to rule out infarcts, hydrocephalus and Wilson’s disease
What is the differential for Parkinson’s disease?
Essential tremor Vascular Parkinsonism Drug induced Parkinson plus syndromes Thyrotoxicosis
When should a parkinson plus syndrome be suspected?
Early signs of showing features of late stage parkinsonism: falls and dementia
Meds are ineffective
Name 3 parkinson plus syndromes
Multisystem atrophy
Progressive supranuclear palsy
Corticobulbar degeneration
Why is dopamine not given alone?
Causes vomiting and broken down by first pass metabolism
What is given with dopamine to reduce breakdown by the liver?
Decarboxylase inhibitor
What is the effect of a COMT inhibitor?
Slows down metabolism of dopamine in the brain
Name a COMT inhibitor
Entacopone
Name a dopamine agonist
Ropinirole
Name a MOAB inhibitor
Rasagiline
What is the most common prescription for Parkinson’s disease?
Levodopa with benserazide or carbidope (decarboxylase inhibitors)
What are motor fluctuations?
Involuntary movements and freezing 2 years after starting drugs due to a reduced response to levodopa
