Parkinsons: Flashcards
What is Parkinsons disease?
Degenerative mood disorder. Caused by progressive degeneration of dopaminergic neurons in the substantia nigra pars compacta of the basal ganglia.
What develop in Parkinsons?
Lewy bodies: eosinophilic cytoplasmic inclusions of ubiquitin and alpha-synuclein
Where is the loss of dopamine observed?
Loss of dopamine and melanin is observed in the striatum, correlating to cell loss and a degree of akinesia.
What is the usual presentation of Parkinsons?
- Impaired dexterity
- Unilateral foot drop
(asymmetrical)
What is the triad of parkinsons?
- Rigidity
- Bradykinesia
- Resting tremor
What are the features of the tremor?
- Pill-rolling
- 4-6Hz
- Seen at rest and can be induced by concentration
- Improves with activity
List 3 other motor features of Parkinsonism:
- Fine motor impairment
- Cog wheeling (jerky resistant to passive movements)
- Parkinsonian gait
Give 2 non-motor features of parkinsonism:
- Depression
- Visual hallucinations
What can cause parkinsonism?
- Multiple cerebral infarcts
- Lewy body dementia
- Typical antipsychotics (haloperidol)
What is the diagnosis of parkinsons based on?
- Clinical diagnosis
- Can confirm with response to Levodopa
- MRI initially normal but later shows atrophy
What 4 medications can be used to treat parkinsons?
- Carbidopa (L-dopa combined with decarboxylase) (GOLD standard)
- Dopamine Agonist (e.g. ropinirole)
- MAO-B inhibitors (selegiline)
- COMT inhibitors (tolcapone)
What does decarboxylase do?
Prevents the peripheral conversion of L-Dopa -> Dopamine = reduces peripheral SE of nausea and vomiting, arrhythmias, alopecia and hypotension.
