Neurology Flashcards
What are the clinical features of parkinsonism?
Resting tremor: -coarse -pill rolling -asymmetrical Bradykinesia: -slowed movement Postural instability Rigidity: -cogwheel or leadpipe Hypomima Festinant gait: -shuffling, reduced arm movement Speech quiet and monotonous
What is the main cause of a resting tremor?
Parkinsonism
What are the causes of postural tremor (worse with arms outstretched):
Benign essential tremor (worse with arms stretched out) Anxiety Thyrotoxicosis Metabolic: CO2 retention Alcohol
What is the main cause of intention tremor?
Cerebellar disease.
What are the causes of parkinsonism?
Idiopathic parkinson’s disease.
Drug induced: dopaminergic receptor blockers, anti-psychotics/anti-emetics
Parkinson’s plus: multisystem atrophy, progressive supranuclear palsy, corticobasal degeneration.
Post encephalitic parkinsonism
Vascular parkinsonism
What is the pathology of idiopathic parkinson’s?
Degeneration of dopaminergic neurones between the substantia nigra and basal ganglia.
Deficient in dopamine (excitatory neurotransmitter) in the basal ganglia
Overall increased inhibitory output and decreased cortical activity.
What are the other symptoms of parkinsons disease?
Depression Fatigue Hyposmia/anosmia Autonomic dysfunction: constipation incontinence dysphagia sleep disturbance
How is parkinsons diagnosed?
Clinical diagnosis: Bradykinesia plus one of rigidity, rest tremor and postural instability. Absence of atypical features Slowly progressive course Response to drug therapy.
What are the investigations of parkinsons?
DAT-SPECT scanning CT or MRI - structural cause of symptoms - degree of cerebrovascular disease - MRI can help identify some parkinson's plus
What are the treatments of parkinsons?
L-dopa Pramiprexole Ropinirole MAO-B inhibitor e.g. selegiline COMT inhibitors e.g. entacapone
How does L-dopa work?
Converted to dopamine in brain.
Used with decarboxylase inhibitor e.g. carbidopa, to prevent peripheral breakdown and reduce side effects like nausesa.
Effects wear out over years
Problems with on/off motor fluctuations - some modified release formulas help.
How do pramiprexole and ropinirole work?
Activate dopamine receptors.
Fewer side effects than L-dopa
Use in younger patients to save L-dopa for later.
Apomorphine can be given by SC injection or pump
Rotigotine as paatch can be used if patients unable to swallow
How do MAO-B inhibitors work?
Inhibit the enzyme MAO-B which breaks down dopamine.
Can be used to delay need for L-dopa and also works well with L-dopa
How do COMT inhibitors work?
Catechol-O-methyltransferase inhibitors prevent peripheral breakdown of L-dopa, reduces motor fluctuations.
Smooth out the action of L-dopa
What are the more invasive treatments of Parkinson’s?
Apomorphine subcut infusion (dopamine agonist)
Intraduodenal levodopa
Neurosurgery e.g. deep brain stimulation.
What is the prognosis of parkinsons?
Progressive neurodegenerative disease.
Typical course:
2-3 years with resolution of symptoms with dopaminergic agents.
Motor compliments after 5 years of levodopa treatment.
After a number of years - freezing, falling and dementia, not responsive to levodopa
Cognitive dysfunction
What are the predictors of parkinsons progression?
Tremor predominance, slower progression.
Rapid rate of progression:
- older age at symptom onset
- rigidity/hypokinesia as presenting symptoms
- associated comorbidities
- decreased response to dopaminergic medications
What is Lewy body dementia?
Progressive cognitive decline to interfere with normal living, hallucinations, fluctuating mental status.