PARKINSON'S DISEASE AND PARKINSONIAN DISORDERS Flashcards
What do the basal ganglia consist of?
Caudate nucleus Globus pallidus Putamen Substantia nigra Subthalamic nucleus
What are the akinetic rigid syndromes?
Parkinson’s disease
Multiple System Atrophy
Progressive Supranuclear Palsy
Corticobasal Degeneration
Is Parkinson’s more common in men or women?
Men
What is the average age of onset for Parkinson’s disease?
60 years
What part of the brain is affected in Parkinson’s disease?
Mainly the dopaminergic neurones of the substantia nigra as well as other brain areas.
What is the first presenting complaint in 60% of people who subsequently are diagnosed with Parkinson’s?
Resting tremor
What part of the substantia nigra contains the dopaminergic neurones that are affected in Parkinson’s disease?
Pars compacta
What are Lewy bodies?
Eosinophilic intra neuronal inclusions which contain alpha-synuclein protein, aggregated with abnormally phosphorylated neurofilaments and ubiquitin.
Where do the pars compacta cells of the substantia nigra project within the basal ganglia?
The striatum
Other than the substantia nigra what other parts of the brain stem may be affected in Parkinson’s disease?
Locus ceruleus
There may be more
What is the classical triad of clinical features of Parkinson’s disease?
Resting tremor
Limb rigidity
Akinesia
Does Parkinson’s normally affect limbs symmetrically?
No. The asymmetry is actually a characteristic feature.
How is the resting tremor associated with Parkinson’s disease often described?
Pin rolling
How might you exacerbate a resting tremor during an examination which might indicate Parkinson’s as a more likely diagnosis?
Distraction - get the patient to concentrate on using the other limb. This should increase the tremor.
How is the increase in tone found in Parkinson’s disease described?
Cog-wheel rigidity (when combined with the tremor)
Lead pipe rigidity
What is the difference between spasticity and rigidity?
Spasticity is an increased resistance to the passive movement of a joint due to abnormally high muscle tone (hypertonus) which varies with the amplitude and speed of displacement of a joint. The increased tone is more marked in the flexors of the arms and the extensors of the legs (decorticate position).
Rigidity is an increased resistance to the passive movement of a joint which is constant throughout the range of joint displacement and not related to the speed of joint movement; resistance is present in both agonist and antagonist muscles.
Rigidity is associated with a lesion in which part of the nervous system?
Basal ganglia and connections
Spasticity is associated with a lesion in which part of the nervous system?
Upper motor neuron
What is bradykinesia?
Slowness of movement with additional fatiguing and decrement of repetitive alternating movement
What is hypokinesia?
Reduced amplitude of movement
What features might be seen in the face of someone with Parkinson’s?
Mask like - hypomimia
Reduced blinking
How is speech altered in someone with Parkinson’s?
Monotomous hypophonic disarthria due to a combination of bradykinesia, rigidity and tremor.
How is power affected in someone with Parkinson’s disease?
It is usually preserved, however bradykinesia and rigidity make testing power difficult in advanced disease.
How is sensation affected in Parkinson’s disease?
Sensation is usually normal but patients may report discomfort and sensory abnormalities in the leg.
How is the gait of a Parkinson’s disease patient affected?
Stooped
Shuffling
Festinant - steps that become increasingly fast
What are the non-motor features of Parkinson’s disease?
Constipation and urinary difficulties
Depression
Dementia is a common complication later on in disease
What is the cumulative incidence of dementia in Parkinson’s patients?
80%
What is the usual cause of death in Parkinson’s patients?
Bronchopneumonia
Name 6 classes of drug used in the management of Parkinson’s disease.
L-dopa (Levodopa) Dopamine agonists Anticholinergics Monoamine oxidase B inhibitors - rasagiline Catechol-O-methyltransferase inhibitors Amantidine
How does L-dopa work in the treatment of Parkinson’s disease?
L-dopa is the precursor to dopamine so dopamine is more readily available to the dopaminergic neurones.