Parkinsonism Flashcards
What is parkinsonism?
Umbrella term that describes many conditions which share some of the symptoms of Parkinson’s. The main symptoms of Parkinson’s – tremor, rigidity and bradykinesia – are also the main symptoms of a number of conditions that are grouped together under the term parkinsonism
What are causes of parkinsonism?
- Idiopathic Parkinson’s disease
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Parkinson’s plus syndromes
- Progressive supranuclear palsy (PSP)
- Mutiple system atrophy (parkinsonism + autonomic + cerebellar signs)
- Corticobasilar degeneration
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Secondary parkinsonism
- Encephalopathy (post-ecephaleptic)
- Drug/toxin induced - antipsychotics, illicit drugs, copper (wilsons)
- Strokes - in midbrain ganglia (multiple cerebral infarcts)
- Hydrocephalus
- Trauma - boxing
- Degenerative Parkinsonism - alzheimers, lewy body
- Genetic disorders - wilson’s, huntington’s
How does parkinson’s disease develop?
- Arises from the death of dopaminergic in the pars compacta of the substantia nigra.
- This leads to striatal actvitiy increasing due to lack of inhibitory influence of the substantia nigra.
- Striatal activity exerts inhibitory affect on pallidum. As substantia nigra is no longer exerting excitatory effect on striatum, it reduces it’s inhibitory effect on the pallidum, which in turn grossly inhibits the thalamus.
- This prevents excitatory signals being sent to the motor cortex, resulting in difficulty initiating movement
https://www.youtube.com/watch?v=I4XXoiWwoNc
SO:
- Substantia Nigra degeneration (reduced dopamine)
- Very high striatal activity (increased GABA)
- Inhibition of pallidum
- Hypokinesia
What are the characteristic features of the resting tremor in parkinson’s disease?
- 4-6 cycles per second
- Pill rolling - thumb over finger
- Disappears with voluntary movement - so worse at rest and anxiety, imbroves by voluntary movement
- Unilateral at presentation, progresses to bilateral
What are the characteristic features of rigidity in parkinsonism?
- Lead-pipe rigidity - A hypokinetic disorder characterized by the inflexibility or stiffness of the limb that is maintained equally throughout the passive flexion
- Cogwheel rigidity - series of catches/stalls when rapid movement performed by examiner
What are the features of bradykinesia/hypokinesia seen in parkinsonism?
Slow to initiate movement
- Problems with fine motor tasks: writing, sewing or getting dressed.
- Decreased blink rate (abnormal glabellar reflex)
- Monotonous hypophonic speech
- Micrographia - (small cramped handwriting)
- Dead pan face
Gait changes
- Decreased arm swing
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Shuffling steps
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What are the core features of parkinson’s disease?
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Bradykinesia/hypokinesia, plus one of:
- Resting tremor
- Rigidity
- Postural instability
What is characteristic about the shuffling gait seen in parkinson’s disease?
Shuffling steps with reduced arm swing and flexed trunk, as if chasing one’s centre of gravity. Have difficulty turning on the spot, taking many steps
Classicalyl stooped posture with tendancy to fall
What are non-motor symptoms of parkinson’s disease?
- Ansomnia - Reduced sense of smell
- Frequency/urgency
- Dribbling of saliva
- Neuropsychiatric - Depression, hallucinatnions, dementia, impulsive behaviour, bradyphrenia - slowed process of thought
- Sleep disorders - insomnia, sleep fragmentation
- GI and autonomic - drooling of saliva, excessive sweating, dysphagia, constipation
What is the typical age of onset of parkinson’s disease?
65 yrs old
What would be a diffirential diagnosis for tremor and bradykinesia?
- Idiopathic parkinsons disease
- Drug induced parkinsonism
- Vascular parkinsonism
- Essential tremor
- Normal pressure hydrocephalus
- Dementia with lewy bodies
What are parkinson’s plus syndromes?
- Progressive supranuclear palsy
- Multiple system atrophy
- Corticobasal degeneration
What are causes of secondary parkinsonism?
- Vascular
- Drug induced
- Hydrocephalus
- Post-encephalitic
How would you investigate someone with parkinsonism?
- Clinical examination - cardinal signs, positive pull test
- Toxicology screen
May also do Imaging: CT/MRI, SPECT, Brain biopsy (Lewy body)
What would a resting tremor potentially indicate?
Parkinson’s disease
What could cause a tremor that occurs on maintaining a posture or with movement?
- Essential tremor
- Exaggerated physiological tremor
- Hyperthyroidism
- Drug-induced
- Dystonic tremor