Parkinson's disease and movement disorders Flashcards
What is Parkinson’s disease?
A degenerative, progressive movement disorder caused by a reduction in dopamine in the substantia nigra with characteristic motor symptoms of tremor, bradykinesia, and postural instability
What is the difference between parkinsonism and Parkinson’s disease?
Parkinsonism is a collection of symptoms that are similar to those of Parkinson’s without the degenerative changes of Parkinson’s
How common is Parkinson’s?
Increasing prevalence with age
Peak age of onset 55-65
More common in men
What can cause Parkinson’s disease?
Idiopathic
Combination of…
- Environmental factors - pesticides, methylphenyl tetrahydropyridine found in illegal opiates
- Parkinson genes - mutation in Parkins gene and alpha synuclein gene
- Oxidative stress and mitochondrial dysfunction
What can cause Parkinsonism?
Drugs - neuroleptics, anti-emetics
Normal pressure hydrocephalus
Vascular Parkinsonism
Parkinson’s plus eg multiple system atrophy
What can increase your risk of Parkinson’s disease?
Male
Increasing age
FHx
Non-smoker
What is the pathology of Parkinson’s disease?
Mitochondrial dysfunction and oxidative stress
Results from progressive degeneration of dopaminergic neurons from pars compacta of SN in midbrain that projects to striatum of basal ganglia
Reduced striatal dopamine levels due to loss of dopaminergic neurons
Less dopamine so thalamus inhibited decreasing movement
Neuronal inclusions - Lewy bodies present in Parkinson’s and becomes gradually more widespread as disease progresses, spreading from lower brainstem to midbrain and then cortex
Degeneration in other basal ganglia nuclei
What makes up the basal ganglia?
Striatum
Globus pallidus
Substantia nigra
Subthalamic nucleus
What makes up the striatum?
Putamen and caudate nucleus
What makes up the globus pallidus?
External and internal
How does dopaminergic cell loss correlate to degree of akinesia?
Increased cell loss = increased akinesia
What is akinesia?
Muscle rigidity
Stiffness
Lack of responsiveness
How does Parkinson’s present (motor symptoms)?
Onset gradual and often presents with impaired dexterity
Asymmetrical
Tremor 70% (4Hz slow resting pill rolling)
Rigidity - cogwheel
Bradykinesia/hypokinesia
Gait problems - festinance, freezing, reduced arm swing)
Expressionless face (hypomimesis)
Cramping
Difficulty with fine movements eg problems doing up buttons
Micrographa
What pre-symptomatic symptoms can you get with Parkinson’s?
Anosmia Depression/anxiety Aches and pains REM sleep disorders Urinary urgency Hypotension Constipation
What is tremor in Parkinson’s like?
Worse at rest
Asymmetrical
Most obvious in hands
Improved with voluntary movements and made worse by anxiety
4-6 cycles/sec
Issue with repetitive hand movements with worsening rhythm longer attempted
What is rigidity like in Parkinson’s?
Increased tone in limbs and trunk
Limbs resist passive extension throughout movement
Rigidity over entire radius of joint movement
Can cause pain and problems with turning in bed
What does bradykinesia look like in Parkinson’s?
Slow to imitate movements
Reduced blink rate, monotonous hypophonic speech
Micrographia
What does gait look like in Parkinson’s?
Reduced asymmetrical arm swing
Narrow gait
Narrow base
Stooped posture and small steps
Festinance - shuffling steps, maybe dragging foot with flexed trunk
Difficulty initiating movement and turning
Poor balance
How does Parkinson’s present (non-motor symptoms)?
Drooling of saliva and swallowing difficulty late feature (aspiration pneumonia as a terminal event) Mood disturbance - depression 40% Sleep disturbance Cognitive disorders Pain Impulse control disorders Autonomic dysfunction Anxiety Psychotic symptoms Dopamine dysregulation syndrome
What sleep disturbance might you get in Parkinson’s?
REM sleep behaviour disturbance Insomnia (due to one/more of lack of muscle and mental relaxation, stiffness, restlessness, difficulty moving into comfortable positions, tremor bothersome, medications wearing off, driving/work implications) Daytime sleepiness Sleep disruptions Restless leg syndrome
What autonomic dysfunction might you get in Parkinson’s?
Orthostatic hypotension Constipation Heat intolerance Urinary frequency and incontinence and urgency Nocturia Sweating Hypersalivation Drooling Sexual dysfunction N&V
What are the phases of Parkinson’s treatment?
Early honeymoon period - quite easy to treat, still have buffer of axons in SN - medication seems to last for longer as dopamine released in brain in response to medication
Middle period wearing off - medication doesn’t last as long, loss of buffer
Later period dyskinesia’s (drug induced chorea), fluctuations between chorea and stiffness, cognitive impairment
What is a differential diagnosis for Parkinson’s?
Benign essential tremor - worse on movement and rare whilst at rest Multiple cerebral infarcts Lewy-body dementia Drug-induced Wilson's disease Trauma All dopamine antagonists
How is Parkinson’s diagnosed?
Clinical - based on Hx and examination
Confirmed by response to L-dopa
MRI head - initially normal but slowly atrophies, used to exclude tumours or normal pressure hydrocephalus
Lack of - incontinence, symmetry, early falls
U&E, LFT, TFT, Ca (rule out differentials)
Diagnose using UK PD society brain bank criteria - cannot diagnose without bradykinesia
Review diagnosis every 6-12 months
Document discussion of risk impulse control disorder, sleep attacks, hallucinations
Consider DAT scan in atypical tremors
PET and SPECT - look at metabolic activity of dopamine transporters in basal ganglia measured with PET and SPECT
How might normal pressure hydrocephalus present?
Forget how to walk
Enlarged ventricles
Dementia
How benign essential tremor treated?
50% respond to medication
Treat with propranolol, primidone, gabapentin
How does benign essential tremor present?
Intention tremor
