parkinsonism Flashcards
parkinsons disease definition
Parkinson’s disease is a progressive neurodegenerative condition caused by degeneration of dopaminergic neurons in the substantia nigra..
cardinal triad of parkinsonism
Cardinal triad: Tremor, rigidity, bradykinesia
Bradykinesia
- poverty of movement also seen, sometimes referred to as hypokinesia
- short, shuffling steps with reduced arm swinging
- difficulty in initiating movement
Tremor
- most marked at rest, 3-5 Hz
- worse when stressed or tired
- typically ‘pill-rolling’, i.e. in the thumb and index finger
Rigidity
- lead pipe
- cogwheel: due to superimposed tremor
Other characteristic features
- mask-like facies
- flexed posture
- micrographia
- drooling of saliva
- psychiatric features: depression is the most common feature (affects about 40%); dementia, psychosis and sleep disturbances may also occur
- impaired olfaction
- REM sleep behaviour disorder
Drug-induced parkinsonism has slightly different features to Parkinson’s disease:
motor symptoms are generally rapid onset and bilateral
rigidity and rest tremor are uncommon
aetiology
- 🎀 Degenerative
- Idiopathic Parkinson’s disease
-
Parkinson’s-plus syndromes (basal ganglia degeneration + other system)à red flags
- Progressive Supranuclear Palsy
· Palsy: vertical gaze
· Postural instability → falls
· rigidity of trunk>limbs (symmetrical onset)
· Speech disturbance, dysphagia
- Multiple Systems Atrophy / Shy-Drager
· Autonomic dysfunction: post hypotension, bladder dysfunction, impotence/incontinence
· Cerebellar + pyramidal signs
· Rigidity > Tremor
- Lewy Body Dementia:
· Fluctuating cognition
· Visual hallucinations
- Cortico-basal Degeneration:
· Akinetic rigidity in one limb
· Astereognosis (cortical sensory loss)
· Apraxia: Alien limb phenomenon – independent interfering limb
- Vascular parkinsonism:
· pyramidal signs – legs
· DM/HTN patients ± falls, gait problem
- 🎀 Drugs: Antipsychotics, metoclopramide, prochlorperazine, neuroleptics
- Rx: anticholinergics
- 🎀 Infection: HIV, encephalopathy post flu
- 🎀 Vascular: Multiple infarcts in SN
- 🎀 Trauma: rarely trauma/boxing
- 🎀 Genetic: Wilson’s disease
clinical features
- Tremor
- Worse at rest
- Exacerbated by distraction
- pill-rolling of thumb over fingers – 4-6 cycles/sec
- Rigidity
- ↑ tone in all muscle groups: lead-pipe rigidity
- Rigidity + tremor → cog-wheel rigidity
- Bradykinesia/hypokinesia
- Slow initiation of movement
- low amplitude on repetitive actions: ↓ blink rate
- Hypomimesis: Expressionless face
- Hypophonic speech: Monotonous voice
- Micrographia: difficulty writing
-
Gait (march a petit pas)
- ↓ arm swing
- Festinance (shuffling gait)
- Freezing (esp. in doorways)
diagnosis
Diagnosis is usually clinical. However, if there is difficulty differentiating between essential tremor and Parkinson’s disease NICE recommend considering 123I‑FP‑CIT single photon emission computed tomography (SPECT).
