Hypokinetic movement disorders Flashcards
What is Parkinson’s disease?
A progressive neurodegenerative condition that results from degeneration of dopaminergic neurones in the substantia nigra
What is the classic triad of clinical features seen in Parkinson’s disease?
- Bradykinesia
- Tremor (resting, ‘pill-rolling’)
- Cogwheel rigidity
Besides the triad of bradykinesia, tremor, and rigidity, what other clinical features are seen in Parkinson’s disease?
- Expressionless face
- Micrographia
- Soft voice
- Drooling
- Shuffling gait
- Glabellar tap
- Depression
- Bowel and bladder symptoms
- Sleep dysfunction
- Sexual dysfunction
What is bradykinesia?
Poverty of movement, with a reduction in amplitude of movements with repetition.
Describe the rigidity seen in Parkinson’s disease.
- Increased resistance to passive movement
- “Cogwheeling” is due to superimposed tremor
Describe the tremor seen in Parkinson’s disease.
- Resting tremor
- Described as pill-rolling
- Unilateral in idiopathic Parkison’s disease
- Bilateral in drug-induced PD
- 4-6 Hz in frequency
What are the causes of parkinsonism?
- Idiopathic Parkinson’s disease
- Parkinson-plus syndromes
- Drug-induced parkinson’s (antipsychotics, antiemetics, lithium, methyldopa)
- Post-encephalitis
- Tumour
- Vascular
List the Parkinson-plus syndromes.
- Multi-system atrophy
- Progressive supranuclear palsy
- Lewy-body dementia
- Corticobasal degeneration
What is multi-system atrophy (MSA)?
- Adult-onset, rapidly progressive disease
- Feature: parkinsonism, autonomic dysfunction (postural hypotension, urogenital dysfunction), cerebellar signs
What is progressive supranuclear palsy (PSP)?
- Neurodegenerative disorder beginning at 50-60 years
- Features: vertical gaze dysfunction, dysarthria, cognitive decline
What is Lewy-body dementia (LBD)?
- Characterised by early onset dementia with features of parkinsonism
- Dementia usually the proceeding feature prior to motor symptoms, characterised by visual hallucinations and fluctuating consciousness
What is corticobasal degeneration?
- Neurodegenerative disease characterised by progressive dementia, parkinsonism, and limb apraxia
- Can be associated with alien limb syndrome
What investigations should be performed for Parkinson’s disease?
- Mainly a clinical diagnosis
- DaT scan/SPECT (to differentiate between Parkinson’s and essential tremor)
- CT/MRI (if secondary cause suspected, or treatment failure)
Describe the differences between a Parkinson’s tremor and essential tremor.
Parkinson’s tremor:
- asymmetrical
- 4-6 Hz
- worse at rest
- improves with intentional movement
- other Parkinson features
- no change with alcohol
Essential tremor:
- symmetrical
- 5-8 Hz
- improves with rest
- worse with intentional movement
- no other Parkinson’s features
- improves with alcohol
What is first-line treatment for idiopathic Parkinson’s disease, if motor symptoms are affecting the patient’s QoL?
- Levodopa, usually with a decarboxylase inhibitor (carbidopa, benserazide)
- Decarboxylase inhibitors prevent the peripheral conversion of levodopa into dopamine
- Reduced effectiveness over time, provides good control of motor symptoms for 4-6 years
