Parkinson/Extrapyramidal Disease Flashcards
What is the classical triad of Parkinsonism?
Tremor
Rigidity
Bradykinesia
What are the features of the Parkinsonian tremor?
4-7Hz
‘Pill-rolling’ movements w/ thumb & finger
Occurs at rest, decreases w/ action, increases w/ anxiety
-increased if clench opposite hand
Positive glabellar tap sign (excessive blinking)
What are the features of Parkinsonian rigidity?
Increased tone throughout range of limb movement
Equal in opposing muscle groups - ‘lead pipe’
What are the features of Parkinsonian bradykinesia?
Difficulty initiating movement
Progressive reduction in speed/amplitude of actions
Spontaneous blinking rate reduced
Hypomimia +/- hypersalivation
What is cogwheeling?
Jerky resistance to passive movement
-rigidity + tremor
What are the causes of Parkinson’s?
Idiopathic - PD Drug induced Vascular - Multiple cerebral infarcts Toxin - Wilson's disease Post-encephalopathy Parkinson's plus syndromes
What are the drug induced causes of Parkinson’s?
Neuroleptics Prochlorperazine Metoclopramide TCAs Methyldopa
What are the Parkinson’s plus syndromes?
Rare alternative causes of PD, screen before diagnosing as idiopathic PD
- Progressive supranuclear palsy
- Multiple system atrophy
- Lewy body dementia
- Vascular Parkinsonism
- Corticobasal degeneration
What are the features of Progressive Supranuclear Palsy?
Symmetrical onset, tremor unusual Early postural instability/speech problems Dementia develops early Vertical gaze palsy present -limitation of movement in down gaze
What are the features of Multiple System Atrophy?
Early autonomic features (postural hypotension, bladder dysfunction, excess sweating) Cerebellar signs (nystagmus in horizontal gaze) Pyramidal signs (extensor plantar, hyperreflexia)
What are the features of Lewy Body Dementia?
Early dementia w/ fluctuating cognition & visual hallucinations
Symmetrical motor signs
What are the features of Vascular Parkinsonism?
Strokes affecting basal ganglia
Sx worse in legs than arms
Pyramidal signs present
What are the features of Corticobasal degeneration?
Akinetic rigidity involving 1 limb
Cortical sensory loss
What is the underlying pathology of Parkinson’s?
Degeneration of nigrostriatal neurones w/ Lewy Body formation
Reduced dopamine activity w/i corpus striatum of basal ganglia
What additional features are present in Parkinson’s?
Postural changes Gait changes Speech changes GI/urological sx Dermatological sx Psychological sx
What are the postural changes present in Parkinson’s?
Characteristic swoop
Fixed flexion of all joints (apart from PIPJ/DIPJ)
What are the gait changes present in Parkinson’s?
Gait becomes quicker (festinant)
Narrow based, shuffling, reduced arm swing
Slow/unsteady on turn (may freeze)
Falls common
What are the speech changes present in Parkinson’s?
Monotonous pronunciation
Progresses to slurring dysarthria/anarthria
What are the GI/urological sx present in Parkinson’s?
Dysphagia
Constipation
Urinary frequency
What are the dermatological sx present in Parkinson’s?
Excessive sweating
Greasy skin
What are the psychological sx present in Parkinson’s?
Cognition preserved til late stages Dementia develops later in disease Depression common (1/3) REM behavioural sleep disorder Insomnia
What is the management of Parkinson’s?
MDT care
Social care assessment
Levodopa
Adjuncts - dopamine receptor agonists, MAO-B inhibitors, COMT inhibitors
How does Levodopa work?
Precursor of dopamine, crosses BBB
Combined w/ carbidopa to prevent conversion peripherally
What are the common side effects of Levodopa?
N/V (treat w/ Domperidone)
Confusion
Visual hallucinations (treat w/ Olanzapine)
Chorea
What are the late side effects of Levodopa?
After 2-5yrs pts develop late side effects
- motor fluctuations
- dyskinesias
- dystonias
What are motor fluctuations?
Response to a given dose is shorter lived
Rapid ‘on-off’ switching from well controlled state to akinesia
Seemingly unrelated to dosage
What is dyskinesia?
Peak dose dyskinesias due to high dopamine levels
What is dystonia?
Painful ‘wearing off’ dystonia as dopamine levels fall
How are dopamine receptor agonists used to treat Parkinson’s?
Adjuncts to L-dopa
Less effective but fewer unwanted dyskinesias
-ergot derivatives (bromocriptine, cabergoline)
-d2 agonists (ropinirole)
-d2/3 agonists (pramipexole)
What are the common side effects of dopamine receptor agonists?
Vomiting
Haemolytic anaemia
Ergot derivatives cause pulmonary/pericardial/retroperitoneal fibrosis
How do MAO-B & COMT inhibitors work?
Both prevent breakdown of dopamine by respective enzymes
- MAO-B inhibitors (selegline, rasagline)
- COMT inhibitors (entacapone)
What is the main side effect of MAO-B inhibitors?
Exacerbate postural hypotension
How can anticholinergic agents be used to treat Parkinson’s?
Address dopamine/ACh imbalance in substantia nigra
Help tremor
Can cause confusion/anti-cholinergic effects in elderly
What are the surgical options for the management of Parkinson’s?
Thalotomy/deep brain stimulation to interrupt overactive vasal ganglia circuits
What is the prognosis of Parkinson’s?
If untreated pts will die due to complications w/i 10yrs
