Erica Partridge Parkinson’s Disease

Definition Aetiology PD vs Parkinsonism Symptoms and signs Differentials Investigations Management Prognosis

1. What is the definition of Parkinson’s disease?

A movement disease characterised by Tremor at rest Rigidity Bradykinesia

2. Aetiology of PD

Degeneration of dopaminergic pathways in the substantia nigra

4. What is the difference between PD and Parkinsonism?

PD is used to describe idiopathic syndrome of Parkinsonism Parkinsonism is symptoms attributable to an underlying cause

5. Causes of Parkinsonism

Drug induced Any drug that blocks dopamine receptors or reduce storage of dopamine Mainly antipsychotics But also antiemetics such as metoclopramide Antihistamines – eg cyclizine 5HT3 receptor blockers – eg ondansetron Dopamine blockers eg metoclopramide, domperidone Following encephalitis Exposure to toxins – manganese dust, sever CO poisioning

6. 3 main features of PD

Tremor 4-6 hz Seen at rest – can be induced by concentration Usually apparent in one limb or one side first Rigiditiy Increase in resistance to passive movement Can produce a characteristic flexed posture Cogwheel rigidity Bradykinesia Slowness of voluntary movement Reduced arm swing Progressive reduction in amplitude of repetitive movements

7. How does PD present

Insidious onset Peak age of onset is 55-65, slightly more common in men Impairment of dexterity Progressive disorder

8. Other symptoms

Fixed facial expression Infrequent blinking Quiet voice Micrographia Gait – short shuffling steps (festination), difficulty in initiating movement and in stopping Non motor Anosmia Depression Dementia Visual hallucinations REM sleep disorders

9. Differential diagnosis

Benign essential tremor Far more common – worse on movement, rare at rest Drug or toxin induced

10. In which type of dementia do patient’s have PD symptoms?

Lewy body dementia Dementia Fluctuating levels of awareness Signs of mild PD Visual hallucinations Sleep disorgers PD dementia Dementia occuring >1 year after PD diagnosis Visual hallucinations Fluctuating lucidity

11. Diagnosis of PD

Bradykinesia plus one of following Muscular rigidity Resting tremor Postural instability Not causes by primary visual, vestibular, cerebellar or proprioceptive dysfunction

12. Investigations

Diagnosis is clinical

13. Management

Levodopa Taken with a decarboxylase inhibitor Start with low dose and build up Keep dose as low as possible N+V/loss of appetite Dopamine agonists Eg bromocriptine, cabergoline Monotherapy or adjuvant COMT inhibitors Must be taken with levodopa Eg entacapone, tolcapone

MAOBi Prevent dopamine being broken down Selegine Has amphetamine metabolites – hallucinations, nightmares, confusion so avoid in elderly Rasagiline No amphetamine metabolites

Levodopa Breakdown product Dopamine COMTMAO COMT AADC (decarboxylase) BBB

14. Other management

14. Management OT SALT Exercises to strengthen voice/help control facial expression/swallowing or drooling problems Suggest communication aids Physio PD nurse Support groups

15. Common management problems

Motor fluctuations – associated with long term L-dopa On off fluctuations – occur randomly Wearing off phenomenon – before next dose is due Involuntary movements while on – dyskinesias Axial problems Do not respond to treatment Balance, speech and gait Physio, SALT, OT Associated disease Dementia (20-40%) Depression (45%)

16. Complications

Infections Aspiration pneumonia Bed sores Poor nutrition Falls Contractures Bowel and bladder disorders

17. Prognosis

Slowly progressive with mean duration of 15 years Severity is hugely varied Some show little disability after 20 years Others severely disabled after 10 years

Explaining things to patients

What do they already know Why they need it What will happen Risks/side effects Do they have any questions? It is fine if you don’t know the answers say you will find out and get back to them Offer to give them information sheets/leaflets

References Patient UK Professional Reference NICE guidelines Parkinson’s UK website