Parkinson’s Disease Dr Rachel Cary, Warwick Hospital
Overview Hopefully not anything new (!) Definition of Parkinson’s disease Aetiology Presentation Investigations Management: conservative, medical, surgical Prognosis Parkinson’s plus syndromes
Definition Parkinson’s disease The idiopathic syndrome of Parkinsonism Described by Dr James Parkinson in 1817 – ‘the shaking palsy’ Parkinsonism Symptom complex: characterised by bradykinesia, tremor and rigidity (classical triad) Causes: Drug induced – anti-dopaminergics e.g. clozapine, metoclopramide, domperidone Post-encephalitis Exposure to toxins: e.g. severe CO poisoning
How common is it? per 100,000 Incidence rises steeply with age: 17.4 in 100,000 person years between age 93.1 in 100,000 person years between 70 and 79 years
Risk factors Age Male gender Pesticide exposure Genetic ?born in the springtime
Aetiology and pathogenesis Death of dopamine generating cells in the substantia nigra Pathology characterised by accumulation of alpha-synuclein into inclusions Lewy bodies Insufficient formation and activity of dopamine in the midbrain
Presentation: symptoms + signs Tremor 4-6Hz – unilateral onset Rigidity Slowness of movement Postural instability Gait: festinating, shuffling, reduced arm swing Gait freezing Turning en bloc Hypomimia Micrographia Hypophonia
How will you elicit these in an OSCE?
Differential diagnosis Benign essential tremor Drug/toxin induced Huntingon’s disease Wilson’s disease Parkinson’s plus syndromes (we’ll come to these later) Lewy body dementia CJD Cerebellar tremor Pick’s disease
Investigations Bedside tests Clinical diagnosis Blood tests Imaging CT Head Special tests: DAT SPECT -> type of PET looking at striatal dopamine transporter
Associated diseases Dementia in 20-40% Depression – 45%
Management - conservative Multidisciplinary management Parkinson’s nurse Physiotherapy Avoid Zimmer frames unless they have wheels and a handbrake Occupational therapy Referral to other services as needed
Medical Dopamine agonists e.g. ropinirole, bromocriptine MAO inhibitors e.g. selegeline Levodopa + decarboxylase inhibitor COMT e.g. entacapaone Continuous dopamine therapy Supportive medication e.g. baclofen
Choice of drug Depends on impact of improving motor disability vs risk of motor complications, and neuropsychiatric complications Levodopa is the most effective drug: Sinemet, Madopar Long term levodopa treatment associated with adverse motor effects that limit its use
Surgery Bilateral subthalamic nucleus stimulation in patients refractory to medical treatment Globus pallidus interna is also recommended by NICE, but rarely performed in the UK Thalamic stimulation is an alternative for patients with sever tremor who are unsuitable for STN stimulation
Longer term problems Motor fluctuations – “on” and “off” Axial problems not responding to treatment Balance Speech Gait disturbance Parkinson’s disease dementia
Complications Infections Aspiration pneumonia Pressure sores Poor nutrition Falls Contractures Bowel and bladder disorders
Prognosis Slowly progressive Mean duration 15 years Large variation in progression
Parkinson’s plus syndromes Features of Parkinson’s disease with additional features Often symmetrical onset Lack of/irregular resting tremor Reduced response to dopaminergic drugs Often more rapidly progressive Multiple system atrophy Autonomic dysfunction Ataxia Progressive supranuclear palsy Supranuclear opthalmoplegia Neck dystonia Pseudobulbar palsy Frequent falls, imbalance, and difficulty walking Behavioural and cognitive impairment Corticobasal degeneration Alien hand syndrome Apraxia Aphasia
Summary Parkinsonism Rigidity, bradykinesia, tremor Clinical diagnosis Multidisciplinary team management Drugs: levodopa and others Problems associated with long-term usage of levodopa etc. DBS Complications and associated comorbidity Prognosis