Parkinson’s Disease

1. Parkinson’s Disease JP

2. Overview • Idiopathic PD • Clinically and pathologically distinct from other parkinsonian syndromes • Degenerative disorder of the CNS • Develops over months or several years • Classification: movement disorder • Combination of tremor, rigidity and akinesia

3. Causes • Not well known • Relatively uniform world-wide prevalence suggests that it is not environmental • Possible factors: • Nicotine • Less prevalent in smokers • Genetic factors • Not usually familial • Mutation in parkin gene may account for cases with an onset below the age of 40

4. Epidemiology • Prevelence (per 100,000): • Sweden 22.5 • USA 20.5 • Japan 16.9 • England 12 • Italy 10 • Hair colour • Black (least) • Brown 40% more likely • Blonde 60% more likely • Red 100% more likely • Melanin (pigment) is initally made the same way as dopamine

5. Epidemiology – cont. • Age • Very uncommon <30 • Risk sharply increases at the age of 60 • Gender • More common in males

6. Pathophysiology • Neurons from the substantianigra (basal ganglia) extend into the putamen and caudate • Release dopamine • PD: • Breakdown in connection between the substantianigra and the putamen • Symptoms occur when 20-50% levels of normal dopamine • Usually around 60-80% of cells die in the substantianigra • Lewy Bodies when found in the substantianigra is characteristic • Dense protein core

8. Clinical Symptoms • Initially tremor and slowness • Limbs and joints feel stiff and ache • Fine movements become difficult • Difficulty “rising from a chair” or “getting in or out of bed” • Writing becomes small (micrographia) and spidery • Relatives notice slowness and an impassive face • Nearly always more prominent on one side

9. Clinical Signs • Tremor • Rest tremor usually decreases with action • Characteristic • Rigidity • Stiffness is equal in opposing muscle groups • ‘Lead pipe’ • Limbs, neck and axial muscles • Akinesia & Bradykinesia • Difficulty initiating movement • Rapid fine finger movements are greatly affected • Facial immobility • Reduced blink rate • Serpentine stare

10. Clinical Signs – cont. • Postural changes • Stoop • Festinant gait (hurrying) and shuffling with poor arm swinging • Balance deteriorates • Speech • Monotone • Progresses to slurring dysarthria • Other symptoms • Heartburn, dribbling, dysphagia, constipation and weight loss • Urinary difficulties • Skin is greasy and sweating excessive

11. Course of the disease • Worsens over 10-15 years • Death results from bronchopneumonia

12. Differentials • Alzheimer’s disease • Multi-infarct dementia • Repeated head injury • Drug-induced • Late effects of severe hypoxia or carbon monoxide poisoning • Hypothyroidism • Depression

13. Diagnosis • No laboratory test • Made by history and recognising physical signs

14. Treatment • No drugs alter the course of disease • Levodopa • Effective in initial symptom treatment • Issues: • Fluctuates between effectiveness • After several years levodopa becomes inefficient • Side effects are severe: • Initially: nausea and vomitting • Later: episodes of immobility, dyskinesias • Dopamine receptor agonists • Generally less effective than levodopa but less side effects • Usually primary treatment unless levodopa is absolutely necessary • Used below the age of 70

15. Surgery • Stereotactic neurosugery • Provides effective, temporary improvement in tremor and dyskinesia • Used before levodopa and in the past decade has become more popular

16. Physiotherapy • Can improve gait • Modifications at home • Eg. Remove fiddly stuff from clothing • Walking aids

17. Psychiatric Aspects • Depression is common

18. Videos • http://www.youtube.com/watch?v=_6u2W1mzCeM&feature=related • http://www.youtube.com/watch?v=gboQaXv9CuM&feature=related • http://www.youtube.com/watch?v=pOhBtTYfSE4