Parkinson's Flashcards
Parkinsons disease
Progressive reduction of dopamine in the basal ganglia of the brain leading to disorders of movement
Characteristically asymmetrical
Classic triad of parkinson’s disease
Resting tremor
Rigidity
Bradykinesia
Pathophysiology
Basal ganglia are in the middle brain and responsible for coordinating habitual movements (walking, looking around, controlling voluntary movements)
Substantia nigra produces dopamine
Dopamine essential for correct functioning of basal ganglia
Presentation
Unilateral tremor
Cogwheel rigidity
Bradykinesia
Depression
Sleep disturbance and insomnia
Anosmia
Postural instability
Cognitive impairment and memory problems
Unilateral tremor
4-6Hz (4-6 times a second)
Pill rolling tremor
More pronounced when resting and improves on voluntary movement
Worse if distracted
Cogwheel rigidity
Resistance to passive movement of a joint (little jerks)
Bradykinesia
Handwriting gets smaller
Shuffling gait
Difficulty initiating movement (standing still to walking)
Difficulty turning round (lots of little steps)
Hypomimia
Multiple system atrophy
Neurones of multiple systems in the brain degenerate
Degeneration of basal ganglia leads to Parkinson’s presentation
Degeneration of other areas leads to autonomic dysfunction (postural hypotension, constipation, abnormal sweating, sexual dysfunction)
Cerebellar dysfunction (causes ataxia)
Dementia with Lewy Bodies
Progressive cognitive decline
Symptoms of visual hallucinations, delusions, disorders of REM sleep and fluctuating consciousness
Features of Parkinsonism
Diagnosis
Clinical based on symptoms and examination
UK Parkinson’s Disease Society Brain Bank Clinical Diagnostic Criteria
Lveodopa
Synthetic dopamine
Most effective treatment for symptoms but becomes less effective over time
Main side effect is dyskinesias when dose too high
Dyskinesias
Dystonia: excessive muscle contraction leads to abnormal postures or exaggerated movements
Chorea: abnormal involuntary movements that can be jerking and random
Athetosis: involuntary twisting or writhing movements usually in fingers, hands or feet
First line treatments
If motor symptoms affecting patients quality of life: levodopa
If not affecting quality of life: dopamine agonist, levodopa or monoamine oxidase B inhibitor
Dopamine agonists
Stimulate dopamine receptors
Less effective than levodopa in reducing symptoms
Side effect: pulmonary fibrosis
e.g. bromocryptine, pergolide, cabergoline
Monoamine oxidase B inhibitors
Stops the breakdown of dopamine, serotonin and adrenaline
e.g. selegiline, rasagiline
