Idiopathic Parkinson's Disease Flashcards
What is Idiopathic Parkinson’s Disease more simply and commonly known as?
Parkinson’s Disease
What is Parkinson’s disease?
A long-term degenerative disorder of the CNS
What part of the nervous system does Parkinson’s disease mostly affect?
The motor system
What are the main pathological features of Parkinson’s disease?
- Cell death in the brain’s basal ganglia
- Presence of Lewy bodies in neurones
- Death of astrocytes
- Increases in microglia in substantia nigra
What cells die in the basal ganglia in Parkinson’s disease?
The dopamine secreting neurones of the substantia nigra pars compacta
What percentage of dopamine secreting neurones are affected by the time of death in people with Parkinson’s disease?
Up to 70%
What are Lewy bodies?
Accumulation of the protein alpha-synuclein
How many major pathways connect the basal ganglia to other brain areas?
5
What are the 5 major pathways connecting the brain to the basal ganglia?
- Motor
- Oculo-motor
- Associative
- Limbic
- Orbitofrontal
Which of the 5 major communicating pathways to the basal ganglia are affected in Parkinson’s disease?
All of them
What is the result of the effect Parkinson’s disease has on the communicating pathways to the basal ganglia?
It explains many of the symptoms of the disease as the circuits are involved in a wide variety of functions
What functions are affected by Parkinson’s disease’s effect on the communicating pathways to and from the basal ganglia?
- Movement
- Attention
- Learning
What is the normal role of the basal ganglia in motor control?
It exerts a constant inhibitory influence on a wide range of motor systems
What is the effect of the basal ganglia exerting a constant inhibitory influence on parts of the motor system?
Stops them from being active at inappropriate times
What happens to the basal ganglia’s inhibitory effects when a decision is made to perform a particular action?
The inhibition is reduced for the required motor system
What facilitates the reduction of inhibition?
Dopamine
What is the result of high levels of dopamine?
Promotion of motor activity
What is the result of low levels of dopamine?
Hypokinesia
What is the result of the hypokinesia caused by dopamine depletion, for example in Parkinson’s disease?
Greater exertion of effort required for any given movement
What are the risk factors for Parkinson’s disease?
- Increasing age
- History of familial PD (younger onset)
- Mutation in the gene encoding glucocerebrosidase
- MPTP exposure
- Pesticide exposure
- Male
- Head injuries
What are the main features of Parkinson’s disease?
- Tremor
- Rigidity
- Bradykinesia
What is the frequency of the tremor in Parkinson’s disease?
4-6 Hz
When is the tremor in Parkinson’s disease present?
At rest
What can be done to make the tremor more noticeable in assessing Parkinson’s disease?
Get the patient to concentrate e.g. recite months backwards
When is the Parkinson’s disease tremor absent?
During activity
Where does the tremor in Parkinson’s disease start?
Usually one limb on one side or both limbs on one side
How can the tremor in Parkinson’s disease progress?
Can become generalised
How is rigidity assessed in Parkinson’s disease?
Seen as an increase in resistance to passive movement
What can rigidity produce in many patients with Parkinson’s disease?
Flexed posture
What may cause the rigidity to increase in a patient with Parkinson’s disease?
Asking them to perform an action in the opposite limb
What is the term for increased rigidity in Parkinson’s disease when performing a task with the opposite limb?
Contralateral synkinesis
How does bradykinesia present in Parkinson’s disease?
Slowness of voluntary movement and reduced autonomic movements
When is bradykinesia particularly noticeable in Parkinson’s disease?
Reduced arm swing when walking
How can further symptoms of Parkinson’s disease be divided?
- Physical
- Cognitive/psychiatric
What are the extra physical symptoms of Parkinson’s disease?
- Gait disturbance
- Balance issues
- Anosmia
- Nerve pain
- Urinary incontinence
- Nocturia
- Constipation
- ED
- Postural hypotension
- Hyperhidrosis
- Dysphagia
- Drooling
- Insomnia
What gait disturbances may be seen in Parkinson’s disease?
- Difficulty in starting to walk
- Shuffling gait
- Unsteadiness on turning
- Difficulty in stopping
What are the cognitive and psychiatric symptoms of Parkinson’s disease?
- Depression
- Anxiety
- Slight memory problems
- Problems with planning and organisation
What long-term problems may patients with Parkinson’s disease suffer from despite treatment with L-dopa?
- Motor fluctuations
- Axial problems
- Parkinson’s disease dementia
What percentage of people experience the long-term problems associated with Parkinson’s disease after L-dopa treatment?
50-90%
When may the long-term problems associated with Parkinson’s disease present?
After a ‘honeymoon period’ of 5-10 years post L-dopa initiation
What is the problem with long-term motor fluctuations seen in later Parkinson’s disease?
They are difficult to treat
What axial problems may be seen in later Parkinson’s disease?
Disturbance of gait, speech and balance that don’t respond to Parkinson’s disease medication