L29: Parkinson's Disease Flashcards
What is idiopathic Parkinson’s Disease?
PD is a clinical diagnosis of movement disorder that responds to dopamine medications
What are the medical tests or scans to confirm PD?
No medical tests or scans to confirm PD
What is premotor Parkinson’s Disease (PD)?
Increasing evidence that olfactory dysfunction, sleep abnormalities, cardiac sympathetic denervation, constipation, depression and pain may precede the onset of motor signs of PD.
What are the first signs ≤12 years prior in PD?
Loss of smell, constipation, REM sleep behaviour disorder
- 80% likely to develop PD in the next 12 years
- Starts in olfactory > guts > brainstem > midbrain > cortex
- REM sleep behaviour: Disconnection between movements & sleep
- REM sleep behaviour disorder: Disinhibition of movements when sleeping - they act out their dreams, often violent dreams, attacking partner next in bed or hurt themselves
- Ask about these things in patient interview
What is REM sleep behaviour?
Disconnection between movements & sleep
What is REM sleep behaviour disorder?
isinhibition of movements when sleeping - they act out their dreams, often violent dreams, attacking partner next in bed or hurt themselves
What are 3 risk factors for Parkinson’s Disease (PD)?
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Genetics: X autosomal dominant and recessive genes or gene loci have been linked to PD (e.g. LRRK2)
- 10-15% PD patients will have an affected first or second degree relative
- Environmental: Unclear, pesticides
- Neuroprotection: Caffeine , tobacco, hyperuricaemia
What are 6 characteristics of pathology for Parkinson’s Disease (PD)?
- Degeneration of substantia nigra cells which produce dopamine causes disruption of dopaminergic neurotransmission.
- Accumulation of Lewy bodies from the lower brainstem to the neocortex
- ≥5 parallel loops associated with projections from the basal ganglia
- Cortex - striatum - Gpe/Gpi/SNr - thalamus - cortex - with input from substantia nigra
- Subserve different functions: Motor, oculomotor, limbic, lateral premotor
- Based on excitatory and inhibitory connections
What is the Braak’s model for PD?
PD is proposed to be a progressive accumulation of intraneuronal alpha synuclein.
What are 3 characteristics of “increasing evidence of involvement of nondopaminergic systems (ACh) in pedunculopontine nucleus (PPN)” for PD?
- Nondopaminergic system is linked to difficulties with attention and dual tasking
- Reduced cholinergic activity in people with PD who fall
- Cholinesterase inhibitor can reduce falls and improve dual tasking in some small trials in older adults with Alzheimer’s Disease
What does a normal basal ganglia loop look like?
What does a PD basal ganglia loop look like?
What are 4 functions of basal ganglia?
- Automatic execution of learned motor plans
- Internally generated movement
- Sequential movement
- Learned motor plans (e.g. gait)
- PD basal ganglia loop
- Contributes to motor set - preparedness for movement
- Provides internal cueing to link sub-movements in sequential movements
- Not as involved in
- Externally generated, simple, or novel movements
- Therapy - make tasks more novel, so they are use cortex more than basal ganglia and will be better at doing those movements
What are 4 characteristics of motor control research in PD?
- PD has no deficit in formulation of motor programs
- Impaired execution of movement: Difficulty modulating amplitude and velocity - smaller amplitude & slower velocity
- Difficulty switching from one motor program to another within a motor plan in sequential movements
- Difficulty superimposing motor programs to form a motor plan in simultaneous movements (dual task)
______ has no deficit in formulation of motor programs
PD
What does “impaired execution of movement” mean?
Difficulty modulating amplitude and velocity - smaller amplitude & slower velocity
What are 2 motor control problems with people with PD?
- Difficulty switching from one motor program to another within a motor plan in sequential movements.
- Difficulty superimposing motor programs to form a motor plan in simultaneous movements (dual task)