Regeneration strat: Parkinsons Flashcards
What is Parkinson’s disease?
A highly prevalent neurodegenerative disorder
What is Parkinson’s characterised by?
Motor dysfunction
AND
Non-motor symptoms
What is the pathology of Parkinson’s
- Degeneration (dysfunction and death) of dopamine neurons in the substansia nigra (nigrastriatal neurons in the basal ganglia)
- Also in other areas
What occurs in normal basal ganglia?
- Cells of the SN produce and released dopamine
- Dopamine especilally affects the dorsal striatum (caudate and putamen)
- Dorsal striatum is involved in motor fucntion
What does dopamine do?
- Transmits signals between the areas of the brain which coordinate smooth and balanced muscle movement
- Controls functions related to mood
What are prescribed to patients with Parkinson’s disease?
- Dopamine precursors
(the brain coverts them to dopamine - Dopamine agonists
(Directly stimulate nerves in the brain which are not naturally stimulated by dopamine)
Where do the inouts to the basal ganglia go through?
The striatum
Where do the outputs from the basal ganglia go to?
The globus palladus and the substansia nigra pars reticula
What are the inhibitory connections in the basal ganglia circuitry?
GABA
What are the excitatory connections in the basal ganglia circuitry?
Glutamate
Describe the basal ganglia circuitry in normal people
When there is cortical input:
- Cortex activates the stratum (caudate and putamen
- Stratum inhibit the globus pallidus and substansia nigra pars reticular, inhibiting the normal inhibition of the thalamus
- Thalamus can then activate the cortex
What happens to the basal ganglia circuitry in Parkinson’s?
- Inputs provided by the substansia nigra are diminished
- More difficult to generate the transient inhibition from the striatum
- Results in TONIC inhibition from the globus pallidus to the thalamus
- Reducing thalamic excitation of the motor cortex
What are the characteristic motor symptoms of Parkinson’s?
- Slowness of movement
- Decreased spontaneous movements (eg. blinking)
- Tremors
- Muscle ridgity
- Drooping eyelids/ open mouth
- Tremor of hands
- Hunched over (postural changes)
- Slow, shuffling gait
What are the non-motor symptoms of Parkinson’s?
- Bowing of shoulders
- Swelling of feet
- Depression, sleep disorders
- Weight loss
- Excessive salivation
- Respiratory problems
- Orthostatic hypotenstion
- Increased sweating
- Constipation
What are the Braak stages of Parkinson’s?
Characterised by the spread of Lewy bodies which effect the brain in different ways
Stage I and stage II:
- Non-motor signs
Stage III:
- Motor signs
Stage IV, V, VI:
- Cognition and emotion signs