Parkinson's disease Flashcards
Symptoms of Parkinson’s disease:
Tremors, rigidity, and bradykinesia
Postural instability and gait difficulties
Loss of smell and constipation
Sleep disturbances and depression
Proposed etiology of Parkinson’s disease:
A combination of genetic and environmental factors
Degeneration of dopaminergic neurons in the substantia nigra
Accumulation of alpha-synuclein protein in Lewy bodies
Neuropathology of Parkinson’s disease:
Degeneration of dopaminergic neurons in the substantia nigra
Accumulation of alpha-synuclein protein in Lewy bodies
Decreased dopamine levels in the striatum
Disruption of basal ganglia-thalamocortical circuits
How does nigrostriatal tract degeneration affect basal ganglia firing in Parkinson’s disease?
Loss of dopamine from the substantia nigra leads to decreased activity in the direct pathway and increased activity in the indirect pathway of the basal ganglia
This results in decreased thalamic stimulation and decreased cortical motor activity, leading to the movement deficit seen in Parkinson’s disease
Current drug treatments for Parkinson’s disease:
Levodopa and dopamine agonists to increase dopamine levels
COMT inhibitors and MAO-B inhibitors to prolong the effects of levodopa
Anticholinergics and amantadine to reduce tremors and dyskinesias
Rationale behind the use of current drug treatments for Parkinson’s disease:
Increasing dopamine levels can improve motor symptoms
Prolonging the effects of levodopa can reduce “off” time and improve motor fluctuations
Anticholinergics and amantadine can reduce tremors and dyskinesias
Limitations of current drug treatments for Parkinson’s disease:
The main limitations of current drug treatments for Parkinson’s disease are that they can have side effects such as:
dyskinesias, and they do not address the underlying neurodegenerative process of the disease.
In addition, long-term use of levodopa can lead to fluctuations in response and dyskinesias.
