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28 Cards in this Set
- Front
- Back
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PD Symptoms |
- Tremor - Rigidity - Bradykinesia - Postural Disturbances |
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Tremor |
- Early sign - present when extremities are at rest - reduced during movement |
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Rigidity |
- increased muscle tone - cogwheel movements - little facial expression - shuffling gait - stooped shoulders |
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Bradykinesia |
- slowness of movement - difficulty initiating movement |
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Postural Disturbances |
- loss of postural stability - in later stages, wheelchair bound |
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Cogwheel Movement |
- |
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PD Epidemiology |
- Effects 1-2% of the population over 60 - found worldwide - most common in industrialized countries - severity increases over time |
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Idiopathic |
- unknown cause |
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Parkin |
- protein if mutated is associated with parkinson's |
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Alpha-synuclein |
-- protein if mutated is associated with parkinson's |
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Striatum |
- subcortical part of the forebrain - major input station for basal ganglia system - gets input from cerebral cortex |
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PD Pathology |
- loss of DA neurons in substantia nigra - clinical symptoms occur when DA is reduced 80% - Also loss of NE, 5-HT, and ACh neurons in brain |
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Substantia nigra (SNc) |
- located in brain stem - project into striatum |
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SNc DA Neurons |
- project to striatum |
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GABA Neurons in Striatum |
- project to globus pallidus |
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GABA Neurons in Globus Pallidus (GP) |
- project to thalamus |
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Globus Pallidus |
- part of basal ganglia - controlling subconscious voluntary movement |
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Glutamate Neurons in Thalamus |
- project to motor regions in cortex |
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PD Drug Therapies |
- L-dopa - Carbidopa - MAO-B Blockers - Dopamine Agonists |
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L-dopa |
- precursor for DA - crosses blood brain barrier via amino acid transporter - then converted into DA - relieves symptoms - no effect on disease progression - gradually lose sensitivity - only effective for several years |
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Carbidopa |
- inhibits dopa-decarboxylase in periphery - helps to ensure L-dopa reaches the brain |
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MAO-B Blockers |
- MAO-B matebolizes DA - Blocking the enxyme increases synaptic levels of DA - For early mild cases, can augment effect of L-dopa |
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Dopamine Agonists |
- Act directly on postsynaptic DA receptors |
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Deep Brain Stimulation |
- Electrodes planted in brain that are switched on - provides symptomatic relief when needed |
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DA Neurons |
- selectively sensitive to toxins - ex. MPP+ is mistaken by DA cell for dopamine. Once inside, MPP disrupts energy production, forming more free radicals |
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Generation of free radicals in DA Neurons |
- produced by normal oxidative metabolism - if toxin increased free radical production, programmed death occurs in DA neuron |
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L-dopa Side Effects |
- psychosis/hullucinations - dyskinesias |
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dyskinesias |
- involuntary movements |
