ParkinsonsDisease.pptx

Parkinsons DiseaseAn Overview of Conventional and Experimental TreatmentsBackground Parkinsons disease is a disorder that affects nerve cells in the part of the brain controlling muscle movementDisease is progressive signs/symptoms worsen over timeEventually is disabling,but progresses graduallyBelieved to be caused by genetics,environmental factors or a combination of the twoParkinsons Disease StatsFirst desribed by James Parkinson in 1817Affects 1 million in the U.S.Onset typically between 50-60 years of age,and slowly progresses with ageAverage onset is 62.4 years of ageNeurological Basis“Neurodegenerative Disease”:caused by degeneration(dysfunction and death)of neurons within the brain(nigrastriatal pathway of the basal ganglia)NORMAL BRAIN FUNCTION Basal GangliaCells in substantia nigra produce/release dopamineDopamine released by SN neurons lands on neurons of other brain centers,controlling their firingMain targets are caudate nucleus and putamen(striatum)This basal ganglia pathway is involved in regulation of movementNeurological BasisPARKINSONS BRAIN FUNCTIONBasal GangliaCells of substantia nigra degenerateThese cells can no longer produce adequate amounts of dopamineNeurons of striatum,etc.are no longer well regulated,thus do not behave in normal mannerResults in loss of control of movements leads to symptoms characteristic of Parkinsons diseaseCharacteristic SymptomsMOTOR tremorbradykinesiarigidity/freezing in placelack of facial expressionpostural instabilitystooped,shuffling gaitNONMOTOR diminished sense of smelllow voice volumefoot crampssleep disturbancedepressionconstipationdroolingConventional Treatments:MedicationLEVODOPA(L-DOPA)precursor to dopamine,converted to dopamine by nerve cells in the brainTreatment with dopamine not possible,because dopamine cant cross blood-brain barrierGenerally combined with carbidopa(Sinemet)helps levodopa get to the brain+reduces some side effectsExtended use often produces dyskinesias uncontrolled movements(writhing,twitching,shaking)among other minor side effectsConventional Treatments:MedicationDOPAMINE AGONISTS not changed into dopamine,but rather act LIKE dopamine at brain synapses where dopamine is usually present(nigrostriatal pathways in Parkinsons patients)Used both as adjuncts to L-Dopa therapy and in younger Parkinsons disease patientsSide effects similar to levodopa,but less likely to develop involuntary movements,more likely to cause hallucinationsConventional Treatments:MedicationMAO Inhibitors(Selegiline)COMT InhibitorsAnticholinergicsConventional Treatments:SurgeryThalamotomyInvolves destruction of small amounts of tissue in the thalamusmajor center for relaying messages/transmitting sensationsCan cause slurred speech and lack of coordination Pallidotomy electric current used to destroy small amount of tissue in the pallidum(globus pallidus)May improve tremors,rigidity by interrupting pathway between globus pallidus and thalamus Conventional Treatments:SurgeryDeep Brain Stimulation implant device,pacemaker-like unit transmits impulses to electrodes placed in subthalamic nucleusProduces same effects of lesion surgeries,but can be turned on and offExperimental Treatment:SurgeryFetal Cell Transplant Therapy stem cells obtained via aborted fetus,grown in culture,transplanted into Parkinsons patient at nigrostriatal pathwayNew cells establish connections and“replace”cells originally lost,these cells function normally and even produce dopamineAutologous“Self”Transplant analagous to fetal cell transplant,except that precursor nerve cells are taken from patient and coaxed to produce dopamine,then implanted back into original patientReduces threat of autoimmune response and reduced“controversial baggage”associated with FCT therapyExperimental Treatment:SurgeryRetinal Pigmented Epithelial Cell Transplant Dopamine-producing cells taken from pigmented retinal epithelium Mechanism of transplant analagous to fetal cell transplant therapy If loss of contact from substrate,these cells dieConsequently,lower risk of aberrant integrationpossible cause of dyskinesias seen in some FCT patientsSourcesAminoff,M.(2003).Parkinson Primer:Overview of Parkinsons Disease.Retrieved November 16,2005,from http:/www.parkinson.org/site/pp.asp?c=9dJFJLPNB&b=71354.This source provided me with the most of the background information necessary in explaining the foundation of the disease.This source was especially helpful in determining the characteristic symptoms of the disorder as well as statistics.Freed,C.R.,Green,P.E.,Breeze,R.E.,Tsai,W.,DuMouchel,W.,Kao,R.,Dillon,S.,et al.(1994).Transplantation of Embryonic Dopamine Neurons for Severe Parkinsons Disease.New England Journal of Medicine,344,(7),710-719.This source played a large part in writing the actual paper.In this article was information on the background of stem cells,implications in stem cell research,and most beneficial,the actual experimental procedure itself.Lieberman,A.(2004).What is Parkinsons Disease?Retrieved November 14,2005,from http:/www.pdcaregiver.org/WhatIsParkinsons.html.This source didnt help much background information on the disease,but did help in providing an comprehendable version of the substantia nigra and its role in development of Parkinsons disease.Also beneficial were the figures associated with this source.