DuodenoscopyCrohn DiseaseParkinson DiseaseAlzheimer DiseaseAmyloid beta-Peptidesalpha-SynucleinAntiparkinson Agentstau ProteinsBrainAmyloid beta-Protein PrecursorParkinsonian DisordersNeurofibrillary TanglesPlaque, AmyloidLewy BodiesDementiaParkinson Disease, SecondaryLewy Body DiseaseLevodopaGlucosylceramidaseCognition DisordersAmyloidNeuropsychological TestsApolipoprotein E4Substantia NigraNeurodegenerative DiseasesNeurofibrilsNeuronsDeep Brain StimulationAmyloid Precursor Protein SecretasesPresenilin-1Multiple System AtrophyAge of OnsetDopamineNerve Degeneration1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridineMild Cognitive ImpairmentAtrophyDopaminergic NeuronsOxidopamineDementia, VascularSupranuclear Palsy, ProgressiveSubthalamic NucleusMental Status SchedulePeptide FragmentsGenetic Predisposition to DiseaseDisease Models, AnimalMPTP PoisoningGait Disorders, NeurologicCognition