Adjunct Faculty
Adjunct faculty typically have an academic or research appointment at another institution and contribute or collaborate with one or more School of Medicine faculty members or programs.
Adjunct rank detailsJohn Seibyl, MD
Professor AdjunctAbout
Research
Publications
2026
Five‐Year Disease Progression in Synuclein Seeding Positive Sporadic Parkinson's Disease
Gonzalez‐Latapi P, Gochanour C, Choi S, Cho H, Caspell‐Garcia C, Coffey C, Brumm M, Lafontant D, Xiao Y, Tropea T, Seibyl J, Tanner C, Venuto C, Kieburtz K, Chahine L, Poston K, Siderowf A, Marek K, Simuni T, Initiative T. Five‐Year Disease Progression in Synuclein Seeding Positive Sporadic Parkinson's Disease. Annals Of Clinical And Translational Neurology 2026 PMID: 41808287, DOI: 10.1002/acn3.70323.Peer-Reviewed Original ResearchDisease progressionCox proportional hazards modelsStage-dependent increaseClinical diagnostic criteriaNeurofilament light chainProportional hazards modelDescription of disease progressionParkinson's diseaseSerum urateDopamine deficitClinical trialsDisease stageDiagnostic criteriaSeed assayInclusion criteriaHazards modelBaseline stageParkinson's Progression Markers InitiativeSporadic Parkinson's diseasePostural instabilityLight chainStage 4Disease populationProgression Markers InitiativeParkinson's disease participantsToward Harmonizing Quantification of Dopamine Neuron Imaging Biomarkers in Parkinson's Disease: The Centamine Scale
Fan Z, Searle G, Rizzo G, Albani J, Cella P, Comley R, Klein G, Passamonti L, Salinas C, Schwarz A, Iaccarino L, Tamagnan G, Eberling J, Marek K, Seibyl J, Gunn R, Marek K, Tanner C, Simuni T, Siderowf A, Galasko D, Chahine L, Coffey C, Merchant K, Poston K, Dobkin R, Foroud T, Mollenhauer B, Weintraub D, Brown E, Kieburtz K, Frasier M, Sherer T, Chowdhury S, Alcalay R, Videnovic A, Tosun‐Turgut D, Poewe W, Bressman S, Hammer J, James R, Riley E, Seibyl J, Shaw L, Standaert D, Mantri S, Dahodwala N, Schwarzschild M, Marras C, Fernandez H, Shoulson I, Rowbotham H, Casalin P, Trenkwalder C, Sherer T, Chowdhury S, Frasier M, Eberling J, Kopil K, O'Grady A, Kuhl M, Kirsch L, Willson T, Adler C, Alcalay R, Amara A, Barone P, Bloem B, Bressman S, Brockmann K, Brüggemann N, Chahine L, Chou K, Dahodwala N, Espay A, Factor S, Fernandez H, Fullard M, Galasko D, Hauser R, Hogarth P, Hu S, Hu M, Isaacson S, Klein C, Krueger R, Lew M, Mari Z, Marras C, Martí M, McFarland N, Mestre T, Mollenhauer B, Moukheiber E, Noyce A, Okubadejo N, O'Shea S, Pahwa R, Pavese N, Poewe W, Postuma R, Riboldi G, Ruffrage L, Martinez J, Russell D, Saint‐Hilaire M, Santos N, Schlett47 W, Schneider R, Shill H, Shprecher D, Simuni T, Standaert D, Stefanis L, Tai Y, Tanner C, Tarakad A, PhD34 E, Videnovic A, Ainscough S, Blair C, Botting E, Chung I, Clark K, Croitoru I, DeLano K, Egner I, Esha F, Eshel M, Ferrari F, Foster V, Garrido A, Grümmer M, Herrera B, Hilt E, Huntzinger C, James R, Kausar F, Koros C, Krasowski60 Y, Le D, Liu Y, Marques T, Santana H, Mosovsky S, Mule J, Ng P, O'Brien L, Ogunleye A, Ojo O, Onyinanya O, Pennente L, Perrotti R, Pileggi M, Ramachandran A, Raymond D, Razzaque J, Reddie S, Ribb K, Rizer K, Rodriguez J, Roman S, Sanchez C, Simonet C, Singh A, Sittig E, Sommerfeld B, Stovall A, Stubbeman B, Valenzuela A, Wandell C, Willeke D, Williams K, Wubuli D. Toward Harmonizing Quantification of Dopamine Neuron Imaging Biomarkers in Parkinson's Disease: The Centamine Scale. Annals Of Neurology 2026, 99: 949-963. PMID: 41556298, PMCID: PMC13011789, DOI: 10.1002/ana.78116.Peer-Reviewed Original ResearchConceptsSingle photon emission computed tomographyClinical trialsParkinson's diseasePhoton emission computed tomographyEmission Computed TomographyDopaminergic neuronal lossBrain regionsSPECT scansMolecular imaging tracersComputed tomographyHealthy subject dataImaging outcomesImaging biomarkersHarmonized quantificationNeuronal lossImaging markersOutcome measuresDopaminergic imagingImaging tracersLevel 1PET dataDiseaseBiomarkersTrialsLevel 2
2025
Evidence for alpha-synuclein aggregation in older individuals with hyposmia: a cross-sectional study
Marek K, Russell D, Concha-Marambio L, Choi S, Jennings D, Brumm M, Coffey C, Brown E, Seibyl J, Stern M, Soto C, Siderowf A. Evidence for alpha-synuclein aggregation in older individuals with hyposmia: a cross-sectional study. EBioMedicine 2025, 112: 105567. PMID: 39893720, PMCID: PMC11835612, DOI: 10.1016/j.ebiom.2025.105567.Peer-Reviewed Original ResearchConceptsDementia with Lewy bodiesCross-sectional studyCognitive symptomsParkinson Associated Risk Syndrome StudyPrevention StudyYear Follow-UpOlder individualsDopamine transporter imagingHigh riskSyndrome studiesParticipantsParkinson's diseaseHyposmic individualsFollow-upSynuclein pathologySymptomsHyposmicsDepartment of DefenseU.S. Department of DefenseIndividualsRiskLewy bodiesClinical parkinsonismMichael J. Fox FoundationDementia
2024
Combining cerebrospinal fluid and PI‐2620 tau‐PET for biomarker‐based stratification of Alzheimer's disease and 4R‐tauopathies
Dilcher R, Wall S, Groß M, Katzdobler S, Wagemann O, Palleis C, Weidinger E, Fietzek U, Bernhardt A, Kurz C, Ferschmann C, Scheifele M, Zaganjori M, Gnörich J, Bürger K, Janowitz D, Rauchmann B, Stöcklein S, Bartenstein P, Villemagne V, Seibyl J, Sabri O, Barthel H, Perneczky R, Schöberl F, Zwergal A, Höglinger G, Levin J, Franzmeier N, Brendel M. Combining cerebrospinal fluid and PI‐2620 tau‐PET for biomarker‐based stratification of Alzheimer's disease and 4R‐tauopathies. Alzheimer's & Dementia 2024, 20: 6896-6909. PMID: 39263969, PMCID: PMC11485081, DOI: 10.1002/alz.14185.Peer-Reviewed Original ResearchConceptsBiomarker-based stratificationNeuronal injury biomarkersInjury biomarkersBiomarker-based algorithmsP-tauCombination of CSF markersHealthy controlsClinical trialsCortical hypoperfusionAlzheimer's diseaseCerebrospinal fluidEmission tomographyDiagnostic workflowBiomarker researchCerebrospinal fluid measuresBiomarkersPatientsHypoperfusionTau-PETCSF markersImproved Tau PET SUVR Quantification in 4-Repeat Tau Phenotypes with [18F]PI-2620
Bischof G, Brendel M, Barthel H, Theis H, Barbe M, Bartenstein P, Claasen J, Danek A, Höglinger G, Levin J, Marek K, Neumaier B, Palleis C, Patt M, Rullmann M, Saur D, Schroeter M, Seibyl J, Song M, Stephens A, Sabri O, Drzezga A, van Eimeren T, Tauopathies F. Improved Tau PET SUVR Quantification in 4-Repeat Tau Phenotypes with [18F]PI-2620. Journal Of Nuclear Medicine 2024, 65: jnumed.123.265930. PMID: 38575191, PMCID: PMC11149601, DOI: 10.2967/jnumed.123.265930.Peer-Reviewed Original ResearchConceptsReference regionAssociated with symptom severitySUV ratioSymptom severitySecond-generation tau tracersGroup of patientsImaging tracersTreatment trialsTau phenotypeTracking disease progressionDisease-modifying treatment trialsSecond-generationProgressive supranuclear palsyDisease durationPatient stratificationTau accumulation is associated with dopamine deficiency in vivo in four-repeat tauopathies
Ferschmann C, Messerschmidt K, Gnörich J, Barthel H, Marek K, Palleis C, Katzdobler S, Stockbauer A, Fietzek U, Finze A, Biechele G, Rumpf J, Saur D, Schroeter M, Rullmann M, Beyer L, Eckenweber F, Wall S, Schildan A, Patt M, Stephens A, Classen J, Bartenstein P, Seibyl J, Franzmeier N, Levin J, Höglinger G, Sabri O, Brendel M, Scheifele M. Tau accumulation is associated with dopamine deficiency in vivo in four-repeat tauopathies. European Journal Of Nuclear Medicine And Molecular Imaging 2024, 51: 1909-1922. PMID: 38366196, PMCID: PMC11139736, DOI: 10.1007/s00259-024-06637-6.Peer-Reviewed Original ResearchConceptsDAT availabilityBasal gangliaSingle-photon emission-computed tomographyStriatal DAT availabilityStriatal dopamine deficiencyTau-PET signalDopamine transporterBrain regionsMidbrain regionsDopamine deficiencyDAT-SPECTDAT SPECT imagingIndirect pathwaysFour-repeat tauopathyClinical severity scoreMethodsThirty-eight patientsTau burdenTau accumulationDATDeficiency in vivoResultsIn patientsMethodsThirty-eightSeverity scoreDopaminePatientsA biological definition of neuronal α-synuclein disease: towards an integrated staging system for research
Simuni T, Chahine L, Poston K, Brumm M, Buracchio T, Campbell M, Chowdhury S, Coffey C, Concha-Marambio L, Dam T, DiBiaso P, Foroud T, Frasier M, Gochanour C, Jennings D, Kieburtz K, Kopil C, Merchant K, Mollenhauer B, Montine T, Nudelman K, Pagano G, Seibyl J, Sherer T, Singleton A, Stephenson D, Stern M, Soto C, Tanner C, Tolosa E, Weintraub D, Xiao Y, Siderowf A, Dunn B, Marek K. A biological definition of neuronal α-synuclein disease: towards an integrated staging system for research. The Lancet Neurology 2024, 23: 178-190. PMID: 38267190, DOI: 10.1016/s1474-4422(23)00405-2.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus Statements
2023
Dopamine Transporter Availability in Early Parkinson's Disease is Dependent on Sunlight Exposure
Booij J, Tellier S, Seibyl J, Vriend C. Dopamine Transporter Availability in Early Parkinson's Disease is Dependent on Sunlight Exposure. Movement Disorders 2023, 38: 2131-2135. PMID: 37670567, DOI: 10.1002/mds.29597.Peer-Reviewed Original ResearchConceptsDopamine transporter availabilityStriatal DAT availabilityDopamine transporterDAT availabilityParkinson's Progression Markers InitiativeEarly Parkinson's diseaseParkinson's diseaseLeft caudate nucleusHealthy controlsSingle-photon emission computed tomography scanDopaminergic functionTransporter availabilityCaudate nucleusProgression Markers InitiativeComputed tomography scanHigh sun exposurePD patientsDopamineTomography scanSun exposurePatientsSunlight exposureDiseaseNeurotheranostics: The Next Frontier for Health Span
Losee M, Seibyl J, Kuo P. Neurotheranostics: The Next Frontier for Health Span. Journal Of Nuclear Medicine Technology 2023, 51: jnmt.123.265502. PMID: 37586855, DOI: 10.2967/jnmt.123.265502.Peer-Reviewed Original ResearchConceptsAlzheimer's diseaseHealth spanGenetic markersPathological stagePathological stages of ADTreatment of Alzheimer's diseaseStages of ADBiomarkers of amyloidAmyloidNeurodegenerative diseasesAD biomarkersBrain amyloid loadMild early symptomsAt-risk populationsAmyloid loadPET biomarkersAntiamyloid therapiesFamily historyAD symptomsNormal patientsPersonalized therapyCognitively normal patientsRisk factorsTherapyU.S. populationAssessment of heterogeneity among participants in the Parkinson's Progression Markers Initiative cohort using α-synuclein seed amplification: a cross-sectional study
Siderowf A, Concha-Marambio L, Lafontant D, Farris C, Ma Y, Urenia P, Nguyen H, Alcalay R, Chahine L, Foroud T, Galasko D, Kieburtz K, Merchant K, Mollenhauer B, Poston K, Seibyl J, Simuni T, Tanner C, Weintraub D, Videnovic A, Choi S, Kurth R, Caspell-Garcia C, Coffey C, Frasier M, Oliveira L, Hutten S, Sherer T, Marek K, Soto C, Initiative P. Assessment of heterogeneity among participants in the Parkinson's Progression Markers Initiative cohort using α-synuclein seed amplification: a cross-sectional study. The Lancet Neurology 2023, 22: 407-417. PMID: 37059509, PMCID: PMC10627170, DOI: 10.1016/s1474-4422(23)00109-6.Peer-Reviewed Original ResearchConceptsNon-manifesting carriersHealthy controlsAt-risk groupsSeed amplification assaysProdromal participantsOlfactory deficitsParkinson's Progression Markers InitiativeBiochemical diagnosisEarly identification of at-risk groupsVariants associated with Parkinson's diseaseIdentification of at-risk groupsSporadic Parkinson's diseaseEarly identificationParkinson's diseaseEvidence of dopaminergic deficitCross-sectional studyCross-sectional analysisAt-risk cohortAnalysis of CSFSubgroups of peopleNeurocrine BiosciencesNormal olfactionAssessment of heterogeneityParkinson's Progression Markers Initiative cohortClinical features