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 markersGlutamatergic Dysfunction in Autism Spectrum Disorder (P1-8.001)
Brasic J, Nandi A, Russell D, Jennings D, Barret O, Slifer K, Sedlak T, Seibyl J, Berry-Kravis E, Wong D, Budimirovic D. Glutamatergic Dysfunction in Autism Spectrum Disorder (P1-8.001). Neurology 2024, 102 DOI: 10.1212/wnl.0000000000204347.Peer-Reviewed Original ResearchBiological Staging of the Parkinson’s Progression Markers Initiative (PPMI) Cohort Using the Research Neuronal α-synuclein Disease Integrated Staging System (NSD-ISS) (P11-3.009)
Tanner C, Simuni T, Chahine L, Poston K, Brumm M, Chowdry 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, Tolosa E, Weintraub D, Xiao Y, Siderowf A, Poewe W, Marek K. Biological Staging of the Parkinson’s Progression Markers Initiative (PPMI) Cohort Using the Research Neuronal α-synuclein Disease Integrated Staging System (NSD-ISS) (P11-3.009). Neurology 2024, 102 DOI: 10.1212/wnl.0000000000204771.Peer-Reviewed Original ResearchImproved 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 Original Research
2023
Biomarker interplay between CSF p‐tau and 18F‐PI‐2620 PET in Alzheimer’s disease and 4R‐tauopathy
Dilcher R, Wall S, Franzmeier N, Katzdobler S, Barthel H, Wagemann O, Palleis C, Weidinger E, Fietzek U, Kurz C, Ferschmann C, Scheifele M, Eckenweber F, Zaganjori M, Gnörich J, Danek A, Bürger K, Janowitz D, Rauchmann B, Stöcklein S, Perneczky R, Schoeberl F, Zwergal A, Höglinger G, Bartenstein P, Villemagne V, Seibyl J, Sabri O, Levin J, Brendel M. Biomarker interplay between CSF p‐tau and 18F‐PI‐2620 PET in Alzheimer’s disease and 4R‐tauopathy. Alzheimer's & Dementia 2023, 19 DOI: 10.1002/alz.075969.Peer-Reviewed Original ResearchP-tau levelsP-tauF-PI-2620Alzheimer's diseaseCSF p-tau levelsTau protein isoformsCerebrospinal fluid p-tauCorticobasal syndromeVoxel-wise multiple regression analysisPositron emission tomographyElevated P-tau levelsTau-PETProtein isoformsPhosphorylated tauProgressive supranuclear palsyDisease-specific regionsTau-PET uptakeStandardized uptake value ratioGroup differencesNeurodegenerative diseasesTau biomarkersCerebrospinal fluidMultiple regression analysisLentiform nucleusHealthy controls