2022
Sensorimotor Cortical Activity during Respiratory Arousals in Obstructive Sleep Apnea
Bahr-Hamm K, Koirala N, Hanif M, Gouveris H, Muthuraman M. Sensorimotor Cortical Activity during Respiratory Arousals in Obstructive Sleep Apnea. International Journal Of Molecular Sciences 2022, 24: 47. PMID: 36613490, PMCID: PMC9820672, DOI: 10.3390/ijms24010047.Peer-Reviewed Original ResearchConceptsModerate OSA patientsSevere OSASensorimotor cortical activityOSA patientsRespiratory arousalsCortical activityObstructive sleep apnea patientsSevere OSA patientsObstructive sleep apneaSignificant decreaseSleep apnea patientsSleep stagesRaw electroencephalography dataModerate OSASleep apneaRespiratory eventsApnea patientsDifferential diagnosisSleep stage N1PatientsAutonomic activationStage N1Cortical arousalPathophysiologic traitsOSAReduced Cross-Frequency Coupling and Daytime Sleepiness in Obstructive Sleep Apnea Patients
Gouveris H, Koirala N, Anwar A, Ding H, Ludwig K, Huppertz T, Matthias C, Groppa S, Muthuraman M. Reduced Cross-Frequency Coupling and Daytime Sleepiness in Obstructive Sleep Apnea Patients. Biology 2022, 11: 700. PMID: 35625429, PMCID: PMC9138271, DOI: 10.3390/biology11050700.Peer-Reviewed Original ResearchRespiratory disturbance indexObstructive sleep apneaCortical sensorimotor areasOSA patientsSensorimotor areasRespiratory distressCross-frequency couplingObstructive sleep apnea patientsEpworth Sleepiness ScaleSleep apnea patientsSleep stagesDistinct sleep stagesMotor dysfunctionSleep apneaPatient groupApnea patientsDaytime sleepinessSleepiness ScalePatientsPolysomnography recordingsObjective markersSubjective sleepinessDisturbance indexSleepinessDistress
2020
Mapping of subthalamic nucleus using microelectrode recordings during deep brain stimulation
Koirala N, Serrano L, Paschen S, Falk D, Anwar A, Kuravi P, Deuschl G, Groppa S, Muthuraman M. Mapping of subthalamic nucleus using microelectrode recordings during deep brain stimulation. Scientific Reports 2020, 10: 19241. PMID: 33159098, PMCID: PMC7648837, DOI: 10.1038/s41598-020-74196-5.Peer-Reviewed Original ResearchConceptsMicroelectrode recordingsBackground activityStereotactic magnetic resonance imagingLow beta frequency rangeDeep brain stimulation surgeryBilateral STN-DBSSide effect ratioDeep brain stimulationBeta frequency rangeMagnetic resonance imagingSTN-DBSAwake patientsLead placementSubthalamic nucleusIntraoperative decisionAnatomical sitesBrain stimulationDBS electrodesOptimal target localizationResonance imagingMaximum spike rateBeta rangeSpike ratePatientsImplantation
2019
Cortical network fingerprints predict deep brain stimulation outcome in dystonia
Gonzalez‐Escamilla G, Muthuraman M, Reich M, Koirala N, Riedel C, Glaser M, Lange F, Deuschl G, Volkmann J, Groppa S. Cortical network fingerprints predict deep brain stimulation outcome in dystonia. Movement Disorders 2019, 34: 1537-1546. PMID: 31433874, DOI: 10.1002/mds.27808.Peer-Reviewed Original ResearchConceptsDeep brain stimulationModerate-outcome groupDystonia patientsEffective evidence-based therapySuperior-outcome groupGlobus pallidus internusGrey matter atrophy patternsEvidence-based therapiesBrain network organizationClinical responseCortical atrophyDBS outcomesIndependent predictorsMotor improvementMulticenter cohortDBS implantationAtrophy patternsPreoperative MRITherapy responseVisuomotor areasCortical thicknessBrain stimulationCortical mantlePatientsUnequivocal predictorsAlterations in White Matter Network and Microstructural Integrity Differentiate Parkinson’s Disease Patients and Healthy Subjects
Koirala N, Anwar A, Ciolac D, Glaser M, Pintea B, Deuschl G, Muthuraman M, Groppa S. Alterations in White Matter Network and Microstructural Integrity Differentiate Parkinson’s Disease Patients and Healthy Subjects. Frontiers In Aging Neuroscience 2019, 11: 191. PMID: 31404311, PMCID: PMC6676803, DOI: 10.3389/fnagi.2019.00191.Peer-Reviewed Original ResearchPD patientsHealthy subject groupParkinson's diseaseNetwork-based statisticsDisease patientsHealthy controlsHealthy subjectsWhite matterMiddle-aged healthy controlsNetwork alterationsProbabilistic tractography analysisParkinson's disease patientsWhite matter changesSubject groupsWhite matter microstructural integrityElderly healthy controlsDistinct brain areasPD pathophysiologyWhite matter networksCorticospinal tractCorpus callosumCorona radiataMatter changesPatientsBrain areasLarge-scale network architecture and associated structural cortico-subcortical abnormalities in patients with sleep/awake-related seizures
Chiosa V, Ciolac D, Groppa S, Koirala N, Pintea B, Vataman A, Winter Y, Gonzalez-Escamilla G, Muthuraman M, Groppa S. Large-scale network architecture and associated structural cortico-subcortical abnormalities in patients with sleep/awake-related seizures. Sleep 2019, 42: zsz006. PMID: 30753617, DOI: 10.1093/sleep/zsz006.Peer-Reviewed Original ResearchConceptsAwake seizuresSleep seizuresHealthy controlsAwake stateSex-matched healthy controlsRight middle temporal cortexDifferent epilepsy typesVolume of hippocampusBrain networksMiddle temporal cortexEpilepsy typePathophysiological alterationsSubcortical abnormalitiesPatientsTemporal cortexSeizuresSubcortical regionsSuperior temporalBilateral insulaOrbitofrontal cortexSleepParietal regionsAbnormalitiesRight hemisphereStructural correlatesLongitudinal cortical network reorganization in early relapsing–remitting multiple sclerosis
Fleischer V, Koirala N, Droby A, Gracien R, Deichmann R, Ziemann U, Meuth S, Muthuraman M, Zipp F, Groppa S. Longitudinal cortical network reorganization in early relapsing–remitting multiple sclerosis. Therapeutic Advances In Neurological Disorders 2019, 12: 1756286419838673. PMID: 31040880, PMCID: PMC6482642, DOI: 10.1177/1756286419838673.Peer-Reviewed Original ResearchRelapsing-remitting MSEarly relapsing-remitting MSHealthy controlsDisease activityEarly relapsing-remitting multiple sclerosisLongitudinal brain volume changesRelapsing-remitting multiple sclerosisCortical atrophy patternsStructural cortical networksPatients' disease activityNetwork reorganizationBrain volume changesClinical disease manifestationsDetectable atrophyMultiple sclerosisAtrophy patternsDisease manifestationsAtrophy measurementsCortical responsesGray matter networksBrain functionPatientsT MRICortical networksGraph theoretical analysisStructural brain network fingerprints of focal dystonia
Chirumamilla V, Dresel C, Koirala N, Gonzalez-Escamilla G, Deuschl G, Zeuner K, Muthuraman M, Groppa S. Structural brain network fingerprints of focal dystonia. Therapeutic Advances In Neurological Disorders 2019, 12: 1756286419880664. PMID: 31798688, PMCID: PMC6859688, DOI: 10.1177/1756286419880664.Peer-Reviewed Original ResearchBSP patientsHFS patientsBoNT treatmentHealthy controlsFocal dystoniaHemifacial spasmSensorimotor cortexFrontal cortexTemporal cortexStructural magnetic resonance imagingReduced connectivityGray matter volumeDifferent brain regionsSymptomatic reductionMovement disordersStructural brain networksGraph-based network analysisPatientsMatter volumeBlepharospasmDystoniaParietal cortexResonance imagingBrain regionsDecreased connectivity
2017
Breakdown of Thalamo-Cortical Connectivity Precedes Spike Generation in Focal Epilepsies
Chiosa V, Groppa S, Ciolac D, Koirala N, Mişina L, Winter Y, Moldovanu M, Muthuraman M, Groppa S. Breakdown of Thalamo-Cortical Connectivity Precedes Spike Generation in Focal Epilepsies. Brain Connectivity 2017, 7: 309-320. PMID: 28494616, DOI: 10.1089/brain.2017.0487.Peer-Reviewed Original ResearchConceptsFrontal lobeVentral anterior nucleusThalamo-cortical connectivityFuture therapeutic approachesSpike generationFocal epileptic seizuresMedial dorsalThalamic volumeFocal epilepsyAnterior nucleusFrontal cortexTherapeutic approachesEpileptic seizuresCerebral networksCortical integrityThalamusEEG recordingsWidespread areasDistinct patternsLobeEpileptogenesisPatientsEpilepsySeizuresCortex
2015
Testing the effects of pre-processing on voxel based morphometry analysis
Chaitanya C, Koirala N, Mideksa K, Anwar A, Schmidt G, Deuschl G, Groppa S, Muthuraman M. Testing the effects of pre-processing on voxel based morphometry analysis. Annual International Conference Of The IEEE Engineering In Medicine And Biology Society (EMBC) 2015, 2015: 4302-4305. PMID: 26737246, DOI: 10.1109/embc.2015.7319346.Peer-Reviewed Original ResearchConceptsGray matter volumeGray matter differencesDifferent time pointsTime pointsMagnetic resonance imagesBotulinum toxin injectionEvidence-based therapiesStructural grey matter differencesVoxel-wise comparisonBase therapyToxin injectionCross-sectional data analysisBotulinum toxinMatter volumeRespective musclesMorphometry analysisLongitudinal data analysisPatientsLongitudinal analysisResonance imagesInjectionBrainTreatmentSecond aimStatistical analysis