Renzo Comolatti1, Andrea Pigorini2, Silvia Casarotto2, Matteo Fecchio2, Guilherme Faria1, Simone Sarasso2, Mario Rosanova2, Olivia Gosseries3, Mélanie Boly4, Olivier Bodart3, Didier Ledoux5, Jean-François Brichant6, Lino Nobili7, Steven Laureys3, Giulio Tononi4, Marcello Massimini8, Adenauer G Casali9. 1. Institute of Science and Technology, Federal University of São Paulo, São José dos Campos, 12231-280, Brazil. 2. Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, 20157, Italy. 3. GIGA-Consciousness, GIGA Research, University of Liège, Liège, 4000, Belgium; Coma Science Group, University Hospital of Liège, Liège, 4000, Belgium. 4. Department of Psychiatry, University of Wisconsin, Madison, 53719, USA. 5. GIGA-Consciousness, GIGA Research, University of Liège, Liège, 4000, Belgium. 6. Department of Anesthesia and Intensive Care Medicine, University Hospital of Liège, Liège, 4000, Belgium. 7. Center of Epilepsy Surgery "C. Munari", Department of Neuroscience, Niguarda Hospital, Milan, 20162, Italy; Child Neuropsychiatry, IRCCS G. Gaslini, DINOGMI, University of Genoa, Genova, 16147, Italy. 8. Department of Biomedical and Clinical Sciences "Luigi Sacco", University of Milan, Milan, 20157, Italy; Istituto Di Ricovero e Cura a Carattere Scientifico, Fondazione Don Carlo Gnocchi, Milan, 20148, Italy. 9. Institute of Science and Technology, Federal University of São Paulo, São José dos Campos, 12231-280, Brazil. Electronic address: casali@unifesp.br.
Abstract
BACKGROUND: The Perturbational Complexity Index (PCI) was recently introduced to assess the capacity of thalamocortical circuits to engage in complex patterns of causal interactions. While showing high accuracy in detecting consciousness in brain-injured patients, PCI depends on elaborate experimental setups and offline processing, and has restricted applicability to other types of brain signals beyond transcranial magnetic stimulation and high-density EEG (TMS/hd-EEG) recordings. OBJECTIVE: We aim to address these limitations by introducing PCIST, a fast method for estimating perturbational complexity of any given brain response signal. METHODS: PCIST is based on dimensionality reduction and state transitions (ST) quantification of evoked potentials. The index was validated on a large dataset of TMS/hd-EEG recordings obtained from 108 healthy subjects and 108 brain-injured patients, and tested on sparse intracranial recordings (SEEG) of 9 patients undergoing intracranial single-pulse electrical stimulation (SPES) during wakefulness and sleep. RESULTS: When calculated on TMS/hd-EEG potentials, PCIST performed with the same accuracy as the original PCI, while improving on the previous method by being computed in less than a second and requiring a simpler set-up. In SPES/SEEG signals, the index was able to quantify a systematic reduction of intracranial complexity during sleep, confirming the occurrence of state-dependent changes in the effective connectivity of thalamocortical circuits, as originally assessed through TMS/hd-EEG. CONCLUSIONS: PCIST represents a fundamental advancement towards the implementation of a reliable and fast clinical tool for the bedside assessment of consciousness as well as a general measure to explore the neuronal mechanisms of loss/recovery of brain complexity across scales and models.
BACKGROUND: The Perturbational Complexity Index (PCI) was recently introduced to assess the capacity of thalamocortical circuits to engage in complex patterns of causal interactions. While showing high accuracy in detecting consciousness in brain-injured patients, PCI depends on elaborate experimental setups and offline processing, and has restricted applicability to other types of brain signals beyond transcranial magnetic stimulation and high-density EEG (TMS/hd-EEG) recordings. OBJECTIVE: We aim to address these limitations by introducing PCIST, a fast method for estimating perturbational complexity of any given brain response signal. METHODS: PCIST is based on dimensionality reduction and state transitions (ST) quantification of evoked potentials. The index was validated on a large dataset of TMS/hd-EEG recordings obtained from 108 healthy subjects and 108 brain-injured patients, and tested on sparse intracranial recordings (SEEG) of 9 patients undergoing intracranial single-pulse electrical stimulation (SPES) during wakefulness and sleep. RESULTS: When calculated on TMS/hd-EEG potentials, PCIST performed with the same accuracy as the original PCI, while improving on the previous method by being computed in less than a second and requiring a simpler set-up. In SPES/SEEG signals, the index was able to quantify a systematic reduction of intracranial complexity during sleep, confirming the occurrence of state-dependent changes in the effective connectivity of thalamocortical circuits, as originally assessed through TMS/hd-EEG. CONCLUSIONS: PCIST represents a fundamental advancement towards the implementation of a reliable and fast clinical tool for the bedside assessment of consciousness as well as a general measure to explore the neuronal mechanisms of loss/recovery of brain complexity across scales and models.
Authors: Andrea I Luppi; Michael M Craig; Ioannis Pappas; Paola Finoia; Guy B Williams; Judith Allanson; John D Pickard; Adrian M Owen; Lorina Naci; David K Menon; Emmanuel A Stamatakis Journal: Nat Commun Date: 2019-10-10 Impact factor: 14.919
Authors: Arnfinn Aamodt; André Sevenius Nilsen; Benjamin Thürer; Fatemeh Hasanzadeh Moghadam; Nils Kauppi; Bjørn Erik Juel; Johan Frederik Storm Journal: Front Psychol Date: 2021-04-23
Authors: Katrin Amunts; Javier DeFelipe; Cyriel Pennartz; Alain Destexhe; Michele Migliore; Philippe Ryvlin; Steve Furber; Alois Knoll; Lise Bitsch; Jan G Bjaalie; Yannis Ioannidis; Thomas Lippert; Maria V Sanchez-Vives; Rainer Goebel; Viktor Jirsa Journal: eNeuro Date: 2022-03-11
Authors: Alessandro Pincherle; Frederic Rossi; Jane Jöhr; Vincent Dunet; Philippe Ryvlin; Mauro Oddo; Nicolas Schiff; Karin Diserens Journal: J Neurol Date: 2020-08-04 Impact factor: 4.849
Authors: Jan Claassen; Yama Akbari; Sheila Alexander; Mary Kay Bader; Kathleen Bell; Thomas P Bleck; Melanie Boly; Jeremy Brown; Sherry H-Y Chou; Michael N Diringer; Brian L Edlow; Brandon Foreman; Joseph T Giacino; Olivia Gosseries; Theresa Green; David M Greer; Daniel F Hanley; Jed A Hartings; Raimund Helbok; J Claude Hemphill; H E Hinson; Karen Hirsch; Theresa Human; Michael L James; Nerissa Ko; Daniel Kondziella; Sarah Livesay; Lori K Madden; Shraddha Mainali; Stephan A Mayer; Victoria McCredie; Molly M McNett; Geert Meyfroidt; Martin M Monti; Susanne Muehlschlegel; Santosh Murthy; Paul Nyquist; DaiWai M Olson; J Javier Provencio; Eric Rosenthal; Gisele Sampaio Silva; Simone Sarasso; Nicholas D Schiff; Tarek Sharshar; Lori Shutter; Robert D Stevens; Paul Vespa; Walter Videtta; Amy Wagner; Wendy Ziai; John Whyte; Elizabeth Zink; Jose I Suarez Journal: Neurocrit Care Date: 2021-07-08 Impact factor: 3.210