Evan S Lutkenhoff1, Micah A Johnson2, Silvia Casarotto3, Marcello Massimini4, Martin M Monti5. 1. Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA; Brain Injury Research Center (BIRC), Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. 2. Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA. 3. Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy. 4. Department of Biomedical and Clinical Sciences "L. Sacco", University of Milan, Milan, Italy; IRCCS Fondazione Don Carlo Gnocchi, Milan, Italy. 5. Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA; Brain Injury Research Center (BIRC), Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA. Electronic address: monti@ucla.edu.
Abstract
BACKGROUND: The complexity of neurophysiological brain responses to direct cortical stimulation, referred to as the perturbational complexity index (PCI), has been shown able to discriminate between consciousness and unconsciousness in patients surviving severe brain injury as well as several other conditions (e.g., wake, dreamless sleep, sleep and ketamine dreaming, anesthesia). OBJECTIVE: This study asks whether, in patients with a disorder of consciousness (DOC), the complexity of the neurophysiological response to cortical stimulation is preferentially associated with atrophy within specific brain structures. METHODS: We perform a retrospective analysis of 40 DOC patients and correlate their maximal PCI to MR-based measurements of cortical thinning and subcortical atrophy. RESULTS: PCI was systematically and inversely associated with the degree of local atrophy within the globus pallidus, a region previously linked to electrocortical and behavioral arousal. Conversely, we fail to detect any association between variance in cortical ribbon thickness and PCI. CONCLUSION: These findings corroborate the previously reported association between pallidal atrophy and low behavioral arousal and suggest that this region's role in maintaining the overall balance of excitation and inhibition may critically affect the emergence of complex cortical interactions in chronic disorders of consciousness. This finding thus also suggests a target for potential neuromodulatory intervention in DOC patients.
BACKGROUND: The complexity of neurophysiological brain responses to direct cortical stimulation, referred to as the perturbational complexity index (PCI), has been shown able to discriminate between consciousness and unconsciousness in patients surviving severe brain injury as well as several other conditions (e.g., wake, dreamless sleep, sleep and ketamine dreaming, anesthesia). OBJECTIVE: This study asks whether, in patients with a disorder of consciousness (DOC), the complexity of the neurophysiological response to cortical stimulation is preferentially associated with atrophy within specific brain structures. METHODS: We perform a retrospective analysis of 40 DOC patients and correlate their maximal PCI to MR-based measurements of cortical thinning and subcortical atrophy. RESULTS: PCI was systematically and inversely associated with the degree of local atrophy within the globus pallidus, a region previously linked to electrocortical and behavioral arousal. Conversely, we fail to detect any association between variance in cortical ribbon thickness and PCI. CONCLUSION: These findings corroborate the previously reported association between pallidal atrophy and low behavioral arousal and suggest that this region's role in maintaining the overall balance of excitation and inhibition may critically affect the emergence of complex cortical interactions in chronic disorders of consciousness. This finding thus also suggests a target for potential neuromodulatory intervention in DOC patients.
Authors: Leandro R D Sanz; Aurore Thibaut; Brian L Edlow; Steven Laureys; Olivia Gosseries Journal: Curr Opin Neurol Date: 2021-08-01 Impact factor: 6.283
Authors: Andrea I Luppi; Joshua Cain; Lennart R B Spindler; Urszula J Górska; Daniel Toker; Andrew E Hudson; Emery N Brown; Michael N Diringer; Robert D Stevens; Marcello Massimini; Martin M Monti; Emmanuel A Stamatakis; Melanie Boly Journal: Neurocrit Care Date: 2021-07-08 Impact factor: 3.210