title: Coherence and Consciousness: Study of Fronto-Parietal Gamma Synchrony in Patients with Disorders of Consciousness.
abstract: Evaluation of consciousness needs to be supported by the evidence of brain activation during external stimulation in patients with unresponsive wakefulness syndrome (UWS). Assessment of patients should include techniques that do not depend on overt motor responses and allow an objective investigation of the spontaneous patterns of brain activity. In particular, electroencephalography (EEG) coherence allows to easily measure functional relationships between pairs of neocortical regions and seems to be closely correlated with cognitive or behavioral measures. Here, we show the contribution of higher order associative cortices of patients with disorder of consciousness (N = 26) in response to simple sensory stimuli, such as visual, auditory and noxious stimulation. In all stimulus modalities an increase of short-range parietal and long-range fronto-parietal coherences in gamma frequencies were seen in the controls and minimally conscious patients. By contrast, UWS patients showed no significant modifications in the EEG patterns after stimulation. Our results suggest that UWS patients can not activate associative cortical networks, suggesting a lack of information integration. In fact, fronto-parietal circuits result to be connectively disrupted, conversely to patients that exhibit some form of consciousness. In the light of this, EEG coherence can be considered a powerful tool to quantify the involvement of cognitive processing giving information about the integrity of fronto-parietal network. This measure can represent a new neurophysiological marker of unconsciousness and help in determining an accurate diagnosis and rehabilitative intervention in each patient.
authors: Neurophysiology Department, San Camillo Foundation, Institute of Care and Research, Via Alberoni, 70, 30126, Venice, Italy, marianna.cavinato@ospedalesancamillo.net.
authors: Marianna
authors: M
authors: Cavinato
authors: Clara
authors: C
authors: Genna
authors: Paolo
authors: P
authors: Manganotti
authors: Emanuela
authors: E
authors: Formaggio
authors: Silvia Francesca
authors: SF
authors: Storti
authors: Stefania
authors: S
authors: Campostrini
authors: Chiara
authors: C
authors: Arcaro
authors: Emanuela
authors: E
authors: Casanova
authors: Valeria
authors: V
authors: Petrone
authors: Roberto
authors: R
authors: Piperno
authors: Francesco
authors: F
authors: Piccione
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001307:Auditory Perception / Q000502:physiology; D003244:Consciousness Disorders / Q000503:physiopathology*; D003344:Cortical Synchronization; D004558:Electric Stimulation; D004569:Electroencephalography; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D065818:Gamma Rhythm; D006801:Humans; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000503:physiopathology; D010296:Parietal Lobe / Q000503:physiopathology*; D010465:Perception / Q000502:physiology*; D010775:Photic Stimulation; D055698:Touch Perception / Q000502:physiology; D014796:Visual Perception / Q000502:physiology