How are different neural networks related to consciousness?
OBJECTIVE
We aimed to investigate the roles of different resting-state networks in predicting both the actual level of consciousness and its recovery in brain injury patients.


METHODS
We investigated resting-state functional connectivity within different networks in patients with varying levels of consciousness: unresponsive wakefulness syndrome (UWS; n = 56), minimally conscious state (MCS; n = 29), and patients with brain lesions but full consciousness (BL; n = 48). Considering the actual level of consciousness, we compared the strength of network connectivity among the patient groups. We then checked the presence of connections between specific regions in individual patients and calculated the frequency of this in the different patient groups. Considering the recovery of consciousness, we split the UWS group into 2 subgroups according to recovery: those who emerged from UWS (UWS-E) and those who remained in UWS (UWS-R). The above analyses were repeated on these 2 subgroups.


RESULTS
Functional connectivity strength in salience network (SN), especially connectivity between the supragenual anterior cingulate cortex (SACC) and left anterior insula (LAI), was reduced in the unconscious state (UWS) compared to the conscious state (MCS and BL). Moreover, at the individual level, SACC-LAI connectivity was more present in MCS than in UWS. Default-mode network (DMN) connectivity strength, especially between the posterior cingulate cortex (PCC) and left lateral parietal cortex (LLPC), was reduced in UWS-R compared with UWS-E. Furthermore, PCC-LLPC connectivity was more present in UWS-E than in UWS-R.


CONCLUSIONS
Our findings show that SN (SACC-LAI) connectivity correlates with behavioral signs of consciousness, whereas DMN (PCC-LLPC) connectivity instead predicts recovery of consciousness.
Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, Taiwan.|Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, Canada.|Brain and Consciousness Research Center, Taipei Medical University-Shuang Ho Hospital, New Taipei City, Taiwan.
Pengmin
P
Qin
Neurosurgical Department of Huashan Hospital, Fudan University, Shanghai, China.
Xuehai
X
Wu
Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, Canada.
Zirui
Z
Huang
Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, Taiwan.|Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, Canada.|Brain and Consciousness Research Center, Taipei Medical University-Shuang Ho Hospital, New Taipei City, Taiwan.|Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China.
Niall W
NW
Duncan
Radiologic Department of Huashan Hospital, Fudan University, Shanghai, China.
Weijun
W
Tang
Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, Taiwan.
Annemarie
A
Wolff
Neurosurgical Department of Huashan Hospital, Fudan University, Shanghai, China.
Jin
J
Hu
Neurosurgical Department of Huashan Hospital, Fudan University, Shanghai, China.
Liang
L
Gao
Neurosurgical Department of Huashan Hospital, Fudan University, Shanghai, China.
Yi
Y
Jin
Neurosurgical Department of Huashan Hospital, Fudan University, Shanghai, China.
Xing
X
Wu
Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China.
Jianfeng
J
Zhang
Radiologic Department of Huashan Hospital, Fudan University, Shanghai, China.
Lu
L
Lu
Radiologic Department of Huashan Hospital, Fudan University, Shanghai, China.
Chunping
C
Wu
Radiologic Department of Huashan Hospital, Fudan University, Shanghai, China.
Xiaoying
X
Qu
Neurosurgical Department of Huashan Hospital, Fudan University, Shanghai, China.
Ying
Y
Mao
Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China.
Xuchu
X
Weng
Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai, China.
Jun
J
Zhang
Graduate Institute of Humanities in Medicine, Taipei Medical University, Taipei, Taiwan.|Institute of Mental Health Research, University of Ottawa, Ottawa, Ontario, Canada.|Brain and Consciousness Research Center, Taipei Medical University-Shuang Ho Hospital, New Taipei City, Taiwan.|Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China.|National Chengchi University Research Center for Mind, Brain, and Learning, Taipei, Taiwan.
Georg
G
Northoff
D000328:Adult; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D001930:Brain Injuries / Q000175:diagnosis* / Q000503:physiopathology*; D003243:Consciousness / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000473:pathology / Q000503:physiopathology*; D018458:Persistent Vegetative State / Q000175:diagnosis* / Q000503:physiopathology*; D012146:Rest / Q000502:physiology