Intrinsic network reactivity differentiates levels of consciousness in comatose patients

Khanmohammadi, Sina; Laurido-Soto, Osvaldo; Eisenman, Lawrence N.; Ching, Shi Nung

doi:10.1016/j.clinph.2018.08.004

Cited by 10 publications

(4 citation statements)

References 74 publications

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“…The debilitating effect of TBI can range from mild cognitive disruption to adverse reduction in brain function, depending on the severity of the injury. In severe TBI, the deleterious effects on the brain were more pronounced in more severe cases ( Khanmohammadi et al, 2018 ). As for mild TBI, they are often misdiagnosed ( Palacios et al, 2017 ; Vergara et al, 2018 ), thus risks being left untreated.…”

Section: Introductionmentioning

confidence: 99%

Alteration in the Functional Organization of the Default Mode Network Following Closed Non-severe Traumatic Brain Injury

et al. 2022

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The debilitating effect of traumatic brain injury (TBI) extends years after the initial injury and hampers the recovery process and quality of life. In this study, we explore the functional reorganization of the default mode network (DMN) of those affected with non-severe TBI. Traumatic brain injury (TBI) is a wide-spectrum disease that has heterogeneous effects on its victims and impacts everyday functioning. The functional disruption of the default mode network (DMN) after TBI has been established, but its link to causal effective connectivity remains to be explored. This study investigated the differences in the DMN between healthy participants and mild and moderate TBI, in terms of functional and effective connectivity using resting-state functional magnetic resonance imaging (fMRI). Nineteen non-severe TBI (mean age 30.84 ± 14.56) and twenty-two healthy (HC; mean age 27.23 ± 6.32) participants were recruited for this study. Resting-state fMRI data were obtained at the subacute phase (mean days 40.63 ± 10.14) and analyzed for functional activation and connectivity, independent component analysis, and effective connectivity within and between the DMN. Neuropsychological tests were also performed to assess the cognitive and memory domains. Compared to the HC, the TBI group exhibited lower activation in the thalamus, as well as significant functional hypoconnectivity between DMN and LN. Within the DMN nodes, decreased activations were detected in the left inferior parietal lobule, precuneus, and right superior frontal gyrus. Altered effective connectivities were also observed in the TBI group and were linked to the diminished activation in the left parietal region and precuneus. With regard to intra-DMN connectivity within the TBI group, positive correlations were found in verbal and visual memory with the language network, while a negative correlation was found in the cognitive domain with the visual network. Our results suggested that aberrant activities and functional connectivities within the DMN and with other RSNs were accompanied by the altered effective connectivities in the TBI group. These alterations were associated with impaired cognitive and memory domains in the TBI group, in particular within the language domain. These findings may provide insight for future TBI observational and interventional research.

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Section: Introductionmentioning

confidence: 99%

Alteration in the Functional Organization of the Default Mode Network Following Closed Non-severe Traumatic Brain Injury

et al. 2022

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“…These dynamics may be a manifestation of covert cognitive information processing ( Cabral et al, 2017 ; Gonzalez-Castillo et al, 2019 ), and reflect the information capacity of the brain that is thought to be central to consciousness ( Cavanna et al, 2017 ; Tononi et al, 2016 ). Such explorative dynamics have also been observed in both humans and animals during deep sleep ( Brodbeck et al, 2012 ; Houldin et al, 2018 ; Stevner et al, 2019 ), anesthesia ( Hudson et al, 2014 ; Li et al, 2019 ; Varley et al, 2021 ; Vlisides et al, 2019 ; Wenzel et al, 2019 ) or disorders of consciousness ( Demertzi et al, 2019 ; Khanmohammadi et al, 2018 ). Specifically, despite differing molecular mechanisms, general anesthetics such as propofol, ketamine, sevoflurane, and isoflurane have been reported to suppress the flexible brain configurations during wakefulness to a rigid brain configuration that is predominantly shaped by brain anatomy ( Barttfeld et al, 2015 ; Ma et al, 2017 ; Uhrig et al, 2018 ; Zhang et al, 2019 ).…”

Section: Introductionmentioning

confidence: 84%

Dynamic reconfiguration of frequency-specific cortical coactivation patterns during psychedelic and anesthetized states induced by ketamine

Li¹,

Vlisides²,

Mashour

2022

NeuroImage

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“…The score in each CRS-R subscale is determined according to the presence or absence of specific responses to a sensory stimulus, with a higher total score indicating a greater level of consciousness [12,37,38]. GCS is a behavioral measure universally accepted as a gold standard for assessing the severity of a brain injury [2,37,39] and level of consciousness [40] [34] in terms of a patient's ability to respond to stimuli; eye opening (maximum 4 points), best motor response (maximum 6 points), and verbal response (maximum 4 points) are all measured. Each level of response is assigned a number and added together to provide a total score between 3 and 15 [41]; the worse the response, the lower the number [36].…”

Section: Clinical Assessments the Clinical Assessments In This Study ...mentioning

confidence: 99%

Influence of High-Frequency Repetitive Transcranial Magnetic Stimulation on Neurobehavioral and Electrophysiology in Patients with Disorders of Consciousness

Chen

Wang

et al. 2022

Neural Plasticity

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Objective. High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) has been proposed as a promising therapeutic intervention for patients with disorders of consciousness (DOC). However, its therapeutic effects in the literature are inconsistently documented. The primary aim of this study was to explore the alterations in neural connectivity and neurobehavioral reactivity during rTMS modulation in patients with DOC. In addition, safety was investigated as a secondary aim. Methods. The presence of bilateral N20 components in DOC patients was determined by somatosensory-evoked potential (SEP) before enrollment in the study. A total of 64 patients were enrolled and randomly placed into the active and sham groups. Ultimately, 50 patients completed the study. Twenty-five patients in the active group underwent real HF-rTMS, and 25 patients in the sham group underwent sham HF-rTMS, which was delivered over the left dorsolateral prefrontal cortex (DLPFC). The outcome measures of performed pre- and postintervention included the latencies of the N20 and N20-P25 amplitudes of SEP, brainstem auditory-evoked potential (BAEP) grade, JFK Coma Recovery Scale-Revised (CRS-R) score, and Glasgow Coma Scale (GCS) score; any adverse events were recorded at any time during the intervention. Result. Following six weeks of treatment, a significant increase was observed in the total CRS-R and GCS scores, and the N20-P25 amplitudes of patients in the two groups were compared with that obtained from preintervention (all p values < 0.05). The waves of BAEP in the two groups also showed a trend toward normalized activity compared with preintervention grades ( p values < 0.05). A significant decrease in the latencies of N20 ( p values < 0.001) was observed in the active group compared with measurements obtained from preintervention, whereas no significant decrease was observed in the sham group ( p values = 0.013). The improvement in total CRS-R scores ( p values = 0.002), total GCS scores ( p values = 0.023), and N20-P25 amplitudes ( p values = 0.011) as well as the decrease in latencies of N20 ( p values = 0.018) and change in BAEP grades ( p values = 0.013) were significantly different between the two groups. The parameters in neural connectivity (N20-P25 amplitudes, N20 latencies, and BAEP grades) were significantly correlated with the total CRS-R and GCS scores at postintervention, and the changes of CRS-R before and after interventions have a positive relationship with N20-P25 amplitudes. No adverse events related to the rTMS protocol were recorded. Conclusion. Neural connectivity levels are affected by HF-rTMS and are significantly related to clinical responses in DOC patients with the presence of bilateral N20. The elevation of neural connectivity levels may lay a foundation for successful HF-rTMS treatment for DOC patients.

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Intrinsic network reactivity differentiates levels of consciousness in comatose patients

Abstract: Our results emphasize the role of intrinsic brain dynamics in assessing the level of consciousness in coma patients and the possibility of employing simple electrophysiological measures to recognize the severity of disorders of consciousness (DOC).

Cited by 10 publications

References 74 publications

Alteration in the Functional Organization of the Default Mode Network Following Closed Non-severe Traumatic Brain Injury

Alteration in the Functional Organization of the Default Mode Network Following Closed Non-severe Traumatic Brain Injury

Dynamic reconfiguration of frequency-specific cortical coactivation patterns during psychedelic and anesthetized states induced by ketamine

Influence of High-Frequency Repetitive Transcranial Magnetic Stimulation on Neurobehavioral and Electrophysiology in Patients with Disorders of Consciousness

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