Conventional Structural Magnetic Resonance Imaging in Differentiating Chronic Disorders of Consciousness

Morozova, S. N.; Кремнева, Е. И.; Сергеев, Д.В.; Синицын, Д. О.; Legostaeva, L.; Iazeva, Elizaveta G.; Кротенкова, М. В.; Ryabinkina, Yu. V.; Супонева, Н. А.; Piradov, М. А.

doi:10.3390/brainsci8080144

Cited by 13 publications

(12 citation statements)

References 27 publications

(36 reference statements)

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“…A growing number of studies have also demonstrated a critical role of thalamo-cortical connections ( Maxwell et al, 2004 , Fernández-Espejo et al, 2011 ) within the fronto-parietal ( Long et al, 2016 , Crone et al, 2014 ) and default mode brain networks ( Fernández-Espejo et al, 2012 , Vanhaudenhuyse et al, 2009 ) in the sustenance of awareness. Our findings also align with the study of Morozova et al (2018 )., who developed a diagnostic MRI scoring system differentiating between the chronic UWS and MCS patients based on brain atrophy. The chronic UWS was marked by a degeneration of the brainstem and thalamus, widespread diffuse cortical atrophy, and degeneration of the corpus callosum, pointing to the importance of the preserved integrity of these brain regions in the sustenance of consciousness.…”

Section: Discussionsupporting

confidence: 93%

Discriminating cognitive motor dissociation from disorders of consciousness using structural MRI

Pozeg

Jöhr

Pincherle

et al. 2021

NeuroImage: Clinical

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An accurate evaluation and detection of awareness after a severe brain injury is crucial to a patient’s diagnosis, therapy, and end-of-life decisions. Misdiagnosis is frequent as behavior-based assessments often overlook subtle signs of consciousness. This study aimed to identify brain MRI characteristics of patients with residual consciousness after a severe brain injury and to develop a simple MRI-based scoring system according to the findings. We retrieved data from 128 patients and split them into a development or validation set. Structural brain MRIs were qualitatively assessed for lesions in 18 brain regions. We used logistic regression and support vector machine algorithms to first identify the most relevant brain regions predicting a patient’s outcome in the development set. We next built a diagnostic MRI-based score and estimated its optimal diagnostic cut-off point. The classifiers were then tested on the validation set and their performance compared using the receiver operating characteristic curve. Relevant brain regions predicting negative outcome highly overlapped between both classifiers and included the left mesencephalon, right basal ganglia, right thalamus, right parietal cortex, and left frontal cortex. The support vector machine classifier showed higher accuracy (0.93, 95% CI: 0.81–0.96) and specificity (0.97, 95% CI: 0.85–1) than logistic regression (accuracy: 0.87, 95% CI: 0.73 – 0.95; specificity: 0.90, 95% CI: 0.75–0.97), but equal sensitivity (0.67, 95% CI: 0.24–0.94 and 0.22–0.96, respectively) for distinguishing patients with and without residual consciousness. The novel MRI-based score assessing brain lesions in patients with disorders of consciousness accurately detects patients with residual consciousness. It could complement valuably behavioral evaluation as it is time-efficient and requires only conventional MRI.

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Section: Discussionsupporting

confidence: 93%

Discriminating cognitive motor dissociation from disorders of consciousness using structural MRI

Pozeg

Jöhr

Pincherle

et al. 2021

NeuroImage: Clinical

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“…Moreover, our structural analyses show a significant atrophy for both patient groups in subcortical structures such as the thalamus, which was also previously found to be damaged in MCS patients. 24,25 In comparison with the group of MCS− patients, MCS+ patients presented higher metabolism preservation in different language-related areas. Using a more conservative correction (ie, FWE), higher metabolism was identified in MCS+ compared with MCS− in the left middle temporal cortex, which has been associated to selective processing of speech, 26,27 semantic processing, 28,29 and word generation.…”

Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Brain Metabolism but Not Gray Matter Volume Underlies the Presence of Language Function in the Minimally Conscious State (MCS): MCS+ Versus MCS− Neuroimaging Differences

Aubinet

Cassol

Gosseries

et al. 2020

Neurorehabil Neural Repair

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Background. The minimally conscious state (MCS) is subcategorized into MCS− and MCS+, depending on the absence or presence, respectively, of high-level behavioral responses such as command-following. Objective. We aim to investigate the functional and structural neuroanatomy underlying the presence of these responses in MCS− and MCS+ patients. Methods. In this cross-sectional retrospective study, chronic MCS patients were diagnosed using repeated Coma Recovery Scale–Revised assessments. Fluorodeoxyglucose-positron emission tomography data were acquired on 57 patients (16 MCS−; 41 MCS+) and magnetic resonance imaging with voxel-based morphometry analysis was performed on 66 patients (17 MCS−; 49 MCS+). Brain glucose metabolism and gray matter integrity were compared between patient groups and control groups. A metabolic functional connectivity analysis testing the hypothesis of preserved language network in MCS+ compared with MCS− was also done. Results. Patients in MCS+ presented higher metabolism mainly in the left middle temporal cortex, known to be important for semantic processing, compared with the MCS− group. The left angular gyrus was also functionally disconnected from the left prefrontal cortex in MCS− compared with MCS+ group. No significant differences were found in gray matter volume between patient groups. Conclusions. The clinical subcategorization of MCS is supported by differences in brain metabolism but not in gray matter structure, suggesting that brain function in the language network is the main support for recovery of command-following, intelligible verbalization and/or intentional communication in the MCS. Better characterizing the neural correlates of residual cognitive abilities of MCS patients contributes to reduce their misdiagnosis and to adapt therapeutic approaches.

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“…Another feasible explanation is that the reduction of the serum BDNF level is caused by the loss of BDNF-secreting neurons as a consequence of acute brain injury and subsequent brain atrophy. Neuroimaging studies have shown that patients with DOCs develop widespread cortical and subcortical atrophy [38][39][40]. Moreover, the degree to which markers of neuronal injury, such as neuron-specific enolase, are released is below normal in the chronic phases of DOCs [41], suggesting the progressive loss of neurons with brain atrophy [42].…”

Section: Discussionmentioning

confidence: 99%

Serum BDNF Levels Are Reduced in Patients with Disorders of Consciousness and Are Not Modified by Verticalization with Robot-Assisted Lower-Limb Training

et al. 2020

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Little is known about plastic changes occurring in the brains of patients with severe disorders of consciousness (DOCs) caused by acute brain injuries at rest and during rehabilitative treatment. Brain-derived neurotrophic factor (BDNF) is a neurotrophin involved in neurogenesis and synaptic plasticity whose production is powerfully modulated by physical exercise. In this study, we compared serum BDNF levels in 18 patients with unresponsive wakefulness syndrome (UWS) and in a minimally conscious state (MCS) with those in 16 sex- and age-matched healthy controls. In 12 patients, serum BDNF levels before and after verticalization with ErigoPro robot-assisted lower-limb training were compared. Serum BDNF levels were significantly lower in patients (median, 1141 pg/ml; 25th and 75th percentiles, 1016 and 1704 pg/ml) than in controls (median, 2450 pg/ml; 25th and 75th percentiles, 2100 and 2875 pg/ml; p<0.001). BDNF levels measured before and after verticalization with robot-assisted lower-limb training did not change (p=0.5). Moreover, BDNF levels did not differ between patients with UWS and MCS (p=0.2), or between patients with traumatic and nontraumatic brain injuries (p=0.6). BDNF level correlated positively with the time since brain injury (p=0.025). In conclusion, serum BDNF levels are reduced in patients with UWS and MCS and cannot be improved by verticalization associated with passive lower-limb training. Additional studies are needed to better understand the mechanisms underlying BDNF reduction in patients with DOCs and to determine the best rehabilitative strategies to promote restorative plastic changes in these patients.

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Conventional Structural Magnetic Resonance Imaging in Differentiating Chronic Disorders of Consciousness

Cited by 13 publications

References 27 publications

Discriminating cognitive motor dissociation from disorders of consciousness using structural MRI

Discriminating cognitive motor dissociation from disorders of consciousness using structural MRI

Brain Metabolism but Not Gray Matter Volume Underlies the Presence of Language Function in the Minimally Conscious State (MCS): MCS+ Versus MCS− Neuroimaging Differences

Serum BDNF Levels Are Reduced in Patients with Disorders of Consciousness and Are Not Modified by Verticalization with Robot-Assisted Lower-Limb Training

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