Associations among civilian mild traumatic brain injury with loss of consciousness, posttraumatic stress disorder symptom trajectories, and structural brain volumetric data.

Posttraumatic stress disorder (PTSD) is prevalent and associated with significant morbidity. Mild traumatic brain injury (mTBI) concurrent with psychiatric trauma may be associated with PTSD. Prior studies of PTSD-related structural brain alterations have focused on military populations. The current study examined correlations between PTSD, acute mTBI, and structural brain alterations longitudinally in civilian patients (N = 504) who experienced a recent Criterion A traumatic event. Participants who reported loss of consciousness (LOC) were characterized as having mTBI; all others were included in the control group. PTSD symptoms were assessed at enrollment and over the following year; a subset of participants (n = 89) underwent volumetric brain MRI (M = 53 days posttrauma). Classes of PTSD symptom trajectories were modeled using latent growth mixture modeling. Associations between PTSD symptom trajectories and cortical thicknesses or subcortical volumes were assessed using a moderator-based regression. mTBI with LOC during trauma was positively correlated with the likelihood of developing a chronic PTSD symptom trajectory. mTBI showed significant interactions with cortical thickness in the rostral anterior cingulate cortex (rACC) in predicting PTSD symptoms, r = .461-.463. Bilateral rACC thickness positively predicted PTSD symptoms but only among participants who endorsed LOC, p < .001. The results demonstrate positive correlations between mTBI with LOC and PTSD symptom trajectories, and findings related to mTBI with LOC and rACC thickness interactions in predicting subsequent chronic PTSD symptoms suggest the importance of further understanding the role of mTBI in the context of PTSD to inform intervention and risk stratification.

Network Localization of Unconscious Visual Perception in Blindsight.

OBJECTIVE: Blindsight is a disorder where brain injury causes loss of conscious but not unconscious visual perception. Prior studies have produced conflicting results regarding the neuroanatomical pathways involved in this unconscious perception. METHODS: We performed a systematic literature search to identify lesion locations causing visual field loss in patients with blindsight (n = 34) and patients without blindsight (n = 35). Resting state functional connectivity between each lesion location and all other brain voxels was computed using a large connectome database (n = 1,000). Connections significantly associated with blindsight (vs no blindsight) were identified. RESULTS: Functional connectivity between lesion locations and the ipsilesional medial pulvinar was significantly associated with blindsight (family wise error p = 0.029). No significant connectivity differences were found to other brain regions previously implicated in blindsight. This finding was independent of methods (eg, flipping lesions to the left or right) and stimulus type (moving vs static). INTERPRETATION: Connectivity to the ipsilesional medial pulvinar best differentiates lesion locations associated with blindsight versus those without blindsight. Our results align with recent data from animal models and provide insight into the neuroanatomical substrate of unconscious visual abilities in patients. ANN NEUROL 2022;91:217-224.

Perioperative Electroencephalogram Spectral Dynamics Related to Postoperative Delirium in Older Patients.

BACKGROUND: Intraoperative electroencephalography (EEG) signatures related to the development of postoperative delirium (POD) in older patients are frequently studied. However, a broad analysis of the EEG dynamics including preoperative, postinduction, intraoperative and postoperative scenarios and its correlation to POD development is still lacking. We explored the relationship between perioperative EEG spectra-derived parameters and POD development, aiming to ascertain the diagnostic utility of these parameters to detect patients developing POD. METHODS: Patients aged ≥65 years undergoing elective surgeries that were expected to last more than 60 minutes were included in this prospective, observational single center study (Biomarker Development for Postoperative Cognitive Impairment [BioCog] study). Frontal EEGs were recorded, starting before induction of anesthesia and lasting until recovery of consciousness. EEG data were analyzed based on raw EEG files and downloaded excel data files. We performed multitaper spectral analyses of relevant EEG epochs and further used multitaper spectral estimate to calculate a corresponding spectral parameter. POD assessments were performed twice daily up to the seventh postoperative day. Our primary aim was to analyze the relation between the perioperative spectral edge frequency (SEF) and the development of POD. RESULTS: Of the 237 included patients, 41 (17%) patients developed POD. The preoperative EEG in POD patients was associated with lower values in both SEF (POD 13.1 ± 4.6 Hz versus no postoperative delirium [NoPOD] 17.4 ± 6.9 Hz; P = .002) and corresponding γ-band power (POD -24.33 ± 2.8 dB versus NoPOD -17.9 ± 4.81 dB), as well as reduced postinduction absolute α-band power (POD -7.37 ± 4.52 dB versus NoPOD -5 ± 5.03 dB). The ratio of SEF from the preoperative to postinduction state (SEF ratio) was ~1 in POD patients, whereas NoPOD patients showed a SEF ratio >1, thus indicating a slowing of EEG with loss of unconscious. Preoperative SEF, preoperative γ-band power, and SEF ratio were independently associated with POD (P = .025; odds ratio [OR] = 0.892, 95% confidence interval [CI], 0.808-0.986; P = .029; OR = 0.568, 95% CI, 0.342-0.944; and P = .009; OR = 0.108, 95% CI, 0.021-0.568, respectively). CONCLUSIONS: Lower preoperative SEF, absence of slowing in EEG while transitioning from preoperative state to unconscious state, and lower EEG power in relevant frequency bands in both these states are related to POD development. These findings may suggest an underlying pathophysiology and might be used as EEG-based marker for early identification of patients at risk to develop POD.

Opportunities for reducing college drinking: The roles of drinking attitudes and blackout experience.

BACKGROUND: As many as 35% of college students report having been drunk in the past month, and greater alcohol use and alcohol-related problems are associated with a positive attitude toward heavy drinking. One serious consequence of heavy drinking is alcohol-induced blackout. When they occur, alcohol-induced blackouts present a unique opportunity to increase motivation to change drinking. However, it is unclear under what conditions an alcohol-related heavy drinking attitude and experiencing a blackout represent an opportunity to change and how experiencing a blackout(s) influences an individual's motivation to reduce drinking and actual behavior. METHODS: This study tested the interplay between one's positive attitude toward heavy drinking and experiencing a blackout in the past year in predicting motivation to reduce drinking (Study 1) and its impact on drinking over time (Study 2). Data were derived from complementary datasets collected at two universities (Study 1 n = 703, mean age = 20.63 years, 44% male, 52% White; Study 2 n = 568, mean age = 19.18 years, 72% male, 84% White). Drinking behavior was measured using a modified Daily Drinking Questionnaire, the Drinking Norms Rating Form, the Alcohol Use Disorders Identification Test (AUDIT), and estimated peak blood alcohol concentration (BAC). Regression analyses were conducted to determine whether a blackout would moderate the association between attitude and motivation to reduce drinking (Study 1) and drinking over time (Study 2). RESULTS: Results revealed a significant interaction between attitude and blackout, such that individuals who experience a blackout (vs. those who do not) and positively evaluate heavy drinking evidenced lower motivation to reduce drinking (Study 1) and higher levels of estimated peak BAC (Study 2). CONCLUSIONS: Drinkers with a negative attitude toward heavy drinking who have experienced a blackout have the strongest motivation to reduce drinking and the greatest reductions in peak drinking behavior over time. These effects are over and above that related to the level of alcohol consumed. For young adults who do not positively endorse heavy drinking, blackouts may present a "moment of opportunity" for intervention.

Similar or dissimilar? Influence of similarity between distraction tasks and target tasks on unconscious thought.

Distraction tasks are known to affect the unconscious-thought (UT) effect. However, the relationship between two task types, namely distraction and target tasks, and their effect on UT effect have not been examined in previous studies. In this study, we assessed whether simultaneously performing dissimilar distraction and target tasks are beneficial to information processing by UT. In Experiment 1, the target task was an Alternate Use Task (speech task). For the similar-task test, the UT group was assigned the speech 1-back task (speech task) as the distraction task; for the dissimilar-task test, the UT group was assigned the spatial 1-back task (spatial task) as the distraction task. The results of the experiment revealed that under dissimilar tasks, the UT group not only provided more answers but also provided answers that were more novel. For Experiment 2, the target task was changed to Creative Mental Synthesis Task (spatial task) to replicate the results of Experiment 1. The results demonstrated that the dissimilarity between the distraction and target tasks facilitates the UT.

Diagnosis clinical criteria of sport related concussion: Toward an operational criteria definition in France.

OBJECTIVE: An expert working group was set up at the initiative of the French Ministry of Sports with the objective of harmonising the management of sport related concussion (SRC) in France, starting with its definition and diagnosis criteria. RESULTS: Definition: A clinical definition in 4 points have been established as follows: Concussion is a brain injury: 1) caused by a direct or indirect transmission of kinetic energy to the head; 2) resulting in an immediate and transient dysfunction of the brain characterised by at least one of the following disorders: a) Loss of consciousness, b) loss of memory, c) altered mental status, d) neurological signs; 3) possibly followed by one or more functional complaints (concussion syndrome); 4) the signs and symptoms are not explained by another cause. Diagnosis criteria: In the context of the direct or indirect transmission of kinetic energy to the head, the diagnosis of concussion may be asserted if at least one of the following signs or symptoms, observed or reported, is present within the first 24hours and not explained by another cause: 1) loss of consciousness; 2) convulsions, tonic posturing; 3) ataxia; 4) visual trouble; 5) neurological deficit; 6) confusion; 7) disorientation; 8) unusual behaviour; 9) amnesia; 10) headaches; 11) dizziness; 12) fatigue, low energy; 13) feeling slowed down, drowsiness; 14) nausea; 15) sensitivity to light/noise; 16) not feeling right, in a fog; 17) difficulty concentrating. CONCLUSION: Sharing the same definition and the same clinical diagnostic criteria for concussion is the prerequisite for common rules of management for all sports and should allow the pooling of results to improve our knowledge of this pathology.

Head injury and neuropsychiatric sequelae in asylum seekers.

OBJECTIVE: Asylum seekers experience a high burden of physical and psychological trauma, yet there is a scarcity of literature regarding the epidemiology and sequelae of head injury (HI) in asylum seekers. We examined HI prevalence and association with neuropsychiatric comorbidities in asylum seekers. METHODS: A retrospective cross-sectional study was performed through review of 139 medical affidavits from an affidavit database. Affidavits written from 2010 to 2018 were included. Demographic and case-related data were collected and classified based on the presence of HI. For neuropsychiatric sequelae, the primary study outcome was headache and the secondary outcomes were depression, posttraumatic stress disorder, and anxiety. Multivariable logistic regression was performed to examine the association between HI and neuropsychiatric sequelae, adjusted for demographic and clinical characteristics. RESULTS: A total of 139 medical affidavits of asylum seekers were included. The mean age was 27.4 ± 12.1 years, 56.8% were female, and 38.8% were <19 years. Almost half (42.5%) explicitly self-reported history of HI. Compared to clients who did not report HI, clients with HI were older and more likely to report a history of headache, physical abuse, physical trauma, concussion, and loss of consciousness. After adjustment for demographic and clinical characteristics, clients with HI had greater odds for neuropsychological sequelae such as headache (odds ratio [OR] 4.2, 95% confidence interval [CI] 2.0-8.7) and depression (OR 2.5, 95% CI 1.1-5.7). CONCLUSIONS: We observed a high prevalence of HI in asylum seekers. Comprehensive screening for HI and neuropsychiatric comorbidities is encouraged when evaluating asylum seekers.

Granger Causality of the Electroencephalogram Reveals Abrupt Global Loss of Cortical Information Flow during Propofol-induced Loss of Responsiveness.

BACKGROUND: It is a commonly held view that information flow between widely separated regions of the cerebral cortex is a necessary component in the generation of wakefulness (also termed "connected" consciousness). This study therefore hypothesized that loss of wakefulness caused by propofol anesthesia should be associated with loss of information flow, as estimated by the effective connectivity in the scalp electroencephalogram (EEG) signal. METHODS: Effective connectivity during anesthesia was quantified by applying bivariate Granger to multichannel EEG data recorded from 16 adult subjects undergoing a slow induction of, and emergence from, anesthesia with intravenous propofol. During wakefulness they were conducting various auditory and motor tasks. Functional connectivity using EEG coherence was also estimated. RESULTS: There was an abrupt, substantial, and global decrease in effective connectivity around the point of loss of responsiveness. Recovery of behavioral responsiveness was associated with a comparable recovery in information flow pattern (expressed as normalized values). The median (interquartile range) change was greatest in the delta frequency band: decreasing from 0.15 (0.21) 2 min before loss of behavioral response, to 0.06 (0.04) 2 min after loss of behavioral response (P < 0.001). Regional decreases in information flow were maximal in a posteromedial direction from lateral frontal and prefrontal regions (0.82 [0.24] 2 min before loss of responsiveness, decreasing to 0.17 [0.05] 2 min after), and least for information flow from posterior channels. The widespread decrease in bivariate Granger causality reflects loss of cortical coordination. The relationship between functional connectivity (coherence) and effective connectivity (Granger causality) was inconsistent. CONCLUSIONS: Propofol-induced unresponsiveness is marked by a global decrease in information flow, greatest from the lateral frontal and prefrontal brain regions in a posterior and medial direction. Loss of information flow may be a useful measure of connected consciousness.

A vertebrate model to reveal neural substrates underlying the transitions between conscious and unconscious states.

The field of neuropharmacology has not yet achieved a full understanding of how the brain transitions between states of consciousness and drug-induced unconsciousness, or anesthesia. Many small molecules are used to alter human consciousness, but the repertoire of underlying molecular targets, and thereby the genes, are incompletely understood. Here we describe a robust larval zebrafish model of anesthetic action, from sedation to general anesthesia. We use loss of movement under three different conditions, spontaneous movement, electrical stimulation or a tap, as a surrogate for sedation and general anesthesia, respectively. Using these behavioral patterns, we find that larval zebrafish respond to inhalational and IV anesthetics at concentrations similar to mammals. Additionally, known sedative drugs cause loss of spontaneous larval movement but not to the tap response. This robust, highly tractable vertebrate model can be used in the detection of genes and neural substrates involved in the transition from consciousness to unconsciousness.

States Move to Ban Pelvic Exams on Unconscious Women.

Despite long-standing ethical concerns, the practice has persisted.

Is Pediatric Traumatic Brain Injury Associated with Adult Alcohol Misuse?

Evidence suggests that pediatric traumatic brain injury (TBI) may be causally related to alcohol misuse later in life; however, the nature and extent of the association has not been well described. This study examined the relationship between pediatric TBI and adult alcohol misuse in a population sample ≥20 years of age. We sought to determine (1) whether first self-reported incidence of TBI with loss of consciousness (LOC) before the age of 20 increased the risk for alcohol misuse later in life; and (2) whether sex, injury severity, and age at time of injury modified the association. We found a greater likelihood of binge but not heavy drinking for those whose first self-reported TBI with LOC occurred before the age of 20 when compared with those whose first self-reported TBI with LOC occurred later in life (28.5% vs. 20.4%, p = 0.003). When limited to those with only mild TBI, the relationship to binge drinking remained significant (31.9% vs. 19.3%, p < 0.001) and was evident for both males (38.4% vs. 25.6%, p = 0.016) and females (20.9% vs. 12.4%, p = 0.044). When controlling for sex, age, and race/ethnicity, reporting a first TBI with LOC before age 20 was associated with binge drinking only for those with mild TBI (adjusted odds ratio [AOR] = 1.32; 95% confidence interval [CI] = 1.00-1.74). Results also showed that those with first TBI with LOC occurring between the ages of 10 and 19 years were more likely to binge drink as adults than those first injured earlier in life, regardless of TBI severity. Further research is needed at both the epidemiological and pre-clinical levels to better understand this relationship.

The Science of Transitional States of Consciousness and Euthanasia.

The science of transitional states of consciousness is reviewed. Despite intensive study, determining the subjective experience of animals during transitional states of consciousness remains inherently limited. Until better assessment tools become available, behavior-based observations, such as loss of righting reflex/loss of posture, remain among our most useful guides to the onset of unconsciousness in animals. To minimize potential animal suffering and to ensure a truly unconscious state is unambiguously achieved, a state of general anesthesia relying on gamma amino butyric acid type A agonists or N-methyl-d-aspartate antagonist agents continues to be a necessary component of the companion animal euthanasia process.

Long-term cognitive impairment following single mild traumatic brain injury with loss of consciousness: Findings from the Canadian Longitudinal Study on Aging.

Objective: We examined the extent to which loss of consciousness (LOC) following mild traumatic brain injury (mTBI) may be associated with impairments in executive functions and declarative memory more than a year after brain injury.Method: Analyses were run on 548 participants who had self-reported LOC of <1 min, 441 with LOC of 1-20 min, and 13,609 no brain injury comparison participants, taken from the Canadian Longitudinal Study on Aging (CLSA), a nationwide study on health and aging.Results: Those that had mTBI with LOC of 1-20 min were more likely than no head injury comparisons to be impaired on measures of executive functioning and declarative memory. Impairments were evident when examining for single- and two-test impairment rates on measures of executive functioning and declarative memory.Conclusions: A subset of people that had reported a single mTBI with LOC more than 12 months ago may experience impairments in executive functioning and declarative memory, particularly those who spent more time unconscious.

Dignity at stake: Caring for persons with impaired autonomy.

Dignity, usually considered an essential ethical value in healthcare, is a relatively complex, multifaceted concept. However, healthcare professionals often have only a vague idea of what it means to respect dignity when providing care, especially for persons with impaired autonomy. This article focuses on two concepts of dignity, human dignity and dignity of identity, and aims to analyse how these concepts can be applied in the care for persons with impaired autonomy and in furthering the practice of respect and protection from harm. Three vignettes were designed to illustrate typical caring situations involving patients with mild to severely impaired autonomy, including patients with cognitive impairments. In situations like these, there is a risk of the patient's dignity being disrespected and violated. The vignettes were then analysed with respect to the two concepts of dignity to find out whether this approach can illuminate what is at stake in these situations and to provide an understanding of which measures could safeguard the dignity of these patients. The analysis showed that there are profound ethical challenges in the daily care of persons with impaired autonomy. We suggest that these two concepts of human dignity could help guide healthcare professionals to develop practical skills in person-centred, ethically grounded care, where the patient's wishes and needs are the starting point.

¿El siglo de las luces? / The lights century?

El siglo de las luces es una reflexión sobre el excesivo racionalismo de la medicina actual frente a los problemas del inconsciente dejando de lado el análisis del inconsciente del sujeto y la posibilidad del sujeto de mirarse así mismo.

This paper is a reflection about the excessive rationalism of current medici-ne against the unconscious problems leaving aside the analysis of the un-conscious of the person and the possibility of the person to look at himself.

Mild traumatic brain injuries with loss of consciousness are associated with increased inflammation and pain in military personnel.

Mild traumatic brain injuries (mTBI) are a pervasive concern for military personnel. Determining the impact of injury severity, including loss of consciousness (LOC) may provide important insights into the risk of psychological symptoms and inflammation commonly witnessed in military personnel and veterans following mTBI. US military personnel and veterans were categorized into three groups; TBI with LOC (n = 36), TBI without LOC (n = 25), Controls (n = 82). Participants reported their history of mTBI, psychological symptoms (post-traumatic stress disorder [PTSD] and depression), health-related quality of life (HRQOL), and underwent a blood draw. ANCOVA models which controlled for insomnia status and combat exposure indicated that both mTBI groups (with/without LOC) reported significantly greater depression and PTSD symptoms compared to controls; however, they did not differ from each other. The mTBI with LOC did report greater pain than both controls and mTBI without LOC. The TBI with LOC group also had significantly elevated IL-6 concentrations than both TBI without LOC and control groups. Within the mTBI groups, increased TNFα concentrations were associated with greater PTSD symptoms. These findings indicate that sustaining an mTBI, with or without LOC is detrimental for psychological wellbeing. However, LOC may be involved in perceptions of pain and concentrations of IL-6.

La clasificación de los trastornos de la conciencia / Classification of disorders of consciousness

Tradicionalmente ha existido una incongruencia entre la definición de conciencia y la caracterización de su patología, que se restringe a aquellos cuadros que afectan la vida consciente en su conjunto, ya sea por un descenso del nivel o por una desorganización de sus contenidos. Los avances en neurociencia cognitiva han demostrado que existen otras perturbaciones de la conciencia que no implican su afectación total. Con el fin de presentar una clasificación integral de estos trastornos, partiremos de las teorías de Edelman y Damasio, quienes diferencian una forma elemental de conciencia (conciencia primaria, para el primero, o central, para el segundo) de una forma compleja (conciencia de orden superior o ampliada, respectivamente). Las enfermedades que afectan a la conciencia primaria producen trastornos globales, pues afectan a la conciencia en su conjunto. Los trastornos de la conciencia superior producen perturbaciones parciales, que involucran mayormente a la autoconciencia, aunque también incluyen las distorsiones y engaños perceptivos

Traditionally, there has been an incongruity between the definition of consciousness and the characterization of its pathology, which is restricted to those disorders that affect consciousness as a whole, either by a decrease in its level or by a disorganization of its contents. Developments in cognitive neuroscience have shown that there are other disturbances of consciousness that do not imply its total involvement. In order to present a comprehensive classification of these disorders, we will build our classification on the theories of Edelman and Damasio, who differentiate an elementary form of consciousness (primary or core consciousness, respectively) from a complex one (higher order or extended consciousness, respectively). Diseases that affect primary consciousness cause global disorders, because they affect consciousness as a whole. Disorders of higher-order consciousness cause partial disturbances, which mostly involve self-consciousness. Perceptual distortions and deceptions are also included here

Loss of consciousness and altered mental state predicting depressive and post-concussive symptoms after mild traumatic brain injury.

Objective: Limited studies exist on the association between loss of consciousness (LOC) and altered mental state (AMS) and development of depressive and post-concussive symptoms within six months after mild traumatic brain injury (mTBI). We tested the hypothesis that presence of both LOC and AMS predict the highest risk of symptoms within the first six months post-mTBI compared to either variable alone, and that LOC alone is more strongly associated with these symptoms. Research design: We analyzed data from 407 subjects with mTBI from the Head injury Serum Markers for Assessing Response to Trauma (HeadSMART) cohort, a prospective cohort of patients post-TBI presenting to two urban emergency departments. Results: There were higher rates of depressive (44%) and post-concussive symptoms (54%) at 1 month post-injury, among participants with both LOC and AMS compared to other groups. AMS was associated with depressive symptoms at one and six months (OR = 1.59, p = .038; OR = 1.60; p = .060) and post-concussive symptoms at one month (OR = 1.56, p = .053). LOC was associated only with post-concussive symptoms at one month (OR = 1.55;p = .048). Among those without LOC, AMS was associated with depressive symptoms at one month (OR = 2.24; p = .028). Conclusions: AMS predicts post-mTBI depressive symptoms both in the acute and chronic mTBI phases whereas LOC is a more sensitive predictor of post-concussive symptoms in the acute mTBI period.

A Novel Framework for Unconscious Processing.

Understanding the distinction between conscious and unconscious cognition remains a priority in psychology and neuroscience. A comprehensive neurocognitive account of conscious awareness will not be possible without a sound framework to isolate and understand unconscious information processing. Here, we provide a brain-based framework that allows the identification of unconscious processes, even with null effects on behaviour.