Loss Of Consciousness Group Research Articles

Use of a structured approach and virtual simulation practice to improve diagnostic reasoning.

In 2015, the National Academy of Medicine IOM estimated that 12 million patients were misdiagnosed annually. This suggests that despite prolonged training in medical school and residency there remains a need to improve diagnostic reasoning education. This study evaluates a new approach. A total of 285 medical students were enrolled in this 8 center, IRB approved trial. Students were randomized to receive training in either abdominal pain (AP) or loss of consciousness (LOC). Baseline diagnostic accuracy of the two different symptoms was assessed by completing a multiple-choice question (MCQ) examination and virtual patient encounters. Following a structured educational intervention, including a lecture on the diagnostic approach to that symptom and three virtual patient practice cases, each student was re-assessed. The change in diagnostic accuracy on virtual patient encounters was compared between (1) baseline and post intervention and (2) post intervention students trained in the prescribed symptom vs. the alternate symptom (controls). The completeness of the student's differential diagnosis was also compared. Comparison of proportions were conducted using χ2-tests. Mixed-effects regressions were used to examine differences accounting for case and repeated measures. Compared with baseline, both the AP and LOC groups had marked post-intervention improvements in obtaining a correct final diagnosis; a 27% absolute improvement in the AP group (p<0.001) and a 32% absolute improvement in the LOC group (p<0.001). Compared with controls (the groups trained in the alternate symptoms), the rate of correct diagnoses increased by 13% but was not statistically significant (p=0.132). The completeness and efficiency of the differential diagnoses increased by 16% (β=0.37, p<0.001) and 17% respectively (β=0.45, p<0.001). The study showed that a virtual patient platform combined with a diagnostic reasoning framework could be used for education and diagnostic assessment and improved correct diagnosis compared with baseline performance in a simulated platform.

Proton magnetic resonance spectroscopy changes in the brainstem in patients after mild traumatic brain injury with loss of consciousness.

Loss of consciousness (LOC) is used as a diagnostic feature of mild traumatic brain injury (MTBI). However, only 10% of concussions result in LOC. There are only a limited number of in-vivo studies dealing with unconsciousness and structural and functional integrity of the brainstem in patients with MTBI. The aim of our pilot study was to assess the sensitivity of proton magnetic resonance spectroscopy (1H-MRS) to detect metabolic changes in the brainstem in patients after MTBI with unconscioussness. Twenty-four patients (12 with LOC, and 12 without LOC) within 3 days of MTBI and 19 healthy controls were examined. All subjects underwent single-voxel 1H-MRS examination of the upper brainstem. Spectra were evaluated using LCModel software. Ratios of total N-acetylaspartate (tNAA), total choline-containing compounds (tCho) and glutamate plus glutamine (Glx) to total creatine (tCre) were used for calculations. We found a significant decrease in tNAA/tCre and tCho/tCre ratios in the patient group with LOC when compared with the control group of healthy volunteers (P=0.002 and P=0.041, respectively), and a significant decrease in the tNAA/tCre ratio in the LOC group when compared with patients without LOC (P=0.04). Other metabolite ratios in the brainstem did not show any significant group differences. Our findings indicate that decrease of tNAA/tCre ratio in the upper brainstem using single-voxel 1H-MRS may provide a potential biomarker for MTBI associated with LOC.

Characteristics and neuropsychological impact of traumatic brain injury in female prisoners

ABSTRACT Objective: To investigate the characteristics of head injury (HI) and its association with offending behaviour, psychological and neurobehavioral functioning, and cognitive performance in female prisoners. Methods: Using a cross-sectional design, female prisoners in the UK reporting a HI with a loss of consciousness (LOC) over ten minutes (n = 10) were compared with a group without a HI with LOC over ten minutes (n = 41) across a range of measures; including scores on standardized clinical questionnaires and performance-based cognitive assessments. Semi-structured clinical interviews assessed HI and forensic history, with forensic history triangulated against the prison database. Results: Domestic abuse was the most frequently reported cause of HI. The HI with LOC group had been to prison a greater number of times and had committed a greater number violent offences. No significant difference was found on self-reported psychological and neurobehavioral measures, or between the groups’ cognitive functioning on neuropsychological tests. Conclusions: Psychosocial factors such as trauma may contribute to higher rates of violent offending and imprisonment in those with a HI with LOC. Domestic abuse is an important factor in HI amongst female prisoners. Forensic screening and interventions need to be designed, adapted and evaluated with consideration of trauma and HI.

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.

Biomechanical comparison of concussions with and without a loss of consciousness in elite American football: implications for prevention

ABSTRACT Loss of consciousness (LOC) associated with concussion is no longer considered an indicator of severity of injury in concussion management protocols. Studies investigating the association between LOC and recovery time or neurophysiological performance have reported ambiguous findings and resulted in a limited understanding of the severity of LOC-inducing head impacts. Concussive injuries with and without LOC from helmet-to-helmet and shoulder collisions and falls in elite American football were reconstructed in laboratory using a hybrid III headform and finite element model to obtain peak linear and rotational acceleration and brain tissue deformation metrics in the cerebral cortex, the cerebral white matter, the corpus callosum, the thalamus and the brainstem. Impact velocity, peak linear and rotational acceleration were significantly greater in the LOC group than the no LOC group. The brain tissue deformation metrics were greater in the LOC group than the no LOC group. The best overall predictor for LOC was impact velocity. Concussions with LOC are characterised by greater magnitudes of brain tissue deformation. This was mainly the result of higher impact velocities in the LOC group providing league decision-makers with an understanding of the importance of managing impact velocity through athlete education and rule enforcement or change.

Isolated LOC in head trauma associated with significant injury on brain CT scan

BackgroundA report of loss of consciousness (LOC) is frequently considered reason enough to obtain a computed tomography (CT) scan in the evaluation of head trauma. We conducted this study to reduce exposure to radiation from CT, while still not overlooking clinically significant injuries.ObjectiveThe objective of the study is to determine the correlation between LOC status and brain CT scan results in patients with blunt head trauma and to determine whether there is a subset of patients for whom CT scan need not be performed, without missing clinically significant intracranial injuries.MethodsThis is a retrospective study conducted in the emergency department of an inner-city hospital. The patient population included patients ranging between 13 and 35 years of age, with blunt head trauma, who presented to the emergency department (ED) between January 2010 and December 2013. Patients were divided into two groups: “LOC” group and “no LOC” group. The results of brain CT scans from each group were compared with LOC status. For study purposes, “clinically significant” were those that required interventions or ICU hospitalization of at least 24 h or extended hospitalization. The results were analyzed using chi-square calculations.ResultsDuring the study period, 494 patients were identified as having suffered head trauma. Of these, 185 (37.5%) reported LOC and 309 (62.5%) did not lose consciousness. In the LOC group, 15 (8.1%) had significant CT findings compared to 1.3% (4/309) of those without LOC (p < .001). Of the 4 who had no LOC and had significant brain CT findings, all 4 patients had positive physical findings of head, neck, or facial trauma. In the LOC group, only 1/15 (6.7%) had significant CT findings with a normal GCS of 15 and no physical signs of the head, neck, or facial trauma.ConclusionsA small proportion of patients with LOC had CT finding requiring intervention. Head trauma patients with no physical injuries to the head, neck, or face and a normal GCS had no significant brain CT findings. This raises the question of whether a routine brain CT scan should be obtained in patients with LOC, no physical findings, and a normal GCS after blunt head trauma.

No Further Yield of Ambulatory EEG for Epileptiform Discharges Beyond 13 Hours

Introduction: This study aimed at evaluating the value added by 24-hour ambulatory EEG (AEEG) by comparing the presence of epileptiform discharges (EDs) between the first 30 minutes of recording versus the following 23.5 hours.Materials and Methods: A retrospective review of AEEGs of subjects divided into two groups, epilepsy and undiagnosed episodes of loss of consciousness, was conducted. AEEGs were divided into early EEG (E-EEG) (first 30 minutes) and extended EEG (remaining 23.5 hours). Extended EEGs were further divided into segments (S): 31st minute to 8th hour (SI), 9th to 16th hours (SII) and 17th to 24th hours (SIII). Each consecutive segment was reviewed to identify new EDs not seen previously.Results: Fifty-seven AEEGs were included, the median age being 36.3 years, the range being 18.7 to 78.6 years. There were 38 (66.6%) females. The collective yield of AEEG for detecting EDs was 19/57 (33.4%). The yield of E-EEG of new EDs was 5/57 (9%). During extended EEG, the distribution of EDs was as follows: SI, 5/57 (9%); SII, 13/55 (24%); and SIII, 1/32 (3%). The yield, however, did not increase beyond the 13th hour. In undiagnosed episodes of loss of consciousness group (11), yield was 0/11 in all segments.Conclusions: (1) There was no value added for yield of EDs by extending the EEG recording beyond 13 hours in epilepsy group. (2) The probability of capturing EDs is negligible if the clinical history does not clearly support the diagnosis of seizure or epilepsy.

White matter abnormalities are associated with chronic postconcussion symptoms in blast-related mild traumatic brain injury.

Blast-related mild traumatic brain injury (mTBI) is a common injury among Iraq and Afghanistan military veterans due to the frequent use of improvised explosive devices. A significant minority of individuals with mTBI report chronic postconcussion symptoms (PCS), which include physical, emotional, and cognitive complaints. However, chronic PCS are nonspecific and are also associated with mental health disorders such as posttraumatic stress disorder (PTSD). Identifying the mechanisms that contribute to chronic PCS is particularly challenging in blast-related mTBI, where the incidence of comorbid PTSD is high. In this study, we examined whether blast-related mTBI is associated with diffuse white matter changes, and whether these neural changes are associated with chronic PCS. Ninety Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) veterans were assigned to one of three groups including a blast-exposed no--TBI group, a blast-related mTBI without loss of consciousness (LOC) group (mTBI--LOC), and a blast-related mTBI with LOC group (mTBI + LOC). PCS were measured with the Rivermead Postconcussion Questionnaire. Results showed that participants in the mTBI + LOC group had more spatially heterogeneous white matter abnormalities than those in the no--TBI group. These white matter abnormalities were significantly associated with physical PCS severity even after accounting for PTSD symptoms, but not with cognitive or emotional PCS severity. A mediation analysis revealed that mTBI + LOC significantly influenced physical PCS severity through its effect on white matter integrity. These results suggest that white matter abnormalities are associated with chronic PCS independent of PTSD symptom severity and that these abnormalities are an important mechanism explaining the relationship between mTBI and chronic physical PCS.

The nature of white matter abnormalities in blast-related mild traumatic brain injury.

Blast-related traumatic brain injury (TBI) has been a common injury among returning troops due to the widespread use of improvised explosive devices in the Iraq and Afghanistan Wars. As most of the TBIs sustained are in the mild range, brain changes may not be detected by standard clinical imaging techniques such as CT. Furthermore, the functional significance of these types of injuries is currently being debated. However, accumulating evidence suggests that diffusion tensor imaging (DTI) is sensitive to subtle white matter abnormalities and may be especially useful in detecting mild TBI (mTBI). The primary aim of this study was to use DTI to characterize the nature of white matter abnormalities following blast-related mTBI, and in particular, examine the extent to which mTBI-related white matter abnormalities are region-specific or spatially heterogeneous. In addition, we examined whether mTBI with loss of consciousness (LOC) was associated with more extensive white matter abnormality than mTBI without LOC, as well as the potential moderating effect of number of blast exposures. A second aim was to examine the relationship between white matter integrity and neurocognitive function. Finally, a third aim was to examine the contribution of PTSD symptom severity to observed white matter alterations. One hundred fourteen OEF/OIF veterans underwent DTI and neuropsychological examination and were divided into three groups including a control group, blast-related mTBI without LOC (mTBI - LOC) group, and blast-related mTBI with LOC (mTBI + LOC) group. Hierarchical regression models were used to examine the extent to which mTBI and PTSD predicted white matter abnormalities using two approaches: 1) a region-specific analysis and 2) a measure of spatial heterogeneity. Neurocognitive composite scores were calculated for executive functions, attention, memory, and psychomotor speed. Results showed that blast-related mTBI + LOC was associated with greater odds of having spatially heterogeneous white matter abnormalities. Region-specific reduction in fractional anisotropy (FA) in the left retrolenticular part of the internal capsule was observed in the mTBI + LOC group as the number of blast exposures increased. A mediation analysis revealed that mTBI + LOC indirectly influenced verbal memory performance through its effect on white matter integrity. PTSD was not associated with spatially heterogeneous white matter abnormalities. However, there was a suggestion that at higher levels of PTSD symptom severity, LOC was associated with reduced FA in the left retrolenticular part of the internal capsule. These results support postmortem reports of diffuse axonal injury following mTBI and suggest that injuries with LOC involvement may be particularly detrimental to white matter integrity. Furthermore, these results suggest that LOC-associated white matter abnormalities in turn influence neurocognitive function.

Chronic Postconcussion Symptoms and Functional Outcomes in OEF/OIF Veterans with Self-Report of Blast Exposure

Postconcussion symptoms (PCS) and functional outcomes were evaluated in 91 OEF/OIF outpatient veterans with reported histories of blast-exposure, with the goal of evaluating (1) the association between these outcomes and a clinical diagnosis of mild traumatic brain injury (mTBI) with or without loss of consciousness (LOC); and (2) the influence of post-traumatic stress disorder (PTSD) and depression on PCS reporting and perceived functional limitations. Individuals who reported mTBI with LOC had greater PCS complaints than individuals who reported mTBI without LOC or individuals without mTBI. However, after adjusting for severity of PTSD and depression symptoms, this group difference disappeared. Functional limitations were particularly prominent in the psychosocial domain. Again, PTSD was significantly associated with functional outcomes, but the mTBI with LOC group had greater psychosocial limitations than the other two groups, even when PTSD and depression symptoms were taken into account. These findings highlight the role of mental health in both outcomes, but additionally point to the impact of mTBI with LOC on long-term psychosocial adjustment.

Prognostic significance of acute pain preceding out-of-hospital cardiac arrest

BackgroundSudden loss of consciousness (LOC) and chest pain are common manifestations of out-of-hospital cardiac arrest (OHCA). History of acute pain may be helpful in estimating aetiology and prognosis of OHCA...

The correlation between mandible fractures and loss of consciousness

Purpose The purpose of the study was to evaluate the relationship between mandible fractures and loss of consciousness (LOC) in patients sustaining maxillofacial trauma in a level I trauma center. Patients and methods The study was a retrospective chart review performed at Lincoln Medical and Mental Health Center, a level I trauma center. A total of 225 hospital charts of patients who sustained mandible fractures during the period from 1997 to 2001 were reviewed. The site of fracture, number of fractures per mandible, degree of displacement, and mechanism of injury were recorded. Percentages of each category were compared among patients with positive and negative LOC. Patients with any concomitant craniofacial fractures or injuries were excluded from the study. Results The incidence of LOC in patients sustaining mandible fractures was 17.6%. Young men were most likely to sustain mandibular fractures. The male-to-female ratio was 5.6:1. More than 70% of mandible fractures were due to interpersonal violence. Among various causes of interpersonal violence, use of a fist was most common. Overall, the number of fractures per patient, the incidence of singular versus multiple mandibular fractures, and the degree of displacement were less in the group with positive LOC. Body and angle regions were subjected to higher numbers of fractures, with slight variation among the 2 groups. The most common locations for mandibular fractures were the body (26% in negative LOC group; 42% in positive LOC group) and the angle (31% in negative LOC group; 26% in positive LOC group). Conclusion Nearly 1 in 5 mandible fractures was associated with positive LOC. The patient group with a positive LOC, on average, sustained fewer fractures. It is possible that when the mandible sustained fewer fractures, the dissipation of energy was reduced and more force was transmitted to the cranial vault, thereby resulting in a higher incidence of LOC.

Cognitive sequelae of repeated head injury in a population of intravenous drug users

The relationship between closed head injury and performance on neuropsychological (NP) tests was investigated in a group of intravenous drug users (IVDUs). Subjects with repeated head traumas involving loss of consciousness (LOC) performed worse than both a control group without LOC and reference group with only a single episode of LOC. There were no significant differences between the last two groups. Performance on tests of memory, attention, and motor performance was significantly worse in the group with repeated head injury. The average time since the last episode of LOC was more than 11 years. We conclude from these findings that a single episode of LOC does not result in significant cognitive impairment in this population. Two or more episodes, however, are more likely to produce chronic cognitive impairment.