The management of severe traumatic brain injury

An approach to the initial evaluation, resuscitation, and treatment of the patient with severe traumatic brain injury is presented in terms of the underlying physiology and literature support. The primary importance of rapid and complete systemic resuscitation in terms of the "ABCs" is stressed, with the goal of optimizing cerebral perfusion and preventing secondary insults to the injured brain. The integration of brain-specific treatments and diagnostic maneuvers into resuscitation protocols is discussed, including the role of mannitol and hyperventilation as well as the prioritization of CT imaging of the brain.     

Significance of intracranial hypertension in severe head injury

Measurements of intracranial pressure (ICP) were begun within hours of injury in 160 patients with severe brain trauma, and continued in the intensive care unit. Some degree of increased ICP (greater than 10 mm Hg) was present on admission in most cases (82%), and in all but two of the 62 patients with intracranial mass lesions requiring surgical decompression; ICP was over 20 mm Hg on admission in 44% of cases, and over 40 mm Hg in 10%. In patients with mass lesions only very high ICP (greater than 40 mm Hg) on admission was significantly associated with a poor neurological picture and outcome from injury, while in patients with diffuse brain injury any increase in ICP above 10 mm Hg was associated with a poorer neurological status and a worse outcome. Despite intensive measures aimed at prevention of intracranial hypertension, ICP rose over 20 mm Hg during the monitoring period in 64 of the 160 patients (40%). Postoperative increases in ICP over 20 mm Hg (mean) were seen in 52% of the patients who had had intracranial masses evacuated, and could not be controlled by therapy in half of these cases. Even in patients without mass lesions, ICP rose above 20 mm Hg in a third of the cases, despite artificial ventilation and steroid therapy. Of the 48 patients who died, severe intracranial hypertension was the primary cause of death in nearly half and even moderately increased ICP (greater than 20 mm Hg) was associated with higher morbidity in patients with mass lesions and those with diffuse brain injury. Measurement of ICP should be included in management of patients with severe head injury.     

Predictors of long-term outcome in severe head injury

Potentiometric choline electrodes were developed on the basis of the mediator-free bioelectrocatalysis. The electrodes made of a composite carbon-polymer material contain choline oxidase and peroxidase coimmobilized on the surface of the electrode. The rate of the potential increase was shown to be proportional to the choline concentration within a broad range of variation. Coupling of choline-sensitive electrodes with butyrylcholinesterase makes possible both the direct detection of butyrylcholine and analysis of butyrylcholinesterase inhibitors.     

Abstract thinking following severe traumatic brain injury

Abstract abilities were studied in a sample of 34 individuals with severe TBI and a control group. The results indicate that TBI interferes with performance on tests requiring individuals to process information into new categories. There appears to be a dissociation between verbal abstract abilities and visual-perceptual abstract abilities. There is evidence that Goldstein and Sheerer's [1] postulate of a general 'abstract attitude' was at least partially correct. This attitude does not appear to be related to a general verbal ideational process, as dysphasic subjects were only deficient on a purely verbal abstract task.     

Sustained attention after severe closed head injury.

Sustained attention was assessed in 20 patients with severe closed head injury (CHI) and 20 normal matched controls. Participants were presented with a visual continuous performance task (CPT) with 3 levels of complexity. Performance was assessed by examining response latencies and error rates. Across all levels of complexity, the CHI patients demonstrated a vigilance decrement, whereas the performance of the matched controls was stable across time. The vigilance decrement was not differentially affected by the manipulation of task complexity in the CHI patients. However, findings suggest that the overall vigilance performance of CHI patients was differentially affected by increasing the complexity of the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual selective attention after severe closed head injury

This study investigated the nature of selective attention deficits after severe closed head injury (CHI). Twenty participants with severe CHI (greater than 1 year postinjury) and 20 matched controls completed search and nonsearch visual selective attention tasks under conditions of low (Experiment 1) and high (Experiment 2) target-distractor similarity. In the search situations, participants searched visual displays that contained 1, 4, or 8 items for the targets. In the nonsearch situations, the location of the targets was visually cued with a peripheral arrow. The results revealed that in both the low and high target-distractor similarity search conditions. CHI participants required a longer time than controls to locate and identify the target. In contrast, in the nonsearch condition, CHI participants were able to successfully ignore irrelevant task information when target-distractor similarity was low. However, when target-distractor similarity was high, CHI participants had more difficulty than controls ignoring the irrelevant information. These results suggest that, in comparison to controls, CHI participants may be at a disadvantage in selective attention situations when visual search is required and when the discriminability between targets and distractors is difficult.     

Automatic process development following severe closed head injury.

Automatic process development was investigated in a closed head injury (CHI) population. Ten severe CHI participants (>1 year postinjury) and 10 matched controls completed consistent mapping (CM) and varied mapping (VM) semantic-category memory search tasks. In VM search, despite a similar pattern of serial memory search, the CHI participants responded slower than controls and exhibited slower memory search rates throughout practice (1,800 trials). In CM search, after extensive practice (1,800 trials) both groups showed the performance characteristics indicative of automatic process development, that is, near-zero slopes and large reductions in response times. However, the CHI participants were slower to automatize the task. These results indicate that for memory-based search tasks the effects of a CHI may slow down the speed with which automatic processes develop but that CHI participants can acquire and use automatic processes in task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Caregiver burden at 6 months following severe traumatic brain injury

We compared the performance of three computer based classification methods when applied to the problem of detecting microaneurysms on digitised angiographic images of the retina. An automated image processing system segmented 'candidate' objects (microaneurysms or spurious objects), and produced a list of features on each candidate for use by the classifiers. We compared an empirically derived rule based system with two automated methods, linear discriminant analysis and a learning vector quantiser artificial neural network, to classify the objects as microaneurysms or otherwise. ROC analysis shows that the rule based system gave a higher performance than the other methods (p = 0.92) although a much greater development time is required.     

Variables associated with employment following severe traumatic brain injury.

Results of a survey of employment outcome and their relationship to psychometric indices indicated that competitive employment following severe traumatic brain injury is an ambitious endeavor. While 98% of the 94 Ss sampled were either employed or in school premorbidly, 43% of them were unemployed postinjury. Psychometric variables were most highly related to employment outcome which suggested a useful role of neuropsychological testing in assisting in vocational rehabilitation planning. Furthermore, the psychometric test results indicated that many Ss who were unemployed may be capable of parttime employment. Future studies are needed to further examine those neuropsychological abilities which subsequently affect employability following severe traumatic brain injury. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term psychosocial adjustment following very severe closed head injury.

Examined the cognitive, psychological, and social functioning of 18 community-dwelling male patients who had experienced a severe closed head injury (CHI) at least 18 mo previously and still required contact with rehabilitation services. Results from Ss with CHI were compared with those from 27 normal control Ss. Information on Ss' behavior was also obtained from their significant others. Results show that Ss with CHI exhibited deficits in their cognitive and social functioning but showed no signs of emotional or psychiatric disturbance. Attempts to find a relationship between the cognitive impairment and social functioning of Ss with CHI were partially successful. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term effects of severe penetrating head injury on psychosocial adjustment.

The long-term effects of severe penetrating head injury on adjustment levels were studied. Forty-one World War II veterans who suffered penetrating injury to the brain were interviewed 40 years after their initial injury using the Washington Psycho-Social Seizure Inventory (WPSI). The results support a comparable behavioral impact of right and left hemispheric lesions. Similarly, no significant relations were found between anterior and posterior locus of damage and psychosocial difficulties, although the results pertaining to the right-anterior group could be interpreted as suggestive of much greater maladjustment in all life dimensions assessed by the WPSI. Findings are discussed in terms of theoretical positions on hemispheric specialization and long-term expectancies that hold implications for planning rehabilitation programs for such patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recovery of time estimation following moderate to severe traumatic brain injury.

Objective: Accurate time estimation abilities are thought to play an important role in efficient performance of many daily activities. This study investigated the role of episodic memory in the recovery of time estimation abilities following moderate to severe traumatic brain injury (TBI). Method: Using a prospective verbal time estimation paradigm, TBI participants were tested in the early phase of recovery from TBI and then again approximately one year later. Verbal time estimations were made for filled intervals both within (i.e., 10 s, 25 s) and beyond (i.e., 45 s 60 s) the time frame of working memory. Results: At baseline, when compared to controls, the TBI group significantly underestimated time durations at the 25 s, 45 s and 60 s intervals, indicating that the TBI group perceived less time as having passed than actually had passed. At follow-up, despite the presence of continued episodic memory impairment and little recovery in episodic memory performance, the TBI group exhibited estimates of time passage that were similar to controls. Conclusion: The pattern of data was interpreted at suggesting that episodic memory performance did not play a noteworthy role in the recovery of temporal perception in TBI participants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Soluble adhesion molecules in CSF are increased in children with severe head injury

Leukocyte-endothelial adhesion molecules, critical to the development of acute inflammation, are expressed in brain as part of the acute inflammatory response to traumatic brain injury (TBI). We measured the concentrations of the adhesion molecules P-selectin, ICAM-1, E-selectin, L-selectin, and VCAM-1 in ventricular cerebrospinal fluid (CSF) from children with severe TBI (Glasgow coma score < 8) and compared these findings with those from children with bacterial meningitis. P-selectin, an adhesion molecule associated with ischemia/reperfusion, was increased in children with TBI versus meningitis and control. Univariate and multivariate regression analyses demonstrated associations between CSF P-selectin and child abuse and age of < 4 years, and a significant, independent association between CSF intercellular adhesion molecule-1 (ICAM-1) and child abuse. These results are consistent with a specific acute inflammatory component to TBI in children. Future studies of secondary injury mechanisms and therapy after TBI should assess on the roles of P-selectin and ICAM-1 in injury and repair processes in brain after TBI.     

Conversational discourse abilities following severe traumatic brain injury: a follow-up study

The major aim of this study was to describe the conversational abilities of a group of severely injured TBI speakers, at a minimum of 2 years post-injury. The association between conversational impairment and (a) selected measures of executive function and (b) psychosocial handicap was also examined. Twenty-four members of the group of 26 severely injured TBI speakers who had initially been assessed between 3 and 6 months post-injury were reviewed at a minimum of 2 years post-injury (mean = 2 years, 10 months). At initial assessment, TBI speakers were compared with non-TBI orthopaedic patients and with a group of university students. At follow-up, however, they were compared only with the orthopaedic patients. Conversational assessment was carried out using a modified form of Damico's Clinical Discourse Analysis. As a group, the TBI speakers' conversational abilities did not improve over time. There was, however, a subgroup (n = 8) of speakers who did improve, and these could be distinguished by greater initial severity of injury and a significantly longer period of speech-language pathology intervention than the speakers who either remained the same or worsened over time. Modest associations between conversational discourse skills and measures of executive function and a measure of psychosocial handicap were identified. These findings indicate that disruptions in conversation persist into the longer term. More assiduous efforts may need to be made to (a) identify subtle discourse changes in the early months after injury and (b) engage TBI speakers in speech-language pathology services. Such services are also required over a longer time frame, in community-based models of service provision.     

Interhemispheric transfer after spontaneous recovery in 43 cases of severe closed head injury.

Examined the possibility of frequent callosal disconnection following closed head injury. Interhemispheric transfer was evaluated in 43 severe closed-head-injured patients (aged 18–51 yrs) using a wide-ranging battery of untimed behavioral tasks, after the period of spontaneous recovery. Only 1 S showed signs of callosal disconnection. Much effective interhemispheric transfer occurred in closed-head-injured Ss after the period of spontaneous recovery. More frequent occurrence of the disconnection syndrome in its acute phase is a possibility that cannot be excluded. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

EBIC-guidelines for management of severe head injury in adults. European Brain Injury Consortium

Guidelines for the management of severe head injury in adults as evolved by the European Brain Injury Consortium are presented and discussed. The importance of preventing and treating secondary insults is emphasized and the principles on which treatment is based are reviewed. Guidelines presented are of a pragmatic nature, based on consensus and expert opinion, covering the treatment from accident site to intensive care unit. Specific aspects pertaining to the conduct of clinical trials in head injury are highlighted. The adopted approach is further discussed in relation to other approaches to the development of guidelines, such as evidence based analysis.     

Comparison of serial S-100 and NSE serum measurements after severe head injury

We investigated the time course of neuron specific enolase (NSE) and S-100 protein after severe head injury in correlation to outcome. We included 30 patients (GCS < 9), who had been admitted within 5 hours after injury, in a prospective study. Blood samples were taken on admission, 6, 12, and 24 hours and every 24 hours up to the fifth day after injury. The outcome was estimated on discharge using the Glasgow Outcome Scale. 70% reached a good outcome. All concentrations of NSE and 83% of the S-100 samples were elevated concerning the first probe (30.2 micrograms/l NSE mean and 2.6 micrograms/l S-100 mean). Patients with bad outcome had an NSE concentration of 38 micrograms/l (mean) compared with 26.9 micrograms/l (mean) in patients with good outcome. Patients with bad outcome had an S-100 concentration of 4.9 micrograms/l (mean) compared with 1.7 micrograms/l (mean) in patients with good outcome (p < 0.05). The mean values of NSE and S-100 decreased during the first 5 days. Four patients with increasing intracranial pressure showed a quick increasing concentration of NSE, in two patients the S-100 level showed a slower rise. The NSE serum levels did not correlate with intracranial pressure values. Our results show that the first serum concentration of S-100 seems to be predictive for outcome after severe head injury.     

Regional cerebral blood volume after severe head injury in patients with regional cerebral ischemia

OBJECTIVE: Recent early cerebral blood flow (CBF) studies in cases of severe head injury have revealed ischemia in a substantial number of patients with a variety of computed tomographically demonstrated diagnoses. The underlying derangements causing this early ischemia are unknown, but cerebral blood volume (CBV) measurements might offer some insight into this pathological abnormality. METHODS: For this purpose, stable xenon-enhanced computed tomography was used for assessment of CBF, and a dynamic computed tomographic imaging technique was used for determining CBV. Based on the occurrence of regional ischemia (CBF < 20 ml/100 g/min), seven patients with varying anatomic lesions revealed by computed tomography were identified for comparison between CBF and CBV in ischemic and nonischemic areas. RESULTS: Both CBF (15+/-4.3 versus 34+/-11 g/min, P < 0.002) and CBV (2.5+/-1.0 versus 4.9+/-1.9 ml/100 g) exhibited significantly lower values in the ischemic zones than in the nonischemic zones (means+/-standard deviations). Among 26 patients with or without ischemia observed during their initial follow-up studies, which were conducted between Days 2 and 8, all patients showed CBF and CBV values within the low-normal range. CONCLUSION: These data evidently support the suggestion that compromise of the microvasculature is the cause of early ischemia, rather than vasospasm of the larger conductance vessels.