Length Of Coma Research Articles

Predictors of outcome following severe head trauma: follow-up data from the Traumatic Coma Data Bank.

Outcome as a function of employment status or return to school was evaluated in severely head-injured patients. A priori we selected the most salient demographic, physiological, neuropsychological and psychosocial outcome predictors with the aim of identifying which of there variables captured at baseline or 6 months would best predict employability at 6 or 12 months. Based on the patients evaluated at 6 months, 18% of former workers had returned to gainful employment and 62% of former students had returned to school. For those not back to work or school at 6 months, 31% of the former workers and 66% of the former students had returned by 12 months. Age, length of coma, speed for both attending and motor movements, spatial integration, and intact vocabulary were all significantly related to returning to work or school. The three most potent predictors for returning to work or school were intactness of the patient's verbal intellectual power, speed of information processing and age.

Electron beam lithography system with new correction techniques

In our electron exposure system, the focal length of the final projection lens is designed to be very short. To decrease aberrations due to beam deflections, which cannot be corrected by a dynamic focus coil or a stigmator, deflection coil parameters are determined by a simulation, which used the conditions: coma length=0, transverse chromatic aberration coefficient=0, and beam incidence is normal to the sample surface. Patterns of the size under 0.2 μm are well resolved inside the whole deflection field of 1.6×1.6 mm. Current density of the system is more than 40 A/cm2. Refocusing and refocus–flyback are necessary to utilize the high current density for spot size between 0.1 and 3.0 μm. Large spot defocusing is refocused by small refocus coils, and refocused beam position shifts are corrected by a refocus–flyback method. Beam-settling retardation caused by an eddy current occurs after an electromagnetic jump. A differentiated electromagnetic signal is added to electrostatic deflectors to compensate for the transitional beam positions between the jump. The beam-settling time is less than 100 μs for a 1 mm jump, about a tenth of that without the compensation.

Risk factors for heterotopic ossification in children and adolescents with severe traumatic brain injury.

Previous reports on the incidence of heterotopic ossification (HO) in children and adolescents with traumatic brain injury (TBI) have ranged from 3% to 20%. These studies mention HO briefly or address patient cohorts with coma more than three months. We reviewed the medical records of 90 children younger than 19 years old, who were comatose more than 24 hours after TBI. Mean followup was 33.1 months (range = 2 to 128 months). Incidence of HO was 14.4% (n = 13). One to five sites were involved, with hip and knee most frequent, followed by shoulder, elbow, and nonjoint sites. Children with HO were older than 11 years (relative risk [RR] = 18.85, confidence interval [CI] = 3.7, 95.7), had a greater length of coma (RR = 7.22, CI = 1.4, 37.1), and had a greater associated risk for poor functional outcome (RR = 2.89, CI = 1.02, 7.9) compared to those without RO. Multiple limb fractures showed a trend toward association with increased incidence of HO. Other factors, including gender, history of skull fracture, brain CAT scan findings, and presence of spasticity, were not predictive of HO. Eleven children were treated with etidronate, four with nonsteroidal antiinflammatory drugs, and one with surgery. Only three children had residual functional impairments attributed to the presence of HO.

Validity of the Kaufman Assessment Battery for Children when employed with children with traumatic brain injury.

The K-ABC and WISC-R were administered to 43 children with traumatic brain injury. The amount of shared variance between standard score indices of these two tests ranged from 42% to 71%, depending on which scores were considered. Correlations with degree of cerebral impairment, as measured by length of coma, were slightly higher for WISC-R IQ scores than for K-ABC global scale scores. Performance on both the K-ABC and the WISC-R was affected by the presence or absence of ocular and/or motor deficits. It is concluded that the K-ABC is not superior to the WISC-R in sensitivity to cerebral impairment and that caution is needed when one is making neuropsychological interpretations on the basis of the K-ABC.

Functional improvement in severe head injury after readmission for rehabilitation.

Early rehabilitation has been shown to minimize complications and optimize functional outcomes in head-injured patients. Although cognitive, behavioural and vocational issues continue for years after injury, many investigations maintain that physical improvement is limited after 6 months. At 12 months after injury, expectations for physical improvement are generally limited. In addition, although repeated inpatient admissions for rehabilitation are common, gains in self-care and mobility skills during readmissions for rehabilitation have not been specifically investigated. In this retrospective study the records of 49 severely head-injured patients were evaluated. All were readmitted to an inpatient rehabilitation facility more than 12 months after injury. Barthel Index scores were obtained to evaluate physical function. Although previous studies would predict few improvements, in this study 53% (26 patients) showed improvement, and the difference between readmission and discharge Barthel scores was statistically significant (p = 0.0001). Gains were highly correlated with length of readmission, but not with age of patient, age at time of injury, length of coma, time since injury, or duration of previous rehabilitation. Patients with mid-range admission Barthel scores (21-85) demonstrated the largest gains, with 79% showing improvement. Gains averaged 11.2 points on the Barthel Index. Severely head-injured patients may show clinically significant improvement in physical function well after current standards predict a plateau.

Predicting clearing of post-traumatic amnesia following closed-head injury

The ability to predict the resolution of post-traumatic amnesia (PTA) early in the course of acute rehabilitation was studied in a sample of 98 closed-head injury (CHI) patients admitted for acute rehabilitation. The subjects' age, length of coma, time post-injury and Orientation Group Monitoring System (OGMS) subscale and aggregate scores were evaluated for the ability to predict if and when a patient would clear PTA. The results indicated that the combination of time post-injury and week one OGMS aggregate score provided the best prediction of whether and when PTA would clear. A shorter time from injury to acute rehabilitation was a positive prognostic indicator, accounting for more variance than either age or duration of coma. Whereas the aggregate OGMS score was a better indicator than any of the subscale scores, the results also suggested that specific aspects of cognition have differential predictive power, which may derive from different types of injury to the brain. Although the prediction model was statistically significant, its practical significance was limited. In particular, the high base rate for clearing PTA, 83.7%, attenuated the potential for differential prediction. Finally, this study provided additional support for the construct validity of the OGMS as a measure of cognitive function during the acute phase of recovery from CHI.

Time of rehabilitation admission and severity of trauma: effect on brain injury outcome.

Outcome after traumatic brain injury, defined by the Glasgow Outcome Scale (GOS) and length of stay in acute rehabilitation, was measured in 59 patients admitted to an intensive rehabilitation program to examine the effects of severity of the initial brain injury, severity of multiple trauma, and length of stay in the acute care hospital. Severity of initial brain injury, best measured by length of coma, was the most significant predictor of GOS outcome. Length of acute hospitalization was a small, but significant, predictor of GOS. Severity of initial brain injury, length of acute hospitalization, and gender emerged as predictors of length of rehabilitation hospital stay. Although length of acute hospitalization is apparently affected by severity of brain injury, it adds significantly--more than severity of brain injury--to the prediction of length of rehabilitation.

Predicting severity of cognitive impairment after severe head injury

It is often assumed that age is an important variable in determining cognitive outcome following severe head injury. The present study was carried out to determine whether age at time of injury predicted severity of cognitive impairment. Our hypothesis was that the older the patient at time of head injury the worse should be the cognitive impairment. Cognitive impairment was assessed by scores on nine standardized tests. Scores were obtained from 144 consecutive referrals to a clinical psychologist; all subjects had sustained a severe head injury. Of these, 115 had suffered a closed head injury. Ages ranged from 13 to 65 years. Apart from Unusual Views and Verbal Fluency no significant correlations were found between age and test performance. Thus there was little evidence that age predicted performance on cognitive tests. A number of significant correlations were found between length of coma and cognitive performance. The findings would seem to confirm that cognitive outcome after severe head injury is predicted by length of coma (which reflects severity of brain damage) whilst age at time of injury does not appear to be a good predictor of outcome.

Neuropsychological recovery in patients with moderate to severe head injury: 2 year follow-up

Neuropsychological outcome and recovery of a group of 31 consecutive adult patients with moderate to severe head injuries were prospectively investigated over a 2-year period. A friend control group was used for comparison purposes. Based on the results we conclude: (1) there is marked impairment of a broad spectrum of neuropsychological functions at 1, 12, and 24 months postinjury; (2) coma length is significantly related to neuropsychological status at all three time periods, although the relationship is weaker at 12 and 24 months; (3) marked improvement in all functions occurs in the first year, while recovery in the second year appears more specific and may depend on the severity of the injury and type of function; (4) practice effects and variability over repeated measures cause difficulties in determining recovery and need to be addressed with larger samples.

Return to work after rehabilitation following traumatic brain injury

The relationship of medical variables and discharge functional status to vocational and educational outcomes was examined in 79 closed head-injured patients who were consecutively admitted to an inpatient rehabilitation hospital during a two-year period. A follow-up study, conducted after hospital discharge (median, 16.5 months), found that 66% (n = 52) of the patients had returned to work or school, while 34% (n = 27) did not. Patients were divided into return and non-return to work groups. Traditional variables included age, severity of brain-damage as characterized by CT head scan, duration of post-traumatic amnesia, duration of coma, length of stay and acute inpatient rehabilitation program. Discharge functional scores were analysed by t-tests and chi-square analysis. Results suggest that traditional factors of younger age, shorter length of coma, minimal CT head scan findings and shorter length of stay were significant contributors to educational/vocational outcome. Their significance was enhanced by discharge functional profile measurement of medical, physical and psychological/neuropsychological integrity. Those functional measures not significant were in social, vocational, recreational and communication areas. These factors may continue to improve over a longer period of time and should be tracked in the post-acute rehabilitation phase for their significance in return to work/school.

Recovery of memory after severe closed head injury: dissociations in recovery of memory parameters and predictors of outcome.

This study examined selective reminding and recognition memory performance of 21 severe closed-head injured patients tested within 6 months of regaining consciousness and then again after at least 1 year. Performances on selective reminding parameters were highly correlated and patients performed significantly worse at both testings than did hospitalized controls matched for age, education, and sex. Patients improved from testing 1 to testing 2 on only four of six memory variables. Average Impairment Rating at testing 1 was a marginally better predictor of memory performance at testing 2 than was length of coma. Results are discussed in terms of (a) utility of selective reminding parameters and predictors of outcome and (b) dissociations in recovery of memory parameters.

Relationships among pre- and post-injury intelligence, length of coma and age in individuals with severe closed-head injuries.

Relationships among pre-injury ability, post-injury verbal intelligence, duration of coma and age were analysed in 34 closed-head injury patients, 7-28 years of age, whose coma lengths ranged from 5 to 180 days. The results obtained suggest that moderate to severe closed-head injury uniformly impairs verbal intellectual functioning without regard to premorbid status. Premorbid ability test scores had a markedly low correlation (0.04) with Wechsler Verbal IQs, obtained after patients had plateaued in intellectual recovery. Even when the effects of coma and age were controlled, the correlation was not significant. Mean post-injury IQs for patients grouped according to pre-injury intelligence (above average, average, below average) were all in the 80s. The findings do not support the prevailing assumption that the greater the premorbid ability, the greater the potential for intellectual recovery and the better the outcome. This study instead suggests that the higher the pre-injury IQ, the greater the IQ point loss. This has important implications for rehabilitation, counselling, discharge planning and follow-up. The greater the disparity between pre- and post-injury IQs, the more profound the loss and, hence, the greater the need for patient and family adjustments, coping and modifications of future personal, educational and vocational plans.

Patients' recollections of their posttraumatic coma.

Patients' recollections of posttraumatic coma as viewed retrospectively were explored in this descriptive study. Fifteen patients from two urban north Texas hospitals who incurred traumatic head injury and associated coma (Glasgow Coma Scale score of 8 or less for at least six hours) were interviewed. A set of open-ended questions was developed and utilized in a semi-structured interview with each subject. Data such as age, sex, type of injury, how injury occurred, Glasgow Coma Scale score, and duration of coma were collected. Responses elicited during the interviews were analyzed qualitatively. In this investigation seven subjects reported no recollections of being comatose. Eight were able to relate experiences with three prevailing themes: imprisonment, sensory experiences, and death-like experiences. Four subjects recalled actions perceived as helpful and not helpful while in coma. Recollections of unconsciousness appeared to have been affected by the length of coma but not by the Glasgow Coma Scale score or the type of head injury sustained. These findings reveal patients in coma from a traumatic head injury have a limited degree of awareness of the environment. That awareness should be incorporated into nursing management of the comatose patient in acute and chronic care settings.

Head Trauma Rehabilitation: Program Evaluation

Thirty-five patients admitted to a head trauma unit with a diagnosis of traumatic head injury were evaluated from admission to discharge for functional and cognitive outcomes. Long-term outcomes after discharge to home from the rehabilitation hospital were also investigated. Significant functional and cognitive gains were made by patients at the time of discharge. Eighty-nine percent of the patients were discharged home. The length of coma significantly correlated with the length of rehabilitation days but did not correlate with either functional or cognitive improvement. The majority of the patients discharged were independent in their daily activities and did not require medical or nursing care more than every three months. However, problems seemed to exist in jobs, at school, with finances, and in relationships with friends.

Variability in Dispersal Ability of Common Milkweed, Asclepias syriaca, Seeds

Common milkweed, Asclepias syriaca L., produces plumed seeds adapted for wind dispersal. Seeds within single pods are variable in coma length (plume length) and seed mass. Coma length variability is related to a seed's location within a pod, while seed mass is not related to seed position. Laboratory studies, using methods developed by Sheldon and Burrows, revealed that seed trait variation can influence variation in a plant's dispersal profile. Field studies indicated that ambient wind speed as well as seed morphological attributes influenced seed dispersal distance. In strong winds, seeds with relatively long comae travelled significantly farther than those with short comae when paired and released simultaneously. Both laboratory and field results suggest that coma length variation is more strongly related to variation in seed dispersal than is seed mass. The pattern of variability of morphological attributes of seeds within pods may lead to increased chances of seeds reaching sporadically opening patches.

Recovery trends of functional skills in the head-injured adult.

This study describes the course of the recovery of functional skills in adults with severe head injuries during a 2-year period. Eighty head-injured patients admitted to an inpatient rehabilitation unit were included in this study. Length of coma could be ascertained for 78 of the patients. These subjects were then divided into two groups by coma length (i.e., less than or equal to 14 days coma and greater than or equal to 15 days coma) as defined by the Glasgow Coma Scale. All 80 patients were rated at 2-, 4-, 6-, 12-, and 24-month intervals after reported date of injury in the following areas: Basic ADLs (feeding, grooming, bed mobility), Wheelchair Mobility, Dressing, Functional Transfers, Basic Hand Skills, Community Skills, Kitchen Skills, and Jebsen Hand Function. Results illustrated improvement over time in mean scores for all areas evaluated up to 2 years post-injury for both coma groups. The shorter coma group appeared initially less disabled, improved more rapidly, and exhibited significantly less disability on these measures at 1-year post-injury than the longer coma group. Frequency distributions of all patients at the 2-month and 1-year time frame supported the recovery trends and also indicated that the majority of clients improved in functional areas over time despite extensive coma lengths. Chi-square analysis of all patients indicated that the amount of change in mean scores between 2 months and 12 months post-injury was statistically significant for all variables and that the amount of change in mean scores between 6 months and 12 months post-injury was also significant for seven variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced emotional reactions in chronic head trauma patients.

The emotional characteristics of head injury patients referred for neuropsychological testing were examined as a function of the time since injury. Patients referred more than 6 months from injury were more emotionally distressed on the MMPI and Katz Adjustment Scale (relatives form) compared to those tested 6 months or earlier. The more chronic head trauma patients were more anxious and depressed, more confused in their thinking, and more socially withdrawn compared to the acute patient group. These differences in emotional functioning appeared to be independent of level of neuropsychological impairment and the initial length of coma. Premorbid personality and increased awareness of impaired functioning with the passage of time are discussed as possible mediators of enhanced emotional distress in some chronic head injury patients.

Long-Term Outcome of Children with Severe Head Trauma and Prolonged Coma

Forty-six children with significant head trauma who remained in coma more than 24 hours were the subjects of this long-term outcome study. Twelve (38%) died. The average length of coma in the 34 survivors was 15.5 days. Follow-up ranged from 9 months to 4 years (mean 21 months). Twenty-nine percent of the survivors were normal at follow-up. An additional 53% had mild cognitive or behavioral problems, but 61% of these had evidence of similar problems prior to the injury. Nine percent of survivors had motor residua but normal intellect. Nine percent had severe intellectual and motor problems. Children less than 2 years of age had a worse outcome. Despite severe injury and prolonged coma after head trauma, most children do well. Intensive medical and surgical care increases the rate of survival and does not result in a large number of severely disabled survivors.

Moderate head injury: completing the clinical spectrum of brain trauma.

We have divided head injury into three categories based on the Glasgow Coma Scale (GCS) (severe, 3-8; moderate, 9-12; and minor, 13-15). In a previous report, we described significant disability after minor head injury. The present report describes 199 patients with moderate head injury, 159 of whom underwent follow-up examinations at 3 months. In contrast to patients with minor head injury, half as many were students (17%) and twice as many were intoxicated (53%). Seventy-five patients were studied with computed tomographic (CT) scanning; 30% of the scans were negative and 31% showed a space-occupying mass. As reported by Gennarelli et al. in patients with severe head injuries, those with moderate head injury and subdural hematoma had a very poor outcome: 65% died or were severely disabled and none made a good recovery as measured by the Glasgow Outcome Scale. At 3 months, 38% of the moderate head injury patients had made a good recovery compared with 75% of the minor head injury patients. Within the good recovery category, however, there was much disability (headache, 93%; memory difficulties, 90%; difficulties with activities of daily living, 87%), and only 7% of the patients were asymptomatic. The Halstead-Reitan Neuropsychological Battery in an unselected subset (n = 32) showed significant deficits on all test measures. Sixty-six per cent of the patients previously employed had not returned to work, compared to 33% of the minor head injury patients. The major predictors of unemployment after minor head injury were premorbid characteristics (age, education, and socio-economic status). In contrast, all predictors in moderate head injury were measures of the severity of injury (length of coma, CT diagnosis, GCS on discharge). We conclude that: (a) moderate head injury, not described previously in the literature, results in mortality and substantial morbidity intermediate between those of severe and minor head injury; (b) unlike minor head injury, the principal predictors of outcome after moderate head injury are measures of the severity of injury; and (c) more attention should be directed to patients with moderate head injury than to those with the most severe injuries, in whom brain damage is probably irreversible and all forms of management have demonstrated little success.

Hyperbaric Oxygen for Carbon Monoxide Poisoning

To the Editor.— The recent report by Myers et al (1981;246:2478) on the value of hyperbaric oxygen therapy for carbon monoxide poisoning deserves some comment. The authors' case reports are impressive, and it does appear that hyperbaric oxygen therapy can shorten the length of coma after carbon monoxide poisoning, even when carboxyhemoglobin levels have already returned to normal. Whether this is due to residual carbon monoxide in the tissues or simply the result of cerebral hypoxia remains unclear. The contribution of direct cellular toxicity of carbon monoxide has not been well established. Animals whose blood was completely replaced by an oxygen-carrying perfluoro chemical emulsion remained asymptomatic indefinitely in a 90% oxygen and 10% carbon monoxide environment, while controls breathing a 95% oxygen and 5% carbon monoxide mixture died within five to ten minutes.1,2 More importantly, the implication that hyperbaric oxygen therapy will prevent long-term neurological sequelae is certainly not