Neuropathology of the vegetative state after head injury.

A detailed neuropathological study of patients identified clinically after head injury as either severely disabled (SD, n = 30) or vegetative (VS, n = 35) has been carried out to determine the nature and frequency of the various pathologies that form the basis of these clinical states. Patients who were SD were older (SD median 49.5 yrs vs. VS median 38 yrs, p = .04), more likely to have a lucid interval (SD 31% vs. VS 9%, p = .03), and to have had an acute intracranial haematoma (SD 70% vs. VS 26%, p < .001). SD patients less often had severe, Grades (2 or 3) of traumatic diffuse axonal injury (SD 30% vs. VS 71%, p = .001) and less often had thalamic damage (SD 37% vs. VS 80%, p < .001). Similar features of both focal and diffuse damage were present in some SD and VS cases with both groups having considerable damage to white matter and to the thalamus. It is concluded that the principal structural basis of both SD and VS is diffuse traumatic axonal injury (DAI) with widespread damage to white matter and changes in the thalami. However, both ischaemic brain damage and the vascular complications of raised intracranial pressure contributed to the clinical signs and symptoms.

Quality of life in patients with traumatic brain injury-basic issues, assessment and recommendations.

INTRODUCTION: Traumatic brain injuries (TBI) are one of the most common consequences of traffic accidents. Patients with mild, moderate or severe brain injuries suffer from physical, cognitive, behavioral, emotional and social problems. Most of these problems have been a long standing focus amongst practitioners and researchers. Only recently a development has started that took interest in the quality of life outcome of TBI patients. The international members of this consensus meeting reviewed the literature on Quality of Life assessment after TBI and discussed the applicability of different measurements to this specific patient group. TIME POINTS: During the acute phase (T1; < 3 month after trauma) QoL it is difficult to assess due to the reduced consciousness of TBI patients. In the phase of rehabilitation (T2; < one year after trauma) and in the post-rehabilitation phase (T3) repeated assessment of QoL is recommended. INSTRUMENTS: Several generic and disease-specific instruments possibly relevant to TBI patients or specifically developed for this group were assessed according to the existing evidence in the literature. Criteria for the evaluation of these instruments were: feasibility, specificity, validity, comprehensiveness, international availability, existence of norms, and psychometric quality. The cognitive impairment and the existential dimension were not sufficiently considered in most of the reviewed instruments. GROUP CONSENSUS: The family's and relatives' view of the patient's QoL should not be used as a proxy but provides an additional source of information in the acute phase. At T2 and T3, assessment of the patient's quality of life should include a generic as well as a disease specific instrument. Among the generic instruments the SF-36, the EuroQol and the WHO-QoL should be considered. The literature about specific instruments for patients with TBI like the EBIC is scarce. Therefore, the group could hardly give an empirically based recommendation. The need for further investigation on QoL instruments in TBI patients is strongly emphasized.

The minimally conscious state: definition and diagnostic criteria.

OBJECTIVE: To establish consensus recommendations among health care specialties for defining and establishing diagnostic criteria for the minimally conscious state (MCS). BACKGROUND: There is a subgroup of patients with severe alteration in consciousness who do not meet diagnostic criteria for coma or the vegetative state (VS). These patients demonstrate inconsistent but discernible evidence of consciousness. It is important to distinguish patients in MCS from those in coma and VS because preliminary findings suggest that there are meaningful differences in outcome. METHODS: An evidence-based literature review of disorders of consciousness was completed to define MCS, develop diagnostic criteria for entry into MCS, and identify markers for emergence to higher levels of cognitive function. RESULTS: There were insufficient data to establish evidence-based guidelines for diagnosis, prognosis, and management of MCS. Therefore, a consensus-based case definition with behaviorally referenced diagnostic criteria was formulated to facilitate future empirical investigation. CONCLUSIONS: MCS is characterized by inconsistent but clearly discernible behavioral evidence of consciousness and can be distinguished from coma and VS by documenting the presence of specific behavioral features not found in either of these conditions. Patients may evolve to MCS from coma or VS after acute brain injury. MCS may also result from degenerative or congenital nervous system disorders. This condition is often transient but may also exist as a permanent outcome. Defining MCS should promote further research on its epidemiology, neuropathology, natural history, and management.

The structural basis of moderate disability after traumatic brain damage.

The objective was to discover the nature of brain damage in survivors of head injury who are left with moderate disability. Macroscopic and microscopic examination was carried out on the brains of 20 persons who had died long after a head injury that had been treated in a neurosurgical unit. All had become independent but had various disabilities (moderate disability on the Glasgow outcome scale) Most deaths had been sudden, which had led to their referral from forensic pathologists. Post-traumatic epilepsy was a feature in 75%. An intracranial haematoma had been evacuated in 75%, and in 11 of the 15 with epilepsy. Diffuse axonal injury was found in six patients, five of the mildest type (grade 1) and one of grade 2. No patient had diffuse thalamic damage but one had a small focal ischaemic lesion in the thalamus. No patient had severe ischaemic brain damage, but three had moderate lesions which were bilateral in only one. No patient had severe cortical contusions. In conclusion, the dominant lesion was focal damage from an evacuated intracranial haematoma. Severe diffuse damage was not found, with diffuse axonal injury only mild and thalamic damage in only one patient.

Neuropathology in vegetative and severely disabled patients after head injury.

OBJECTIVE: To discover if the neuropathology differs in head-injured patients who were in a vegetative state (VS) or were severely disabled at time of death. METHODS: Review of 35 VS cases and 30 severely disabled cases treated in this institute in the acute stage, surviving at least a month; all brains were fixed for 3 weeks before full neuropathologic examination. RESULTS: The severely disabled cases were older, had a higher incidence of skull fracture and of evacuated intracranial hematoma, and they had more cortical contusions. Diffuse axonal injury (DAI) was less common in the severely disabled cases, particularly its most severe grade. Structural damage in the thalamus was much less common in severely disabled cases. Half of the severely disabled patients had neither grade 2 or 3 DAI nor thalamic damage and 10 of these 15 cases did not have ischemic brain damage either. These combinations did not occur in a single VS case. However, some severely disabled cases had similar lesions to VS cases, and this included some patients who were in a minimally conscious state as well as some who were out of bed and mobile. CONCLUSIONS: Half the severely disabled cases had only focal brain damage, a feature not found in any VS cases. In the severely disabled patients with lesions similar to those of VS cases it is likely that a greater quantitative amount of damage occurred in the VS cases.

The neuropathology of the vegetative state after an acute brain insult.

The vegetative state is often described clinically as loss of function of the cortex while the function of the brainstem is preserved. In an attempt to define the structural basis of the vegetative state we have undertaken a detailed neuropathological study of the brains of 49 patients who remained vegetative until death, 1 month to 8 years after an acute brain insult. Of these, 35 had sustained a blunt head injury and 14 some type of acute non-traumatic brain damage. In the traumatic cases the commonest structural abnormalities identified were grades 2 and 3 diffuse axonal injury (25 cases, 71%). The thalamus was abnormal in 28 cases (80%), and in 96% of the cases who survived for more than 3 months. Other abnormalities included ischaemic damage in the neocortex (13 cases, 37%) and intracranial haematoma (nine cases, 26%). In the non-traumatic cases there was diffuse ischaemic damage in the neocortex in nine cases (64%) and focal damage in four (29%); the thalamus was abnormal in every case. There were cases in both groups where the cerebral cortex, the cerebellum and the brainstem were of structurally normal appearance. In every case, however, there was profound damage to the subcortical white matter or to the major relay nuclei of the thalamus, or both. These lesions render any structurally intact cortex unable to function because connections between different cortical areas via the thalamic nuclei are no longer functional, and there is also extensive damage to afferent and efferent cerebral connections.

Analyzing outcome of treatment of severe head injury: a review and update on advancing the use of the Glasgow Outcome Scale.

The Glasgow Outcome Scale (GOS), two decades after its description, remains the most widely used method of analyzing outcome in series of severely head-injured patients. This review considers limitations recognized in the use of the GOS and discusses a new approach to assessment, using a structured questionnaire-based interview. Assignments can be made to an extended eight-point scale (GOSE) as well as the original five-point approach-in each case, with a high degree of interobserver consistency. The assignments are coherent with the principles of the World Health Organization classification of impairments, disabilities, and handicaps, and their validity is supported by strong associations with the results of neuropsychological testing and assessment of general health status. The need to allow for disability existing before injury, issues concerning the time of assessment after injury, and subdivisions of the scale into "favorable" and "unfavorable" categories are discussed. It is concluded that, in its improved structured format, the Glasgow Outcome Scale should remain the primary method of assessing outcome in trials of the management of severe head injury.

The history of the Glasgow Coma Scale: an interview with professor Bryan Jennett. Interview by Carole Rush.

An interview with one of the founders of the Glasgow Coma Scale provides a partial history of the development and dissemination of this assessment tool. Professor Bryan Jennett credits nurses with the rapid spread and universal acceptance of the scale.

Does prediction of outcome alter patient management?

A patient's prognosis is a key factor for the clinicians involved in management. We set out to determine if provision of computer-based predictions of outcome after severe head injury resulted in measurable changes in patient management. In particular, we wondered whether introduction of the predictive system would alter the relation between severity of injury and "intensity" of management. 1025 patients admitted to four British neurosurgical units between 1986 and 1989 following a severe head injury, and who were either in coma for 6 h or had an operation for acute intracranial haematoma, were studied. Specified aspects of intensive management were recorded and all patients were followed up after six months. The study had three phases: a baseline period of at least one year before the introduction of computer-based outcome prediction, one year when predictions were provided at specified times, and a final six months when prediction was withdrawn. While predictions were being provided, there was an increase in the use of specified aspects of intensive care in patients predicted to have a good outcome, but a 39% reduction in the use of these same aspects of intensive care in patients predicted to have the worst outcome. There was no evidence that the provision of predictions affected overall outcome, length of stay, or the recording of explicit decisions to limit treatment. We have demonstrated that the introduction of a routine prediction service can alter patient management.