Coma prognosis in children. Part I: definitional and methodological challenges

Children in Vegetative State and Minimally Conscious State: A Survey of Sensory and Cognitive Intervention

There is little information available about the management of children in a vegetative state and a minimally conscious state (VS and MCS), including diagnosis, assessment and treatment. This study investigated the intervention of occupational therapists in VS and MCS in the United Kingdom paediatric population.

A survey design was used and a postal questionnaire was sent to a group of 892 occupational therapists who were members of a paediatric or a neurological specialist section. Two hundred and seventy-one completed questionnaires were returned and the results of these were analysed. Two hundred and six (76%) of the respondents worked in a rehabilitation setting.

Twenty-five occupational therapists who worked with children in VS and MCS completed further questions about their assessments and interventions. The results indicate that children in VS and MCS receive fragmented and inconsistent occupational therapy services. Adult assessments are used with a paediatric population and therapists are not wholly satisfied with their interventions. A core group of occupational therapists involved with this population was identified as a result of this survey. It is suggested that these therapists may be able to form a working party to investigate a consistent therapeutic approach for this complex group of children.

Prognostic value of somatosensory evoked potentials in comatose children: a systematic literature review

PURPOSE

To review the predictive powers of SEPs in comatose children after acute brain injury.

METHODS

MEDLINE, EMBASE, OVID, ISI Web of Knowledge, BIOMED Central and the Cochrane Library (1981-2007) were searched. First, predictive values were calculated for each primary study. Second, we analysed effects of different factors on the SEP diagnostic odds ratio by meta-regression. Third, we compared SEP predictive values in children and in adults.

RESULTS

We selected 14 studies covering 732 patients; analysis was conducted in 11, while the other 3 were used for simple qualitative examination. In individual papers, the presence of SEP predicted favourable outcomes as shown by the area under both sROC curves being 0.958. The same value was shown by SEP absence for predicting unfavourable outcomes. All covariates showed no significant effects on diagnostic accuracy, but only a slight non-significant trend. For SEP grading, a simple sub-group analysis showed a high predictive value for non-awakening for absence of SEPs (PPV 97.0%) and a high prognostic power to predict awakening for normal SEPs (PPV 92.2%). Pathological SEPs did not show reliable predictivity. In children, the presence of SEPs showed a high prognostic power similar to that in adults.

CONCLUSION

This study supports the use of SEPs in the integrated process of outcome prediction after acute brain injury in children. Caution is recommended in predicting unfavourable outcomes in patients with an absence of SEPs in both TBI and HIE comas. Future studies are needed to resolve the issue of the effect of aetiology and age on SEP's predictive power.

The reliability and validity of the PALOC-s: a post-acute level of consciousness scale for assessment of young patients with prolonged disturbed consciousness after brain injury

The objective of the study was the validation of the Post-Acute Level of Consciousness scale (PALOC-s) for use in assessing levels of consciousness of severe brain injured patients in a vegetative state or in a minimally conscious state. A cohort of 44 successively admitted patients (between 2 and 25 years of age), who were treated in an early intensive neurorehabilitation programme, were included in the study. Each patient was examined, using the Western Neuro Sensory Stimulation Profile (WNSSP) and the Disability Rating Scale (DRS), once every two weeks resulting in 327 examinations (all videotaped). To determine the reliability of the PALOC-s, six observers rated one videotape of each patient. One of the observers rated the same tapes a second time, 3-4 months later. Validity was determined by correlating 100 ratings of one observer with the scores on the WNSSP and the DRS. To determine the responsiveness of the PALOC-s, the size of change between the scores of the first and last examinations was calculated. The inter-observer correlations and agreement scores varied between .82 and .95. The intra-observer correlation and agreement scores varied between .94 and .96. Correlations with the WNSSP varied between .88 and .93, and with the DRS between .75 and .88. The responsiveness was significantly high (t=8.2), with a standardised effect size of 1.30. It is concluded that the PALOC-s is a reliable, valid, and responsive observation instrument provided it is administered after a structured assessment by an experienced and trained clinician. The PALOC-s is feasible for use in clinical management, as well as in outcome research.

MRI patterns in prolonged low response states following traumatic brain injury in children and adolescents

OBJECTIVES

To explore the relationship between location and pattern of brain injury identified on MRI and prolonged low response state in children post-traumatic brain injury (TBI).

METHODS

This observational study compared 15 children who spontaneously recovered within 30 days post-TBI to 17 who remained in a prolonged low response state.

RESULTS

92.9% of children with brain stem injury were in the low response group. The predicted probability was 0.81 for brain stem injury alone, increasing to 0.95 with a regional pattern of injury to the brain stem, basal ganglia, and thalamus.

CONCLUSIONS

Low response state in children post-TBI is strongly correlated with two distinctive regions of injury: the brain stem alone, and an injury pattern to the brain stem, basal ganglia, and thalamus. This study demonstrates the need for large-scale clinical studies using MRI as a tool for outcome assessment in children and adolescents following severe TBI.

Reactive EEG patterns in pediatric coma

This study was designed to determine whether the observed reactive electroencephalographic patterns in comatose children were associated with a better outcome. All electroencephalograms performed in comatose children aged 2 months to 18 years during the period 1996-2003 were retrospectively analyzed and classified according to modified Young's classification. Reactivity to painful/auditory stimuli and passive eye closure (at least two modalities) was checked in all electroencephalograms. The clinical outcome at 1 year or during the last clinic/inpatient follow-up was scored according to the Pediatric Cerebral and Overall Performance Category Scale. Outcomes were then compared using Fisher exact test and the Mann-Whitney test. Thirty-three patients had electroencephalography within 72 hours after the onset of coma. Fourteen of 33 electroencephalograms revealed reactive patterns. Outcome was unfavorable in 4 (28.6%) of these patients. Three children had no residual neurologic impairment. Among the 19 children with nonreactive electroencephalogram, 13 (65%) had unfavorable outcome, which included 10 deaths. All the survivors had residual neurologic impairment. Outcome was better in children with reactive electroencephalographic patterns (Fisher exact test; P = 0.023). Comatose children with reactive electroencephalographic patterns have better clinical outcome in terms of morbidity and mortality. A careful assessment of electroencephalographic reactive patterns in all comatose children is required for better understanding of the clinical outcome.

Outcome of coma in children

Coma following a hypoxic-ischemic event is a serious condition and common reason for admission to the pediatric intensive care unit. Because coma has a high rate of mortality and morbidity in children, and the clinician may be unsure of the outcome very early in the course, it is important to have strategies to define prognosis. Although most studies have been conducted in adults, we review factors predicting outcome from coma of nontraumatic causes in infants and children. We consider the relation between physical findings, commonly accessible laboratory tools, and outcome, and comment on some newer techniques that may become more available for clinical purposes.