Pharmacological advance in the treatment of acute brain injury

Outcome Rating Scales for Pediatric Head Injury

Intensivists, surgeons, neurologists, and others involved in pediatric intensive care units (PICUs) have an important investment in both short-and long-term outcomes of children and adolescents with head injury who are treated under their care. Outcomes are most often documented by either single-or multiple-item rating scales and are implemented both during and after hospital care. For this review, the authors have organized the content of rating scales into 6 general classes: (1) mortality prediction, (2) severity, (3) global recovery, (4) activity restrictions, (5) secondary adverse conditions, and (6) limitations in participation, quality of life, and health status. Rating scales that describe the outcomes of children and adolescents after head injury are used to monitor medical and functional recovery, guide clinical management, drive quality assurance initiatives, and conduct clinical research. The authors restrict their selective review to rating scales that describe child outcomes (vs family) and that have been reported and applied in the outcome literature. Although head injury is a major cause of mortality and short-and long-term morbidity in children and adolescents, there is no consensus on which rating scales are optimal for hospital care or community follow-up. Major considerations for clinical use are feasibility, type of outcome information needed, content breadth across multiple ages and levels of recovery, and utility in determining the short-term impact of PICU care on long-term outcome.

Pediatric neurocritical care: is it time to come of age?

PURPOSE OF REVIEW

Neurocritical care in adults with life-threatening neurological disease is a distinct discipline that has developed out of critical care medicine and neurology. This review considers whether it is time for such a specialized service to be developed in pediatrics.

RECENT FINDINGS

Recent reports describe how some institutions and pediatric professional bodies have set about transferring the specialist neurocritical care experience in adults to pediatric practice. The issue, now, is whether such a development would improve pediatric healthcare, medical education and training in the newly defined field. Adult neurocritical care did not develop in a void. The historical influences were the polio epidemics and the investment in experimental neuroprotection. These traditions provided a foundation for success in recent clinical trials, patient outcomes and healthcare research. Pediatric neurocritical care does not have the equivalent parallels and track record in healthcare research. Size of practice and casemix is also significantly different, with one-third of potential beneficiaries of the new field having a primary medical, rather than neurological, disorder. Three types of development for pediatric neurocritical services are, therefore, suggested by the literature and the implications of these on cross-discipline staffing and education are discussed.

SUMMARY

Pediatric neurocritical care is the new frontier for pediatric critical care medicine and pediatric neurology. There is sufficient specialist interest and momentum for the development of a multidisciplinary collaboration that has the aim of improving patient care.

Antibody formation against beta-tubulin class III in response to brain trauma

Brain trauma typically leads to neuronal damage and loss. Assuming a transient autoimmune response to debris of the damaged neurones, we have monitored serum titres of IgG and IgM antibodies to beta-tubulin class III (betaTcIII), which is almost exclusively found in neuronal cytoskeletons. In 15 out of 18 patients, the peak of the IgG or IgM antibody titre appeared in the serum within 3 weeks of a brain trauma.

Neuro-cognitive impairment following acquired central nervous system infections in childhood: a systematic review

The morbid consequences of central nervous system (CNS) infections are often overlooked in the face of high mortality rates. However, neurological impairments not only affect the child's development and future prospects but also place an economic and social burden on communities and countries that often have few resources to deal with such problems. We conducted a systematic review to investigate the occurrence and pattern of persisting neurological impairment after common CNS infections. A comprehensive search of MEDLINE, EMBASE and PsycINFO databases, supplemented by hand-searches of key journals, resulted in forty-six eligible studies, five of which gave information on the spectrum of developmental domains. Despite the lack of comprehensive, methodologically-sound studies, the results show that postinfectious neurological impairment persists, most commonly in cognition and motor functions. Deficits include more subtle problems, which can be difficult to detect on gross neurological assessment but may still be deleterious to the child's social and educational functioning. Higher morbidity for similar mortality in acute bacterial meningitis compared with cerebral malaria in the epidemiological data may suggest future research directions for clinical research to devise more effective interventions.

Pharmacological treatment of traumatic brain injury: a review of agents in development

Successful treatment strategies for patients with traumatic brain injury (TBI) remain elusive despite standardised clinical treatment guidelines, improved understanding of mechanisms of cellular response to trauma, and a decade of clinical trials aimed at identifying therapeutic agents targeted at mediators of secondary injury. The information explosion relative to mechanisms of secondary injury has identified several potential targets for intervention. Depending on the type of injury to the brain and the intensity and the success of resuscitation, necrosis, apoptosis, inflammatory and excitotoxic cellular damage can be seen. These same processes may continue postinjury, depending on the adequacy of clinical care. Each of these mechanisms of cellular damage can initiate a cascade of events mediated by endogenous signals that lead to secondary neurological injury. Several factors contributed to the failure of earlier clinical trials. Now that these have been recognised, a positive impact on future drug development in TBI has been realised. Both the US and Europe have organised brain injury consortiums where experts in the treatment of TBI provide insight into study design, implementation, conduct and oversight in conjunction with the pharmaceutical industry. Consequently, future clinical trials of new investigational treatments have greater potential for identifying therapies of merit in specific populations of patients with TBI. Pharmacological strategies under investigation are targeting sites involved in the secondary cascade that contribute to overall poor outcome following the primary injury. These treatments include ion channel antagonists including calcium channel antagonists, growth factors, antioxidants, stem cells, apoptosis inhibitors, and inhibitors of other signal modulators. In conclusion, the complexity of TBI pathology and the mechanisms contributing to secondary injury present unique therapeutic challenges. Appropriate research targets for intervention continue to be investigated, however, the likelihood of improving outcomes with a single approach is extremely small. There is a need for collaborative efforts to investigate the optimal time for drug administration and the logical sequence or combination of treatments that will ultimately lead to improved neurological outcomes in this population.

An improved survival model of hypoxia/ischaemia in the piglet suitable for neuroprotection studies

The purpose of this study was to develop a newborn piglet model of hypoxia/ischaemia which would better emulate the clinical situation in the asphyxiated human neonate and produce a consistent degree of histopathological injury following the insult. One-day-old piglets (n=18) were anaesthetised with a mixture of propofol (10 mg/kg/h) and alfentinal (55.5 microg/kg/h) i.v. The piglets were intubated and ventilated. Physiological variables were monitored continuously. Hypoxia was induced by decreasing the inspired oxygen (FiO(2)) to 3-4% and adjusting FiO(2) to maintain the cerebral function monitor peak amplitude at < or =5 microV. The duration of the mild insult was 20 min while the severe insult was 30 min which included 10 min where the blood pressure was allowed to fall below 70% of baseline. Control piglets (n=4 of 18) were subjected to the same protocol except for the hypoxic/ischaemic insult. The piglets were allowed to recover from anaesthesia then euthanased 72 h after the insult. The brains were perfusion-fixed, removed and embedded in paraffin. Coronal sections were stained by haematoxylin/eosin. A blinded observer examined the frontal and parietal cortex, hippocampus, basal ganglia, thalamus and cerebellum for the degree of damage. The total mean histology score for the five areas of the brain for the severe insult was 15.6+/-4.4 (mean +/-S.D., n=7), whereas no damage was seen in either the mild insult (n=4) or control groups. This 'severe damage' model produces a consistent level of damage and will prove useful for examining potential neuroprotective therapies in the neonatal brain.

Neonatal brain injury

Complacency about long-term outcomes in newborns is being eroded rapidly with new information. We have examined developments in the area from an explicitly clinical approach, focusing on etiology, diagnostic modalities, and therapies. We attempt to discuss relevance from the preterm and the term perspective. Emerging evidence implicating chorioamnionitis as a significant contributor to neonatal brain injury is discussed. Therapeutic modalities such as magnetic resonance imaging and electrophysiological monitoring offer some potentially new tools for the clinician. An exploding series of basic advances suggest several potentially new strands of therapy. We discuss two that deserve further clinical exploration, namely anti-inflammatory strategies and thread hormone supplementation. In the arena of therapy, however, the paucity of large trials from which to guide therapies is a predominant theme, leaving a large reservoir of uncertainty for the clinician.

Neurological critical care

Of utmost importance in the practice of neurological critical care is the treatment of cerebral edema, when possible, and the control of life-threatening seizures. In this regard, severe traumatic head injury and refractory status epilepticus are useful clinical therapeutic paradigms. Evidence-based treatment established for these conditions has, by necessity, a wider application to other much less frequent causes of coma and acute neurological illness managed in the intensive therapy unit. Therefore, this review of pediatric neurocritical care literature in 1999 highlights central clinical reports of the medical management of severe traumatic brain injury, the benzodiazepines used in the treatment of status epilepticus, and the emerging or recently appreciated encephalopathies occurring in children.