Outcome at two years of age in a Swiss national cohort of extremely preterm infants born between 2000 and 2008

Background While survival rates of extremely preterm infants have improved over the last decades, the incidence of neurodevelopmental disability (ND) in survivors remains high. Representative current data on the severity of disability and of risk factors associated with poor outcome in this growing population are necessary for clinical guidance and parent counselling. Methods Prospective longitudinal multicentre cohort study of preterm infants born in Switzerland between 240/7 and 276/7 weeks gestational age during 2000–2008. Mortality, adverse outcome (death or severe ND) at two years, and predictors for poor outcome were analysed using multilevel multivariate logistic regression. Neurodevelopment was assessed using Bayley Scales of Infant Development II. Cerebral palsy was graded after the Gross Motor Function Classification System. Results Of 1266 live born infants, 422 (33%) died. Follow-up information was available for 684 (81%) survivors: 440 (64%) showed favourable outcome, 166 (24%) moderate ND, and 78 (11%) severe ND. At birth, lower gestational age, intrauterine growth restriction and absence of antenatal corticosteroids were associated with mortality and adverse outcome (p < 0.001). At 360/7 weeks postmenstrual age, bronchopulmonary dysplasia, major brain injury and retinopathy of prematurity were the main predictors for adverse outcome (p < 0.05). Survival without moderate or severe ND increased from 27% to 39% during the observation period (p = 0.02). Conclusions In this recent Swiss national cohort study of extremely preterm infants, neonatal mortality was determined by gestational age, birth weight, and antenatal corticosteroids while neurodevelopmental outcome was determined by the major neonatal morbidities. We observed an increase of survival without moderate or severe disability.

Evidence that N-acetylcysteine inhibits TNF-alpha-induced cerebrovascular endothelin-1 upregulation via inhibition of mitogen- and stress-activated protein kinase

N-acetylcysteine (NAC) is neuroprotective in animal models of acute brain injury such as caused by bacterial meningitis. However, the mechanism(s) by which NAC exerts neuroprotection is unclear. Gene expression of endothelin-1 (ET-1), which contributes to cerebral blood flow decline in acute brain injury, is partially regulated by reactive oxygen species, and thus a potential target of NAC. We therefore examined the effect of NAC on tumor necrosis factor (TNF)-alpha-induced ET-1 production in cerebrovascular endothelial cells. NAC dose dependently inhibited TNF-alpha-induced preproET-1 mRNA upregulation and ET-1 protein secretion, while upregulation of inducible nitric oxide synthase (iNOS) was unaffected. Intriguingly, NAC had no effect on the initial activation (i.e., IkappaB degradation, nuclear p65 translocation, and Ser536 phosphorylation) of NF-kappaB by TNF-alpha. However, transient inhibition of NF-kappaB DNA binding suggested that NAC may inhibit ET-1 upregulation by inhibiting (a) parallel pathway(s) necessary for full transcriptional activation of NF-kappaB-mediated ET-1 gene expression. Similar to NAC, the MEK1/2 inhibitor U0126, the p38 inhibitor SB203580, and the protein kinase inhibitor H-89 selectively inhibited ET-1 upregulation without affecting nuclear p65 translocation, suggesting that NAC inhibits ET-1 upregulation via inhibition of mitogen- and stress-activated protein kinase (MSK). Supporting this notion, cotreatment with NAC inhibited the TNF-alpha-induced rise in MSK1 and MSK2 kinase activity, while siRNA knock-down experiments showed that MSK2 is the predominant isoform involved in TNF-alpha-induced ET-1 upregulation.

Gene expression in cortex and hippocampus during acute pneumococcal meningitis

BACKGROUND: Pneumococcal meningitis is associated with high mortality (approximately 30%) and morbidity. Up to 50% of survivors are affected by neurological sequelae due to a wide spectrum of brain injury mainly affecting the cortex and hippocampus. Despite this significant disease burden, the genetic program that regulates the host response leading to brain damage as a consequence of bacterial meningitis is largely unknown.We used an infant rat model of pneumococcal meningitis to assess gene expression profiles in cortex and hippocampus at 22 and 44 hours after infection and in controls at 22 h after mock-infection with saline. To analyze the biological significance of the data generated by Affymetrix DNA microarrays, a bioinformatics pipeline was used combining (i) a literature-profiling algorithm to cluster genes based on the vocabulary of abstracts indexed in MEDLINE (NCBI) and (ii) the self-organizing map (SOM), a clustering technique based on covariance in gene expression kinetics. RESULTS: Among 598 genes differentially regulated (change factor > or = 1.5; p < or = 0.05), 77% were automatically assigned to one of 11 functional groups with 94% accuracy. SOM disclosed six patterns of expression kinetics. Genes associated with growth control/neuroplasticity, signal transduction, cell death/survival, cytoskeleton, and immunity were generally upregulated. In contrast, genes related to neurotransmission and lipid metabolism were transiently downregulated on the whole. The majority of the genes associated with ionic homeostasis, neurotransmission, signal transduction and lipid metabolism were differentially regulated specifically in the hippocampus. Of the cell death/survival genes found to be continuously upregulated only in hippocampus, the majority are pro-apoptotic, while those continuously upregulated only in cortex are anti-apoptotic. CONCLUSION: Temporal and spatial analysis of gene expression in experimental pneumococcal meningitis identified potential targets for therapy.

Strategies to prevent neuronal damage in paediatric bacterial meningitis

PURPOSE OF REVIEW: The mortality of bacterial meningitis can reach 30%, and up to 50% of survivors suffer from persisting neurological deficits as a consequence of the disease. The incidence of neurological sequelae of bacterial meningitis has not improved over the last decade. Adjunctive therapeutic options are limited, and ongoing research into the pathophysiology of brain damage in bacterial meningitis aims at providing the scientific basis for future development of more efficient adjunctive options. RECENT FINDINGS: In a population with good access to health care, dexamethasone given before or at the time of initiation of antibiotic therapy acts beneficially in paediatric pneumococcal meningitis, but not in meningococcal meningitis. In experimental animal models, brain-derived neurotrophic factor protected against brain injury and improved hearing while melatonin, which has antioxidant properties among other effects, reduced neuronal death. Transgene technology can be used to provide new insights into the pathophysiology of the disease and to identify potential therapeutic targets. SUMMARY: Although dexamethasone improves outcome of bacterial meningitis under defined circumstances, the morbidity of bacterial meningitis still remains unacceptably high. Experimental models may help to identify new therapeutic strategies to further improve the neurological outcome in young children suffering from bacterial meningitis.

Femoral head injuries: Which treatment strategy can be recommended?

Despite different operative and non-operative treatment regimens, the outcome after femoral head fractures has changed little over the past decades. The initial trauma itself as well as secondary changes such as posttraumatic osteoarthritis, avascular necrosis or heterotopic ossification is often responsible for severe loss of function of the afflicted hip joint. Anatomic reduction of all fracture fragments seems to be a major influencing factor in determining the outcome quality. Eight years ago we inaugurated a new surgical approach for better access and visualisation for the treatment of femoral head fractures, using the "trochanteric flip" (digastric) osteotomy. Thus inspection of the entire hip joint and accurate fragment reduction under direct visual control are possible. After good initial experiences with this operative procedure we changed our standard treatment regimen to this approach in an attempt to achieve the most accurate anatomic reduction of the femoral head in every affected patient. Between 1998 and 2006 we operated on 12 patients with femoral head fractures associated with posterior hip dislocation, using the new surgical approach. Patients were followed for 2-96 months and outcome was documented with the Merle d'Aubigne and Postel score as well as the Thompson and Epstein score. The posttraumatic formation of heterotopic bone was documented with the Brooker score. Retrospective analysis of these 12 patients showed good or excellent results in 10 patients (83.3%). The two patients with poor outcome developed an avascular necrosis of the femoral head and underwent total hip arthroplasty. Periarticular heterotopic ossification was seen in five patients. In four patients this caused a significantly reduced range of motion and was therefore considered as a posttraumatic complication. The two patients with the most severe heterotopic bone formation (Brooker III and IV) had initially sustained multiple injuries including brain injury. Comparing our results with earlier published series including our own before changing the treatment protocol, the data suggest a favorable outcome in patients with trochanteric flip (digastric) osteotomy for the treatment of femoral head fractures.

Inhibition of matrix metalloproteinases and tumour necrosis factor alpha converting enzyme as adjuvant therapy in pneumococcal meningitis

Matrix metalloproteinases (MMPs) and tumour necrosis factor alpha (TNF-alpha) converting enzyme (TACE) contribute synergistically to the pathophysiology of bacterial meningitis. TACE proteolytically releases several cell-surface proteins, including the proinflammatory cytokine TNF-alpha and its receptors. TNF-alpha in turn stimulates cells to produce active MMPs, which facilitate leucocyte extravasation and brain oedema by degradation of extracellular matrix components. In the present time-course studies of pneumococcal meningitis in infant rats, MMP-8 and -9 were 100- to 1000-fold transcriptionally upregulated, both in CSF cells and in brain tissue. Concentrations of TNF-alpha and MMP-9 in CSF peaked 12 h after infection and were closely correlated. Treatment with BB-1101 (15 mg/kg subcutaneously, twice daily), a hydroxamic acid-based inhibitor of MMP and TACE, downregulated the CSF concentration of TNF-alpha and decreased the incidences of seizures and mortality. Therapy with BB-1101, together with antibiotics, attenuated neuronal necrosis in the cortex and apoptosis in the hippocampus when given as a pretreatment at the time of infection and also when administration was started 18 h after infection. Functionally, the neuroprotective effect of BB-1101 preserved learning performance of rats assessed 3 weeks after the disease had been cured. Thus, combined inhibition of MMP and TACE offers a novel therapeutic strategy to prevent brain injury and neurological sequelae in bacterial meningitis.

The free radical scavenger alpha-phenyl-tert-butyl nitrone aggravates hippocampal apoptosis and learning deficits in experimental pneumococcal meningitis

The effect of adjuvant therapy with the radical scavenger alpha-phenyl-tert-butyl nitrone (PBN; 100 mg/kg given intraperitoneally every 8 h for 5 days) on brain injury and learning function was evaluated in an infant rat model of pneumococcal meningitis. Meningitis led to cortical necrotic injury (median, 3.97% [range, 0%-38.9%] of the cortex), which was reduced to a median of 0% (range, 0%-30.9%) of the cortex (P<.001) by PBN. However, neuronal apoptosis in the hippocampal dentate gyrus was increased by PBN, compared with that by saline (median score, 1.15 [range, 0.04-1.73] vs. 0.31 [range, 0-0.92]; P<.001). Learning function 3 weeks after cured infection, as assessed by the Morris water maze, was decreased, compared with that in uninfected control animals (P<.001). Parallel to the increase in hippocampal apoptosis, PBN further impaired learning in infected animals, compared with that in saline-treated animals (P<.02). These results contrast with those of an earlier study, in which PBN reduced cortical and hippocampal neuronal injury in group B streptococcal meningitis. Thus, in pneumococcal meningitis, antioxidant therapy with PBN aggravates hippocampal injury and learning deficits.

Effects of clinically used antioxidants in experimental pneumococcal meningitis

Reactive oxygen intermediates mediate brain injury in bacterial meningitis. Several antioxidant drugs are clinically available, including N-acetylcysteine (NAC), deferoxamine (DFO), and trylizad-mesylate (TLM). The present study evaluated whether these antioxidants are beneficial in a model of pneumococcal meningitis. Eleven-day-old rats were infected intracisternally with Streptococcus pneumoniae and randomized to intraperitoneal treatment every 8 h with NAC (200 mg/kg), DFO (100 mg/kg), TLM (10 mg/kg), or saline (250 microL). TLM-treated animals showed a significantly reduced mortality compared with controls (P<.03). Meningitis led to extensive cortical injury at 22+/-2.2 h after infection (median, 14. 6% of cortex; range, 0-61.1%). Injury was significantly (P<.01) reduced to 1.1% (range, 0-34.6%) by NAC, to 2.3% (range, 0-19.6%) by DFO, and to 0.2% (range, 0-36.9%) by TLM (the difference was not significant among the 3 groups). None of the drugs reduced hippocampal injury. Thus, several clinically used antioxidants reduced cortical injury in experimental pneumococcal meningitis.

Toxicity of Streptococcus pneumoniae in neurons, astrocytes, and microglia in vitro

The toxicity of pneumococci and endotoxin in primary cultures of rat neurons, astrocytes, and microglia and in a human astrocyte and two human glial cell lines was determined. Heat-inactivated, rough pneumococci (up to 10(8) cfu/mL) or their cell wall (up to 50 micrograms/mL) produced dose-dependent toxicity after 48 h in microglial cells and to a lesser extent in astrocytes but not in neurons. Toxicity was similar for equivalent doses of heat-inactivated organisms and pneumococcal cell wall, but time-course experiments showed significant differences between the two stimuli. Endotoxin at concentrations of up to 5 micrograms/mL did not induce significant toxicity in any of the cells. Thus, pneumococci can induce toxicity in two brain cell types, microglia and astrocytes, and the pneumococcal cell wall appears to mediate toxicity. Direct toxic effects of bacteria on brain cells may in part be responsible for brain injury during meningitis.

Experimental pneumococcal meningitis causes central nervous system pathology without inducing the 72-kd heat shock protein

We examined whether experimental pneumococcal meningitis induced the 72-kd heat shock protein (HSP72), a sensitive marker of neuronal stress in other models of central nervous system (CNS) injury. Brain injury was characterized by vasculitis, cerebritis, and abscess formation in the cortex of infected animals. The extent of these changes correlated with the size of the inoculum (P less than 0.003) and with pathophysiologic parameters of disease severity, i.e., cerebrospinal fluid (CSF) lactate (r = 0.61, P less than 0.0001) and CSF glucose concentrations (r = -0.55, P less than 0.0001). Despite the presence of numerous cortical regions having morphologic evidence of injury, HSP72 was not detected in most animals. When present, only rare neurons were HSP72 positive. Western blot analysis of brain samples confirmed the paucity of HSP72 induction. The lack of neuronal HSP72 expression in this model suggests that at least some of the events leading to neuronal injury in meningitis are unique, when compared with CNS diseases associated with HSP72 induction.

Cognitive functioning, behavior, and quality of life after stroke in childhood

Rationale: To provide a better understanding of cognitive functioning, motor outcome, behavior and quality of life after childhood stroke and to study the relationship between variables expected to influence rehabilitation and outcome (age at stroke, time elapsed since stroke, lateralization, location and size of lesion). Methods: Children who suffered from stroke between birth and their eighteenth year of life underwent an assessment consisting of cognitive tests (WISC-III, WAIS-R, K-ABC, TAP, Rey-Figure, German Version of the CVLT) and questionnaires (Conner's Scales, KIDSCREEN). Results: Twenty-one patients after stroke in childhood (15 males, mean 11;11 years, SD 4;3, range 6;10-21;2) participated in the study. Mean Intelligence Quotients (IQ) were situated within the normal range (mean Full Scale IQ 96.5, range IQ 79-129). However, significantly more patients showed deficits in various cognitive domains than expected from a healthy population (Performance IQ p = .000; Digit Span p = .000, Arithmetic's p = .007, Divided Attention p = .028, Alertness p = .002). Verbal IQ was significantly better than Performance IQ in 13 of 17 patients, independent of the hemispheric side of lesion. Symptoms of ADHD occurred more often in the patients' sample than in a healthy population (learning difficulties/inattention p = .000; impulsivity/hyperactivity p = .006; psychosomatics p = .006). Certain aspects of quality of life were reduced (autonomy p = .003; parents' relation p = .003; social acceptance p = .037). Three patients had a right-sided hemiparesis, mean values of motor functions of the other patients were slightly impaired (sequential finger movements p = .000, hand alternation p = .001, foot tapping p = .043). In patients without hemiparesis, there was no relation between the lateralization of lesion and motor outcome. Lesion that occurred in the midst of childhood (5-10 years) led to better cognitive outcome than lesion in the very early (0-5 years) or late childhood (10-18 years). Other variables such as presence of seizure, elapsed time since stroke and size of lesion had a small to no impact on prognosis. Conclusion: Moderate cognitive and motor deficits, behavioral problems, and impairment in some aspects of quality of life frequently remain after stroke in childhood. Visuospatial functions are more often reduced than verbal functions, independent of the hemispheric side of lesion. This indicates a functional superiority of verbal skills compared to visuospatial skills in the process of recovery after brain injury. Compared to the cognitive outcome following stroke in adults, cognitive sequelae after childhood stroke do indicate neither the lateralization nor the location of the lesion focus. Age at stroke seems to be the only determining factor influencing cognitive outcome.

Improving outcome after stroke: overcoming the translational roadblock

Stroke poses a massive burden of disease, yet we have few effective therapies. The paucity of therapeutic options stands contrary to intensive research efforts. The failure of these past investments demands a thorough re-examination of the pathophysiology of ischaemic brain injury. Several critical areas hold the key to overcoming the translational roadblock: (1) vascular occlusion: current recanalization strategies have limited effectiveness and may have serious side effects; (2) complexity of stroke pathobiology: therapy must acknowledge the 'Janus-faced' nature of many stroke targets and must identify endogenous neuroprotective and repair mechanisms; (3) inflammation and brain-immune-system interaction: inflammation contributes to lesion expansion, but is also instrumental in lesion containment and repair; stroke outcome is modulated by the interaction of the injured brain with the immune system; (4) regeneration: the potential of the brain for reorganization, plasticity and repair after injury is much greater than previously thought; (5) confounding factors, long-term outcome and predictive modelling. These 5 areas are linked on all levels and therefore need to be tackled by an integrative approach and innovative therapeutic strategies.

Effect of the NMDA-receptor antagonist dextromethorphan in infant rat pneumococcal meningitis

Excitatory amino acids (EAA) and particularly glutamate toxicity have been implicated in the pathogenesis of neuronal injury occurring in bacterial meningitis by activating the N-methyl-d aspartate (NMDA) receptor complex. Here, we evaluated the effect of adjuvant treatment with the antitussive drug dextromethorphan (DM), a non-competitive NMDA receptor antagonist with neuroprotective potential, in an infant rat model of pneumococcal meningitis. The experiments were carried out in postnatal day 6 (P6) and 11 (P11) animals. Pharmacokinetics of DM and its major metabolite dextrorphan (DO) were performed for dose finding. In our study, DM did not alter clinical parameters (clinical score, motor activity, incidence of seizures, spontaneous mortality) and cortical neuronal injury but increased the occurrence of ataxia (P<0.0001). When DM treatment was started at the time of infection (DM i.p. 15 mg/kg at 0, 4, 8 and 16 hours (h) post infection) in P11 animals, an aggravation of apoptotic neuronal death in the hippocampal dentate gyrus was found (P<0.05). When treatment was initiated during acute pneumococcal meningitis (DM i.p. 15 mg/kg at 12 and 15 h and 7.5 mg/kg at 18 and 21 h after infection), DM had no effect on the extent of brain injury but reduced the occurrence of seizures (P<0.03). We conclude that in this infant rat model of pneumococcal meningitis interference of the EEA and NMDA pathway using DM causes ataxia, attenuates epileptic seizures and increases hippocampal apoptosis, but is not effective in protecting the brain from injury.

Ultrastructural quantification of cell death after injurious compression of bovine calf articular cartilage

OBJECTIVE: It has been suggested that chondrocyte death by apoptosis may play a role in the pathogenesis of cartilage destruction in osteoarthritis, but the results of in-vivo and in-vitro investigations have been conflicting. To investigate further the cell death in our in-vitro model for traumatic joint injury, we performed a quantitative analysis by electron microscopy (EM) of cell morphology after injurious compression. For comparison, the TUNEL assay was also performed. DESIGN: Articular cartilage explant disks were harvested from newborn calf femoropatellar groove. The disks were subjected to injurious compression (50% strain at a strain rate of 100%/s), incubated for 3 days, and then fixed for quantitative morphological analysis. RESULTS: By TUNEL, the cell apoptosis rate increased from 7 +/- 2% in unloaded controls to 33 +/- 6% after injury (P=0.01; N=8 animals). By EM, the apoptosis rate increased from 5 +/- 1% in unloaded controls to 62 +/- 10% in injured cartilage (P=0.02, N=5 animals). Analysis by EM also identified that of the dead cells in injured disks, 97% were apoptotic by morphology. CONCLUSIONS: These results confirm a significant increase in cell death after injurious compression and suggest that most cell death observed here was by an apoptotic process.

[The comatose child]

The child who presents with acute coma runs a high risk of cardiopulmonary insufficiency, direct brain injury or even cerebral herniation. The case-management of such child requires a coma-specific emergent evaluation, immediate treatment of any hypoxicischemic insults and of the underlying cause. The coma-specific examination includes performance of child-adapted Glasgow Coma Score, the evaluation of brain stem functions such as pupillary response to light, cough- and gag reflex, and determination of all vital signs including body temperature. Treatment of hypoxicischemic insults includes control of airways and ventilation in patient with coma defined as GCS <8; liberal treatment of impaired cardiovascular states with isotonic fluids such as 0.9% sodium chloride; and treatment of cerebral herniation with head elevation, mannitol, hypertonic sodium chlorid fluids, steroids and hyperventilation. Immediately treatable causes are hypoglycemia, meningitis/encephalitis, opioid overdose and status epilepticus. Exclusion of rapidly progressive intracranial lesions almost always requires referral to the tertiary centre with head CT-scan facilities. Finally, an extensive etiology search of the stable coma is performed by looking for disease or trauma of the brain, for metabolic causes, for intoxications and for cardiopulmonary problems.