Fausto Iannotti

EBIC-Guidelines for Management of Severe Head Injury in Adults

SummaryGuidelines for the management of severe head injury in adults as evolved by the European Brain Injury Consortium are presented and discussed. The importance of preventing and treating secondary insults is emphasized and the principles on which treatment is based are reviewed. Guidelines presented are of a pragmatic nature, based on consensus and expert opinion, covering the treatment from accident site to intensive care unit. Specific aspects pertaining to the conduct of clinical trials in head injury are highlighted. The adopted approach is further discussed in relation to other approaches to the development of guidelines, such as evidence based analysis.

Postoperative Hematoma: A 5-Year Survey and Identification of Avoidable Risk Factors

This study examines the surgical practice at the Wessex Neurological Centre over the 5-year period from 1989 to 1993 to determine the incidence of postoperative hematoma and to identify risk factors for a perioperative bleeding disorder. The study includes only those postoperative hematomas (at any site) that followed and were related to a neurosurgical operation and were surgically evacuated. The study is prospective for the year 1993 and retrospective for the preceding years. Over the 5 years, 6668 operations were performed and 71 postoperative hematomas were surgically evacuated, accounting for an overall rate of 1.1% of operations. The records were available for 69 cases

The European Brain Injury Consortium. Nemo solus satis sapit: nobody knows enough alone.

tUniversity Department of Neurosurgery, Institute of Neurological Sciences, Southern General Hospital, Glasgow, U.K., 2Berkel Enschot, The Netherlands, 3Department of Neurosurgery, Hopital Pellegrin, Bordeaux, France, 4Department of Anaesthetics, Leeds General Infirmary, Leeds, U.K., 5Department of Clinical Neurosciences, Southampton General Hospital, Southampton, U.K., 6Neurochirurgische Klinik, Universitfit K61n, K61n, Federal Republic of Germany, 7Centre Hospitalier Universitaire de Poitiers, Service de Neurochirurgie, Poitiers, France, 8Department of Neurosurgery, University Hospital Rotterdam, Rotterdam, The Netherlands, 9Medical Statistics Unit, University of Edinburgh Medical School, Edinburgh, U.K., 1~ of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland, l lDepartment of Neurosurgery, Akademiska Hospital, Uppsala, Sweden, ~2Azienda USL Cesena, Ospedal M. Bufalini, Cesena, Italy, 13Terapia Intensiva Nenrochirurgica, Serv. Anestesia e Rianimazione-Ospedale Policlinico, IRCCS, Milano, Italy, 14Department of Neurosurgery, University Medical School, Lublin, Poland, and 15Department of Neurosurgery, Virchow-Klinikum, Medizinische Fakultfit, Humboldt UniversitSt Berlin, Berlin, Federal Republic of Germany

Neuroprotection by both NMDA and non-NMDA receptor antagonists in in vitro ischemia

We have investigated the relative contributions of oxygen and glucose deprivation to ischaemic neurodegeneration in organotypic hippocampal slice cultures. Cultures prepared from 10-day-old rats were maintained in vitro for 14 days and then deprived of either oxygen (hypoxia), glucose (hypoglycaemia), or both oxygen and glucose (ischaemia). Hypoxia alone induced degeneration selectively in CA1 pyramidal cells and this was greatly potentiated if glucose was removed from the medium. We have also characterised the effects of both pre- and post-treatment using glutamate receptor antagonists and the sodium channel blocker tetrodotoxin (TTX). Neuronal death following either hypoxia or ischaemia was prevented by pre-incubation with CNQX, MK-801 or tetrodotoxin. MK-801 or CNQX also prevented death induced by either hypoxia or ischaemia if added immediately post-insult, however, post-insult addition of TTX prevented hypoxic but not ischaemic damage. Organotypic hippocampal slice cultures are sensitive to both NMDA and non-NMDA glutamate receptor blockade and thus represent a useful in vitro system for the study of ischaemic neurodegeneration paralleling results reported using in vivo models of ischaemia.

Traumatic Subarachnoid Hemorrhage: Demographic and Clinical Study of 750 Patients from the European Brain Injury Consortium Survey of Head Injuries

OBJECTIVE Previous reports identified the presence of traumatic subarachnoid hemorrhage (tSAH) on admission computed tomographic (CT) scans as an independent prognostic factor in worsening outcomes. The mechanism underlying the link between tSAH and prognosis has not been clarified. The aim of this study was to investigate the association between CT evidence of tSAH and outcomes after moderate or severe head injuries. METHODS In a survey organized by the European Brain Injury Consortium, data on initial severity, treatment, and subsequent outcomes were prospectively collected for 1005 patients with moderate or severe head injuries who were admitted to one of the 67 European neurosurgical units during a 3-month period in 1995. The CT findings were classified according to the Traumatic Coma Data Bank classification system, and the presence or absence of tSAH was recorded separately in the initial CT scan forms. RESULTS Complete data on early clinical features, CT findings, and outcomes at 6 months were available for 750 patients, of whom 41% exhibited evidence of tSAH on admission CT scans. There was a strong, highly statistically significant association between the presence of tSAH and poor outcomes. In fact, 41% of patients without tSAH achieved the level of good recovery, whereas only 15% of patients with tSAH achieved this outcome. Patients with tSAH were significantly older (median age, 43 yr; standard deviation, 21.1 yr) than those without tSAH (median age, 32 yr; standard deviation, 19.5 yr), and there was a significant tendency for patients with tSAH to exhibit lower Glasgow Coma Scale scores at the time of admission. A logistic regression analysis of favorable/unfavorable outcomes demonstrated that there was still a very strong association between tSAH and outcomes after simultaneous adjustment for age, Glasgow Coma Scale Motor Scores, and admission CT findings (odds ratio, 2.49; 95% confidence interval, 1.74–3.55;P < 0.001). Comparison of the time courses for 164 patients with early (within 14 d after injury) deaths demonstrated very similar patterns, with an early peak and a subsequent decline; there was no evidence of a delayed increase in mortality rates for either group of patients (with or without tSAH). CONCLUSION These findings for an unselected series of patients confirm previous reports of the adverse prognostic significance of tSAH. The data support the view that death among patients with tSAH is related to the severity of the initial mechanical damage, rather than to the effects of delayed vasospasm and secondary ischemic brain damage.

Differential vulnerability of the CA1 and CA3 subfields of the hippocampus to superoxide and hydroxyl radicals in vitro

Abstract: The relative roles of the superoxide and hydroxyl radicals in oxidative stress‐induced neuronal damage were investigated using organotypic hippocampal slice cultures. Cultures exposed to 100 µM duroquinone, a superoxide‐generating compound, for 3 h developed CA1‐selective lesions over a period of 24 h. The damage accounted for ∼64% of the CA1 subfield, whereas CA3 showed just 6% damage, a pattern of damage comparable to that observed following hypoxia/ischaemia. Duroquinone‐induced damage was attenuated by a spin‐trap agent. In contrast, hydroxyl radical‐mediated damage, generated by exposure to 30 µM ferrous sulphate for 1 h, resulted in a CA3‐dominant lesion. The damage developed over 24 h, similar to that observed with duroquinone, but with ∼45% damage in CA3 compared with only 7% in CA1. These data demonstrate a selective vulnerability of the CA1 pyramidal neurones to superoxide‐induced damage and suggest that of the free radicals generated following hypoxia/ischaemia, superoxide, rather than hydroxyl radical, is instrumental in producing neuronal damage.

A microdialysis method for the recovery of IL-1β, IL-6 and nerve growth factor from human brain in vivo

Intracerebral microdialysis is used extensively as a research tool in the investigation of the neurochemical and metabolic changes that occur following acute brain injury. Microdialysis has enabled elucidation of intra-cerebral levels of substances such as lactate, pyruvate and glycerol but, as yet, has not been used effectively to recover macromolecules from the human brain. Traumatic brain injury is known to result in the generation of cytokines and neurotrophins into extracellular fluid compartment of the brain, with effects on neuronal damage and repair. We have developed a technique of in vivo sampling of the interstitial fluid of the brain of patients with severe head injuries which has allowed the measurement of IL-1beta, IL-6 and nerve growth factor. This report confirms the safety and effectiveness of this modified microdialysis method in the clinical setting of a neurological intensive care unit. The technique provides a timely addition to the armamentarium of the clinical scientist and will potentially lead to a greater understanding of neuroinflammation following acute traumatic brain injury.

Attenuation and augmentation of ischaemia-related neuronal death by tumour necrosis factor-alpha in vitro.

Upregulation of the pro‐inflammatory cytokine tumour necrosis factor‐α (TNF) occurs rapidly in the brain following ischaemia, although it is unclear whether this represents a neurotoxic or neuroprotective response. We have investigated whether TNF has different actions in the pre‐ and postischaemic periods in a tissue culture model of cerebral ischaemia. Organotypic hippocampal slice cultures were prepared from 8–10‐day‐old rats and maintained in vitro for 14 days. Neuronal damage was induced by either 1 h oxygen–glucose deprivation or 3 h exposure to NMDA or the superoxide generator duroquinone, and assessed after 24 h by propidium iodide fluorescence. TNF pretreatment was neuroprotective against both oxygen–glucose deprivation and duroquinone. This effect was associated with an activation of the transcription factor NFκB and upregulation of manganese superoxide dismutase, and was prevented by a free radical scavenger. When addition of TNF was delayed until the postinsult period, an exacerbation of neurotoxicity occurred, which was also prevented by a free radical scavenger. The actions of TNF are determined by whether TNF is present before or after an ischaemia‐related insult. Both actions are mediated through the production of free radicals, and the response to TNF is determined by whether a cell is metabolically competent to respond by synthesis of antioxidant defences.

Ischaemic pre-conditioning in organotypic hippocampal slice cultures is inversely correlated to the induction of the 72 kDa heat shock protein (HSP72).

In vivo, preconditioning with a sublethal insult can confer resistance to normally lethal episodes of cerebral ischaemia. This phenomenon has been linked with the induction of the 72 kDa heat shock protein (HSP72), but this has not been clearly demonstrated in vitro. We have used organotypic hippocampal slice cultures to investigate whether tolerance to lethal ischaemia is dependent on HSP72. Cultures were maintained in vitro for 14 days, and neuronal damage assessed using propidium iodide fluorescence. Prolonged neuronal HSP72 upregulation occurred following exposure to 30 min ischaemia, 45 min hypoxia and 1 microM kainate, but not 1 microM NMDA or 20 min ischaemia, all sublethal insults. Preconditioning with ischaemia, kainate or hypoxia 24 h prior to lethal ischaemia (45 min) was not protective, and when the delay was increased to 48 h, damage in the CA3 pyramidal cell region was significantly increased compared to cultures exposed to 45 min ischaemia alone. Preconditioning with 20 min ischaemia had no effect on the severity of ischaemic damage. Preconditioning with 1 microM NMDA significantly reduced neuronal damage produced by either 45 or 60 min ischaemia when the delay between insults was 48 h. NMDA pre-treatment also prevented neurotoxicity produced by glutamate (5-10 mM) but not NMDA (10-30 microM). These data suggest that in vitro, the increased expression of HSP72 following some sublethal insults should be considered as a marker of cell stress prejudicial to the survival of neurones subsequently exposed to ischaemia, while tolerance can be produced through mechanisms independent of HSP72 induction.

L-arginyl-3,4-spermidine is neuroprotective in several in vitro models of neurodegeneration and in vivo ischaemia without suppressing synaptic transmission

Stroke is the third most common cause of death in the world, and there is a clear need to develop new therapeutics for the stroke victim. To address this need, we generated a combinatorial library of polyamine compounds based on sFTX‐3.3 toxin from which L‐Arginyl‐3,4‐Spermidine (L‐Arg‐3,4) emerged as a lead neuroprotective compound. In the present study, we have extended earlier results to examine the compounds neuroprotective actions in greater detail. In an in vitro ischaemia model, L‐Arg‐3,4 significantly reduced CA1 cell death when administered prior to induction of 60 min of ischaemia as well as when administered immediately after ischaemia. Surprisingly, L‐Arg‐3,4 continued to prevent cell death significantly when administration was delayed for as long as 60 min after ischaemia. L‐Arg‐3,4 significantly reduced cell death in excitotoxicity models mediated by glutamate, NMDA, AMPA, or kainate. Unlike glutamate receptor antagonists, 300 μM L‐Arg‐3,4 did not suppress synaptic transmission as measured by evoked responses in acute hippocampal slices. L‐Arg‐3,4 provided significant protection, in vitro, in a superoxide mediated injury model and prevented an increase of superoxide production after AMPA or NMDA stimulation. It also decreased nitric oxide production after in vitro ischaemia and NMDA stimulation, but did so without inhibiting nitric oxide synthase directly. Furthermore, L‐Arg‐3,4 was significantly neuroprotective in an in vivo model of global forebrain ischaemia, without any apparent neurological side‐effects. Taken together, these results demonstrate that L‐Arg‐3,4 is protective in several models of neurodegeneration and may have potential as a new therapeutic compound for the treatment of stroke, trauma, and other neurodegenerative diseases.