Corticosteroids for acute traumatic brain injury

Visual-Evoked-Response-Supported Outcome of Intravitreal Erythropoietin in Management of Indirect Traumatic Optic Neuropathy

PURPOSE

Investigating the efficacy of intravitreal injection of erythropoietin (EPO) in managing indirect traumatic optic neuropathy (ITON) of different durations.

METHODS

A case series that included two groups of ITON patients: recent ITON group (<3 months trauma duration; 7 eyes) and old duration ITON group (3-36 months; 7 eyes). Diagnostic computerized tomography (CT) and baseline flash visual evoked response (VER) were performed at the presentation time. At the initial visit and each follow-up, all patients had undergone assessment of best-corrected visual acuity (BCVA), pupil reaction, and anterior and posterior segments. VER was repeated 1 and 3 months after injection. All patients received an intravitreal injection of 2000 IU EPO in 0.2 ml of commercially available sterile EPREX 4000 solution, Jansen Cilag, Zug, Switzerland. Five patients had received a second injection 3 months later.

RESULTS

Significant improvement was found in BCVA, VER amplitude, and latency (P < 0.0001, 0.0154, and 0.0291, respectively). Initial values of BCVA, VER amplitude, and latency correlated significantly to the final values. Differences between recent and old trauma groups were insignificant in the three parameters. In patients who received second injection, further clinical but statistically insignificant improvement was noted in BCVA in 60% of patients, VER amplitude in 50% of patients, and in VER latency in 100% of patients. No complications were recorded.

CONCLUSION

Intravitreal injection of EPO may be effective and safe in treatment of recent and old indirect traumatic optic neuropathy.

Recent developments in clinical trials for the treatment of traumatic brain injury

The clinical understanding of traumatic brain injury (TBI) and its manifestations is beginning to change. Both clinicians and research scientists are recognizing that TBI and related disorders such as stroke are complex, systemic inflammatory and degenerative diseases that require an approach to treatment more sophisticated than targeting a single gene, receptor, or signaling pathway. It is becoming increasingly clear that TBI is a form of degenerative disorder affecting the brain and other organs, and that its manifestations can unfold days, weeks, and years after the initial damage. Until recently, and despite numerous industry- and government-sponsored clinical trials, attempts to find a safe and effective neuroprotective agent have all failed - probably because the research and development strategies have been based on an outdated early 20th century paradigm seeking a magic bullet that will affect a narrowly circumscribed target. We propose that more attention be given to the development of drugs, given alone or in combination, that are pleiotropic in their actions and that have systemic as well as central nervous system effects. We review current Phase II and Phase III trials for acute pharmacologic treatments for TBI and report on their aims, methods, status, and important associated research issues.

Progesterone in the treatment of acute traumatic brain injury: a clinical perspective and update

Despite decades of laboratory research and clinical trials, a safe and effective treatment for traumatic brain injury has yet to reach clinical practice. The failure is due in part to the prevalence of a reductionist philosophy and research praxis that targets a single receptor mechanism, gene, or brain locus. This approach fails to account for the fact that traumatic brain injury is a very complex disease caused by a cascade of systemic toxic events in the brain and throughout the body. Attention is now turning to pleiotropic drugs that act on multiple genomic, proteomic, and metabolic pathways to enhance morphological and functional outcomes after brain injury. Of the agents now in clinical trial, the neurosteroid progesterone appears to hold considerable promise. Many still assume that progesterone is "just a female hormone" with limited, if any, neuroprotective properties, but this view is outdated. This review will survey the evidence that progesterone has salient pleiotropic properties as a neuroprotective agent in a variety of central nervous system injury models. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain.

Progesterone exerts neuroprotective effects after brain injury

Progesterone, although still widely considered primarily a sex hormone, is an important agent affecting many central nervous system functions. This review assesses recent, primarily in vivo, evidence that progesterone can play an important role in promoting and enhancing repair after traumatic brain injury and stroke. Although many of its specific actions on neuroplasticity remain to be discovered, there is growing evidence that this hormone may be a safe and effective treatment for traumatic brain injury and other neural disorders in humans.

Neuronal degeneration and iNOS expression in experimental brain contusion following treatment with colchicine, dexamethasone, tirilazad mesylate and nimodipine

BACKGROUND

The pathophysiological mechanisms of secondary neurological injury after traumatic brain injury are complex. Post-traumatic biochemical reactions include parenchymal inflammation, free radical production, increased intracellular calcium and lipid peroxidation and nitric oxide production. The relative importance of each mechanism is unknown in brain contusions. This study was undertaken to investigate protection by the neuroprotective and/or anti-inflammatory drugs that have different putative mechanisms of action: colchicine, dexamethasone, tirilazad mesylate and nimodipine.

METHOD

A brain contusion was produced using a weight-drop model in rats. The animals were treated with either one of the drugs at previously defined relevant dosage or control. Fluoro-Jade labelling, TUNEL-staining and immunohisto-chemistry were used to study neuronal degeneration, cellular apoptosis and iNOS expression. In addition, the number of surviving neurons after 14 days was determined.

FINDINGS

The number of degenerating neurons was significantly reduced in all treatment groups at 24 hours while the total number of apoptotic cells including inflammatory cells and glia was unchanged. iNOS-expression was reduced in all treatment groups at 24 hours but not later. Only colchicine and tirilazad mesylate significantly enhanced neuronal survival at 14 days after injury.

CONCLUSIONS

The findings underscored that an early neuroprotective effect does not necessarily lead to increased long-term neuronal survival. The absence of a significant long-term effect with nimodipine and dexamethasone agrees with clinical studies. Colchicine with an anti-macrophage/anti-inflammatory activity and the free radical scavenger tirilazad mesylate were effective for amelioration of experimental contusion with moderate energy transfer. Early neuroprotection may to some extent target iNOS via different pathways since all tested drugs affected both iNOS expression and neuronal degeneration.

[Shock trauma room management of the multiple-traumatized patient with skull-brain injuries. A systematic review of the literature]

This overview reviews the literature on multiply injured patients with traumatic brain injuries. Clinical trials were systematically collected (MEDLINE, Cochrane, and hand searches) and classified into evidence levels (1 to 5 according to the Oxford system).A detailed analysis of the literature of traumatic brain injuries has been elaborated by the Brain Trauma Foundation and has been published in the World Wide Web (http://www2.braintrauma.org/). The following procedures should be performed in the emergency room for multiply injured patients with traumatic brain injuries: (1) recording of precise history to identify risk factors for severe traumatic brain injury, (2) measurement of the Glasgow Coma Scale (GCS), pupillary reflex, and mean arterial pressure, (3) diagnostic evaluation with a CT scan, and (4) rapid surgical decompression if indicated.

Aquaporins and brain edema

Aquaporins are a family of transmembrane proteins that selectively allow the passage of water through the plasma membrane. Their importance is highlighted by their ubiquitous presence from bacteria to mammals. In humans, they are found throughout the body and recent work has highlighted their function within the brain. They are intimately involved in the production of cerebrospinal fluid and the control of water movement at the blood-brain barrier. Aquaporin levels are up-regulated in animal models of trauma, stroke and water intoxication as well as around human malignant brain tumors. They have thus been implicated in the formation of brain edema. Knockout mice, without the aquaporin gene, appear to have reduced brain edema compared to their wild type brethren in models of brain edema. Currently, the clinical treatment of brain edema is limited. Increased knowledge of the aquaporins may open new targeted therapies for brain edema.

Neurocritical care and traumatic brain injury

The majority of severely head injured children will not require neurosurgery. For the pediatrician, the central question must be whether medical interventions are effective in limiting morbidity and treating the problem of cerebral oedema. However, in order to address this issue we need to give some thought to the system of care in which we practice, how we assess the severity of brain injury and whether, in regard to pathophysiology, responses in children are significantly different from those seen in adults. In this regard, this review highlights some of the recent pediatric neurocritical care literature and provides, for the clinician, a framework on which to base ones medical management of severe traumatic brain injury occurring in childhood.

Current Controlled Trials: an opportunity to help improve the quality of clinical research

Some problems with the quality of controlled clinical trials can be addressed by following these procedures: registering all trials at inception; using systematic reviews to inform the design of new studies; posting and obtaining feedback on preprints; reporting all well conducted trials, regardless of their results; reducing biased and inefficient assessment of reports submitted for publication; publishing sufficiently detailed reports; linking trial reports to relevant external information; providing readier access to reports; and reviewing and amending reports after initial publication. The launch of a new range of electronic journals by Current Controlled Trials offers an opportunity to contribute to progress in these ways.