Early hyperglycemia is a frequent component of the stress response to head injury, a significant indicator of its severity, and a reliable predictor of outcome.

Many previous studies have constructed several predictive models for outcome after severe head injury, but these have often used expensive, time consuming, or highly specialized measurements. The goal of this study was to develop a simple, easy to use a model involving only variables that are rapidly and easily achievable in daily routine practice. To this end, a classification and regression tree (CART) technique was employed in the analysis of data from 345 patients with isolated severe brain injury who were admitted to Asclepeion General Hospital of Athens from January, 1993, to December, 2000. A total of 16 prognostic indicators were examined to predict neurological outcome at 6 months after head injury. Our results indicated that Glasgow Coma Scale was the best predictor of outcome. With regard to the other data, not only the most widely examined variables such as age, pupillary reactivity, or computed tomographic findings proved again to be strong predictors, but less commonly applied parameters, indirectly associated with brain damage, such as hyperglycemia and leukocytosis, were found to correlate significantly with prognosis too. The overall cross-validated predictive accuracy of CART model for these data was 86.84%, with a cross-validated relative error of 0.308. All variables included in this tree have been shown previously to be related to outcome. Methodologically, however, CART is quite different from the more commonly used statistical methods, with the primary benefit of illustrating the important prognostic variables as related to outcome. This technique may prove useful in developing new therapeutic strategies and approaches for patients with severe brain injury.

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✓ Unintended incidental durotomy is not a rare complication of lumbar microsurgery and is usually recognized and treated immediately. The reconstruction process can be complicated further by unpredictable factors. To their knowledge, the authors report the first case of a symptomatic pneumorachis associated with the accidental awakening of a patient during reconstruction of an incidental durotomy following lumbar microdiscectomy. Incomplete cauda equina syndrome developed in the patient on awakening from surgery after reconstruction of an unintended incidental dural tear that occurred during lumbar microdiscectomy. Symptomatic pneumorachis was revealed on an emergency computed tomography scan, and the patient underwent immediate repeated operation to remove air and decompress the spinal canal. The increasing number and complexity of surgical procedures in the lumbar spine contribute to the growing incidence of unintended durotomy. The surgeon should be aware of rare complications that may arise. Development of a vacuum phenomenon in conjunction with a ball–valve mechanism may lead to pneumorachis during durotomy repair. If this rare complication is promptly recognized and confronted, the outcome will not be associated with long-term sequelae.

The main metabolites of the neurotransmitters noradrenaline, dopamine, and serotonin, methoxy-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5HIAA) respectively, were estimated by HPLC with electrochemical detection in CSF samples from 24 patients in coma after head injury, 1 to 12 (mean 3.0) days from accident, and from 24 age- and sex-matched subjects undergoing myelography for possible herniated disk. Analysis of variance with age as covariate, revealed significantly elevated levels of all three metabolites in the patients group. The concentrations of 5HIAA were negatively correlated to the score in the Glasgow Coma Scale. Fourteen patients who recovered with no or minor neurological deficits, had significantly lower CSF 5HIAA levels compared to the ten patients who had a bad outcome (death), while there were no differences regarding HVA or MHPG concentrations. The possibility of a connection of the high neurotransmitter turnover during coma to the development of post-traumatic depression is discussed.