Effect of magnesium on functional outcome and paraclinical parameters of patients undergoing supratentorial craniotomy for brain tumors: a randomized controlled trial.

BACKGROUND: Several studies have demonstrated that magnesium (Mg) plays an important role in the prevention and treatment of central nervous system (CNS) insults. In this study, we tested the effect of intravenous magnesium sulfate (MgSO4) on the outcome of patients with brain tumors who underwent craniotomy. The outcome was defined clinically as the Barthel index score and paraclinically as blood levels of NSE (neuron-specific enloase) and S100Β protein. METHODS: Sixty patients were randomly divided into two groups of 30 patients: the treatment and control groups. In the treatment group, 5 g of MgSO4 in normal saline was infused in 6 h 2 days before surgery, and the same dosage was repeated the day before and during surgery. The control group received placebo. Serum S100Β and NSE concentrations were measured at baseline before administration of magnesium, before surgery, and on the 2nd postoperative day. The Barthel index score was evaluated and registered before surgery, 3, and 6 months after the operation. RESULTS: The study results showed a significant change in S100Β protein levels before and after surgery (p < 0.05), but we could not find similar results for NSE protein and the Barthel index score. There was a correlation between NSE protein and the Barthel index. CONCLUSIONS: The results of this study revealed that administration of intravenous MgSO4 before and during surgery is safe and effective in reducing S100B protein levels in patients undergoing supratentorial craniotomy for brain tumors. Further studies to elucidate the pathophysiology of brain injuries and role of magnesium are warranted.

Pilomyxoid astrocytoma with involvement of the sella turcica in an adolescent.

Pilomyxoid astrocytoma (PMA) is a recently described tumor typically occurring in the hypothalamic-chiasmatic region of very young children. PMA is characterized by a more aggressive course than pilocytic astrocytoma and exhibits certain differing histological features. We report a PMA in an adolescent patient with visual field disturbance. Imaging studies revealed enlargement of the sella turcica due to a homogenously enhancing sellar and suprasellar mass identifiable both on CT scans and MRI. We believe that PMA may be included in the list of differential diagnoses of the lesions expanding the sella turcica.

Are the distributions of variations of circle of Willis different in different populations? - Results of an anatomical study and review of literature.

BACKGROUND: Previous studies have proposed correlation between variants of the cerebral arterial circle (also known as circle of Willis) and some cerebrovascular diseases. Differences in the incidence of these diseases in different populations have also been investigated. The study of variations in the anatomy of the cerebral arterial circle may partially explain differences in the incidence of some of the cerebrovascular diseases in different ethnic or racial groups. While many studies have investigated the variations in the anatomy of each segment of the cerebral arterial circle, few have addressed the variants of the cerebral arterial circle as a whole. Similarly, the frequency of occurrence of such variants in different ethnic or racial groups has not been compared. METHODS: 102 brains of recently deceased Iranian males were dissected, in order to observe variations in the anatomy of the cerebral arterial circle. The dissection process was recorded on film and digitized. One resized picture from each dissection, showing complete circle has been made available online. The variations of the circle as whole and segmental variations were compared with previous studies. RESULTS: On the whole, the frequencies of the different variants of the entire cerebral arterial circle and segmental variations were comparable with previous studies.More specifically variants with uni- and bilateral hypoplasia of posterior communicating arteries were the most common in our study, similar to the previous works. No hypoplasia of the precommunicating part of the left anterior cerebral artery (A1), aplasia of A1 or the precommunicating part of the posterior cerebral artery (P1) was seen. In 3% both right and left posterior communcating arteries were absent. CONCLUSION: The anatomical variations found in the cerebral arterial circle of the Iranian males in the current study were not significantly different to those of more diverse populations reported in the literature. While taking into account potential confounding factors, the authors conclude that based on available studies, there is no evidence suggesting that the distributions of the variations of cerebral arterial circle differ in different populations.

Prophylactic antibiotic for prevention of posttraumatic meningitis after traumatic pneumocephalus: design and rationale of a placebo-controlled randomized multicenter trial [ISRCTN71132784].

BACKGROUND: The purpose of this study is to compare the efficacy of prophylactic antibiotic for prevention of meningitis in acute traumatic pneumocephalus patients. METHODS: In this prospective, randomized controlled clinical trial, 200 selected head injury patients with traumatic pneumocephalus are randomly assigned to receive intravenous antibiotics (2 grams Ceftriaxone twice a day), oral antibiotics (Azithromycin) or placebo for at least 7 days after trauma. The patients will be followed for one month posttrauma. CONCLUSION: The authors hope that this study helps clarifying the effectiveness and indications of antibiotics in prevention of meningitis in traumatic pneumocephalus after head injury and in specific subgroup of these patients.

Comparing logistic models based on modified GCS motor component with other prognostic tools in prediction of mortality: results of study in 7226 trauma patients.

A simple reproducible and sensitive prognostic trauma tool is still needed. In this article we have introduced modified GCS motor response (MGMR) and evaluated the performance of logistic models based on this variable. The records of 8452 trauma patients admitted to major hospitals of Tehran from 1999 to 2000 were analysed. 7226 records with known outcome were included in our study. Logistic models based on outcome (death versus survival) as a dependent variable and Injury Severity Score (ISS), Revised Trauma Score (RTS), Glasgow Coma Scale (GCS), GCS motor component (GMR) and MGMR (following command [=2], movement but not following [=1] command and without movement [=0]) were compared based on their accuracy and area under the Receiver Operating Characteristic (ROC) curve. The accuracy of the Trauma and Injury Severity Score (TRISS), RTS, GCS, GMR and MGMR models were almost the same. Considering both the area under the ROC curve and accuracy, the age included MGMR model was also comparable with other age included models (RTS+age, GCS+age, GMR+age). We concluded that although in some situations we need more sophisticated models, should our results be reproducible in other populations, MGMR (with or without age added) model may be of considerable practical value.

Play dough as an educational tool for visualization of complicated cerebral aneurysm anatomy.

BACKGROUND: Imagination of the three-dimensional (3D) structure of cerebral vascular lesions using two-dimensional (2D) angiograms is one of the skills that neurosurgical residents should achieve during their training. Although ongoing progress in computer software and digital imaging systems has facilitated viewing and interpretation of cerebral angiograms enormously, these facilities are not always available. METHODS: We have presented the use of play dough as an adjunct to the teaching armamentarium for training in visualization of cerebral aneurysms in some cases. RESULTS: The advantages of play dough are low cost, availability and simplicity of use, being more efficient and realistic in training the less experienced resident in comparison with the simple drawings and even angiographic views from different angles without the need for computers and similar equipment. The disadvantages include the psychological resistance of residents to the use of something in surgical training that usually is considered to be a toy, and not being as clean as drawings or computerized images. CONCLUSION: Although technology and computerized software using the patients' own imaging data seems likely to become more advanced in the future, use of play dough in some complicated cerebral aneurysm cases may be helpful in 3D reconstruction of the real situation.

Comparison of artificial neural network and logistic regression models for prediction of mortality in head trauma based on initial clinical data.

BACKGROUND: In recent years, outcome prediction models using artificial neural network and multivariable logistic regression analysis have been developed in many areas of health care research. Both these methods have advantages and disadvantages. In this study we have compared the performance of artificial neural network and multivariable logistic regression models, in prediction of outcomes in head trauma and studied the reproducibility of the findings. METHODS: 1000 Logistic regression and ANN models based on initial clinical data related to the GCS, tracheal intubation status, age, systolic blood pressure, respiratory rate, pulse rate, injury severity score and the outcome of 1271 mainly head injured patients were compared in this study. For each of one thousand pairs of ANN and logistic models, the area under the receiver operating characteristic (ROC) curves, Hosmer-Lemeshow (HL) statistics and accuracy rate were calculated and compared using paired T-tests. RESULTS: ANN significantly outperformed logistic models in both fields of discrimination and calibration but under performed in accuracy. In 77.8% of cases the area under the ROC curves and in 56.4% of cases the HL statistics for the neural network model were superior to that for the logistic model. In 68% of cases the accuracy of the logistic model was superior to the neural network model. CONCLUSIONS: ANN significantly outperformed the logistic models in both fields of discrimination and calibration but lagged behind in accuracy. This study clearly showed that any single comparison between these two models might not reliably represent the true end results. External validation of the designed models, using larger databases with different rates of outcomes is necessary to get an accurate measure of performance outside the development population.

Prophylactic administration of ceftriaxone for the prevention of meningitis after traumatic pneumocephalus: results of a clinical trial.

OBJECT: The purpose of this study was to compare the efficacy of the prophylactic use of ceftriaxone for the prevention of meningitis in patients with acute traumatic pneumocephalus. METHODS: In this prospective, single-institution, randomized clinical trial, 109 patients with mild head injury and traumatic pneumocephalus were randomly assigned to receive or not receive an antibiotic medication (ceftriaxone, 1 g given twice a day) until occurrence of meningitis or at least 5 days after trauma. The patients were followed up for 1 month posttrauma. The 109 patients were divided into two groups: 53 were assigned to the prophylactic antibiotics therapy group and 56 to the control group. The overall rate of meningitis was 20.1% and the rates of meningitis in the two groups were not significantly different. The results were the same when adjusted for the patient's Glasgow Coma Scale score, sex, and age, as well as for an intradural location of air, air volume, presence of cerebrospinal fluid (CSF) rhinorrhea or CSF otorrhea, radiological sign of a skull base fracture, or intracranial hemorrhage. CONCLUSIONS: The results of this study do not substantiate the efficacy of ceftriaxone used in the prevention of meningitis in patients with traumatic pneumocephalus after mild head injury or in any specific subgroup of these patients. Cerebrospinal fluid rhinorrhea and intracranial hemorrhage may be considered primary risk factors for the development of meningitis in patients with posttraumatic pneumocephalus and, in the absence of these symptoms, intradural location of air and air volume greater than 10 ml may be considered secondary risk factors. Further studies in this area are warranted.

Bilateral asynchronous acute epidural hematoma : a case report.

BACKGROUND: Bilateral extradural hematomas have only rarely been reported in the literature. Even rarer are cases where the hematomas develop sequentially, one after removal of the other. Among 187 cases of operated epidural hematomas during past 4 years in our hospital, we found one case of sequentially developed bilateral epidural hematoma. CASE PRESENTATION: An 18-year-old conscious male worker was admitted to our hospital after a fall. After deterioration of his consciousness, an emergency brain CT scan showed a right temporoparietal epidural hematoma. The hematoma was evacuated, but the patient did not improve afterwards. Another CT scan showed contralateral epidural hematoma and the patient was reoperated. Postoperatively, the patient recovered completely. CONCLUSIONS: This case underlines the need for monitoring after an operation for an epidural hematoma and the need for repeat brain CT scans if the patient does not recover quickly after removal of the hematoma, especially if the first CT scan has been done less than 6 hours after the trauma. Intraoperative brain swelling can be considered as a clue for the development of contralateral hematoma.

Spinal subdural hematoma revealing hemophilia A in a child: A case report.

BACKGROUND: Intraspinal bleeding especially in the form of subdural hematoma is rare in hemophiliacs. In the present case, we report a neglected hemophilic A child with such a problem and discuss its management options. CASE PRESENTATION: A 9-year old hemophilic A boy presented with quadriparesis, confusion and meningismus after a fall 4 days previously. There was no sign of direct trauma to his back. His CT Scan and MRI showed spinal extramedullary hematoma extended from C5 to L2. We corrected the factor VIII level, but two days later, the patient's lower limbs weakened to 1/5 proximally as well as distally. We performed a laminectomy from T11 to L2, according to the level of the maximal neurological deficit and recent deterioration course. The subdural hematoma was evacuated. The hematoma in other spinal levels was managed conservatively. In the week following the operation, the patient's neurological status approached normal. CONCLUSION: This case calls attention to the clinical manifestation, radiological features and management options of the rarely reported intraspinal hematoma in hemophilic children. Although this case has been managed operatively for its hematoma in the thoracolumbar region, at the same time it can be considered a successful case of conservative management of intraspinal hematoma in the cervicothoracic region. Both conservative and surgical management could be an option in managing these patients considering their neurological course.

Vestibular schwannoma with contralateral facial pain - case report.

BACKGROUND: Vestibular schwannoma (acoustic neuroma) most commonly presents with ipsilateral disturbances of acoustic, vestibular, trigeminal and facial nerves. Presentation of vestibular schwannoma with contralateral facial pain is quite uncommon. CASE PRESENTATION: Among 156 cases of operated vestibular schwannoma, we found one case with unusual presentation of contralateral hemifacial pain. CONCLUSION: The presentation of contralateral facial pain in the vestibular schwannoma is rare. It seems that displacement and distortion of the brainstem and compression of the contralateral trigeminal nerve in Meckel's cave by the large mass lesion may lead to this atypical presentation. The best practice in these patients is removal of the tumour, although persistent contralateral pain after operation has been reported.

Surgical simulation software for insertion of pedicle screws.

OBJECTIVE: As the first step toward finding noninvasive alternatives to the traditional methods of surgical training, we have developed a small, stand-alone computer program that simulates insertion of pedicle screws in different spinal vertebrae (T10-L5). METHODS: We used Delphi 5.0 and DirectX 7.0 extension for Microsoft Windows. This is a stand-alone and portable program. RESULTS: The program can run on most personal computers. It provides the trainee with visual feedback during practice of the technique. At present, it uses predefined three-dimensional images of the vertebrae, but we are attempting to adapt the program to three-dimensional objects based on real computed tomographic scans of the patients. The program can be downloaded at no cost from the web site: www.tums.ac.ir/downloads CONCLUSION: As a preliminary work, it requires further development, particularly toward better visual, auditory, and even proprioceptive feedback and use of the individual patient's data.