Subarachnoid Haemorrhage Incidence Pattern Analysis with Circular Statistics

Knowledge about biological rhythms of diseases may not only help in understanding the pathophysiology of diseases but can also help health service policy makers and emergency department directors to allocate resources efficiently. Aneurysmal subarachnoid haemorrhage (SAH) has high rates of morbidity and mortality. The incidence of SAH has been attributed to patient-related factors such as characteristics of aneurysms, smoking, and hypertension. There are studies showing that the incidence of aneurysmal SAH appears to behave in periodic fashions over long time periods. However, there are inconsistencies in the literature regarding the impact of chronobiological factors such as circadian, seasonal, and lunar cycle factors on the occurrence of SAH. In this study, we focused on the analysis of a temporal pattern of SAH (infradian rhythms) with a novel approach using circular statistical methods. We aimed to see whether there is a circular pattern for the occurrence of SAH at all and if so, whether it can be related to known temporal patterns based on available literature. Our study did not support the notion that aneurysmal subarachnoid haemorrhages occur on any specific day in a cycle with specific lengths up to 365 days including specific weekdays, full moon, equinoxes, and solstices. Hence, we found no relationship between SAH incidence and timing. Study in larger populations using similar circular statistical methods is suggested.

Neurosurgical literature classification - Evaluation of three automated methods and time trend analysis of the literature

Background

Automated supervised text classification methods require preclassified training data. Their application in scenarios that a large amount of preclassified data is not accessible is challenging. Neurosurgical literature classification into subspecialties is an example of this situation. We have introduced an automated similarity-based text classification method, evaluated it along with two other automated methods and applied the introduced method in neurosurgical literature classification.

Methods

Performance of an introduced similarity-based text classification method along with two other automated methods (Lbl2Vec and keyword counting-based methods) was compared with performance of two senior neurosurgery registrars in classification of neurosurgical literature to 5 subspecialties. The Kappa-statistic measure of interrater agreement, overall marginal homogeneity using the Stuart-Maxwell test, marginal homogeneity relative to individual categories using McNemar tests and the sensitivity and specificity of each of the three methods were calculated.The introduced method was used to classify 211617 neurosurgical publications indexed in Pubmed to different subspecialties based on keywords extracted from subspecialty sections of a neurosurgery textbook.

Results

The introduced similarity-based method showed the highest agreement with the registrars (raw agreement and Kappa value) followed by the Lbl2Vec and the counting-based method. Classifications of the English neurosurgical publications indexed in Pubmed into categories of Oncology, Vascular, Spine and functional using the introduced similarity-based method were more reliable (closer to the registrars' classifications) than Cranial trauma. The classifications and future forecast showed highest publications in Oncology, followed by Cranial trauma, Vascular, spine and functional neurosurgery.

Conclusion

The classification of the English neurosurgical publications indexed in Pubmed to different subspecialties, using the introduced method, shows that Oncology and tumour has been the main battleground for the neurosurgeons over years and probably in the near future. The performance of the introduced classification method in comparison with the human performance shows its potential application in the situations that enough preclassified data are not accessible for automated text classification.

Hemianopia: A complication of epidural injection in a patient with arachnoid cyst - case report

Epidural injections are routinely used for short-term management of radicular pain and chronic low back pain. Prescription of this intervention, in the presence of intracranial abnormalities, is a topic of debate. Intracranial arachnoid cysts are cerebrospinal fluid-filled spaces, which are usually asymptomatic despite being a formidable size. As far as the authors know, there have been no cases depicted in indexed literature regarding asymptomatic supratentorial arachnoid cysts becoming symptomatic post undertaking of spinal epidural injections. We depict this phenomenon in a 53-year-old woman, who ultimately required a craniotomy to address their symptoms. Asymptomatic supratentorial arachnoid cysts can become symptomatic post undertaking of spinal epidural injections. In cases of known cranial arachnoid cysts with mass effect, the small risk that the cranial arachnoid cyst may become symptomatic during or after epidural injections should be a consideration and the patients should be informed of the potential associated risks.

Optimal Temperature of Irrigation Fluid for Hemostasis in Neurosurgery - A Narrative Literature Review

Haemostasis in neurosurgery is crucial to patient and surgery outcomes, with many techniques developed for this. One area that is not appropriately characterised despite continuous anecdotal evidence, is the use of irrigation fluid (IF) temperature and its effects on stemming haemorrhages. Given the ubiquitous use of IF in neurosurgery for clearing blood from the surgical field, it is useful to explore its role as a haemostat and whether or not the temperature of IF influences its haemostatic capacity. This review explored the literature for an optimal temperature of irrigation for haemostasis in neurosurgery.

METHODS

Database searches were conducted using MEDLINE, Scopus, Web of Science and CINAHL, withcitation chaining occurring where applicable. Standard terms around neurosurgery, haemostasis and irrigation were used.

RESULTS

Seven pieces of literature were identified. No optimal temperature for haemostasis could be confidently synthesised from the literature owing to no primary investigation into the subject. After collating available information into common themes it is suggested that that temperatures >38 °C are preferred..

CONCLUSION

The literature in this area is limited. Despite a lack of applicable systematic investigation on the topic, by exploring the physiology of haemostasis and IF, best practice guidelines for IF and the literature on the role of the temperature of IF in other surgical specialties, it is suggested that a temperature in the range of 38 °C to 40° C would be most applicable to a value optimal for neurosurgery.

Significant Disparity of Access to Stroke Treatment Between the Western Parts and Eastern and Northern Parts of Sydney

Objective To provide an estimate of access times and distances to an endovascular clot retrieval (ECR) service provider for a typical stroke patient in the western part of Sydney and to compare it with the eastern and northern parts. Methods Incidences of stroke were simulated through a population-weighted randomized selection of addresses in the studied western, eastern, and northern areas of Sydney (100,000 times for each). The access times and distances were calculated from those addresses to the closest ECR hub for the eastern and northern parts and to all five ECR hubs, as well as the Nepean Public Hospital (NPH) for the western part. The access times and distance means were compared statistically using ANOVA. Results In the western areas, the estimated average access times and distances to different ECR hubs varied from 38.5 (+/- 15) to 45 (+/- 15) minutes and from 42 (+/- 15.9) to 46.8 (+/- 16) km in working hours and from 45 (+/- 15) to 64 (+/- 15) minutes and 46.8 (+/- 16) to 69.6 (+/- 16) km in after hours. However, the estimated average access times and distances to the local ECR hub were 12.25 (+/- 6) minutes and 9.1 (+/- 5.6) km for northern and 7.5 (+/- 4) minutes and 4.4 (+/- 2.5) km for the eastern areas. The differences between the estimated average access times and distances for a typical stroke patient to an ECR hub in the western areas in comparison with eastern or northern areas were statistically significant (p<0.0001). The average access times and distances in the western part to NPH were 17 (+/- 16) minutes and 15.6 (+/- 16.6) km. Conclusions The patients in the western part of Sydney had significantly longer access times to ECR hubs than those living in comparable areas of the eastern and northern parts. This study supports the Nepean Public Hospital supplying an ECR service to achieve travel times, and, therefore, treatment times for a typical stroke patient in the western parts, similar to patients in the eastern and northern parts of Sydney.

An Ocular Chameleon

Patients presenting with transient visual loss is common in emergency departments. Neurologists, ophthalmologists and emergency care physicians may be called upon to evaluate such patients. Monocular visual loss should be differentiated from the binocular involvement as the oetologies, investigations and management of such patients differ considerably. We report a case of monocular visual loss that involved predominantly one eye but affected the other side independently, albeit less frequently. A meticulous history, thorough general, neurological and ophthalmological examinations are necessary in such patients to identify the cause and to treat appropriately. Ocular ischemic syndrome (OIS) is due to chronic hypoperfusion of the structures supplied by ophthalmic artery leading to monocular visual loss. Stenosis of the ipsilateral internal carotid artery from a variety of causes is the main underlying mechanism. The first case of OIS was reported by Hedges in 1963 and the term was coined later by Barry and Magargal. Ocular ischemic syndrome is an important differential diagnosis to consider especially in older people and those with vascular risk factors. An overview of important differential diagnosis, clinical features and treatment of OIC are discussed in this article. A multidisciplinary team is optimal for the management of ocular ischemic syndrome.

Results of Surgery for Low-Grade Brain Arteriovenous Malformation Resection by Early Career Neurosurgeons: An Observational Study

BACKGROUND

For sustainability of arteriovenous malformation (AVM) surgery, results from early career cerebrovascular neurosurgeons (ECCNs) must be acceptably safe.

OBJECTIVE

To determine whether ECCNs performance of Spetzler-Ponce Class A AVM (SPC A) resection can be acceptably safe.

METHODS

ECCNs completing a cerebrovascular fellowship (2004-2015) with the last author were included. Inclusion of the ECCN cases occurred if they: had a prospective database of all AVM cases since commencing independent practice; were the primary surgeon on SPC A; and had made the significant management decisions. All SPC A surgical cases from the beginning of the ECCN's independent surgical practice to a maximum of 8 yr were included. An adverse outcome was considered a complication of surgery leading to a new permanent neurological deficit with a last modified Rankin Scale score >1. A cumulative summation (Cusum) plot examined the performance of each surgery. The highest acceptable level of adverse outcomes for the Cusum was 3.3%, derived from the upper 95% confidence interval of the last author's reported series.

RESULTS

Six ECCNs contributed 110 cases for analysis. The median number of SPC A cases operated by each ECCN was 16.5 (range 4-40). Preoperative embolization was performed in 5 (4.5%). The incidence of adverse outcomes was 1.8% (95% confidence interval: <0.01%-6.8%). At no point during the accumulated series did the combined cohort become unacceptable by the Cusum plot.

CONCLUSION

ECCNs with appropriate training appointed to large-volume cerebrovascular centers can achieve results for surgery for SPC A that are not appreciably worse than those published from high-volume neurosurgeons.

A Simple Retractor for Anterior Cervical Diskectomy

BACKGROUND

 The insertion of available cervical retractor systems is relatively complex for the limited exposure required for single-level anterior cervical diskectomy.

OBJECTIVE

 To introduce a novel cervical retractor system and report the initial experience of its application.

METHODS

 A simple retractor system was designed that is fixed to the vertebral body through Caspar pins. The design allows the retractor to move with the vertebrae during distraction via the traditional Caspar distractor system. The advantages and limitations of the device based on the initial experience are discussed.

RESULTS

 The author has used the current version of the retractor on 32 single-level anterior cervical diskectomies. The insertion of the retractor is easy, and its application provides safe and satisfactory anterior cervical exposure. There have not been related complications, although transient dysphagia has not been prevented.

CONCLUSION

 This newly designed retractor system is simple and efficient for a single-level anterior cervical diskectomy, and its insertion is relatively easy.

Virtual Reality Angiogram vs 3-Dimensional Printed Angiogram as an Educational tool—A Comparative Study

BACKGROUND

Three-dimensional (3D) visualization of the neurovascular structures has helped preoperative surgical planning. 3D printed models and virtual reality (VR) devices are 2 options to improve 3D stereovision and stereoscopic depth perception of cerebrovascular anatomy for aneurysm surgery.

OBJECTIVE

To investigate and compare the practicality and potential of 3D printed and VR models in a neurosurgical education context.

METHODS

The VR angiogram was introduced through the development and testing of a VR smartphone app. Ten neurosurgical trainees from Australia and New Zealand participated in a 2-part interactive exercise using 3 3D printed and VR angiogram models followed by a questionnaire about their experience. In a separate exercise to investigate the learning curve effect on VR angiogram application, a qualified neurosurgeon was subjected to 15 exercises involving manipulating VR angiograms models.

RESULTS

VR angiogram outperformed 3D printed model in terms of resolution. It had statistically significant advantage in ability to zoom, resolution, ease of manipulation, model durability, and educational potential. VR angiogram had a higher questionnaire total score than 3D models. The 3D printed models had a statistically significant advantage in depth perception and ease of manipulation. The results were independent of trainee year level, sequence of the tests, or anatomy.

CONCLUSION

In selected cases with challenging cerebrovascular anatomy where stereoscopic depth perception is helpful, VR angiogram should be considered as a viable alternative to the 3D printed models for neurosurgical training and preoperative planning. An immersive virtual environment offers excellent resolution and ability to zoom, potentiating it as an untapped educational tool.

Peritoneum as an origin of epilepsy from the viewpoint of Avicenna

There are studies that show that the concepts of epilepsy have been rooted in Persian medicine; Avicenna "Ibn-e-Sina"-one of the great Persian physicians in the Islamic golden age (9th-12th century AD)-has considered some types of epilepsy with the association of the stomach, the spleen, the "Maraqq," and the whole body which has not been reviewed properly. These organs influence on the brain and can cause epilepsy. This article presents concept of Maraqq-related epilepsy; according to Avicenna's view, "Maraqq" is a membranous structure which is located in the abdomen (equivalent of parietal peritoneum in current nomenclature). We discuss his viewpoint about the diagnosis and treatment of Maraqq-related epilepsy with focus on herbal remedies. The concept of a relationship between the "Maraqq" and the brain is well discussed in the old Persian medicine texts; however, it seems that further studies in this area are required to clarify Avicenna's view about the pathophysiological mechanisms, clinical manifestations, and treatment strategies.

Pharmacokinetic Behavior of Phenytoin in Head Trauma and Cerebrovascular Accident Patients in an Iranian Population

Objective:

Acute brain injury is one of the leading causes of morbidity and mortality worldwide. Phenytoin has been commonly used as an anticonvulsant agent for the treatment or prophylaxis of seizures following acute brain injury. After a severe head injury, several pharmacokinetic changes occur. The aim of this study is the comparative evaluation of phenytoin serum concentration in patients with traumatic and nontraumatic brain injury (TBI).

Methods:

This prospective observational study was performed on twenty adult brain injury patients who were admitted to an Intensive Care Unit and required phenytoin for the treatment or prophylaxis of postinjury seizures. For all the patients, phenytoin serum concentration was determined in three scheduled time points. Phenytoin serum concentration and pharmacokinetic parameters were compared between patients with TBI and cerebrovascular accident (CVA).

Findings:

The V_maxand K_mwere significantly higher in head trauma (HT) patients than the CVA group. The phenytoin concentration (C_p) and the C_p/dose ratio were significantly higher in the CVA group patients during the first sampling (P < 0.05). The Acute Physiology and Chronic Health Evaluation П (APACHE П) score was significantly lower than the baseline at the end of the study in each group of patients (P < 0.05). In addition, no significant correlation was observed between V_max, K_m, C_p, C_p/dose ratio, and APACHE II scores at the time of sampling.

Conclusion:

Due to significant differences in phenytoin plasma concentration and pharmacokinetic parameters between HT and CVA patients, close attention must be paid to the pharmacokinetic behavior of phenytoin in the efforts to improve the patient's outcome after a severe HT.

Smartphone as a Remote Touchpad to Facilitate Visualization of 3D Cerebral Angiograms during Aneurysm Surgery

Background During aneurysm surgery, neurosurgeons may need to look at the cerebral angiograms again to better orient themselves to the aneurysm and also the surrounding vascular anatomy. Simplification of the intraoperative imaging review and reduction of the time interval between the view under the microscope and the angiogram review can theoretically improve orientation. Objective To describe the use of a smartphone as a remote touchpad to simplify intraoperative visualization of three-dimensional (3D) cerebral angiograms and reduce the time interval between the view under the microscope and the angiogram review. Methods Anonymized 3D angiograms of the patients in Virtual Reality Modelling Language format are securely uploaded to sketchfab.com, accessible through smartphone Web browsers. A simple software has been developed and made available to facilitate the workflow. The smartphone is connected wirelessly to an external monitor using a Chromecast device and is used intraoperatively as a remote touchpad to view/rotate/zoom the 3D aneurysms angiograms on the external monitor. Results Implementation of the method is practical and helpful for the surgeon in certain cases. It also helps the operating staff, registrars, and students to orient themselves to the surgical anatomy. I present 10 of the uploaded angiograms published online. Conclusion The concept and method of using the smartphone as a remote touchpad to improve intraoperative visualization of 3D cerebral angiograms is described. The implementation is practical, using easily available hardware and software, in most neurosurgical centers worldwide. The method and concept have potential for further development.

App-assisted external ventricular drain insertion

The freehand technique for insertion of an external ventricular drain (EVD) is based on fixed anatomical landmarks and does not take individual variations into consideration. A patient-tailored approach based on augmented-reality techniques using devices such as smartphones can address this shortcoming.

The Sina neurosurgical assist (Sina) is an Android mobile device application (app) that was designed and developed to be used as a simple intraoperative neurosurgical planning aid. It overlaps the patient's images from previously performed CT or MRI studies on the image seen through the device camera. The device is held by an assistant who aligns the images and provides information about the relative position of the target and EVD to the surgeon who is performing EVD insertion. This app can be used to provide guidance and continuous monitoring during EVD placement.

The author describes the technique of Sina-assisted EVD insertion into the frontal horn of the lateral ventricle and reports on its clinical application in 5 cases as well as the results of ex vivo studies of ease of use and precision. The technique has potential for further development and use with other augmented-reality devices.

Cerebral metastasis from malignant pleural mesothelioma

Malignant mesothelioma is an uncommon, highly invasive tumor derived from the mesothelial cells of pleura or peritoneum characterized by poor outcome. Mesothelioma was thought to metastasize locally only via direct invasion and not have distant spread. Distant metastases were discovered mostly on post-mortem examination. The authors present a case of 62-year-old man with pleural mesothelioma and brain metastasis.

Surgical management of dural arteriovenous fistulas of the transverse-sigmoid sinus in 42 patients

A retrospective study was performed to analyse a prospectively collected database from a single surgeon (M.K.M.) of transverse-sigmoid sinus dural arteriovenous fistulas (DAVF) between 1991 and August 2011. During the study period, 144 patients with 160 DAVF were managed. Sixty-five of the DAVF were located in the transverse-sigmoid sinus and 42 were treated with surgery, or embolisation and surgery. All patients who underwent surgery were symptomatic with retrograde cortical venous drainage. The average follow-up period was 18months (range, 2-82months). Total elimination of the DAVF was achieved in all instances, including two patients (5%) who required further surgery after postoperative cerebral angiography showed that some venous drainage had persisted after the first operation. There was no new permanent neurological deficit or mortality attributable to surgery. Our institutional experience shows that in selected patients with transverse-sigmoid sinus DAVF, the involved sinus can be surgically resected with a high success rate and it is as safe as many alternative options. We suggest that this definitive treatment option should be offered to patients, and the outcome should be compared to other treatment modalities.

A simple technique for morphological measurement of cerebral arterial circle variations using public domain software (Osiris)

This article describes a straightforward method to measure the dimensions and identify morphological variations in the cerebral arterial circle using the general-purpose software program Osiris. This user-friendly and portable program displays, manipulates, and analyzes medical digital images, and it has the capability to determine morphometric properties of selected blood vessels (or other anatomical structures) in humans and animals. To ascertain morphometric variations in the cerebral arterial circle, 132 brains of recently deceased fetuses, infants, and adults were dissected. The dissection procedure was first digitized, and then the dimensions were measured with Osiris software. Measurements of each vessel's length and external diameters were used to identify and classify morphological variations in the cerebral arterial circle. The most commonly observed anatomical variations were uni- and bilateral hypoplasia of the posterior communicating artery. This study demonstrates that public domain software can be used to measure and classify cerebral arterial circle vessels. This method could be extended to examine other anatomical regions or to study other animals. Additionally, knowledge of variations within the circle could be applied clinically to enhance diagnostic and treatment specificity.

Trauma research in Iran: a report of the Sina Trauma Data Bank

BACKGROUND

Injuries are a major health problem in developing countries. Recently, the occurrence of injuries and those related to mortality have increased dramatically in Iran. We have conducted this study to report domestic research publications in the field of trauma from 2000 to 2006 in Iran.

METHODS

The contents of 128 biomedical journals were analyzed. Sina Trauma Data Bank (STDB) was selected as an indicator of trauma related articles that have been published in Iranian biomedical journals.

RESULTS

The number of trauma related articles in Iran increased during the seven year period (2000 - 2006), but the percentage of total publications was not significantly different. The mean number of authors per article was 2.7+1.3 (1 to 12) and all first authors were Iranian. Females constituted 15.4% (n=156) of first authors. Original articles were the most frequently published articles (n=871; 86.2%). Treatment of injuries and ensuing complications were the most common topics (42%) followed by war injuries (14.1%). Traffic accidents, as the leading cause of trauma death in Iran, were investigated in 27 (2.7%) articles.

CONCLUSION

According to our results, it seems that more attention from researchers and health-policy makers towards trauma is necessary in our country. In addition, publishing a journal with the main theme of injury and trauma could be an effective means for increasing the proportion of trauma related articles.

Outcomes and recurrence rates in chronic subdural haematoma

The object of this study was to determine the relationship between outcome (assessed by Glasgow Outcome Scale) and recurrence in chronic subdural haematoma (CSDH). Eighty-two consecutive patients who underwent surgery for CSDH were included in this study. The relationship between the following variables and CSDH recurrence was studied: sex; age; history of trauma; Glasgow Coma Scale (GCS) at the time of admission (stage 1: GCS>12, stage 2: GCS: 8 - 12, stage 3: GCS<8); interval between head injury (when a history of trauma was present) and surgery; presence of a midline shift on CT scans; presence of intracranial air 7 days after surgery; haematoma density; haematoma width; presence of brain atrophy; and Glasgow Outcome Scale (GOS, both quantitative and non-quantitative) at the time of discharge. Throughout the analysis, p<0.05 was considered statistically significant. The results showed lower GCS (p<0.001), higher GOS (p<0.001), presence of intracranial air 7 days after surgery (p=0.002), and a high density haematoma (p<0.001) were significantly associated with recurrence of CSDH. It was concluded that GOS is related with recurrence in CSDH.

Opium use in a rural area of the Islamic Republic of Iran

Because of its geographic proximity to the major drug production centres, there is easy access to narcotic drugs in the Islamic Republic of Iran despite efforts by governmental and nongovernmental organizations. Using a structured questionnaire as a basis for conversation, local health workers interviewed 310 residents of a rural area in Babol province about opium use. The self-reported rate of opium use, adjusted due to a bias in the sex ratio of the sample, was 8.9%. All the 42 opium users reported opium use at least 2-3 times per week in the previous 3 months. Opium was smoked by 95.2% and taken orally by 4.8%; there was no injecting use. There was no reported use of other substances, including alcohol. There was a statistically significant relationship between opium use and male sex, unemployment and cigarette smoking.

Prognostic factors in the persistence of posttraumatic epilepsy after penetrating head injuries sustained in war

Object

The goal of this paper was to investigate the long-term outcome and the possible prognostic factors that might have influenced the persistence of posttraumatic epilepsy after penetrating head injuries sustained during the Iraq–Iran war (1980–1988).

Methods

In this retrospective study, the authors evaluated 189 patients who sustained penetrating head injury and suffered posttraumatic epilepsy during the Iraq–Iran war (mean 18.6 ± 4.7 years after injury). The probabilities of persistent seizures (seizure occurrence in the past 2 years) in different periods after injury were estimated using the Kaplan-Meier method. The possible prognostic factors (patients and injury characteristics, clinical findings, and seizure characteristics) were studied using log-rank and Cox regression analysis.

Results

The probability of persistent seizures was 86.4% after 16 years and 74.7% after 21 years. In patients with < 3 pieces of shrapnel or no sphincter disturbances during seizure attacks, the probability of being seizure free after these 16 and 21 years was significantly higher.

Conclusions

Early seizures, prophylactic antiepileptics drugs, and surgical intervention did not significantly affect long-term outcome in regard to persistence of seizures.

Scapular fracture: lower severity and mortality

CONTEXT AND OBJECTIVE

The presence of scapular fracture is believed to be associated with high rates of other injuries and accompanying morbidities. The aim was to study injury patterns and their overall outcomes in patients with scapula fractures.

DESIGN AND SETTING

Cross-sectional study of trauma patients treated at six general hospitals in Tehran.

METHODS

One-year trauma records were obtained from six general hospitals Among these, forty-one had sustained a scapular fracture and were included in this study.

RESULTS

Scapular fracture occurred predominantly among 20 to 50-year-old patients (78%). Road traffic accidents (RTAs) were the main cause of injury (73.2%; 30/41). Pedestrians accounted for 46.7% (14/30) of the injuries due to RTAs. Falls were the next most common cause, accounting for seven cases (17.1%). Body fractures were the most common type of scapular fractures (80%). Eighteen patients (43.9%) had isolated scapular fractures. Limb fracture was the most common associated injury, detected in 18 cases (43.9%). Three patients (7.3%) had severe injuries (injury severity score, ISS >or= 16) which resulted in one death (2.4%). The majority of the patients were treated conservatively (87.8%).

CONCLUSIONS

Patients with scapula fractures have more severe underlying chest injuries and clavicle fractures. However, this did not correlate with higher rates of injury severity score, intensive care unit admission or mortality.

Ventriculoperitoneal shunt blockage due to spontaneous knot formation in the peritoneal catheter. Case report

The authors report the third case of ventriculoperitoneal shunt blockage due to spontaneous knot formation in the peritoneal catheter that had been placed in a 3.5-year-old boy 8 months earlier. On surgical exploration a double knot was found 10 cm from the distal end of the peritoneal catheter. Although the underlying mechanism remains unknown, the authors used the analogy of related physical studies and true knot formation in the umbilical cord and determined the possible causes as related to the catheter, volume and configuration of the abdomen, and kinetics of the catheter movements. If further study should reveal a significantly higher incidence of this complication, the authors suggest further in vitro studies, designed to investigate the optimal characteristics and safe range of length of peritoneal catheters in different situations.

The cerebral arterial circle (circulus arteriosus cerebri): an anatomical study in fetus and infant samples

BACKGROUND

Many studies have investigated the variations in the anatomy of each segment of the cerebral arterial circle while a few have addressed the variations of the cerebral arterial circle as a whole.

METHODS

Thirty brains of recently deceased Iranian infants and fetuses were dissected. The dissection process was filmed and digitized so as to be readily available for further studies. The variations of the circle as a whole and segmental variations were evaluated.

RESULTS

Variants with uni- and bilateral hypoplasia of posterior communicating arteries (PcoAs) were the most common in our study, similar to previous works. No aplasia of the precommunicating part of the anterior cerebral artery (A1), the precommunicating part of the posterior cerebral artery (P1) and anterior communicating artery was seen. Hypoplasia of the right and left PcoA was observed in 8 and 5 cases, respectively. Aplasia of the right PcoA was found in 16.6% and of the left PcoA in 3.3%.

CONCLUSION

In this study, we confirmed the previously described finding that the symmetrical, circular configuration of the circulus arteriosus cerebri is present in only about 42.1%. The main differences between the fetal and adult disposition are the diameter of the PcoA and the circular part of the posterior cerebral artery. According to previous studies, the fetal brain older than 4 months has anatomical characteristics very similar to the adult's circle; our finding was mostly similar to adult samples as most samples were from infants, not fetuses.

The relationship between Glasgow coma/outcome scores and abnormal CT scan findings in chronic subdural hematoma

OBJECTIVES

Chronic subdural hematoma (CSDH) is one of the most frequent types of intracranial hemorrhage. We evaluated the independent association between abnormal CT findings in CSDH and both Glasgow coma score (GCS) on admission as a measure of consciousness and Glasgow outcome score (GOS) at discharge as a measure of outcome.

PATIENTS AND METHODS

One hundred and sixteen consecutive patients with CSDH were studied. The variables considered were brain atrophy, hydrocephalus, hematoma location, midline shift, and hematoma density. After univariate analysis and evaluation of the role of age as a confounder in bivariate analysis, variables that had significant association with Glasgow scores were included in the final multivariate model.

RESULTS

Brain atrophy was the only variable with significant independent association (p<0.001; OR=77.214; 95% CI=8.336-715.212) with unfavorable outcome as defined by GOS. On the other hand, hydrocephalus (p=0.042; OR=6.503; 95% CI=1.072-39.449) and higher hematoma densities (p=0.027; OR=2.597; 95% CI=1.116-6.024) independently and significantly increased the risk of severe consciousness impairment when the group with GCS>12 was considered as the reference category.

CONCLUSION

Brain atrophy independently increases the risk of unfavorable outcome after CSDH. Hydrocephalus and higher hematoma densities independently increase the risk of severe consciousness impairment after CSDH.

The use of head CT scanning in mild head injury

OBJECTIVE

To determine the number of brain CT scans carried out in patients with mild head injury (MHI) during 13 months of trauma registry, and to investigate means of reducing the rate of unnecessary scans.

METHODS

During a trauma registry (from August 23, 1999 to September 21, 2000) in 6 general Hospitals (Imam Hussein, Moayer, Sina, Hafteteer, Imam Khomeini and Shariatti) in Tehran, Iran, 1209 cases with Glasgow Coma Scale (GCS) score >13 underwent brain CT scan. To be included in the study, patients must have sustained their injury within one week prior to presentation to Emergency Rooms, and were hospitalized for more than 24 hours. The attending physicians formally reported all brain CT scan findings.

RESULTS

For 1209 patients, there were the following characteristics: mean age was 29.4 years; the main cause of injury was traffic accidents (60.1%), followed by falls (28.5%), fights (7.2%), and other reasons (4.2%). Seventy-seven cases (6.4%) had a GCS score of 13, 212 (17.5%) had a score of 14, and 920 (76%) had a score of 15. A total of 481 abnormalities on CT scan were reported for 405 patients (33.5%) with positive report of brain CT scan, while 804 cases (66.5%) did not report abnormalities. The most common intracranial lesion was epidural hemorrhage with 146 cases (30.3%). The rate of negative reporting of brain CT scan in patients who had GCS score of 15 was 72.2%.

CONCLUSION

Patients who have GCS score of 13 or 14 on admission should be considered to have a moderate rather than a mild head injury. For reduction of unnecessary brain CT scan performance in MHI patients, we must define the appropriate criteria.

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.

Bilateral retro-auricular dermal sinus tracts with intradural extension. Case report

The authors describe a previously unreported malformation involving paired, bilaterally symmetrical dermal sinus tracts in the retro-auricular area, both of which passed through the asterion and posterior fossa dura mater to end intracranially. Cranial dermal sinus tracts are congenital lesions that virtually always originate from the midline scalp posteriorly at the external occipital protuberance, anteriorly at the nasion or along the nasal dorsum, or in the posterior parietal midline. A lateral origin is extremely rare, and intracranial extension of a lateral dermal sinus tract has not been reported previously. The authors propose an embryological mechanism to explain the origin of this rare malformation and discuss its management.

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.