Is Asterion a Reliable Surgical Landmark for the Transverse and Sigmoid Sinus Junction in Indian Skulls?

Background: Asterion is the junction of lambdoid, parietomastoid, and occipitomastoid sutures. In traditional anatomy teaching, it is believed that asterion sits over the transverse-sigmoid sinus junction (TSSJ). It is a significant surgical landmark for the placement of a burr hole in the retrosigmoid approach. Objective: The purpose of this study was to evaluate the asterion's accuracy as a TSSJ-specific external surgical landmark in the Indian population. Materials and Methods: 16 human dried skulls were obtained from the Department of Anatomy, AIIMS, New Delhi. The point of TSSJ was taken between the two lips and just posterior to the entry of the superior petrosal sinus. Asterion internally was localized with the help of a geometrical divider. The x- horizontal/ anterior and y- vertically superior (+)/ inferior (-) distances were measured from asterion (internally) to the TSSJ by a digital vernier caliper. Results: The mean horizontal distance (x) of the left side asterion & TSSJ was 10.3±1.0mm whereas the vertical distance (y) ranged between +2 to -4.3 mm. The mean horizontal distance (x) of the right side asterion & TSSJ was 13.5±1.4mm whereas the vertical distance (y) ranged between +3 to -4.2 mm. Conclusion: Asterion is not a reliable landmark for TSSJ in Indian skulls. The TSSJ with respect to asterion was found on average 10mm and 13.5mm anterior on the left and right side respectively, and mostly inferior (average 4.2mm) in 75% of the skulls. The TSSJ was closer to the asterion on the left side in comparison with the right side. However, further studies with a larger sample size will be needed to evaluate the population-specific relation of asterion with the TSSJ.

O-Arm Assisted Anterior Odontoid Screw Fixation in Type II and Rostral Type III Odontoid Fractures: Single Center Surgical Series of 50 Patients.

Background: Accuracy of screw placement is one of the important factors necessary for adequate union in odontoid fractures with malposition rates as high as 27.2% with standard techniques. Objective: To evaluate efficacy of intraoperative O-arm assistance in improving accuracy of anterior odontoid screw placement and clinco-radiological outcome in type II and III odontoid fractures. Material and Methods: In this retrospective study, surgery consisted of anterior odontoid screw fixation under intraoperative O-arm assistance over 5 years. Demographical, clinical, radiological, operative details and postoperative events were retrieved from hospital database and evaluated for fusion and surgical outcome. Results: 50 patients (Mean age 34.6 years, SD 14.10, range: 7-70 years; 44 males and 6 females) with Type II and Type III odontoid fracture underwent O-arm assisted anterior screw placement. The mean interval between injury and surgery was 12 days (range 1-65 days). Mean operating time was 132.2 min ± SD 33.56 with average blood loss of 93 ml. ±SD 61.46. With our technique, accurate screw placement was achieved in 100% patients. At the mean follow-up of 26.4 month (SD13.75), overall acceptable fusion rate was 97.8% with non-union in 2.2% patients. Morbidity occurred in two patients; one patient developed fixation failure while other patient had nonunion which was managed with posterior C1-C2 arthrodesis. We had surgical mortality in one patient due to SAH. So overall our procedure was successful in 94% patients and among patients whose follow-up was available, acceptable fusion rates of 97.8% were achieved. Conclusion: We conclude that use of intraoperative three-dimensional imaging using O-arm for anterior odontoid screw fixation improves accuracy and leads to improved radiological and clinical outcomes. It further enables us to extend the indications of odontoid screw fixation to selected complex Type II and rostral Type III odontoid fractures.

Efficacy of antimicrobial medicated ventricular catheters: a network meta-analysis with trial sequential analysis.

There is paucity of evidence regarding relative performance of antibiotic-medicated (AM), silver-medicated (SM) and non-medicated (NM) ventricular catheters in controlling infection rate. We aim to quantitatively synthesize the current evidence after addition of the three-armed British Antibiotic and Silver Impregnated Catheters for ventriculoperitoneal Shunts (BASICS) trial, understand the need for further evidence using trial sequential analysis (TSA) and incorporate the indirect evidence using network meta-analysis (NMA). Randomized controlled trials (RCTs) comparing AM, SM and NM ventriculoperitoneal shunt (VPS) or external ventricular drain (EVD) were included. Antibiotic-medicated VPS show a significantly lower infection rate as compared to non-medicated VPS (RR 0.44; 95% CI: 0.27-0.73; p = 0.001), however, TSA reveals need for further evidence. SM including both EVD as well as VPS were found to be inferior to AM while no significant difference was found in comparison to the NM catheters. In NMA for VPS, the AM were found to be significantly better than SM (RR 0.41, 95% CI: 0.22-0.75) as well as NM (RR 0.42; 95% CI: 0.25-0.71) with a SUCRA of 99.8% and a mean rank of 1. However, antibiotic medicated shunts did not show a statistically significant association with reoperation rate (RR 0.99; 95% CI:0.81-1.20; p = 0.9) with no further need for evidence as per TSA.

Anterior Odontoid Screw Fixation for Pediatric and Adolescent Odontoid Fractures: Single-Center Experience Over a Decade.

OBJECTIVE: Management of pediatric odontoid fractures is tricky and controversial. This study will enrich world literature with intricacies of anterior odontoid screw (OS) fixation in the pediatric population learned over the last decade. METHODS: In this retrospective study, all patients with pediatric odontoid fracture who underwent anterior odontoid screw fixation from January 2010 to December 2019 were included and evaluated for surgical outcome. RESULTS: Thirteen patients were included in this study (mean age, 15 years; range, 6-18 years; male/female, 11:2; type II, 10; type IIA, 1; type III, 2). Common causes of injury were motor vehicle accidents (61.5%) followed by fall from height (38.5%) and all were acute fractures (2-30 days). Five patients had neurologic deficits. Accurate placement of screw was achieved in 92.3% of patients, including all 9 patients who used intraoperative O-arm. K wire migration during bicortical drilling resulted in neurovascular injury, with 1 mortality (7.7%). The remaining 12 patients were available for follow-up (mean, 36 months; range, 20-72 months) and all had preservation of neck movements. Successful OS fixation was achieved in 84.6% of patients, including 1 patient (7.7%) who had a fibrous union. One patient (8.3%) had nonunion because of migration of the screw head in the C2 body. CONCLUSIONS: Anterior odontoid screw fixation in the pediatric population provides good functional outcomes with instant fixation by direct osteosynthesis. However, the surgeon should be meticulous in the surgical approach and should achieve a lag effect. The surgeon should stop after engaging the outer cortex of the odontoid peg with K wire to avoid cranial migration. Intraoperative O-arm guidance is useful.

Increased levels of α4-containing GABAA receptors in focal cortical dysplasia: A possible cause of benzodiazepine resistance.

Benzodiazepines are the first choice of anti-epileptic drugs used to treat seizures. However, it has been seen that their efficacy decreases with time leading to drug insensitivity, plausibly caused by an alteration in the expression of the benzodiazepine biding site on GABAA receptors. This study was designed to investigate if the differential expression of GABAA receptor subunits α1/α4/γ2/δ across the postsynaptic sites could contribute to benzodiazepine resistance in patients with focal cortical dysplasia (FCD), the most common cause of drug resistant epilepsy in pediatric population. Differential gene and cellular expression of GABAA receptor subunits α1, α4, γ2 and δ were evaluated and validated using qPCR and immunohistochemistry. Whole cell patch clamp studies were performed on pyramidal neurons of resected cortical FCD samples to measure the spontaneous GABAA receptor activity. Upregulation of α4-and γ2-subunits containing GABAA receptors were observed at both mRNA and protein level. α1-and δ-subunits containing GABAA receptors did not show any significant changes. Flumazenil treatment did not affect the kinetics of GABAergic events in FCD; however, it significantly reduced the frequency and amplitude of spontaneous GABAergic activity in non-seizure control samples. Our results demonstrate the enhanced expression of α4-containing GABAA receptors and GABAergic activity in pyramidal neurons which in turn may contribute to benzodiazepine resistance in FCD patients.

Transpedicular Approach for Corpectomy and Circumferential Arthrodesis in Traumatic Lumbar Vertebral Body Burst Fractures: A Retrospective Analysis of Outcome in 35 Patients.

BACKGROUND: Traumatic vertebral burst fractures can be surgically approached via different approaches (anterior/posterior, or combined). Transpedicular approach (TA) is a posterior approach that has the advantage of achieving circumferential arthrodesis via single posterior only approach. The purpose of this study was to analyze our experience with TA in management of traumatic lumbar burst fractures (TLBFs). MATERIALS AND METHODS: All consecutive patients with TLBFs managed with TA over 5 years duration were included in this retrospective study. Correction of kyphotic deformity and change in neurological status were analyzed to assess outcome. Cobb's angle and ASIA grade were used for this purpose. RESULTS: There were 21 males and 14 females. Eight patients had complete (ASIA-A) while 22 had incomplete injury. All patients had a TLICS score >=4. The mean preoperative Cobb's angle was 13.97° that improved to -3.57° postoperatively (mean kyphosis correction-17.54°). None of the patients developed iatrogenic nerve root injury. There was no perioperative mortality. The mean cobb's angle was 1.23° at 39.1 months follow-up. Eight patients developed cage subsidence but none required revision surgery. Postoperatively, 27 (77.1%) patients showed neurological improvement and none deteriorated. The median ASIA score improved from 3 to 5. A fusion rate of 91.4% was observed at last follow-up. CONCLUSIONS: The advantages of TA including sense of familiarity with posterior approach amongst spine surgeons, lesser approach-related morbidity, and results comparable to anterior/combined approaches, make TA an attractive option for managing TLBFs. Although technically difficult, it can be successfully used for circumferential arthrodesis in lumbar region without sacrificing nerve roots.

Perioperative Management of a Child with Klippel-Feil Syndrome and Severe Uncorrected Aortic Stenosis Undergoing Cervical Spine Stabilization.

Severe stenotic aortic valve poses serious anesthetic challenges because of the fixed cardiac output and complex hemodynamics. The challenges magnify in the presence of a difficult airway which not only puts the airway at risk but also disturbs the hemodynamics, which can negatively impact the patient outcome. Moreover, prone positioning, intraoperative hemodynamics, recovery, and extubation are equally challenging for management. This case report highlights the perioperative management of a child with severe uncorrected aortic stenosis and Klippel-Feil syndrome posted for cervical spinal stabilization under anesthesia.

Meta-Analysis with Trial Sequential Analysis on the Efficacy and Safety of Erythropoietin in Traumatic Brain Injury: A New Paradigm.

OBJECTIVE: Erythropoietin (EPO) has been shown to be beneficial in traumatic brain injury (TBI). We have attempted to quantitatively synthesize the findings of current randomized controlled trials (RCTs) in this meta-analysis and analyzed the need for further trials using trial sequential analysis (TSA). METHODS: A systematic search was performed in PubMed, the Cochrane Library databases, and Google Scholar for RCTs until December 2019 evaluating the role of EPO in patients with TBI. Seven RCTs were finally included in the quantitative analysis. TSA was done to evaluate the need for further studies. RESULTS: The pooled estimate demonstrated that EPO significantly reduced mortality at 6 months (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.43-0.97; P = 0.04) but not in hospital mortality (OR, 0.84; 95% CI, 0.31-2.32; P = 0.74). There was no significant difference in the rate of favorable outcomes with EPO (OR, 1.58; 95% CI, 0.84-2.99; P = 0.16). The rate of deep vein thrombosis (RD, -0.02; 95% CI, -0.06 to 0.02; P =0.41) was also not found to be significantly different in the 2 groups. TSA showed that the accrued information is insufficient to make any definitive conclusions. CONCLUSIONS: EPO seems to be beneficial in terms of reducing 6-month mortality, however, its effect on in-hospital mortality, neurologic outcomes, and risk of deep vein thrombosis fails to reach statistical significance. TSA suggests a need for large trials to evaluate the role of EPO in patients with TBI in a more systematic way.

Contralateral Ventriculostomy for Intraoperative Brain Relaxation in Supratentorial Brain Tumors.

BACKGROUND: CSF drainage from the ventricular system is a popular and effective technique for intraoperative brain relaxation as it reduces ICP, enlarges extra-axial operative corridors, and slackens the brain increasing its tolerance for surgical manipulation. However, sometimes when the ventricular chambers distant from the site of pathology are tapped, there is a risk of neurological worsening due to paradoxical herniation of the brain, exemplified by the phenomenon of upward transtentorial herniation observed in posterior fossa tumors, consequent to a supratentorial ventriculostomy. Expectation of an analogous phenomenon precludes contralateral ventricular drainage in supratentorial brain tumors producing midline shift, subfalcine herniation, and resultant distension of the opposite lateral ventricles. OBJECTIVE: Demonstrating the safety and efficacy of intraoperative contralateral ventricular drainage in the presence of sub-falcine herniation. METHODS: Clinical and imaging information were retrospectively collected for four cases in which this technique was adopted. RESULTS: The first case was a large clinoidal meningioma with a midline shift and contralateral ventriculomegaly. EVD from the dilated ventricle provided optimum brain conditions for safe resection of the tumor through an orbitopterional approach. The second case required a contralateral EVD to reduce ICP intraoperatively, for a recurrent anaplastic ependymoma with severe mass effect. It reduced the venous hypertension related to raised ICP minimizing the blood loss. Contralateral EVD was utilized to enlarge the working corridor for interhemispheric approach in two cases. CONCLUSION: Contralateral ventricular drainage is a safe, effective, and convenient operative step for reducing brain turgor in the presence of sub-falcine herniation produced by large supratentorial tumors.

Management of Cushing's Disease: Changing Trend from Microscopic to Endoscopic Surgery.

BACKGROUND: Cushing's disease (CD) is a spectrum of clinical manifestations due to adrenocorticotropic hormone-secreting pituitary adenoma. Transsphenoidal adenomectomy remains the standard treatment. There has been a paradigm shift from microscopic to endoscopic transsphenoidal surgery in recent years. However, the efficacy of endoscopic transsphenoidal surgery has not been established. Therefore, it is of interest to determine the superiority of endoscopic transsphenoidal surgery, if any, over microscopic surgery. OBJECTIVE: To assess the efficacy of endoscopic endonasal transsphenoidal surgery for the treatment of CD and to determine the factors affecting remission. METHODS: Patients undergoing surgery for CD from 2009 to 2017 were analyzed retrospectively. Transsphenoidal resection was the preferred treatment, with recent trends in favor of the endonasal endoscopic skull base approach. Postoperative cortisol level of <2 µg/dL was taken as remission and value between 2 and 5 µg/dL as possible remission. RESULTS: In total, 104 patients operated primarily for CD were included for analysis; 47 patients underwent microscopic surgery, 55 endoscopic surgery, and 2 were operated transcranially. Remission was achieved in 76.47% of patients. In univariate analysis, factors significantly associated with remission were 1) type of surgery (P = 0.01); remission in endoscopy surgery (88.23%) is better than microscopy (56.6%); 2) postoperative day 1 morning cortisol (P = 0.004); and 3) postoperative day 1 morning ACTH (P = 0.015). In multivariate analysis, only postoperative day 1 cortisol was found to be significant predictor of remission (P = 0.02). CONCLUSIONS: Postoperative plasma cortisol level is a strong independent predictor of remission. Remission provided by endoscopy is significantly better than the microscopic approach.

Incipient Transcalvarial Cerebral Herniation: Underrecognized Complication of Elective Craniotomy.

BACKGROUND: Herniation of the brain through an osseodural defect has been well described in small children as an uncommon occurrence after closed head injury. Pressure from the growing brain has been implicated in progressive enlargement and reshaping of the fracture line. An analogous phenomenon in adults has been observed in the described cases where neurosurgical intervention led to a persistent dural defect. Transcalvarial herniation of the brain through the dural defect resulted in characteristic neurologic and imaging findings producing symptoms disproportionately greater than expected from the extent of the affected brain, accompanied by enlargement of the underlying ventricle and elevation of the bone flap. Disruption of the axonal conduction due to distortion of the axons in the herniated brain is probably responsible for these observations. CASE DESCRIPTION: A series of 3 cases is described. In all cases, the dural reconstitution at the conclusion of surgery was incomplete. Brain herniation was evident in the postoperative scan. The transcalvarial herniation of the brain was precipitated by either a seizure and resultant brain swelling or persistently raised intracranial tension from a tumor residual. In 2 cases, surgical reexploration resulted in improvement in the neurologic symptoms. CONCLUSIONS: In symptomatic patients with transcalvarial herniation of the brain, identified on imaging, the neurologic syndrome is quite characteristic. Recognition of this condition and prompt treatment lead to lasting neurologic improvement.

Traumatic Posterior Fossa Extradural Hematoma: Experience at Level I Trauma Center.

INTRODUCTION: Posterior fossa extradural hematoma (PFEDH) is rare among the traumatic brain injury and represent about 4-7% cases of all EDHs. This rare condition is rapidly fatal unless identified and intervened timely. Because of limited space in posterior fossa, comparatively small volume can cause clinical deterioration. Early diagnosis by cranial computed tomography and emergent evacuation is vital for a good outcome. MATERIALS AND METHODS: This study was conducted at Level I trauma center at All India Institute of Medical Sciences, New Delhi, India. Hospital medical records were reviewed from September 2007 to June 2015. There were 856 cases of acute EDHs and of these 69 cases had PFEDHs. Records of patients with PFEDHs were reviewed for the mode of injury, Glasgow Coma Scale (GCS) at admission, imaging, type of intervention, outcome, and follow-up. GCS was assessed at 6 months and 12 months follow-up. Pertinent literature is reviewed. RESULTS: Of these 69 patients, 51 were males and 18 females. The mean age of patients was 28.6 years (range 4-43 years). Forty-three patients had GCS 15 at admission, and only 4 of them had admission GCS <8. Mean EDH volume was 29.2 ml. Sixty-six patients were operated, three managed conservatively. Sixty-seven patients were discharged, of which, 56 (81.1%) had GCS 15. Two patients died. Most common associated injuries were long bone fractures (18, 26.1%) followed by blunt injury thorax (11, 15.9%). Mean follow-up duration was 69.2 months (range 6-94 months). At 6 months follow-up, 61 (88.4%) patients had good recovery (Glasgow Outcome Score [GOS] 5) and at 12 months, 62 (89.8%) had GOS 5. CONCLUSION: PFEDH are rare. They are usually associated with occipital bone fractures and may also have a supratentorial hematoma. It may be rapidly fatal due to the expansion of hematoma and compromise of the posterior cranial fossa space leading to brainstem compression, tonsillar herniation, and/or obstructive hydrocephalus. Early diagnosis and emergent evacuation lead to good outcome.

Cavernous malformations of central nervous system in pediatric patients: our single-centered experience in 50 patients and review of literature.

PURPOSE: Cavernous malformations (CMs) are rare developmental cerebrovascular malformations of the central nervous system with a childhood prevalence of 0.3 to 0.53%. Our purpose was to assess the clinical features and microsurgical outcome in pediatric central nervous system (CNS) CMs. MATERIAL AND METHODS: We retrospectively enrolled all the CM patients admitted to our institute from 1 January 2001 to 31 December 2014. Data was analyzed for their clinical features and surgical outcome. RESULTS: A total of 50 patients with CMs (30 supratentorial, 14 infratentorial, and 6 spinal) with a mean age of 14 years (3-18 years, SD ±4.64) were enrolled into the study. Most of these patients (78%) were male. Size varied from 1.2 to 6 cm. Three patients had multiple CMs. Symptoms of CMs were site specific. Seizure was the most common symptom (63.3%) of CMs at supratentorial location followed by headache (46%) and neurodeficiency (26%), while all brainstem and spinal CMs presented with neurodeficiencies. History of clinically significant acute hemorrhage was present in 19.2% of supratentorial (ST) superficial CMs, 50% of ST deep CMs, 25% of cerebellar CMs, 44.4% of brainstem CMs, and 50% of spinal CMs. Forty-five CMs in 44 patients were surgically excised. Their follow-up ranged from 6 to 162 months (mean 47.2 months, SD ±53). All supratentorial CM patients showed improvement in their symptoms. Patients with preoperative seizure showed good seizure control with Engel scale I in 16 (94.1%) and Engel scale II in 1 (5.9%). In infratentorial (IT) and spinal CM patients, 92.3 and 66.7% had improvement in their neurodeficiencies, respectively. There was no mortality in our series. CONCLUSION: Microsurgical excision of CNS CM results in excellent neurological outcome in pediatric patients. Early intervention is necessary in spinal CMs for better outcome.

Internal Carotid Artery Aneurysms Presenting with Epistaxis - Our Experience and Review of Literature.

AIM: Intracranial internal carotid artery aneurysms are an extremely rare cause of spontaneous epistaxis, with a few documented cases. The management of such cases is challenging due to the relative anatomical inaccessibility of the bleeding point. The aim of the present study was to acquaint the readers with this rare type of aneurysm presenting with epistaxis and to report our experience of treating cases of severe epistaxis due to internal carotid artery (ICA) aneurysms. MATERIAL AND METHODS: Data of 4 patients with ICA aneurysms presenting with epistaxis from June 2011 to July 2013 was retrospectively reviewed. RESULTS: The age of patients ranged from 16 to 62 years. Duration of epistaxis ranged from 3 months to 3 years. Two patients had severe epistaxis following transnasal biopsy. Two patients had a history of trauma. Two patients developed hemodynamically instability. All the patients were managed with trapping of the aneurysm. Complete exclusion of aneurysm from circulation was achieved in all the patients. CONCLUSION: ICA aneurysms can rarely present as life-endangering epistaxis. In patients presenting with a history of craniocerebral trauma, traumatic pseudoaneurysm must be considered as a differential diagnosis. Trapping of the aneurysm is a good option if there is good cross circulation.