Raghav Singla

Intracerebral hypoglycemia and its clinical relevance as a prognostic indicator in severe traumatic brain injury: A cerebral microdialysis study from India.

CONTEXT Traumatic brain injury (TBI) remains a major cause of morbidity and mortality worldwide. Largely, the prognosis is dependent on the nonmodifiable factors such as severity of the initial injury, Glasgow coma scale score, pupillary response, age, and presence of additional physiological derangements such as hypoxia or hypotension. However, secondary insults continue to take place after the initial injury and resuscitation. The study hypothesis in the present research article was that hypoglycemia is an independent outcome prognosticator in severe traumatic brain injury. The study aimed to assess the role of glucose monitoring in the brain parenchyma as an independent outcome prognosticator and also to study its association with plasma glucose levels. AIMS The aim of the study was to analyze the relationship of intracerebral glucose measured by intraparenchymal cerebral microdialysis (CMD), and also to study its relationship with blood glucose levels. We also evaluated the relationship of these values to the outcome of patients. SETTINGS AND DESIGN Prospective nonrandomized study conducted at a tertiary care trauma center in India. SUBJECTS AND METHODS Twenty-five patients with severe TBI, who underwent decompressive craniectomy, were prospectively monitored with CMD catheters. Twenty cases had unilateral catheters placed intraparenchymally (20 mm inside the brain parenchyma to accommodate 10 mm of the semipermeable catheter tip and another 10 mm of extra catheter length). Frontotemporal contusions were noted in 21 cases and an acute subdural hematoma (with/without associated contusions) were noted in 15 cases in the present series. Bilateral CMD catheters were placed during bifrontal decompressive craniectomies in five patients (two patients had peri-contusional catheters placement; these patients had bilateral frontal contusions); while, the remaining 3 patients had a contralateral catheter placement in the normal brain parenchyma [Table 1]. The position of the catheters was confirmed on postoperative computerized tomographic scan carried out in these subjects. However, bilateral catheter placement to compare the difference in cerebral biochemical values of glucose in the penumbric zone as well as the normal brain could not be done in all cases due to cost restraints. The relation between plasma glucose and CMD-measured interstitial brain glucose concentrations, as well as the temporal pattern of CMD glucose was studied for 3-5 days following a decompressive craniectomy using a CMD analyzer at the patients bedside at 1 hourly intervals. STATISTICAL ANALYSIS USED All data were tabulated in Microsoft Excel 2011 and analyzed using SPSS version 21. To calculate the correlation between plasma and CMD glucose, Pearsons correlation was used with a two-tailed test of significance. Students t-test was used to calculate the difference in means between the two groups. Significance was assumed at P ≤ 0.05. RESULTS Fifteen patients (60%) had a good outcome in terms of the Glasgow Outcome Scale (GOS) at 3 months while the rest (10 patients) had a poor GOS at 3 months. There was a significant difference in the incidence of hyperglycemia (random blood sugar >10 mmol/L) between the two groups (P < 0.0001). The difference between the two groups while comparing episodes of hypoglycemia was also significant (P = 0.0026). The good outcome group had fewer episodes of brain hypoglycemia during the presence of systemic hypoglycemia (P = 0.0026). Neither the mean blood glucose values nor the mean cerebral glucose values predicted the outcome at 3 months. CONCLUSIONS After decompressive craniectomy in severe TBI, there was a poor correlation between the plasma and CMD glucose concentration. A higher degree of variation was seen in the correlations for individual patients. Neither the mean blood glucose values nor the mean cerebral glucose values predicted the outcome at 3 months. The good outcome group had fewer episodes of both hyperglycemia and hypoglycemia.

Stereotactic radiosurgery in hemangioblastoma: Experience over 14 years.

Background: Although gamma knife has been advocated for hemangioblastomas, it is not used widely by neurosurgeons. Objective: We review our experience over 14 years in an attempt to define the role of stereotactic radiosurgery (SRS) in the management of hemangioblastomas. Patients and Methods: A retrospective study was conducted on all patients of hemangioblastoma who underwent SRS at our institute over a period of 14 years (1998–2011). Gamma knife plans, clinical history, and radiology were reviewed for all patients. Results: A total of 2767 patients underwent gamma knife during the study period. Of these, 10 (0.36%) patients were treated for 24 hemangioblastomas. Eight patients (80%) had von Hippel-Lindau disease while two had sporadic hemangioblastomas. The median peripheral dose (50% isodose) delivered to the tumors was 29.9 Gy. Clinical and radiological follow-up data were available for eight patients. Of these, two were re-operated for persisting cerebellar symptoms. The remaining six patients were recurrence-free at a mean follow-up of 48 months (range 19–108 months). One patient had an increase in cyst volume along with a decrease in the size of the mural nodule. Conclusions: SRS should be the first option for asymptomatic hemangioblastomas. Despite the obvious advantages, gamma knife is not widely used as an option for hemangioblastomas.

Detection of metabolic pattern following decompressive craniectomy in severe traumatic brain injury: A microdialysis study.

ABSTRACT Objective: The aim of the study was to detect mitochondrial dysfunction and ischaemia in severe traumatic brain injury and their relationship with outcome. Methods: Forty-one patients with severe traumatic brain injury (TBI) who underwent decompressive craniectomy were prospectively monitored with intracerebral microdialysis catheters (MD). Variables related to energy metabolism were studied using microdialysis. Results: Twentysix patients (63.4%) had a good outcome in terms of Glasgow outcome score (GOS) at 6 months while the rest (15 patients) had poor GOS at 6 months. Mitochondrial dysfunction was defined as Lactate Pyruvate ratio (LP ratio) > 25 and pyruvate <70 while ischaemia was defined as LP ratio > 25 and pyruvate >70. The poor outcome group showed significantly higher proportion of mitochondrial dysfunction 65.9% vs. 55.9% (p<0.001) and ischemia 13.9% vs. 7.2% (p<0.001) Conclusions: After decompressive craniectomy in severe TBI, patients with higher incidence of mitochondrial dysfunction and ischaemia were more likely to have poorer outcome with ischaemia having a more profound effect. Abbreviations: Traumatic brain injury (TBI), microdialysis (MD), lactate pyruvate ratio (LP ratio), Glasgow coma scale (GCS), Glasgow outcome scale (GOS), cerebral perfusion pressure (CPP), intracranial pressure (ICP), mitochondrial transition pore (MTP), non-contrast computed tomography (NCCT), traumatic axonal injury (TAI).

Massive life-threatening bifrontal epidural hematoma following placement of an external ventricular drain.

Dear Editor: External ventricular drainage is a life-saving neurosurgical procedure for CSF drainage in acute hydrocephalus. External ventricular drain (EVD) was first described by Dandy [2]. Most common EVD-related complications include infection and hemorrhage; however, literature on hemorrhagic complications of EVD remains sparse [4, 5]. Epidural hematoma is a rare complication and can occur at site of placement or at a distant site due to sudden decompression and dural stripping from the overlying bone. A 17-year-old male patient, a diagnosed case of thalamic glioma who received primary radiotherapy, presented to us with complaints of headache, repeated vomiting, and drowsiness. On examination, his GCS was E1VtM2. Non-contrast CT (NCCT) scan of the head showed right thalamic tumor with hydrocephalus (Fig. 1a). An EVD was inserted through right frontal twist drill craniostomy, at the Kocher’s point. CSF was under high pressure, and the EVD bag was kept at a level of patient’s tragus. The patient became conscious (GCS E4VtM6) after the placement of the EVD. After 4 h of EVD placement , pat ient again became unresponsive (GCS E1VtM1), and the EVD had drained 50 ml of CSF by then. NCCT scan of the head revealed massive bifrontal epidural hematoma (EDH) and the EVD tip was in the frontal horn of the right lateral ventricle (Fig. 1b). A bicoronal scalp incision, bilateral frontal bone flap was elevated and EDH was evacuated. The superior sagittal sinus and the bifrontal dura were found stripped from the bone. Multiple central and peripheral dural hitches were applied and the bone flap was placed back. The patient regained consciousness after surgery and his sensorium improved following surgery to E4VtM6 with CT head showing complete evacuation of EDH (Fig. 1c). Eight hours after EDH evacuation, the patient again became E1VtM1. NCCT scan showed dilatation of ventricles, so a right parietal EVD was inserted. The patient again regained consciousness (GCS E4VtM6). The EVD was converted to a ventriculo-peritoneal shunt as a definitive measure of CSF diversion after 48 h (Fig. 2a, b). The patient was doing good at 3 months follow-up with a functioning shunt. External ventricular drainage is one of the life-saving procedures in neurosurgery, although tapping ventricle still can cause hemorrhagic complications due to injury to cortical vein or the subependymal vasculature. The reported hemorrhagic complications of an EVD include a parenchymal bleed, intraventricular bleed, and subdural or epidural hematomas [1, 3]. Intra-parenchymal and subdural hematomas are mostly due to direct trauma, whereas an EDH occurs as a result of direct trauma to the dural vessel, venous lacunae, and diploe or may be due to the sudden decompression of the ventricles, * Kanwaljeet Garg gargneuro@hotmail.com

Extensive long-segment cervicothoracic traumatic spinal epidural hematoma with avulsion of C7, C8, and T1 nerve roots

Traumatic spinal epidural hematoma (TSEH) is of rare clinical occurrence. We report a case of a young man with posttraumatic long-segment spinal epidural hematoma. Evacuation of the hematoma led to complete neurologic recovery in our patient. Our case highlights the importance of early diagnosis and prompt surgical intervention for the evacuation of hematoma in preservation or maximum recovery of neurologic function. Imaging findings, management options, and the relevant literature are reviewed.

Armored brain-massive bilateral calcified chronic subdural hematoma in a patient with ventriculoperotoneal shunt.

Khoshyomn 2002 M, 73 Multiple nodules of lateral, third, fourth ventricles Headache, nausea, vomiting Right shoulder with negative axillary node 36 No Neuroendoscopic biopsy of lateral ventricle lesions, radiotherapy, chemotherapy (methotrexate, cytosine arabinoside) Cipri 2009 M, 22 Septum pellucidum Intermittent headache, vomiting, disequilibrium Unknown Left inguinal, bilateral suprarenal, left bronchopulmonary parailar Neuroendoscopic biopsy, pellucidostomy, VP‐shunt, stereotactic radiosurgery, chemotherapy (TMZ, thalidomide) for systemic locations Present case F, 60 Left lateral ventricle Headache, vomiting, confusion Left knee 10 No Surgery, chemotherapy, radiotherapy 8 months, no recurrence

Craniovertebral junction evaluation by computed tomography in asymptomatic individuals in the Indian population

Background: The available literature on the anatomy and imaging of the craniovertebral junction (CVJ) focusses on the osteometric indices described for the detection of abnormal relationships between the components of CVJ. However, a knowledge of the normal osteometry of this region in the Indian population is critically important for the operating surgeon as it may influence the surgical technique as well as the choice, size and configurations of the implants. It is also important to determine whether critical differences exist between the osteometric data of Indians and the rest of the world for this part of the anatomy. Accordingly, the present study is an attempt to quantitate the osteometric indices for the anatomically normal CVJ in Indian subjects Materials and Methods: We retrospectively studied the imaging data of 49 consecutive adult patients (31 males, 18 females) who underwent a computed tomographic (CT) angiogram for suspected vascular conditions unrelated to the craniovertebral junction. Several parameters related to the atlanto-dental relationship, foramen magnum, atlas and axis vertebrae were recorded, including the dimensions of the commonly instrumented bony regions and also the indices related to the CVJ bony relationships. The data was also compared between the two genders, statistically through the Students t-test using the statistical program “R”. Results: No patient had an atlanto dens interval >2.5 mm. The mean distance of the odontoid tip from the McRae line in this series was 5.11 mm and no patient had the odontoid tip above the McRae line. Female subjects had significantly smaller diameters of C1 lateral masses and odontoid screw trajectory length when compared to males. Additionally, in the Indian population, the length range of odontoid screw trajectory and the thickness of the narrowest part of the C2 pedicles was smaller with respect to similar data from other geographical regions. However, the rest of the parameters resembled the data from studies conducted on populations with other ethnicities. Conclusion: The osteometric parameters of the CVJ in the Indian population are largely similar to those described globally. However, there are some important differences too which can influence the design of surgical implants suited to the Indian population.

Is decision-making easier post RESCUE ICP trial?

Dear editor, We studied with keen interest the article by Wettervik et al. regarding their experience of the role of decompressive craniectomy in patients with traumatic brain injury (TBI) as a primary or a stepwise procedure [4]. It is commendable that in this study, the authors have attempted to evaluate the role of decompressive craniectomy with a protocol that resembles the realworld scenario. The authors have correctly pointed out the artificiality of the decision-making process used in the only two large randomized controlled trials (RCTs), i.e., DECRA trial and RESCUE ICP [2, 3]. The findings of these RCTs have been a reason for major controversy since their publication. While DECRA included only bifrontal craniectomies done as an early intervention as a stage 2 treatment, RESCUE ICP evaluated unilateral decompressive craniectomies as well and only as the last tier treatment. However, there was a high crossover rate of 37.2% from medical to decompressive craniectomy group in the RESCUE ICP trial. The two RCTs have brought forth contrasting conclusions as well. While the DECRA trial shows that decompressive craniectomy results in a worse outcome at 6 months, RESCUE ICP shows the results to be similar between the two groups at 6 months and better outcome with decompressive craniectomy at 12 months. The differences in the inclusion criteria may be responsible for this difference in the findings. An important finding that was missing in both these trials was whether cranioplasty was done before the outcome assessment in some of the patients as cranioplasty has been shown to improve outcomes and thus may act as a confounding factor distorting the results [1]. By virtue of being randomized clinical trials, the selection criteria used seem to be unrelated to the routine clinical decision-making. By classifying the patients under no thiopental/no DC, no thiopental/No DC, thiopental/DC, and thiopental/No DC groups, the authors have attempted to capture the usual decision-making process in a clinical scenario. However, we would like to point out that since such classification was done nonrandomly on the basis of clinical features, it is capable of providing only descriptive results, as a control group with similar clinical features is not available. It is necessary to capture the merits of RCT and simulate clinical decision-making together; however, for that, a very large sample size with random allocation at each point of clinical decision-making will be needed. Also, there must be a clear protocol regarding the intensity and appropriateness of the medical treatment instituted. There must also be an attempt to evaluate decompressive craniectomy as the primary procedure which DECRA and RESCUE ICP have not discussed. Thus, we commend the effort of the authors to match the clinical scenario closely; however, since there is no clinically similar comparison group, this study just serves to describe authors’ experience. Due to the systematic nonrandom choice of treatment modality based on clinical status, it is not feasible to draw any conclusion regarding what might be the best management protocol in such patients. Thus, the need of the hour is to conduct RCTs with randomization at each objectively defined clinical decisionmaking point. Such a study might go a long way in putting forth guidelines to choose between the medical and surgical management in TBI according to the clinical scenario.

Letter to the Editor Regarding “Burr-Hole Drainage for Chronic Subdural Hematoma under Low-Dose Acetylsalicylic Acid: a Comparative Risk Analysis Study”

LETTER: This is in reference to the article “Burr-Hole Drainage for Chronic Subdural Hematoma Under Low-Dose Acetylsalicylic Acid: A Comparative Risk Analysis Study” by Kamenova et al. The authors compared the perioperative and postoperative bleeding and cardiovascular complication rates of patients undergoing burr-hole drainage for chronic subdural hematoma with and without discontinuation of low-dose acetylsalicylic acid (ASA). We would like to point out a few limitations of the study that we found on reading the article.

Letter to the Editor: Whole-brain CT perfusion and subarachnoid hemorrhage

TO THE EDITOR: We read with keen interest the article by Malinova et al.3 (Malinova V, Dolatowski K, Schramm P, et al: Early whole-brain CT perfusion for detection of patients at risk for delayed cerebral ischemia after subarachnoid hemorrhage. J Neurosurg 125:128–136, July 2016). The authors have described the utility of wholebrain CT perfusion (CTP) in predicting the occurrence of delayed ischemic neurological deficits and delayed cerebral infarction in patients with acute subarachnoid hemorrhage (aSAH). We commend the authors for their study, which sheds light on the enigma of delayed ischemic neurological deficits and delayed cerebral infarction following aSAH. In days to come, CTP may become part of routine study in patients with aSAH. Global cerebral edema (GCE) occurs after aSAH and is associated with functional and cognitive dysfunction. It usually occurs during the early phase (0–3 days) after aSAH. GCE is identified on CT scan by the following characteristics: 1) effacement of hemispheric sulci and basal cisterns, and 2) bilateral and extensive disruption of the cerebral gray-white matter junction at the level of the centrum semiovale.1,2 Patients with GCE have global perfusion deficits when compared to patients without GCE.1 This may affect early CT perfusion studies, and it probably was not considered by the authors. The number of such patients and the CTP findings in such patients should be addressed. Acute hydrocephalus after aSAH is known to be associated with reduced cerebral blood flow in the deep gray matter and periventricular white matter.4 This could also have affected the results, and interpretation of this study and the number of patients with hydrocephalus have not been mentioned. The authors’ study has very few patients with Fisher Grade 2 SAH and no patient with Fisher Grade 1 SAH, and it may be very difficult to generalize the result of this study to patients in these two groups. Thus, a study with a larger patient population and one composed of these two groups needs to be done, considering the radiation and the use of contrast agents for CTP studies. We once again commend the authors for this study and concur with them that a larger study group is required to compare various subgroups and to analyze the effects of CTP on outcome of patients with aSAH.