Bal Krishna Ojha

Surgical outcome of tuberculous meningitis hydrocephalus treated by endoscopic third ventriculostomy: prognostic factors and postoperative neuroimaging for functional assessment of ventriculostomy

OBJECT Endoscopic third ventriculostomy (ETV) is increasingly being used as an alternative treatment for post-tuberculous meningitis (TBM) hydrocephalus. The aim of this study was to affirm the role of ETV in patients with TBM hydrocephalus and also to study the usefulness of cine phase-contrast MR imaging (cine MR imaging) for functional assessment of the ETV stoma. An additional goal was to identify factors that influence the outcome of ETV, so as to define patients with TBM hydrocephalus in whom ETV is warranted. METHODS Twenty-six patients with TBM hydrocephalus treated with ETV were evaluated clinically and with cine MR imaging postoperatively. The duration of follow-up ranged from 1 to 15 months. The authors evaluated flow void changes in the floor of the third ventricle and analyzed parameters from the preoperative data, which they then used as a basis for comparison between endoscopically successful and endoscopically unsuccessful cases. RESULTS The overall success rate of ETV in TBM hydrocephalus was 73.1% in this case series. Cine MR imaging showed a sensitivity of 94.73% and specificity of 71.42% for the functional assessment of third ventriculostomy in these patients, with the efficacy being maintained during follow-up. The outcome of ETV showed a statistically significant correlation with the stage of illness and presence of intraoperative cisternal exudates. Although duration of symptoms and duration of preoperative antituberculous therapy (ATT) appeared to influence the outcome, their correlation with outcome was not statistically significant. CONCLUSIONS Endoscopic third ventriculostomy should be considered as the first surgical option for CSF diversion (that is, before shunt surgery) in patients with TBM hydrocephalus. Cine MR imaging is a highly effective noninvasive tool for the postoperative functional assessment of stomata. Patients who presented with a history of longer duration and those who were administered preoperative ATT for a longer period had a better outcome of endoscopic treatment. Outcome was poorer in patients who presented with higher stages of illness and in those in whom cisternal exudates were observed intraoperatively.

Comparative evaluation of 3-dimensional pseudocontinuous arterial spin labeling with dynamic contrast-enhanced perfusion magnetic resonance imaging in grading of human glioma.

Introduction The study was performed to compare dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) with 3-dimensional (3D) pseudocontinuous arterial spin labeling (PCASL) MRI in gliomas with an aim to see whether arterial spin labeling (ASL)–derived cerebral blood flow (CBF) values can be used as an alternative to DCE-MRI for its grading. Materials and Methods Sixty-four patients with glioma (37 male; mean age, 43 years; 38 high grade and 26 low grade) underwent 3D-PCASL and DCE-MRI. The DCE indices (relative cerebral blood volume, rCBV; relative CBF, rCBF; permeability, ktrans and kep; and leakage, ve) and ASL (absolute and rCBF) values were quantified from the tumors. Student independent t test was used to compare ASL and DCE-MRI indices. Pearson correlation was used to see correlation between DCE- and ASL-derived CBF values in tumor and normal parenchyma. Results On Student t test, neither ASL-derived absolute CBF (P = 0.78) nor rCBF (P = 0.12) values were found to be significantly different in 2 groups, whereas DCE indices except ve were significantly higher in high-grade gliomas. Arterial spin labeling–derived rCBF values weakly correlated with DCE-derived rCBF values, whereas these did not show correlation in normal grey (P = 0.12, r = 0.2) and white (P = 0.26, r = 0.14) matter regions. Conclusions Three-dimensional pseudocontinuous arterial spin labeling does not appear to be a reliable technique in the current form and may not be a suitable replacement for DCE in grading of glioma.

T2*-weighted MR angiography substantially increases the detection of hemorrhage in the wall of brain abscess: implications in clinical interpretation

IntroductionThe purpose of the present study was to identify the true prevalence of hemorrhage in the abscess using T2*-weighted angiography (SWAN) imaging and to study its influence on diffusion tensor imaging (DTI) metrics.MethodsFifteen patients of brain abscess underwent conventional, SWAN, and DT imaging on a 3-T MRI followed by its confirmation with histology. DTI metrics were quantified by region-of-interest analysis on hemorrhagic and non-hemorrhagic regions of the abscess wall. Prussian blue staining was performed on excised abscess walls to confirm hemorrhage on histology.ResultsEleven of 15 patients showed evidence of hemorrhage on both Prussian blue staining as well as SWAN imaging. Fractional anisotropy (FA) and linear anisotropy (CL) values were significantly higher, while spherical anisotropy was significantly lower in hemorrhagic compared to non-hemorrhagic regions of the abscess wall.ConclusionHemorrhage in the abscess wall is a common feature and may not always indicate neoplasm. The presence of intracellular iron in addition to concentrically laid collagen fibers may have synergistic effect on FA and CL values in the abscess wall. Inclusion of SWAN to MRI protocol will define the true prevalence of hemorrhage in brain abscess.

Diffusion tensor tractography indices in patients with frontal lobe injury and its correlation with neuropsychological tests.

OBJECTIVES Diffusion tensor tractography (DTT) was performed to quantify diffuse axonal injury (DAI) in major white matter (WM) fiber bundles (FBs) of patients with frontal lobe injury and to correlate these changes with neuropsychological tests (NPT) at 6 month follow-up. PATIENTS AND METHODS DTT was performed in 21 patients with moderate traumatic brain injury (TBI) within week and after 6 month follow-up, and in controls. DTI indices were calculated from the entire FBs in patients as well as controls. Bonferroni multiple comparisons Post hoc test was performed for determining the changes in DTI indices. Paired t-test was performed between DTI indices at baseline and follow-up. Pearsons correlation was performed between NPT scores and DTI indices. RESULTS Significant changes in DTI indices were observed in some of the FBs as compared to controls which incompletely recovered at 6 month follow-up. DTI indices of different WM FBs correlated significantly with some of the NPT. CONCLUSION We conclude that DTT based quantification helps in assessment of DAI in patients with moderate frontal lobe injury. Some of the FBs recover partially at 6 month follow-up and correlate with NPT scores.

Dumbbell-Shaped Paraganglioma of the Cervical Spine in a Child

Paragangliomas are tumors arising from extra-adrenal paraganglia and account for 0.3% of all neoplasms. The carotid body and temporal bone are the most frequent sites of paraganglioma, though it has been reported to occur in almost every part of the body. Spinal paragangliomas are uncommon and mainly take the form of intradural compression of the cauda equina or thoracic cord. Extradural paragangliomas are still rare; only few cases involving the dorsolumbar spine have been reported. We are reporting an interesting case of a dumbbell-shaped primary extradural paraganglioma of the cervical spine in an 8-year-old boy that presented with progressively increasing spastic quadriparesis.

Multimodal approach for diagnosis of bacterial etiology in brain abscess

BACKGROUND AND PURPOSE Proton magnetic resonance spectroscopy (PMRS) has high sensitivity and specificity for the detection of pyogenic brain abscess and the categorization of bacteria. But the metabolite patterns failed to evaluate the etiology of disease when the culture results are sterile. The aim of the present study is to compare the multimodality techniques viz., conventional culture, MR spectroscopy and 16S rRNA PCR and sequencing for rapid diagnosis of etiology in brain abscess and evaluate the PMRS in culture sterile samples and also demonstrate the sensitivity and specificity of these techniques. METHODS Thirty five patients underwent MRI on a 3T MRI and in-vivo PMRS for the diagnosis and evaluation of various resonances of metabolites such as lipid (LIP), lactate (LAC), acetate (AC), amino acid (AC), succinate (SUC). Pus was collected for identification of etiologic agents by culture and molecular method. RESULTS In 35 samples, metabolite patterns were as follows: LIP/LAC/AA, n=17, LIP/LAC/AA/SUC with or without AC, n=17 and LIP/LAC/AA/AC, n=1. Culture showed bacterial growth in 22 samples (18 aerobic/facultative anaerobic, 9 anaerobic) whereas molecular method was detected 26 aerobic/facultative anaerobic, 13 anaerobic, 4 microaerophilic bacteria. Among the 13 sterile samples, molecular method detected 16 microorganisms along with 3 mixed infections and PMRS recognized metabolite patterns as LIP/LAC/AA, n= 5 and LIP/LAC/AA/SUC with or without AC, n=8. The sensitivity of in-vivo PMRS in sterile samples was 100% and 75%, and specificity was 75% and 100% for aerobic and anaerobic organisms respectively. CONCLUSION Based on metabolite resonances, PMRS can detect slow growing and fastidious organisms and classify them into aerobic and anaerobic bacteria which are difficult to culture by conventional method. It can categorize microorganisms even in culture sterile samples with rational sensitivity and specificity which may allow early choice of targeted therapy.

Isolated intramedullary spinal cord cysticercosis

Neurocysticercosis is a major cause of epilepsy in developing countries. Cysticercal involvement of the spinal cord is rare even in endemic areas and accounts for 0.7 to 5.85% of all cases. We present a 19-year-old man who presented with weakness of both lower limbs and urinary complaints in the form of straining of micturition with increased frequency, in whom preoperative MRI revealed a well-defined cystic lesion in dorso-lumber cord extending from D11 to L1 level, which on pathological examination was found to be intramedullary cysticercosis.

Intraoperative ventriculo-stomographic evaluation of endoscopic cerebrospinal fluid diversion and flow restoration procedures.

Purpose. This prospective study was designed for intra-operative demonstration of cerebrospinal fluid (CSF) flow in ventricles and cisternal spaces before and after neuroendoscopic procedure. The aim of this study was to evaluate site of obstruction of CSF flow and subsequent stomal or aqueductal patency after endoscopic third ventriculostomy (ETV) or aqueductoplasty in patients with hydrocephalus of diverse aetiology. Method. Seventeen patients with hydrocephalus due to diverse aetiology underwent ETV (n = 15) and aqueductoplasty (n = 2) or cysto-ventrticulostomy (n = 1) or transaqueductal removal of neurocysticercus cyst (NCC) (n = 1). Intra-operatively, radio-opaque contrast agent (iohexol) instillation into the third ventricle was used for qualitative evaluation of obstruction and post-procedure CSF flow across the stoma into cisternal spaces. Result: 11 male and 6 female patients ranging from 3 to 50 years of age were included in the study. Post-procedure intra-operative ventriculo-stomography (IOVSG) showed free flow of dye across the endoscopic stoma (n = 13) or aqueduct (n = 2) into cisternal spaces. Diagnosis of fourth ventricular NCC was made in one patient with panventriculomegaly. In two patients of tuberculous meningitis hydrocephalus, poor flow of contrast in the prepontine area and basal cisterns was seen on IOVSG. They were subjected to ventriculoperitoneal shunt insertion in the same sitting. Cine MRI confirmed the patency of stoma or aqueduct in follow-up period in all patients with successful endoscopic procedure. Conclusion. IOVSG is a simple and safe technique that helps in confirming the adequacy of endoscopic procedure during surgery and thereby facilitates intra-operative decision about further management.

CD24 and Nanog expression in Stem Cells in Glioblastoma: Correlation with Response to Chemoradiation and Overall Survival

Background and aim: Glioblastoma (GBM) is one of the most common and aggressive brain tumors with a median survival of 12-14 months. The aim of present study was to evaluate the gene expression profile of stem cell markers Nanog and CD24 in GBM and to determine its relationship to outcome in terms of treatment response and overall survival. Material and methods: This was a retrospective as well as retrospective study which included 51 histologically confirmed cases of GBM. Expression of CD24, and Nanog was evaluated by RT-PCR. Control tissue included debrided brain tissue from open head injury cases. All cases of GBM underwent total surgical resection and subsequently chemotherapy. Immediate treatment response was evaluated at 3 months using Response Evaluation Criteria In Solid Tumors (RECIST) guidelines and overall survival was measured at 36 months. Result: As compared to control gene, expression of CD24 and Nanog was seen to be unregulated to 24.5% and 31.7% respectively. However, the difference in mean expression of cases and controls was not statistically significant. Correlation between expressions of these two markers was also not statistically significant. On univariate cox regression analysis, cases with >2 fold expression of CD24 and Nanog had significantly poor survival as compared to those with <2 fold expression. On multivariate analysis > 2 fold CD24 expression had a statistically significant correlation with poor survival. Conclusion: An overexpression of CD24 by more than two fold was associated with poor overall survival in GBM. Poor survival may be related to increased “stemness” of tumour cells. Targeted therapy inclusive of drugs targeting stem cells directly or indirectly may be a promising therapeutic option.

Torticollis as a late complication of ventriculoperitoneal shunt surgery

The pathophysiological mechanisms related to aging of the material of a ventriculoperitoneal (VP) shunt and how mechanical stresses and mechanical traction applied to the VP shunt catheter contributed to the development of torticollis are discussed. We report a 14-year-old boy with torticollis developing as a late complication 12 years after placement of a left VP shunt for the treatment of aqueductal stenosis. The shunt tube and the surrounding fibrocalcified band were removed, and the patients torticollis resolved completely without recurrence. Biomechanical dysfunction of shunt material with resultant tethering at the most mobile part of the shunt tubing (neck) in a growing child can lead to the development of torticollis. To our knowledge this is the first report of this VP shunt complication.