Manish Kolakshyapati

Multicentric Glioma Develops via a Mutant IDH1-Independent Pathway: Immunohistochemical Study of Multicentric Glioma

Multicentric gliomas are very rare. Due to differences in their tumor types they remain enigmatic. We focused on the pathogenesis of multicentric gliomas and compared their immunoprofile with that of solitary gliomas. This retrospective study included 6 males and 8 females with multicentric glioma (8 glioblastomas, 2 anaplastic astrocytomas, 4 diffuse astrocytomas). Their age ranged from 27 to 75 years and all were treated between 2004 and June 2015. The expression of mutant isocitrate dehydrogenase 1 (IDH1), α-thalassemia X-linked intellectual disability (ATRX), p53, phosphatase and tensin homolog (PTEN), and epidermal growth factor receptor (EGFR) was examined immunohistochemically; for 1p19q analysis we used fluorescence in situ hybridization (FISH). In all patients, immunohistochemical staining was negative for mutant IDH1 and cytoplasmic PTEN; only 1 patient (7.1%) manifested nuclear PTEN positivity. FISH for 1p19q codeletion was negative in all 9 examined samples; 5 of 14 specimens (35.7%) were p53-positive, 9 (64.3%) were EGFR-positive, and 4 (28.6%) were ATRX-negative. The MIB-1 labeling index was 0.9-15.6% for grades II and III, and ranged between 17.3 and 52.4% for glioblastoma. Our results suggest that the pathogenesis of multicentric gliomas is different from the mutant IDH1-R132H pathogenesis of lower-grade glioma and secondary glioblastomas. More studies are needed to confirm the molecular mechanisms underlying the pathogenesis of multicentric glioma.

Preoperative simulation of the running course of the abducens nerve in a large petroclival meningioma: a case report and literature review

One of the most important and useful pieces of information in the preoperative evaluation of a large petroclival meningioma is the running course of the abducens nerve. The abducens nerve is small and has a long intracranial course, making it prone to compression by the tumor at various anatomical points. In relatively large tumors, it is difficult to confirm the entire course of the abducens nerve, even by heavy T2-thin slice imaging. We report a case of successful preoperative estimation of the course of the abducens nerve that aided in its complete preservation during the resection of a large petroclival tumor.

Post-traumatic Unilateral Avulsion of the Abducens Nerve with Damage to Cranial Nerves VII and VIII: Case Report

Traumatic injuries of the abducens nerve as a consequence of facial and/or head trauma occur with or without associated cervical or skull base fracture. This is the first report on unilateral avulsion of the abducens nerve in a 29-year-old man with severe right facial trauma. In addition, he exhibited mild left facial palsy, and moderate left hearing disturbance. Magnetic resonance imaging (MRI) using fast imaging employing steady-state acquisition (FIESTA) revealed avulsion of left sixth cranial nerve. We recommend thin-slice MR examination in patients with abducens palsy after severe facial and/or head trauma.

Surgical resection of large encephalocele: a report of two cases and consideration of resectability based on developmental morphology

IntroductionThe first-line treatment of encephalocele is reduction of herniated structures. Large irreducible encephalocele entails resection of the lesion. In such case, it is essential to ascertain preoperatively if the herniated structure encloses critical venous drainage.Case reportsTwo cases of encephalocele presenting with large occipital mass underwent magnetic resonance (MR) imaging. In first case, the skin mass enclosed the broad space containing cerebrospinal fluid and a part of occipital lobe and cerebellum. The second case had occipital mass harboring a large portion of cerebrum enclosing dilated ventricular space. Both cases had common venous anomalies such as split superior sagittal sinus and high-positioned torcular herophili. They underwent resection of encephalocele without subsequent venous congestion. We could explain the pattern of venous anomalies in encephalocele based on normal developmental theory.ConclusionDevelopmental theory connotes that major dural sinuses cannot herniate into the sac of encephalocele. Irrespective to its size, encephalocele can be resected safely at the neck without subsequent venous congestion.

Somatosensory evoked potentials in carotid artery stenting: Effectiveness in ascertaining cerebral ischemic events

Somatosensory evoked potentials (SSEP) have been used in various endovascular procedures and carotid endarterectomy, but to our knowledge no literature deals exclusively with the utility of SSEP in carotid artery stenting (CAS). The purpose of this study was to evaluate the efficacy of SSEP in detecting cerebral ischemic events during CAS. We conducted a prospective study in 35 CAS procedures in 31 patients during an 18month period. Thirty-three patients without near occlusion underwent stenting using dual protection (simultaneous flow reversal and distal filter) combined with blood aspiration, while two patients with near occlusion underwent stenting without dual protection. All 35 patients underwent SSEP monitoring. SSEP were generated by stimulating median and/or tibial nerves and recorded by scalp electrodes. During the aspiration phase post-dilation, seven patients (20%) exhibited SSEP changes with a mean duration of 11.3±8.5minutes (range: 3-25minutes), three of whom later developed minor stroke/transient ischemic attack. Diffusion-weighted imaging showed new lesions in 10 patients (28.6%). Change in SSEP exhibited mean sensitivity of 100% (95% confidence interval, 0.29-1.0) and specificity of 88% (95% confidence interval, 0.71-0.96) in predicting clinical stroke post-CAS. Intra-procedural SSEP change was predictive of post-procedural complications (p=0.005, Fishers exact test). Longer span of SSEP change was positively correlated with complications (p=0.032, Mann-Whitney test). Intra-procedural SSEP changes are highly sensitive in predicting neurological outcome following CAS. Chances of complications are increased with prolongation of such changes. SSEP allows for prompt intra-procedural ischemia prevention measures and stratification to pursue an aggressive peri-procedural protocol for high risk patients to mitigate neurological deficits.

Usefulness of Preoperative Simulation in Skull Base Approach: A Case Report

&NA; Skull base approach is a neurosurgical challenge requiring dexterity of the operating surgeon for good postoperative outcome. In addition to the experience of the operating surgeon, adequate preoperative information of the tumor is necessary to ensure better outcome. In clinoid meningioma, it is sometimes difficult to determine its relationship with the surrounding structure and the feeding artery. Previously, preoperative simulation has been utilized to determine the intracranial course of the compressed nerves in relation to the petroclival meningioma. We report a case of clinoid meningioma where preoperative fusion of three dimensional computed tomography angiography (3D‐CTA) and 3T‐fast imaging employing steady‐state acquisition (FIESTA) images was useful in determining the exact location of the feeding artery to devascularize the tumor and aid in surgery. Preoperative simulation with three‐dimensional digital subtraction angiography (3D‐DSA) and 3T‐FIESTA fusion images can be a useful adjunct tool to supplement surgery and to train neurosurgical trainees.

Isolated Tuberculoma Mimicking Foramen Magnum Meningioma in the Absence of Primary Tuberculosis: A Case Report

Central nervous system tuberculosis is a devastating complication of systemic tuberculosis. Intradural extramedullary (IDEM) tuberculoma at the foramen magnum is rare, and mimics en plaque meningioma. We report the case of a 53-year-old woman who presented with dysesthesia of the tongue and lower cranial nerve (CN) palsy, with onset 4 months prior to admission. The neurologic examination revealed left upper-limb weakness and hypoesthesia on the sole and dorsum of the left foot. Other physical examinations revealed no features of tubercular infection. Laboratory investigations likewise showed no signs of infection or inflammation. Magnetic resonance imaging of the brain showed an IDEM mass originating from the left intradural surface at the foramen magnum extending to the C2 segment and compressing the brainstem and upper cervical cord. The mass was isointense/hypointense on T1- and T2-weighted images and homogeneously-enhanced on postcontrast images. The lesion also exhibited the dural-tail sign and was preoperatively diagnosed as en plaque meningioma. The patient underwent surgery via the left transcondylar fossa approach with partial laminectomy of the atlas. Intraoperatively, the mass exhibited a dural origin and encased the vertebral artery and lower CNs, with strong adhesions. While the histopathological study of the mass was strongly suggestive of tuberculoma with multifocal granulomas, caseous necrosis, and Langerhans giant cells, extensive diagnostic studies failed to detect Mycobacterium tuberculosis itself. Although the patient had recurrence with multisystem involvement, she responded well to antitubercular treatment. IDEM tuberculoma of the foramen magnum may present as en plaque meningioma. Histopathology is required for a definitive diagnosis. Prompt surgical resection and decompression with adequate antitubercular treatment yield better neurological outcomes.

Occult community acquired Klebsiella pneumoniae purulent meningitis in an adult: A case report.

Rationale: Klebsiella pneumonia (K. pneumonia), primarily a hospital-acquired pathogen, can cause a variety of deep-seated infections with significant morbidities. However, in the current scenario of global rise in antibiotic abuse, unexpected infection could be caused by K. pneumoniae. Patient concerns: A 56-year-old male who presented with intermittent headache and low fever was admitted, he had transsphenoidal surgery for pituitary adenoma 3 years ago. Routine laboratory tests revealed an elevated WBC count of 10.12 × 109/L and C-reactive protein (CRP) 12.9 mg/L. computed tomography (CT) revealed the sellar region with suspicious hemorrhage. Diagnoses: The patient was initially diagnosed with acute residual tumor hemorrhage. But the consequent diagnose of Klebsiella pneumoniae purulent meningitis was made based on the cerebrospinal fluid lab test and cerebrospinal fluid (CSF) and blood culture, and CT scan. Interventions: Lumbar puncture examination was made and the antibiotics were adjusted to meropenem and vancomycin according to the antibiotic sensitivity test. But because of the patients unstable vital signs, his family refuse further lateral ventricular drainage. Outcomes: The infection was out of control and the patient died of spontaneous breath and heartbeat arrest. Lessons: Through this case, we could learn that any clue of suspicious intracranial infection should be carefully considered in the current scenario of global rise in antibiotic abuse. The manifestation of intermittent headache and mild fever could be potential signs of fatal infection, and prompt appropriate measures should be taken timely.

RELA fusion-positive anaplastic ependymoma: molecular characterization and advanced MR imaging

Ependymoma is the third most common primary brain tumor in children arising from ependymal cells of the three major anatomical locations: supratentorial, infratentorial and spinal cord. The 2016 WHO Classification of Tumors of the Central Nervous System has undergone major revision. Ependymoma as well as astrocytoma and oligodendroglioma could be diagnosed with histopathological and molecular feature because histopathological classification was not reliable from a view point of concordance with the grading of ependymoma and the clinical outcome [1]. The molecular analysis revealed that supratentorial and infratentorial ependymomas were classified into 4 subgroups, RELA fusion positive, YAP-1 fusion positive, PF-A and PF-B [2]. Only RELA fusion-positive ependymoma was included as a distinct entity in the new revised WHO classification [3]. The ependymoma is characterized by a novel oncogenic fusion involving the C11orf95 and RELA genes accounting for approximately 70% of all childhood supratentorial tumors. RELA fusion-positive ependymoma showed the worst prognosis among the supratentorial ependymomas. Therefore, the importance of preoperative diagnosis in ependymoma is focused on. Recently, advanced MR imaging, such as diffusion-weighted imaging, perfusion analysis or single voxel proton MR spectroscopy, has been reported as the useful technique to determine the tumoral behavior. However, there has been no report about advanced MR imaging of RELA fusion-positive ependymoma. We provide the advanced MR imaging characteristics of RELA fusion-positive ependymoma. A 1-year-old boy presented with the complaints of persistent vomiting and anorexia. He only babbled and could not stand without support, thereby suggesting the developmental delay. CT and MRI revealed the left parieto-occipital cystic brain tumor with diffuse calcification. The tumor consisted of isoto hypo-intense and enhancement with gadolinium on T1-weighted image, and isoto moderately hyper-intense on T2-weighted image and FLAIR. The tumor was hyper-intense on diffusion-weighted imaging (DWI) with low minimum apparent diffusion coefficient (ADC) value (0.592 9 10 mm/sec). Perfusion imaging by arterial spin labeling (ASL) revealed low tumor blood flow. Single voxel proton MR spectroscopy (1HMRS) showed high choline peak without lactate and lipids peak (Fig. 1). The tumor was gross totally resected without neurological deficit. The tumor specimen showed diffusely proliferating tumor cells with solid growth pattern and abundant perivascular pseudorosettes (Fig. 2a). Occasional honeycomb appearance was also present. The smallto intermediate-sized tumor cells showed little pleomorphism with prominent atypical nuclei and scanty cytoplasm (Fig. 2b). Microvascular endothelial proliferation and necrosis of the & Shumpei Onishi shumpei.ohnishi@gmail.com

Neurologic Decline in an Older Patient with Repaired Myelomeningocele Complicated with Lumbar Canal Stenosis

BACKGROUND Tethered cord syndrome is a well-known complication after myelomeningocele (MMC) repair in childhood. However, late complications in adults with a repaired MMC are not well understood. In particular, the influence of a degenerative spinal deformity on a sustained tethered cord is still unclear. CASE DESCRIPTION A 63-year-old man with a repaired MMC exhibited a progressive gait disturbance and numbness in both lower limbs. Magnetic resonance imaging demonstrated that the tethered spinal cord was compressed by severe canal stenosis along the entire lumbar spine. After a multi-level lumbar decompression surgery, the patient recovered to baseline neurologic status. CONCLUSION In adults with a repaired MMC, lumbar canal stenosis should be investigated as a possible cause of late neurologic decline. Clinical manifestations may be complicated by the coexistence of both the original and subsequent neurologic disorders. Because these additional disorders result from compressive myelopathy, early surgical decompression is indicated to avoid irreversible spinal cord dysfunction.