Shyam Sundar Krishnan

Cervical Subependymoma: A rare case report with possible histogenesis.

Subependymomas are extremely rare lesions of the spinal cord. Only 33 cases including ours have been reported in the cervical cord. These are typically benign slow growing tumors occurring eccentrically within the cord, producing minimal neurological deficits. The clinical, radiological, and histopathological aspects of this unusual lesion have been reviewed in detail. As the histogenesis of this tumor is much debated, we propose an alternate origin for the same.

Crescent posterior fossa durotomy for occipito-marginal venous sinus preservation: A pilot study

PurposeThe standard approach of midline suboccipital craniectomy entails sacrifice of the Occipito—marginal sinus. We have attempted to preserve this venous channel by using a durotomy technique which preserves this system. In a pilot study initiative, two groups of patients using this technique versus the standard approach, were compared in terms of per and post operative benefits, morbidity and complications. The literature with reference to the anatomy and venous flow dynamics of the occipital and marginal sinuses and their significance has been reviewed. Similarly, literature regarding dural closure technique with reference to postoperative complications has also been reviewed.MethodsIn this novel approach, the dura is opened as a crescent to avoid damage to the occipital sinus. This technique was compared with the standard midline dural opening technique by random usage of both techniques in 24 patients.ResultsThe ‘crescent’ approach has been found to reduce the need for duroplasty, with comfortable primary closure and to reduce the risk of postoperative pseudomeningocele.ConclusionsThis is a novel dural opening technique which attempts to preserve the normal venous flow physiology. In essence it helps in increased primary dural closures and reduction of Pseudomeningiocele/CSF leak as well as blood loss and venous hypertension.

Postoperative Central Nervous System Infection After Neurosurgery in a Modernized, Resource-Limited Tertiary Neurosurgical Center in South Asia

OBJECTIVE Postoperative central nervous system infections (PCNSIs) are rare but serious complications after neurosurgery. The purpose of this study was to examine the prevalence and causative pathogens of PCNSIs at a modernized, resource-limited neurosurgical center in South Asia. METHODS A retrospective analysis was conducted of the medical records of all 363 neurosurgical cases performed between June 1, 2012, and June 30, 2013, at a neurosurgical center in South Asia. Data from all operative neurosurgical cases during the 13-month period were included. RESULTS Cerebrospinal fluid (CSF) analysis indicated that 71 of the 363 surgical cases had low CSF glucose or CSF leukocytosis. These 71 cases were categorized as PCNSIs. The PCNSIs with positive CSF cultures (9.86%) all had gram-negative bacteria with Pseudomonas aeruginosa (n = 5), Escherichia coli (n = 1), or Klebsiella pneumoniae (n = 1). The data suggest a higher rate of death (P = 0.031), a higher rate of CSF leak (P < 0.001), and a higher rate of cranial procedures (P < 0.001) among the infected patients and a higher rate of CSF leak among the patients with culture-positive infections (P = 0.038). CONCLUSIONS This study summarizes the prevalence, causative organism of PCNSI, and antibiotic usage for all of the neurosurgical cases over a 13-month period in a modernized yet resource-limited neurosurgical center located in South Asia. The results from this study highlight the PCNSI landscape in an area of the world that is often underreported in the neurosurgical literature because of the paucity of clinical neurosurgical research undertaken there. This study shows an increasing prevalence of gram-negative organisms in CSF cultures from PCNSIs, which supports a trend in the recent literature of increasing gram-negative bacillary meningitis.

Does cerebellar flocculus size affect subjective outcomes in pediatric auditory brainstem implantation

OBJECTIVES The objectives of study was to 1) Describe relevant surgical anatomy in defining and accessing the lateral recess for placement of electrode, 2) Propose a working classification for grades of Flocculus; 3) To determine if different grades of cerebellar flocculus effects placement of ABI electrode and subjective outcomes in implantees. METHODS Our study was a prospective study, and comprised of cohort of 12 patients who underwent ABI surgery via retrosigmoid approach between 1 Jan 2012 to 31 Dec 2014. All children with congenital profound sensorineural hearing loss with either absent cochlea or cochlear nerve were included in the study. Relevant anatomy was noted. We also noted down the difficulty encountered during the placement of ABI electrode. Auditory perception and speech intelligibility was scored post operatively for 1 year. RESULTS Cerebellar flocculus was divided into 4 grades depending on the morphology of cerebellar flocculus. It was noted that Grade 3 & 4 flocculus (Group B) had difficult ABI electrode placement in comparison to Grade 1 & 2 flocculus (Group A). The subjective outcomes of Group A was better than Group B. However the p value was not statistically significant. CONCLUSION Cerebellar flocculus can be graded depending on morphology and size. Flocculus of higher grades can make the placement of ABI electrodes difficult and adversely effects the postoperative subjective outcomes.

Abscess within a meningioma: pathogenesis and rare case report.

196 Neurology India | Mar-Apr 2014 | Vol 62 | Issue 2 an acoustic schwannoma; those from the foraminal portion predominantly expand the bone and jugular foramen and present with involvement of lower cranial nerves; and tumors originating from the extracranial part present with major extracranial growth, and may extend to the parapharyngeal space inferiorly presenting as neck mass. Intracranial and foraminal tumors have the longer duration as opposed to extracranial tumors, because of their slow insidious growth pattern.[1] Of these, vagal nerve schwannomas are rare.[2-4] Even large reported series of jugular foramen schwannomas have only a few Type D lesions.[5-7] However, the exact site of origin of these Type D tumors is unclear in any of the above series. The site of origin is likely to determine the growth. A lesion arising from inferior ganglion mainly produces a extracranial mass whereas the superior ganglion produces an intracranial lesion.[2] However, this theory cannot explain Type D lesion. The clinical features are usually those of jugular foramen schwannomas. Occasionally, they may present with hypertension.[3] Appropriate radiological evaluation differentiates vagal nerve schwannoma from glomus jugulare tumors. Lack of vascular blush and fl ow voids in a heteregenously enhancing tumor favors the diagnosis of schwannoma. Vagal nerve lesions usually displace the carotid anteriorly.[4] However, in our case carotid artery was pushed medially and the tumor was seen popping out between the jugular vein and the carotid.

Falcine and parasagittal intracranial chondrosarcomas of the classical variant: Report of two cases with review of literature

Intracranial primary extraskeletal chondrosarcomas are extremely rare. We report two cases of the classical variant which were dural based: one falcine and the other parasagittal are presented. Only 10 cases of this variant have been reported in this location. The pathology and management of these lesions have been reviewed.

Spinal accessory nerve schwannomas masquerading as a fourth ventricular lesion

Schwannomas are benign lesions that arise from the nerve sheath of cranial nerves. The most common schwannomas arise from the 8th cranial nerve (the vestibulo-cochlear nerve) followed by trigeminal and facial nerves and then from glossopharyngeal, vagus, and spinal accessory nerves. Schwannomas involving the oculomotor, trochlear, abducens and hypoglossal nerves are very rare. We report a very unusual spinal accessory nerve schwannoma which occupied the fourth ventricle and extended inferiorly to the upper cervical canal. The radiological features have been detailed. The diagnostic dilemma was due to its midline posterior location mimicking a fourth ventricular lesion like medulloblastoma and ependymoma. Total excision is the ideal treatment for these tumors. A brief review of literature with tabulations of the variants has been listed.

Neuroplasticity in hemispheric syndrome: An interesting case report

Functional hemispherectomy is an accepted treatment in hemispherical intractable epilepsy syndromes. We report a patient who had functional hemispherectomy for intractable seizures secondary to right hemispheric cortical dysplasia. Preoperatively, the patient had mild left hemiparesis and functional magnetic resonance imaging (fMRI) showed bilateral motor function lateralization to normal left hemisphere. The patient remains seizure free at 1-year follow-up, with no deterioration of motor power on left side. This report reviews physiology of neural plasticity for motor function lateralization and also reliability of fMRI in determining the functional shift.

Modified high cervical approach for C3-4 anterior pathology in difficult neck patients

Introduction: The anterior approach to cervical pathologies is a time-tested versatile approach. It is, however, associated with a number of pharyngo-tracheo-laryngeal complications (PTL complications) such as dysphonia, dysphagia, and aspiration, more commonly in high cervical C3-4 inclusive pathologies and even more so in patients with “difficult neck.” The modified high cervical approach was devised and employed to address these issues at our institution. Materials and Methods: Patients who underwent surgery for anterior cervical C3-4 inclusive pathologies between January 2015 and April 2018 were included in the study. Parameters for considering difficult neck were defined. Patient subgroup with difficult neck underwent surgery through a modified high cervical approach, whereas others underwent surgery through a standard approach. The incidence of pharyngo-tracheo-laryngeal complications in both subgroups of this patient set was compared among itself as well with a similar patient set with the same two subgroups, both of which underwent surgery through standard approach alone from May 2010 to December 2014 – before the introduction of modified high cervical approach. Results: A total of 280 patients underwent surgery for C3-4 level pathology between May 2010 and April 2018. There were 197 males and 93 females in this population. Mean age was 45.8 ± 6.3 years. Incidence of pharyngo-tracheo-laryngeal complications was 20.3% in patients who underwent surgery before the employment of modified high cervical approach – 32.4% of difficult neck and 16.6% of others developed features of pharyngo-tracheo-laryngeal complications. After employment of modified high cervical approach, 16.67% of difficult neck and 16.2% of other patients developed features of pharyngo-tracheo-laryngeal complications. Conclusion: The modified high cervical technique is a good surgical option to prevent pharyngo-tracheo-laryngeal complications in cases of anterior C3-4 pathology when operating of patients with difficult neck.

Quad fever: Treatment through lowering of ambient temperature

Hyperpyrexia is a rare and at times fatal condition seen in an Intensive Care Unit setup. We encountered a case of a 65-year-old patient with road traffic accident presenting with dorsal spine fracture at D10level. He underwent decompression and fusion for the same. He developed hyperpyrexia of sudden onset on the 10th day of admission with no source of infection and adequate broad-spectrum antibiotic coverage with adequate thrombo-embolic prevention in place. The patient showed no response to antipyretic agents and other cooling methods. The origin of hyperthermia was idiopathic, and we speculate that the cause was secondary to hyperthermic thermoregulatory dysfunction often quoted as “quad fever,” seen in spinal cord injury. We present a brief review of literature and the importance of early identification and treatment of this potentially fatal condition.