Telemedicine in Follow-up after Spine Surgery: Need of the Hour.

Purpose There is an acute shortage of neurosurgeons and spine surgeons especially in rural areas of low- and middle-income countries including India. Patients of spine surgery need to travel long distances for follow-up at tertiary care hospitals. This study was done to evaluate role and success rate of telemedicine in follow-up after spine surgery based on patients' diagnosis and demographic features and to identify barriers to successful telemedicine consultations. Materials and Methods All patients undergoing spine surgeries including craniovertebral junction (CVJ) surgeries from January 2021 to June 2022 were included in the study. Success rate of telemedicine was calculated using a simple formula: Success rate of telemedicine = successful telemedicine consultations / total number of telemedicine consultation × 100. Success rate was evaluated with respect to demographic features and underlying disease-related factors. Results Eighty-four patients formed the study group in which a total of 181 video teleconsultations were done. Overall success rate of telemedicine was 82.87%. Higher socioeconomic and educational statuses were related to higher success rates of tele-consultations ( p < 0.05). Difficulty in assessing neurological condition using video call in follow-up cases of CVJ and issues related to Internet communication network leading to inability to video call and share image/videos were major causes of failures. Conclusion Telemedicine may prove an effective option for following up patients undergoing spine surgeries except CVJ, which is likely to improve further with improvements in Internet connectivity.

Evaluation of Utility of Invasive Electroencephalography for Definitive Surgery in Patients with Drug-Resistant Epilepsy: A Systematic Review and Meta-Analysis.

When noninvasive tests are unable to define the epileptogenic zone in patients, intracranial electroencephalography (iEEG) is a method of localizing the epileptogenic zone. Compared with noninvasive evaluations, it offers more precise information about patterns of epileptiform activity, which results in useful diagnostic information that supports surgical decision-making. The primary aim of the present study was to assess the utility of iEEG for definitive surgery for patients with drug-resistant epilepsy. Online databases such as PubMed, Medline, Embase, Scopus, Cochrane Library, Web of Science, and IEEE Xplore were searched for MeSH terms and free-text keywords. The ROBINS I (risk of bias in non-randomized studies - of interventions) critical appraisal tool was used for quality assessment. The prevalence from different studies was pooled together using the inverse variance heterogeneity method. Egger's regression analysis and funnel plot were used to evaluate publication bias. The systematic review included 18 studies, and the meta-analysis included 10 studies to estimate the prevalence of seizure freedom (Engel class I) in patients undergoing surgery after iEEG. A total of 526 patients were included in the meta-analysis. The follow-up period ranged from 1 to 10 years. The overall pooled estimate of the prevalence of seizure freedom (Engel class I) for patients undergoing surgery after iEEG was 53% (95% confidence interval, 44%-62%). The results additionally demonstrated that 12 studies had a moderate risk of bias and 6 had a low risk. Future studies are crucial to enhance our understanding of iEEG to guide patient choices and unravel their implications.

Clear Cell Meningioma with Tyrosine Crystals: a Case Report with Review of Literature.

INTRODUCTION OR BACKGROUND: Clear cell meningioma is a rare WHO grade 2 tumour and runs an aggressive course. Tyrosine crystals are very uncommon in meningioma. CASE PRESENTATION: We present a case of a 43-year female with right middle and posterior cranial fossa space occupying lesion (SOL) diagnosed as clear cell meningioma with presence of numerous tyrosine crystals. DISCUSSION AND CONCLUSION: Whether these crystals are incidentally noted or if there is an actual relationship of these crystals with tumour environment must be found as they are seen in many other conditions too.

Optochiasmatic Cavernomas: Updated systematic review and proposal of a novel classification with surgical approaches.

Cavernomas are histologically benign vascular malformations found at different sites in the brain. A rare site for such cavernomas, however, is the anterior optic pathway, comprising the optic nerve, chiasma, and optic tract-called optochiasmatic cavernomas (OCC). These lesions usually present with sudden onset or progressive vision loss, headache, and features mimicking pituitary apoplexy. In this paper, we describe a case of OCC operated at our center. We carry out an updated review of literature depicting cases of OCC, their clinical presentation, management, and postoperative complications. We also propose a novel classification system based on lesion location and further analyze these cavernoma types with respect to the surgical approach used and visual outcome. A 30-year-old lady had presented with a 3-week history of progressive bilateral vision loss and headache. Based on imaging, she was suspected to have a cavernous angioma of the chiasma and left optic tract. Due to progressive vision deterioration, the lesion was surgically excised using pterional craniotomy. Postoperatively, her visual symptoms improved, but she developed diabetes insipidus. Clinical and radiological follow-up has been done for 18 months after surgery. A total of 81 cases have been described in the literature, including the present case. Chiasmal apoplexy is the most common presentation. Surgical excision is the standard of care. Our analysis based on lesion location shows the most appropriate surgical approach to be used for each cavernoma type. Visual outcome correlates with the preoperative visual status. Visual outcome is good in patients presenting with acute chiasmal apoplexy, and when complete surgical excision is performed. The endonasal endoscopic approach was found to provide the best visual outcome. In addition to preoperative visual status, complete surgical excision predicts favorable visual outcomes in OCC. Our proposed classification system guides the appropriate surgical approach required for a particular location of the cavernoma.

Multiple Symptomatic Spinal Intradural Arachnoid Cysts: A Case Report.

A spinal arachnoid cyst is a rare entity representing only 1 to 3% of spinal canal lesions. Very few of them are reported to be symptomatic. Moreover, occurrence in multiples is even rarer. Extradural type is more common than intradural. In the spine, it is rare in the sacral region. Other common pathologies, such as a dermoid or epidermoid cyst, are often considered at presentation. Even magnetic resonance imaging can miss the diagnosis sometimes. We report a case with symptoms of paraparesis and incontinence at presentation, initially misdiagnosed as a dermoid cyst, later found to be multiple intradural arachnoid cysts located in the sacral region. Spinal arachnoid cysts may cause debilitating symptoms. The disease is completely curable if the detection and classification are early as in our case.

Skull base dural reflection models: tool for teaching neuroanatomy at resource-scarce centers.

Skull base dural reflections are complex, and along with various ligaments joining sutures of the skull base, are related to most important vessels like internal carotid arteries (ICA), vertebral arteries, jugular veins, cavernous sinus, and cranial nerves which make surgical approaches difficult and need thorough knowledge and anatomy for a safe dissection and satisfactory patient outcomes. Cadaver dissection is much more important for the training of skull base anatomy in comparison to any other subspecialty of neurosurgery; however, such facilities are not available at most of the training institutes, more so in low- and middle-income countries (LMICs). A glue gun (100-Watt glue gun, ApTech Deals, Delhi, India) was used to spread glue over the superior surface of the bone of the skull base over desired area (anterior, middle, or lateral skull base). Once glue was spread over the desired surface uniformly, it was cooled under running tap water and the glue layer was separated from the skull base. Various neurovascular impressions were colored for ease of depiction and teaching. Visual neuroanatomy of the inferior surface of dural reflections of the skull base is important for understanding neurovascular orientations of various structures entering or exiting the skull base. It was readily available, reproducible, and simple for teaching neuroanatomy to the trainees of neurosurgery. Skull base dural reflections made up of glue are an inexpensive, reproducible item that may be used for teaching neuroanatomy. It may be useful for trainees and young neurosurgeons, especially at resource-scarce healthcare facilities.

Chondrosarcoma Skull Base: A Case Report.

INTRODUCTION: Chondrosarcomas are primary malignant bone tumor that rarely occurs in the head and neck region. Squash cytology of skull base neoplasm shows atypical chondrocytes and myxoid stroma, which suggests many possibilities like chordoma, chordoid glioma, chordoid meningioma and chondrosarcoma. Isocitrate dehydrogenase gene (IDH) mutations have been reported in 50% to 60% of the head and neck region chondrosarcoma. CASE PRESENTATION: A 37-year-old female came to the outpatient department and complaint of difficulty in walking and swaying to the right side for one year. The radiology was suggestive of right-sided trigeminal schwannoma. However, the squash cytology showed the presence of necrosis, and pink to bluish-coloured myxoid stroma. The tumor cells were pleomorphic and had a hyperchromatic nucleus, hyalinized condensed to granular cytoplasm. The histopathological examination of intraoperative soft tissue showed the presence of cellular lobules of atypical chondrocytes arranged in the myxoid background. The features were of Chondrosarcoma. No parenchymal invasion was found. CONCLUSION: This case report aims to create awareness about a rare tumor, which rarely forms a differential diagnosis for skull base neoplasms. As chondrosarcoma are immunoreactive to IDH1 so this marker can be useful in clinching the diagnosis in conjunction with other immunohistochemical markers in a small biopsy from skull base neoplasms.

The Yin and Yang of Operating on a Posterior Fossa Meningioma: The Schmahmann Syndrome.

The cerebellum is classically linked with control of motor function, such as coordination, balance, and regulation of movement. There is an increasing awareness, now, of the non-motor functions of the cerebellum, and the occurrence of behavioral anomalies with cerebellar disorders. We present the first report of Schmahmann syndrome (cerebellar cognitive affective syndrome [CCAS]) occurring secondary to posterior fossa meningioma excision. A 35-year-old lady with a posterior fossa meningioma developed an infarct of the right posterosuperior cerebellar hemisphere and ipsilateral superior vermis, following suboccipital craniotomy and tumor resection. Few days after the surgery, she presented with aggressive and emotional behavior, irrelevant talk, and emotional lability. The CCAS scale was administered, and she scored poorly on almost all parameters. A neuropsychological evaluation was also done. The occurrence of CCAS, posterior fossa syndrome (PFS), and behavioral abnormalities like abnormal pathological laughter/crying provides further clinical evidence of the "affective" functions of the cerebellum, modulated mainly by the posterior lobe and vermis of the cerebellum.

Cerebral Ptosis: A Revisit.

Ptosis, unilateral or bilateral, partial or complete, occurring in cases of cerebral ischemic or hemorrhagic stroke, trauma or tumor without involvement of brainstem or oculo-sympathetic mechanism can be termed as cerebral ptosis. Such eyelid dysfunction can occur with hemispheric involvement of either side. It is associated with higher frequency of gaze preference to side of lesion as well as upgaze limitation compared to patients without cerebral ptosis. Here, we present our observations in four such patients with stroke and discuss its evaluation and implications with a brief review of literature.

Handmade models for aneurysm surgery: A useful tool for training.

Background: Aneurysm surgery is considered difficult by young and trainee neurosurgeons. This is due to difficulty in understanding orientation of aneurysm complex (proximal and distal vessels, aneurysm neck, and fundus) in relation to the surrounding structures (skull, brain, vessels, and nerves) after head is rotated, extended, and fixed on the head frame. Virtual three-dimensional (3D) imaging studies and 3D-printed models help young neurosurgeons but are not accessible to most of the centers due to need for resources (human and equipment). Authors used handmade 3D models of aneurysm complex to train young neurosurgeons before and during surgery to make them understand steps to treat it. Methods: RadiAnt DICOM viewer software (2022.1.1, 64-bit, Medixant, Poznan, Poland) was used for acquiring 3D Volume Rendering Technique images to make aneurysm models preoperatively. Twisted 20 Gauze galvanized iron wires were used for making proximal and distal branches and Epoxy Putty (M-seal, Pidilite ® industries, Mumbai, India) was used to make smooth surfaces of the vessels, aneurysm necks, and fundi. Models were used in operating room (OR) before and during surgery to help surgeons and trainees get oriented to the aneurysm complexes. Results: Handmade models, oriented as per patients' head position, were useful to make surgeons and trainees to understand projection of various components of the aneurysm complex in relation to adjacent structures, especially skull base, during both preoperative planning and in OR even before completion of the dissection. Conclusion: Handmade models of aneurysms are inexpensive tool and can help trainee neurosurgeons to plan and execute surgical management of aneurysms.

Methylmethacrylate Inter-Facetal and Inter-Vertebral Body Spacers for Cranio-Vertebral Junction and Various Spine Surgeries: Technical Note.

STUDY DESIGN: Prospective. PURPOSE: Over past one and half decade, ready-to-use magnetic resonance imaging (MRI) compatible spinal implants have changed the clinical practice and economics of spinal surgery. These are beyond reach of majority of population of developing countries like India due to financial reasons and also availability in remote areas. There is a growing need for a MRI compatible cost-effective spinal implant of proven quality. The authors used bone cement spacers for the said purpose for various level spine surgeries. OVERVIEW OF LITERATURE: Methylmethacrylate, known as bone cement, was used extensively for spinal surgeries from craniovertebral junction to sacrum for augmentation and replacement of various spinal elements. Its biochemical and biomechanical properties were tested for safe clinical use and was a favored material for spinal surgeons. MATERIALS AND METHODS: The authors made molds for making bone cement spacers for various spine levels with the help of silicone material. RESULTS: Sixteen patients (12 males, 4 females with an average age of 31 years) of various spine level surgeries were done where bone cement spacers were used. It included patients of basilar invagination (n = 9), dorsal Pott's disease (n = 1), lumbar (n = 2), and lumbo-sacral spondylolisthesis (n = 1). Spacers could be used without any difficulties and postoperative day 1- and 3-months follow-up computed tomography scan of the patients revealed no change in the dimensions of the spacer and fusion at 3 months of operated levels. CONCLUSION: The authors feel that bone cement spacers may be an effective and low-cost alternative to the existing costly alternatives.

Volume Rendering Technique (VRT) for Planning and Learning Cranio-Vertebral Junction (CVJ) Surgeries: Technical Note.

AIM: To present the application of volume rendering technique (VRT) of computed tomography (CT) scan in cranio-vertebral junction (CVJ) surgeries. MATERIAL AND METHODS: The authors used VRT images of CT scan in patients of congenital CVJ anomalies who were subjected to various surgeries through midline posterior approach. The screw entry points and courses of vertebral arteries were identified in relation to various landmarks on the VRT images, preoperatively and intra-operatively. RESULTS: A total of 15 patients of CVJ anomalies, who underwent surgeries through midline posterior approach, formed the study group. The screw entry points and courses of the vertebral arteries could be effectively identified in the surgical fields. CONCLUSION: We conclude that VRT images are an inexpensive and user friendly tool to identify the screw insertion points in the surgeries of CVJ anomalies. They also help in identifying the course of the vertebral artery in the surgical field. On the whole, their use makes the surgery in this region, safer.

Simulation of surgery for supratentorial gliomas in virtual reality using a 3D volume rendering technique: a poor man's neuronavigation.

OBJECTIVE: Different techniques of performing image-guided neurosurgery exist, namely, neuronavigation systems, intraoperative ultrasound, and intraoperative MRI, each with its limitations. Except for ultrasound, other methods are expensive. Three-dimensional virtual reconstruction and surgical simulation using 3D volume rendering (VR) is an economical and excellent technique for preoperative surgical planning and image-guided neurosurgery. In this article, the authors discuss several nuances of the 3D VR technique that have not yet been described. METHODS: The authors included 6 patients with supratentorial gliomas who underwent surgery between January 2019 and March 2021. Preoperative clinical data, including patient demographics, preoperative planning details (done using the VR technique), and intraoperative details, including relevant photos and videos, were collected. RadiAnt software was used for generating virtual 3D images using the VR technique on a computer running Microsoft Windows. RESULTS: The 3D VR technique assists in glioma surgery with a preoperative simulation of the skin incision and craniotomy, virtual cortical surface marking and navigation for deep-seated gliomas, preoperative visualization of morbid cortical surface and venous anatomy in surfacing gliomas, identifying the intervenous surgical corridor in both surfacing and deep-seated gliomas, and pre- and postoperative virtual 3D images highlighting the exact spatial geometric residual tumor location and extent of resection for low-grade gliomas (LGGs). CONCLUSIONS: Image-guided neurosurgery with the 3D VR technique using RadiAnt software is an economical, easy-to-learn, and user-friendly method of simulating glioma surgery, especially in resource-constrained countries where expensive neuronavigation systems are not readily available. Apart from cortical sulci/gyri anatomy, FLAIR sequences are ideal for the 3D visualization of nonenhancing diffuse LGGs using the VR technique. In addition to cortical vessels (especially veins), contrast MRI sequences are perfect for the 3D visualization of contrast-enhancing high-grade gliomas.

Efficacy of Hyaluronidase in the Mannitol Extravasation Induced Compartment Syndrome-A Case Report and Review of Literature.

Mannitol is one of the indispensable drugs in neurosurgery to manage the raised intracranial pressure. Though considered safe, extravasation of mannitol into the tissues can cause considerable morbidity with the consequent development of compartment syndrome. We report a case of a 50-year-old female who developed forearm compartment syndrome due to mannitol extravasation after undergoing surgery for frontal glioma under general anaesthesia. The severe forearm compartment syndrome could be successfully managed without fasciotomy using hyaluronidase. We describe the pathophysiology, prevention and treatment strategies emphasising the use of hyaluronidase in the management of mannitol extravasation induced compartment syndrome.

Coexistent pituitary adenoma and frontal convexity meningioma with frontal sinus invasion: A rare association.

The coexistence of pituitary adenoma (PA) and meningioma in the same patient is rare, after excluding radiotherapy-induced meningiomas. Most of the literature on their coexistence describes meningiomas located in the close vicinity to PA, that is, in the sellar/parasellar region. We describe a case of a 65-year-old lady with a nonfunctioning PA and an associated frontal convexity meningioma with frontal sinus invasion. The imaging was nonspecific for the meningioma, and its association with concomitant PA has not been reported before.

Biomechanical modelling and computer aided simulation of deep brain retraction in neurosurgery.

BACKGROUND AND OBJECTIVES: Surgical simulators are widely used to promote faster and safer surgical training. They not only provide a platform for enhancing surgical skills but also minimize risks to the patient's safety, operation theatre usage, and financial expenditure. Retracting the soft brain tissue is an unavoidable procedure during any surgery to access the lesioned tissue deep within the brain. Excessive retraction often results in damaging the brain tissue, thus requiring advanced skills and prior training using virtual platforms. Such surgical simulation platforms require an anatomically correct computational model that can accurately predict the brain deformation in real-time. METHODS: In this study, we present a 3D finite element brain model reconstructed from MRI dataset. The model incorporates precisely the anatomy and geometrical features of the canine brain. The brain model has been used to formulate and solve a quasi-static boundary value problem for brain deformation during brain retraction. The visco-hyperelastic framework within the theory of non-linear elasticity has been used to set up the boundary value problem. Consequently, the derived non-linear field equations have been solved using finite element solver ABAQUS. RESULTS: The retraction simulations have been performed for two scenarios: retraction pressure in the brain and forces required to perform the surgery. The brain was retracted by 5 mm and retained at that position for 30 minutes, during which the retraction pressure attenuates to 36% of its peak value. Both the model predictions as well as experimental observations on canine brain indicate that brain retraction up to 30 minutes did not cause any significant risk of induced damage. Also, the peak retraction pressure level indicates that intermittent retraction is a safer procedure as compared to the continuous retraction, for the same extent of retraction. CONCLUSIONS: The results of the present study indicate the potential of a visco-hyperelastic framework for simulating deep brain retraction effectively. The simulations were able to capture the dominant characteristics of brain tissue undergoing retraction. The developed platform could serve as a basis for the development of a detailed model in the future that can eventually be used for effective preoperative planning and training purposes.

Suction Pressure Control Valve for Microneurosurgery.

A suction pressure control valve (SPCV) for microneurosurgery is designed to place control of safe suction pressure in the hands of an operating neurosurgeon. Tumor tissue needs more negative suction pressure as compared to normal brain tissue, cranial nerves, and vessels in the neurosurgical operating field. The authors present the details of a prototype of a simple and inexpensive device for dynamic adjustment of negative suction pressure by the surgeon or the assistant while working on different tissue types during microneurosurgery.