Cases of Mixed Schwannoma-Meningioma With and Without Neurofibromatosis 2 with Emphasis on Tumorigenesis.

Concurrent occurrence of schwannoma and meningiomas are rare, and are found especially in association with neurofibromatosis type 2 (NF2). Occurrence of mixed tumor without the aforementioned conditions is extremely rare. We present three cases of mixed tumor in different locations, including two with NF2 and one without NF2. We analyse the relationship of mixed tumor with NF2 and its clinical implications. Presence of mixed schwannoma-meningioma should prompt screening for NF2. Thus aids in early diagnosis of unsuspected NF2 cases. We observed that irrespective of different locations, cases with NF2 showed frequent recurrence of schwannoma as compared to case who did not fit in the existing clinical criteria for NF2. Collision tumor and thereby NF2 mutations indicates the prognosis and recurrence of the tumor, thereby guides in deciding the management.

Paraspinal extramedullary hematopoiesis masquerading as nerve sheath tumor.

Paraspinal tumors are uncommon tumors involving the soft-tissue around the vertebrae. The lesion could originate from nerve roots, soft tissue, or blood vessels. The diversity of the lesions poses diagnostic dilemma, warranting robust histopathological diagnosis. We report such a case presenting with radicular pain due to paraspinal extramedullary hematopoiesis (EMH) masquerading as nerve sheath tumor. EMH is presence of hematopoietic tissue outside the bone marrow. EMH is usually seen as a compensatory mechanism associated with underlying hematological disorder. Our case presented primarily as paraspinal mass without underlying hematological disorder on evaluation. Thus, recognizing that EMH can present as paraspinal mass even without a diagnosis of pre-existing hematological disorder is crucial.

Thoracic Compressive Myelopathy in a Patient With Takayasu Arteritis.

Takayasu arteritis (TA), also known as occlusive thromboaortopathy, is a type of chronic inflammatory arteritis that primarily affects large vessels. Compressive thoracic myelopathy is a rare and distinct manifestation of TA. We present the case of a 60-year-old woman who developed gradually progressive spastic paraplegia over one year. Magnetic resonance imaging revealed a well-defined extra-dual, intensely enhancing ventrodorsal lesion with severe spinal cord impingement. The aortogram revealed dilatation of the aortic arch (with narrowing of arch vessels) and descending aorta, as well as a right paravertebral soft tissue mass at the D4 level. Given the likelihood of TA, the patient underwent decompressive laminectomy and spinal fusion due to severe spinal cord compression. The biopsy of the dural-based lesion revealed an inflammatory granuloma, and the patient was treated postoperatively with oral prednisolone and mycophenolate mofetil. After six months of immunotherapy, there was excellent neurological recovery and near-total resolution of the lesion.

Stimulation artefact on EEG trace with BIS monitoring during D-wave recording.

The D-wave reflects the corticospinal fibre potentials and is frequently recorded intraoperatively for intramedullary spinal tumours to ensure maximum safe resection. A 38-year-old male had an intramedullary spinal cord tumour surgically removed while being monitored with D-wave from a single distal electrode technique. Total intravenous anaesthesia (TIVA) with propofol (without a muscle relaxant and with intermittent intravenous fentanyl boluses) was used for the maintenance of anaesthesia guided by processed electroencephalography (EEG) using a bispectral index (BIS®) monitor. Regular spike artefacts were observed in the EEG signal recorded by the BIS® monitor during the application of the single-pulse transcranial electrical stimulus and were used as a visual indicator of stimulus delivery. Finally, we propose a novel method of confirming stimulus delivery during D-wave recording based on stimulation artefacts in the EEG signal recorded by the BIS® monitor.

Massive Congestive Facial and Submandibular Oedema Due to Extreme Neck Flexion Following Suboccipital Craniectomy: A Case Report.

A variety of factors could contribute to facial oedema during a prone neurosurgical procedure. For optimal surgical exposure, suboccipital cranial surgeries frequently necessitate extreme neck flexion. Extreme neck flexion in the prone position can impair venous drainage of the facial and oropharyngeal structures, leading to life-threatening oedema, so a two-fingerbreadth space between the chin and the sternum is critical. We present a case of massive facial oedema with submandibular swelling in a patient who underwent foramen magnum decompression in the prone position for Arnold Chiari malformation.

Multidisciplinary Management of Primary Sacral Tumors: A Tertiary Care Center's Experience and Literature Review.

Sacral tumors are rare and can be benign or malignant. Their management is multifactorial and is based on the pathology, extent, and local and distant spread. Managing sacral tumors is challenging due to their proximity to visceral and neural structures. Surgical wide excision has been the standard of care for aggressive benign and malignant tumors. Our purpose was to evaluate the outcomes of a multimodal approach to managing primary sacral tumors in Sakra World Hospital, a tertiary spine care center in Bengaluru, India and perform a literature review to determine a workflow pathway. Our study was a retrospective review of patient records and included 15 patients with primary sacral tumors. Eleven surgically treated patients were evaluated clinically and radiologically and underwent biopsy before surgical excision by an all-posterior approach. A multidisciplinary approach that included intraoperative neural monitoring, plastic reconstruction, adjuvant chemotherapy, and radiotherapy was implemented whenever necessary. Sacral root preservation was attempted whenever feasible. Functional outcomes (based on the Visual Analog Scale [VAS] and Biagini scoring system) were analyzed along with disease control, with a minimum of 2 years of follow-up. The mean follow-up was 29±9.8 months. The mean VAS score significantly improved from 7.8±2.6 to 3.7±3.8 (p =0.026). Bowel function showed statistically significant improvement, from a mean score of 0.81±0.47 to 0.63±0.52 (p =0.026) at 2 years of follow-up. The mean pretreatment motor and bladder function scores were 0.53±0.31 and 0.74±0.44, respectively, improving to 0.48±0.33 and 0.68±0.56 at follow-up but without statistical significance. There was no significant loss of function, which is expected in radical sacral resections. In conclusion, primary sacral tumors require a multidisciplinary approach and management for optimal outcomes. A stand-alone posterior approach can be employed to treat most sacral lesions. En-bloc wide resection is the optimal treatment for primary malignant and aggressive benign tumors. Preservation of at least one functional S2 nerve root is imperative to preserve bowel and bladder function.

Distal Junctional Failure Secondary to Nontraumatic Fracture of Lower Instrumented Vertebra: Our Experience and Review of Literature.

BACKGROUND: Junctional kyphosis (JK) is usually observed in long-level instrumented fusion surgeries. Various contributing factors are proposed, the pre-existing and postoperative spinal imbalance is considered as the single most important factor for the development of JK in adult spinal deformity surgeries. Distal JK (DJK) is seldom reported compared to proximal JK (PJK), and scarce literature exists. METHODS: We report 2 unique cases of distal junctional failure (DJF) with worsening of neurology, secondary to nontraumatic fracture of a lower instrumented vertebra operated for thoracic canal stenosis without deformity. The first case had acute worsening of the Neurology during follow up and on evaluation, the supine CT and MRI scan revealed well decompressed spinal canal, no implant migration to the canal, no screw loosening, or rod failure. Supine sitting radiographs demonstrated DJK with Fracture and the patient underwent extension of fusion till the pelvis with 3-rod construct and interbody fusion, because of the instability at the L1 level.The second case remained neurologically stable for a month and then had an acute onset of back pain, sensory deficit, and urine incontinence. The supine-sitting dynamic radiograph done demonstrated L1 fracture with DJK at D12-L1 levels. The patient was counseled for extension of fusion, which was deferred by the patient. RESULTS: Patients in our series, had an acute worsening of neurological deficit within a month of posterior spinal fixation. Their supine imaging was almost normal, and the diagnosis of DJK with L1 fracture instability was possible only on a supine-sitting dynamic radiograph. Various factors like obesity, TL kyphosis, osteoporosis, etc. can be the attributing factors for the development of DJK CONCLUSION: A high index of suspicion is required for diagnosing nontraumatic fracture in long-level fusion patients with acute neurological worsening. The supine-sitting dynamic radiograph is an important diagnostic tool for DJF in patients having difficulty standing erect. LEVEL OF EVIDENCE: 4. CLINICAL RELEVANCE: Application of sitting and supine dynamic radiographs to diagnose instability in patients unable to stand for flexion and extension radiographs.

Customized and Cost-Effective 3D Printed Mold for Cranioplasty: India's First Single Center Experience.

CONTEXT: Autologous bone is the most commonly used flap in cranioplasty to repair the defect; however, synthetic materials are available. Poly methyl methacrylate (PMMA) is an effective polymer owing to its thermoplastic and radiolucent properties comparable to bone strength. Three-dimensional (3D) printing combined with computer-assisted design (CAD) is a simple, low-cost method to print molds that ensure surgical success. MATERIALS AND METHODS: A total of 114 patients underwent cranioplasty (July 2015-April 2018), and 25 of them using 3D printed template molds due to unavailability of autologous bone. The clinical features, patient demographics, and surgical parameters were analyzed. The visual analog score for cosmesis (VASC) and Odom's score was obtained pre and post-op. RESULTS: The mean age of the patients is 38.4 ± 14.6 years (Range, 9-66). The primary pathology for undergoing craniectomy is stroke (n = 13; 52%), traumatic brain injury (10; 40%) and tumor (2; 8%). The reason for nonavailability of flap was infection (n = 14;56%), flap resorption (4;16%), and trauma or tumor (7;28%). The mean time for manufacturing the 3D printed template is 13.2 ± 2.1 h. On follow-up, median Odom's score is excellent in 52% of cases, good in 40%, and fair in 8%. The mean VASC score on follow up is 8.2 ± 1.3. Three patients developed minor postoperative complications. CONCLUSION: This is the first study from a single tertiary care center in India to systematically evaluate the outcomes in 3D cranioplasty using CAD and 3D printing technology. This method would be optimal especially in developing countries since PMMA is cost effective and also gives an ideal cosmetic effect.

Unstable Hangman Fracture Complicated by Vertebral-Venous Fistula: Surgical Considerations and Review of Literature.

BACKGROUND: Hangman fracture or traumatic spondylolisthesis of the axis associated with a traumatic vertebral venous fistula (VVF) is a rare entity and sparsely reported in literature. Standard recommendations for management of such rare and complex scenarios are not available and hence the strategy has to be individualized on a case-by-case basis. METHODS: We report a 70-year-old man having an unstable hangman fracture with VVF. Both pathologies were simultaneously managed uniquely. The VVF was managed by endovascular occlusion. The fracture was managed by anterior fusion alone as posterior fusion was deemed riskier in the aftermath of a recently occluded VVF. The patient had good neck function and bony fusion at 1-year follow-up. CONCLUSION: This case report emphasizes the need for timely recognition and management of a VVF, which can rarely coexist with hangman fracture, and discusses the interesting surgical paradigms in the management. We also present a review of literature.

Multimodal Intraoperative Neurophysiological Monitoring in Spine Surgeries: The Experience at a Spine Centre through Years.

STUDY DESIGN: Retrospective observational study. PURPOSE: To share our experience of multimodal intraoperative neurophysiological monitoring (IONM) used in Sakra World Hospital, Bengaluru in various spine surgeries. OVERVIEW OF LITERATURE: The development of new onset postoperative neurological deficits can be completely avoided. In order to avoid these, IONM has become a standard of care in recent times for early detection and manipulation of the surgical procedure to prevent postoperative neurological deficits. METHODS: This retrospective study was performed on 408 patients who had undergone spine surgeries with IONM during April 2014 to March 2020 at a single center. The operative report, anesthesia record, and IONM were reviewed. All the patients were reassessed for postoperative neurological deficits in the postoperative period and followed up based on the intraoperative findings and neurological deficits for 4 weeks. Signal changes in IONM were reviewed, and the obtained results were further categorized into true positive, true negative, false positive, or false negative. If changes were observed during the IONM, the patients were managed as per the algorithm. RESULTS: Of the 408 patients being monitored continuously during the intraoperative period, 38 showed changes in recordings, 28 developed postoperative neurological deficits, and one developed neurological deficit without any change in the IONM. Nine patients had transient neurological deficits, and the other 20 had permanent neurological deficits. Overall, the multimodal IONM used in our study had a sensitivity of 96.6%, specificity of 97.4%, a positive predictive value of 73.7%, and a negative predictive value of 99.7%. CONCLUSIONS: Use of decision algorithm and multimodal neuromonitoring consisting of motor evoked potentials, somatosensory evoked potentials, and electromyography complement each other in the detection of neurological injury during the course the surgery, improve intraoperative care, and prevent further damage and morbidity in patients.

Is Transoral Surgery Still a Relevant Procedure in Atlantoaxial Instability?

BACKGROUND: The treatment of atlantoaxial instability (AAI) involves stable fixation and fusion with adequate decompression of spinal cord. After the advent of the Goel posterior joint manipulation technique, most of the once irreducible atlantoaxial dislocations (AAD) could be reduced and the need for transoral odontoidectomy became almost nil. Here we tried to iterate the indications of anterior transoral odontoid surgery for AAI in the current scenario. METHODS: A retrospective study compiling the clinical, radiological, and surgical characteristics of 6 cases (5 scenarios). These patients underwent anterior transoral surgery alone or in combination with a posterior approach. RESULTS: Two patients had a well-formed occipito-cervical fusion mass, with a displaced odontoid and unreduced C1-C2 joint causing cervical myelopathy. A middle-aged woman presented with unreduced AAD following failed C1-C2 joint distraction technique. A displaced dystopic os odontoideum ossicle was found in an adolescent boy, prohibiting the reduction of AAD. A young man had displacement of the fractured odontoid segment with intact transverse alar ligament and C1-C2 joint complex. One patient had a rare scenario of abnormal orientation of the C1-C2 joint. All 6 patients were successfully treated with adequate spinal cord decompression achieved by the anterior transoral route and stabilization by either the anterior approach itself or in combination with posterior surgery. All had significantly better postoperative outcomes except for 1 patient who expired due to poor respiratory reserve. CONCLUSION: We tried to emphasize the indications for using transoral anterior odontoid surgery over the posterior approach in the management of AAI. This will prevent the surgical technique of anterior odontoidectomy from becoming an obsolete procedure in the current practice.

Anterior Surgical Techniques for Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations.

OBJECTIVE: This study was performed to review the literature and to present the most up-to-date information and recommendations on the indications, complications, and success rate of anterior surgical techniques for cervical spondylotic myelopathy (CSM). The commonly performed anterior surgical procedures are multiple-level anterior cervical discectomy and fusion, anterior cervical corpectomy and fusion and its variants (skip corpectomy and hybrid surgery), and oblique corpectomy without fusion. METHODS: A comprehensive literature search and analysis were performed using MEDLINE (PubMed), the Cochrane Register of Controlled Trials, and the Web of Science for peer-reviewed articles published in English during the last 10 years. RESULTS: Corpectomy is mandated for ventral compression of fewer than 3 vertebral segments where single-level disc and osteophyte excision is inadequate to decompress the cord. Endoscopic or oblique partial corpectomy improves the sagittal canal diameter by 67% and obviates the need for an additional bone graft procedure. CONCLUSION: The indications of anterior surgery in patients with CSM include a straightened or kyphotic spine with a compression level lower than 3. With an appropriate choice of implants and meticulous surgical technique, surgical complications can be seen only rarely. Improvements after anterior surgery for CSM have been reported in 70% to 80% of patients.

Hydrocephalic Attack-An Uncommon Complication of Spine Surgery: A Case Series and Review of Literature.

BACKGROUND: Spinal pseudomeningocele refers to an abnormal accumulation of cerebrospinal fluid (CSF) in a fibrous sac without arachnoid lining that occurs mostly as a result of an accidental dural opening. When accidental dural openings are found intraoperatively, they should be repaired to prevent further complications. Sometimes inadequately dealt dural openings, unnoticed, or postoperative dural openings may produce complications. CASE DESCRIPTION: Three patients had complications as a result of spine surgery and presented several days after the surgery with episodic symptoms of raised intracranial pressure, including headache, opisthotonos, altered breathing patterns, and altered sensorium. These symptoms increased whenever pressure was applied on the operated area suggesting hydrocephalic attacks. All 3 patients had a giant pseudomeningocele at the operated area, a complication that resulted from the spine surgery. Magnetic resonance imaging CSF flow study revealed hyperdynamic flow and increase in absolute stroke volume across the cerebral aqueduct when constant pressure was applied on the pseudomeningocele sac. CONCLUSIONS: Usually pseudomeningoceles are asymptomatic, and if symptomatic, the common presentations are local swelling, back pain, radiculopathy, and orthostatic headache. To our knowledge, this is the first article in the literature reporting the uncommon presentation of hydrocephalic attacks in 3 cases subsequent to CSF backflow from the sac, confirmed with MRI CSF flow study. This case series emphasizes rare presentations can result from transiently increased intracranial pressure related to postoperative pseudomeningocele in spine surgeries.

Rosette-Forming Glioneuronal Tumor in Opticochiasmatic Region-Novel Entity in New Location.

BACKGROUND: Rosette-forming glioneuronal tumour [RGNT] is a relatively rare entity first identified as a separate entity in 2002. We are reporting the second case of RGNT in the opticochiasmatic region. CASE DESCRIPTION: We report a case report and literature review of RGNT with syndromic association. CONCLUSIONS: Although initial reports were predominantly in the fourth ventricle, many recent reports have identified the possibility of its occurrence outside fourth ventricle in pineal gland, spinal cord, septum pellucidum, lateral ventricle, and suprasellar region. To date, only 1 case of RGNT involving the opticochiasmatic region has been reported in a patient with neurofibromatosis type 1. Genetic analysis of this rare tumor identified 3 hotspots involving somatic mutations of FGFR-1 and PIK3CA and a germline mutation involving PTPN11, which can be targets for therapeutic intervention in cases where complete resection is not possible. To the best of our knowledge, we report the first case of RGNT involving the opticochiasmatic region without any syndromic association. Other cases of RGNT with syndromic associations provide us with insight into possible therapeutic interventions.