Extended Unifrontal craniotomy for midline anterior cranial fossa meningiomas: A better shot at preservation of neurovascular structures

Numerous surgical approaches have been described for the resection of anterior cranial fossa meningioma. The common problems associated with these approaches are excessive brain retraction, injury to neurovascular structures, transection of superior sagittal sinus (SSS), and a higher risk of new-onset anosmia. The authors describe a unilateral extended frontal approach with the aim to minimize brain handling without the need for SSS transection and possibly better olfaction preservation.

METHODS

Thirteen patients with anterior cranial fossa meningioma were operated on using the novel technique of unilateral extended frontal skull base approach. The clinical presentation, radiological studies, intraoperative findings, and outcome at follow-up were recorded.

RESULTS

Gross total tumor resection could be achieved in 12 out of 13 patients. At least one of the olfactory tracts could be anatomically preserved in all patients, and superior sagittal sinus was preserved in all patients. Functional olfaction preservation was achieved in 8 patients. No patient developed new-onset anosmia.

CONCLUSIONS

The extended unilateral frontal approach is a viable and reliable alternative for extended bifrontal technique for the resection of large midline anterior cranial fossa meningiomas with avoidance of SSS ligation, decreased brain handling with better olfaction preservation while achieving comparable tumor resection and acceptable cosmetic outcomes.

Isolated embryonal rhabdomyosarcoma of the anterior petrous bone in a young child: Focusing on the intra-operative diagnosis and differentials

OBJECTIVE

Rhabdomyosarcoma is a common soft tissue tumor, but isolated involvement of anterior portion of petrous bone is exceedingly rare. Here, we present a case of embryonal rhabdomyosarcoma involving the anterior petrous without involvement of the mastoid and middle ear.

PATIENT

A 6-year-old boy presented with a progressive right side lower motor neuron facial paresis for 1-month duration along with headache and recurrent vomiting episodes. Radiology showed a contrast-enhancing lesion involving the right petrous apex. He underwent craniotomy and excision of the lesion. Based on the frozen section, a diagnosis of rhabdomyosarcoma was rendered, and gross total resection could be achieved. Postoperative course was uneventful.

CONCLUSION

Isolated petrous bone involvement of embryonal rhabdomyosarcoma is a rare presentation. Intra-operative frozen section plays a key role in decision making regarding the extent of excision. Hence, a prompt and accurate diagnosis is essential in managing these cases.

Suprasellar masquerader: Chordoid glioma

BACKGROUND

Chordoid glioma is a rare well-circumscribed glial neoplasm arising in adults and predominantly affects females. Tanycytes of the third ventricle have been proposed as the cell of origin owing to its location. It is characterized by chordoid features with myxoid and inflammatory stroma and recurrent PRKCA p.D463H missense mutation.

CASE REPORT

We present two cases (30-year-old female and 45-year-old male) with similar complaints of behavioral change and headache. Midline suprasellar homogeneously enhancing mass was seen on contrast-enhanced magnetic resonance imaging. Histopathology and immunohistochemistry was characteristic of chordoid glioma with cords and clusters of epithelioid cells arranged in a solid pattern. There were variable amounts of myxoid stroma and lymphoplasmacytic infiltrate. No mitosis, necrosis, or brain invasion was noted. The cells expressed strong diffuse positivity for glial fibrillary acid protein (GFAP) and weak nuclear thyroid transcription factor (TTF-1). Epithelial membrane antigen (EMA)and brachyury were negative. Subsequently, the lady underwent gross total excision and died soon after the operation. The male patient received radiotherapy and is currently doing well after 6 months of follow-up.

CONCLUSION

The rare occurrence as well as the radiological and morphological overlaps in chordoid gliomas make them a true masquerader. Combination of GFAP and TTF-1 in the immunohistochemical panel can be useful in differential diagnosis. Mainstay of treatment is complete surgical excision, with adjuvant radiotherapy becoming increasingly important.

Delayed yet effective response of an endolymphatic sac tumor to radiosurgery: case report focusing on its radio-biological behavior

Endolymphatic sac tumors (ELST), though benign are locally invasive lesions. Owing to its vascularity, complete surgical resection is often not possible and adjuvant gamma knife radiosurgery (GKRS) is advocated to control tumor growth. These lesions do not uniformly respond to radiation therapy in the initial phase and their early radiobiological course after GKRS is less understood. We discuss a case of residual ELST where a mild increase was noted at 36 months following GKRS and then regressed completely after a decade. This report possibly has the longest follow-up revealing the true efficacy of GKRS in these tumors. ELST shows a variable response in the early years after GKRS. They may remain static, regress or increase in size. One should be aware of these patterns of early radiological responses and a long term follow up is warranted as some lesions may show radiosurgical effectiveness after a long latent period.

Controlled arachnoid opening to aid endoscopic trans-sphenoidal extrarachnoidal dissection of pituitary macroadenoma

OBJECTIVES

The arachnoid often bulges prematurely during surgical excision of large pituitary tumors obscuring the deeper regions and crevices preventing total excision. Pushing the arachnoid may not be helpful and may tear it inadvertently and extensively leading to complications. We have described controlled arachnoid opening in large pituitary macroadenomas during the final stages of excision to gain access to the hidden portions and compared our results to the conventional technique.

PATIENTS AND METHODS

Patients with pituitary macroadenoma of Hardy's III and KNOSP II in whom arachnoid had bulged prematurely were considered for study. They were grouped temporally. In first group (n = 12), the arachnoid was pushed to retrieve the tumor and in the second group (n = 10) it was punctured to aid resection. The extent of resection was assessed on postoperative scans, and complications in both groups, were noted.

RESULTS

In the first group where arachnoid was pushed to retrieve tumor, Gross Total Resection (GTR) could be achieved in 5 patients. Inadvertent large arachnoid tear occurred in 3 patients of which, 2 developed CSF Rhinorrhoea. No patient had neurovascular injury.In the second group, GTR could be achieved in all without any added complications.

CONCLUSION

Deliberate needle puncture and controlled drainage of CSF from arachnoid that bulges prematurely while endoscopic Transsphenoidal surgery for large pituitary tumors is a safe and effective method to gain access to the hidden portions of tumor to achieve GTR.

Immunohistochemical Surrogates for Molecular Stratification in Medulloblastoma

BACKGROUND

The WHO classification of central nervous system neoplasms (2016) recognized 4 histologic variants and genetically defined molecular subgroups within medulloblastoma (MB). Further, in the 2021 classification, new subtypes have been provisionally added within the existing subgroups reflecting the biological diversity. YAP1, GAB1, and β-catenin were conventionally accepted as surrogate markers to identify these genetic subgroups.

OBJECTIVES

We aimed to stratify MB into molecular subgroups using 3 immunohistochemical markers. TP53 mutation was also assessed in Wingless (WNT), and Sonic Hedgehog (SHH) subgroups. Demographic profiles, imaging details, and survival outcomes were compared within these molecular subgroups.

PATIENTS AND METHODS

Our cohort included 164 MB cases diagnosed over the last 10 years. The histologic variants were identified on histology, and tumors were molecularly stratified using YAP1, GAB1, and β-catenin. Further, TP53 mutation was assessed using immunohistochemical in WNT and SHH subgroups. The clinical details and survival outcomes were retrieved from the records, and the mentioned correlates were evaluated statistically.

RESULTS

The age ranged from 1 to 52 years with M:F ratio of 2:1. Group 3/group 4 constituted the majority (48.4%), followed by SHH (45.9%) and WNT subgroups (5.7%). Desmoplastic/nodular and MB with extensive nodularity had the best survival, whereas large cell/anaplastic had the worst. The follow-up period ranged from 1 to 129 months. The best outcome was observed for the WNT subgroup, followed by the SHH subgroup; group 3/group 4 had the worst. Among the SHH subgroup, TP53 mutant tumors had a significantly poorer outcome compared with SHH-TP53 wildtype.

CONCLUSIONS

Molecular stratification significantly contributes to prognostication, and a panel of 3 antibodies is helpful in stratifying MB into its subgroups in centers where access to advanced molecular testing is limited. Our study reinforces the efficacy of incorporating this cost-effective, minimal panel into routine practice for stratification. Further, we propose a 3-risk stratification grouping, incorporating morphology and molecular markers.

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

BACKGROUND

Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.

METHODS

This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low-middle-income countries.

RESULTS

In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of 'single-use' consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low-middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.

CONCLUSION

This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high- and low-middle-income countries.

Technique of C2 Nerve Root Preservation in the Presence of Anomalous Vertebral Artery in Atlantoaxial Operations

While accessing the C1-C2 joint during posterior atlantoaxial fixation, the C2 nerve root along with its perineural venous plexus remains an obstacle for a panoramic visualization of the entry point of the C1 lateral mass and joint preparation. Therefore, many surgeons frequently advocate its intentional sectioning during this approach, with no related major complications.^1,2 However, this sectioning has at times been associated with symptoms such as hypoesthesia, numbness, dysesthesia, and neuropathic ulcers.³ Thus C2 nerve root preservation during posterior approach for atlantoaxial dislocation (AAD) could potentially avoid such consequences.⁴ Its preservation has been described for AAD cases with relatively normal C1-C2 joint anatomy with no osseovascular abnormalities.² In contrast, attempt at C2 nerve root preservation in patients with congenital AAD harboring bony and vascular anomalies poses a greater challenge owing to a restricted operative space and the potential for perineural venous bleeding during dissection. This is more so for young neurosurgeons in the initial part of their learning curve. Video 1 details the technique of C2 nerve root dissection and preservation in a case of congenital AAD with an anomalous vertebral artery (VA). Computed tomography (CT) of this 30-year-old male patient with spastic quadriparesis showed AAD/basilar invagination with an assimilated C1-arch and right anomalous VA on CT angiography. He underwent C1-C2 joint manipulation and short-segment fixation. At 1-year follow-up, the patient's limb weakness had improved and CT showed good bony fusion. The salient operative steps involve gentle teasing and dissection of perineural soft tissues above and below the nerve root; the key to minimize venous bleeding is to dissect, coagulate, and divide them sequentially. A thorough release of the perineural soft tissues allows adequate nerve root mobilization, which in turn provides clear visualization of the C1-C2 joint space, preventing an undue nerve stretching during the C1-lateral mass screw insertion. The anomalous VA usually lies anterior to the C2 nerve root, and careful imaging evaluation allows its anticipation.³ We do not prefer the easy alternative of C2 nerve root sacrifice because of its inherent complications we noticed in our earlier clinical practice.³.

Deceptive Appearances - Spastic Paretic Hemifacial Contractures in Cases of Seventh Nerve Involvement 'Inside' and 'Outside' the Brainstem

Spastic paretic hemifacial contracture (SPHC) is a rare clinical phenomenon characterized by facial weakness and simultaneous well-sustained contraction of the unilateral half of the face, mimicking a paresis of the normal contralateral side on casual inspection. We present three cases with such phenomenon and have postulated the underlying mechanisms. One patient had intrinsic brainstem glioma, and the others were operated for extra-axial lesions compressing the pons. The former presented with SPHC, whereas the latter two gradually developed this phenomenon following postoperative facial paresis. This condition is possibly due to denervation hyper-excitability of the facial supranuclear pathway or an aberrant regeneration secondary to nerve injury leading to functional facial-nerve nuclear reorganization. SPHC occurrence is not limited to intra-axial lesions but can also be seen after partial injury to the facial nerve beyond its exit from the brainstem.

Feasibility of awake endoscopic third ventriculostomy in selected patients of obstructive hydrocephalus

BACKGROUND

Endoscopic third ventriculostomy (ETV) is usually performed under general anesthesia (GA) with proper head immobilization. However a few patients with hydrocephalus (HCP) may not be suitable for GA. Once the surgeon is familiar with endoscopic ventricular anatomy and gains adequate surgical experience with the procedure, ETV can be attempted under local anesthesia (LA) in selected patients. Here we discuss our experience of treating 32 patients of HCP with ETV under LA.

METHODS

32 symptomatic HCP patients with in the age range of 13 and 65 years, conscious, alert, cooperative and at high risk for GA owing to deranged liver or renal function, associated co-morbidities, pregnancy were considered for ETV under scalp block. All patients were evaluated for any discomfort during the surgical intervention.

RESULT

All procedures were completed under LA. Four patients needed additional sedation prior to the scalp block to alleviate their apprehension. Four patients complained of bilateral orbital pain. In three it coincided with irrigation of fluid lower than body temperature. One patient had pain while touching the dorsum sella and needed analgesic supplement. All of them improved and none required additional CSF diversion within the average follow up of 9.5 months.

CONCLUSION

ETV can be performed under local anesthesia in conscious, alert and cooperative patients in experienced hands. Unnecessary stimulation of the painful structures should be avoided and fluid for irrigation should be at body temperature. This ensures patient comfort and safety of the procedure.

A Randomized Study of Short Course (One Week) Radiation Therapy with or without Temozolomide in Elderly and/or Frail Patients with Newly Diagnosed Glioblastoma (GBM)

OBJECTIVE

Short-course radiotherapy (25 Gy in 5 fractions) has been shown to be non-inferior to standard course radiotherapy in elderly and frail patients (60 Gy in 30 fractions). The purpose of this study was to determine the effects of temozolomide combined with short-course radiotherapy on the outcome of elderly and frail patients.

METHODS

Between January 2017 and November 2018, 90 patients (65 years old and KPS score of 50-70; 65 years old and KPS score of 80-100; and 65 years old and KPS score of 50-70) were assessed for eligibility. Nine patients were excluded because they did not meet the inclusion criteria, six patients declined to participate, and four patients were unable to complete the quality-of-life questionnaire. The remaining 71 patients were divided into two arms at random in a 1:1 ratio. Short-course radiotherapy with concurrent temozolomide and adjuvant temozolomide was given to Arm 1, while short-course radiotherapy alone was given to Arm 2.

RESULTS

In terms of overall survival and progression-free survival, radiotherapy with concurrent temozolomide and adjuvant temozolomide outperformed short-course radiotherapy alone. The median overall survival in arm 1 was 146 days and 121 days in arm 2 (P=0.146). The median progression-free survival in arm 1 was 109.50 days, while it was 77 days in arm 2 (P=0.028). With a median follow-up time of 6 months, the quality of life at 4 weeks and 12 weeks after treatment was not different between the two arms.

CONCLUSION

We concluded that adding temozolomide to short-course radiotherapy significantly improved progression-free survival and showed an increasing trend in overall survival without compromising the quality of life.

Multiple Fusarium brain abscesses in a young child

Isolated intracranial fungal infection is infrequent and mostly seen in high-risk, immunocompromised patients. Fusarium, a primary plant fungus, rarely contributes to such disease. Amongst the very few cases of Fusarium brain abscess that have been reported, the infection has occurred mostly in adults. We present a case of a 6-year-old boy with tuberculous meningitis diagnosed with multiple Fusarium brain abscess caused by Fusarium falciforme during his clinical course. An immunocompromised state secondary to tuberculous meningitis presumably led to this infection. After tapping the abscesses, the child was treated with a combination of amphotericin B, voriconazole and terbinafine. Despite an aggressive therapy, he remained in poor neurological state. This is the second report of an isolated Fusarium abscess in pediatric age and the first one in a young child and provides pertinent review of this unusual central nervous system fungal infection. Such unusual infectious spectrum should be borne in mind in patients with co-existent immunosuppression.

IgG4-related Pachymeningitis as a Cause of Spinal Epidural Compression: Can Intraoperative Frozen Sections Predict the Underlying Pathology?

At times, spinal lesions are part of systemic manifestations of autoimmune disease. Awareness regarding their clinicopathological spectrum, particularly the lesions which usually respond to steroids/immunotherapy, is essential to avoid unwanted surgical morbidity. We discuss a case of a young-man presenting with thoracic spinal epidural compressive lesion which was indeed a manifestation of IgG4-related hypertrophic pachymeningitis. The mass was firmly adherent to the dura and extended into left neural foramen/paravertebral space which precluded complete excision. Frozen sections suggested fibro-inflammatory stroma with large areas of fibrosis and lymphoplasmacytic infiltrate. After subtotal excision, the patient improved with medical therapy at 1-year follow-up. Although uncommon, the case highlights the need to consider spinal presentation of this rare entity, especially in the context of autoimmune disorders or even in isolation. In this regard, intraoperative frozen section can hint the underlying inflammatory/autoimmune pathology, guide further course of surgery as well as limit unwarranted operative morbidity.

Surgical Outcome Analysis of Large and Giant Petroclival Meningiomas with Special Reference to Quality of Life Issues

BACKGROUND

Management strategies for petroclival menigiomas remain controversial.

OBJECTIVES

We share our experience in management of large and giant true petroclival meniongiomas with special emphasis on patient reported quality of life parameters.

METHODS

This is a single center study of 47 patients between 2008 and 2018. All patients were checked for tumor specific parameters, clinical parameters, extent of surgical excision, and outcome, as assessed by Karnofsky performance score (KPS), Glasgow outcome score, clinical status, and by SF-36 questionnaire.

RESULTS

32/47 patients' data were assessed. Symptoms included headache (62.5%), involvement of 5^th nerve (47%), facial nerve (40.6%), lower cranial nerves (37.5%), cerebellar signs (84%), and long tract signs in (50%) of patients. The mean preoperative KPS was 83.75+/-6.59. Surgical approaches included retromastoid suboccipital craniotomy (50%), Kawase's approach (31.25%), and others in 18.25% patients. 40.625% (n = 13) had a gross total excision, near total resection (NTR) was achieved in 53.125% (n = 17), and 6.25% (n = 2) had a subtotal excision (STE). In 13 patients who had gross total resection (GTR), there were 12 (70.5%) new neurological deficits, while among the 19 patients with NTR, only 5 (29.5%) new neurological deficits were seen. No new onset neurological deficit was seen in patients with STE of tumor. Patient assessed QoL parameters were worse in patients with GTR and best in patients with NTR/STE + GKRS.

CONCLUSION

In patients of large/giant petroclival meningiomas, NTE/STE with adjuvant GKRS provided better preservation of quality of life.

Molecular subgrouping of ependymoma across three anatomic sites and their prognostic implications

The 2021 WHO classification stratifies ependymoma (EPN) into nine molecular subgroups according to the anatomic locations which outperforms histological grading. We aimed at molecularly reclassifying 200 EPN using immunohistochemistry (IHC) and sequencing for ZFTA fusions in supratentorial (ST) EPN. Further, we assessed the utility of L1CAM, cyclinD1, and p65 markers in identifying ZFTA fusion. Demographic profiles, histologic features, molecular subgroups and clinical outcome were retrospectively analyzed. IHC for L1CAM, cyclinD1, p65, H3K27me3, and H3K27M and sequencing for ZFTA fusion were performed. ZFTA fusions were identified in 44.8% ST EPN. p65 displayed the highest specificity (93.8%), while L1CAM had the highest sensitivity (92.3%) in detecting ZFTA fusions. The negative predictive value approached 96.6% and sensitivity improved to 96.2% with combinatorial IHC (L1CAM, cyclinD1, p65). H3K27me3 loss (PF-A) was noted in 65% PF EPN. Our results provide evidence that a combination of two of three (L1CAM, p65, and cyclinD1) can be used as surrogate markers for predicting fusion. ZFTA fusion, and its surrogate markers in ST, and H3K27me3 and younger age (< 5 years) in PF showed significant correlation with PFS and OS on univariate and Kaplan-Meier analysis. On multivariate analysis, H3K27me3 loss and younger age group are associated with poor clinical outcome.

Setting up a Neurosurgical Skills Laboratory and Designing Simulation Courses to Augment Resident Training Program

BACKGROUND

The surgical skill practice in neurosurgery is being compromised in the recent past owing to the duty time constraint, patient safety concerns, and medico-legal issues. Surgical practice outside the operating room is essential to enhance a resident's operative skills and to gain confidence.

OBJECTIVE

To discuss the experience of establishing an 'in-house neurosurgery skills laboratory' and various training sessions conducted with cadaveric and non-cadaveric simulation modules.

METHODS

A skills laboratory was set up in the existing resident teaching hall with nine workstations. Each station has been equipped with an operating table, surgeon's chair, basic microscope, endoscope, high-speed drill system, and a suction machine. Vascular anastomosis, high-speed drilling, and basic neuroendoscopy were planned on low-cost non-cadaveric modules. Craniotomy and various surgical approaches were designed on cadaveric modules obtained from the anatomy department.

RESULT

A total of 18 residents in divided groups during their initial three semesters had participated in the non-cadaveric simulation courses. Twenty-six residents had participated and 12 sessions were conducted on the cadaveric modules. Three workshops were conducted and 20 residents and faculty members from five other institutions had participated in the cadaveric hands-on training session.

CONCLUSION

A well-equipped skills laboratory provides an opportunity for the residents to acquire operative expertise in a similar atmosphere to that of the operating theater. A structured program comprising various operative practice sessions should be incorporated into the resident training program.

Revisiting Surgery in the Current Era of Gamma Knife for Cavernous Sinus Lesions

BACKGROUND

The challenges associated with surgeries of cavernous sinus (CS) lesions have shifted the management trend towards upfront gamma knife radiosurgery (GKRS). Although GKRS is effective in arresting the progression of certain small residual/recurrent lesions, its efficacy in alleviating neurological deficits is less evident. Furthermore, GKRS without establishing the histopathological diagnosis, at times can be detrimental.

OBJECTIVE

We present our clinical experience to reemphasize the role of surgery for CS lesions in the current era of upfront GKRS.

MATERIALS AND METHODS

We reviewed our database of 32 patients with various CS lesions treated by surgery for progressive cranial nerve deficits. The follow-up data were analyzed for the extent of resection, and in particular for improvement in their symptoms.

RESULTS

The lesions were confirmed as hemangioma (CSH)-8, meningioma-8, trigeminal schwannoma-6, chordoma-3, residual pituitary with CS extension-3, fungal granuloma-3, and dysgerminoma-1. Symptoms improved in 23 (complete in 13) and remained at least static in six patients. Follow-up ranged from 4-36 months.

CONCLUSIONS

The nature of pathology should determine the management modality in CS lesions. Excision of CS schwannomas and chordomas yields rapid clinical improvement and good long-term outcomes. Resection is preferred for large CSH and functioning pituitary tumors. Although the clinical improvement may be less dramatic, surgery debulks the meningiomas. Most importantly, surgery also establishes the histopathological diagnosis of CS lesions. Even with an easy alternative of upfront GKRS, resection has a definite role in the primary management of most CS pathologies.

C1-C2 arthroplasty for craniovertebral junction instability: A preliminary proof of concept in human cadavers

Background:

The atlantoaxial complex contributes to significant neck movements, especially the axial rotation. Its instability is currently treated with various C1-C2 fusion techniques. This however, considerably hampers the neck movements and affects the quality of life; a C1-C2 motion preserving arthroplasty could potentially overcome this drawback.

Objectives:

We evaluate the range of motion (ROM) of lateral C1-C2 artificial joints in cadaveric models.

Materials and Methods:

This is an in vitro cadaveric biomechanical study. After C1-C2 arthroplasty through a posterior approach, the C1-C2 ROM was tested in 4 fresh-frozen human cadaveric specimens, before and after destabilization.

Results:

The mean axial rotation demonstrated after the placement of C1-C2 joint implants was 15.46 degrees on the right and 16.03 degrees on the left side; the prosthesis provided stability, with 46% of the baseline C1-C2 axial rotation on either side. The ROM achieved in the other axes was less compared with that of intact specimens. To initiate rotation, a higher moment of 1.5 Nm was required in the presence of joint implants compared to 0.5 NM in unimplanted specimens.

Conclusions:

In our preliminary ROM evaluation, the C1-C2 arthroplasty appears to be stable and provides about half of the range of atlantoaxial rotation. It has the potential for joint motion preservation in the treatment of atlantoaxial instability resulting from lateral C1-C2 joint pathologies.

Temozolomide Nonresponsiveness in Aggressive Prolactinomas and Carcinomas: Management and Outcomes

Context

Temozolomide (TMZ) is endorsed as the treatment of choice in aggressive or malignant pituitary adenomas.

Objective

Herein we describe a case of an aggressive prolactinoma that was resistant to TMZ. We performed a literature review of similar nonresponsive, aggressive prolactinomas.

Methods

A 40-year-old woman presented with a giant prolactinoma that required cabergoline, transsphenoidal surgery, and radiotherapy to achieve near-normal prolactin and apparently no residual tumor. A year later, she presented with multiple cranial nerve involvement due to a recurrent tumor extending to the infratemporal fossa. She underwent transfrontal surgery, second radiotherapy, and was started on TMZ. Despite 8 cycles of temozolomide (200 mg/m², 5/28-day cycle), she had progressive disease and ultimately succumbed to the disease. PubMed/MEDLINE, Google Scholar, and prior review articles were searched for manuscripts about patients with aggressive prolactinomas who had been treated with TMZ. Data on demography, duration of therapy, and management outcomes were analyzed in those with progressive disease.

Results

We identified 94 cases of patients with aggressive/malignant prolactinomas in the literature who had received TMZ. Progressive disease despite TMZ was present in 36 cases (38%). There was a male preponderance (65%) among these and 40% had aggressive prolactinomas, whereas the rest had carcinomas. Patients received a median of 8 cycles (interquartile range, 3.5-11.5) of TMZ. O6‐methylguanine‐DNA‐methyltransferase (MGMT) immunostaining was negative in 35%. Overall mortality at the time of publication was 40%, at a duration varying from 2 to 20 years from diagnosis.

Conclusion

TMZ resistance in aggressive/malignant prolactinomas is challenging. Progressive disease on optimal TMZ treatment entails the use of newer agents.

Primary Spinal Intradural Ewing's Sarcoma: Hemorrhagic Presentation with Acute Neurological Deterioration in Two Pediatric Patients

Extraosseous primary spinal intradural Ewing's sarcoma (ES) is an unusual entity. Bleed within such tumors with acute neurological worsening is extremely rare, especially in the pediatric age. In this article, we present two children with intradural-extramedullary ES who had sudden decline in their neurological status consequent to an intratumoral hemorrhage. We discuss their clinical course and also briefly review the pertinent literature. Spinal intradural Ewing's sarcomas possibly have a tendency to bleed. A short clinical symptomatology along with an acute neurological deterioration and radiologic evidence of intratumoral hemorrhage in a spinal intradural tumor should raise the suspicion of an ES.

Revisiting Intraoperative 2D USG with Saline-Air Mixture as Contrast for Resection of Eloquent Area Glioma in Resource-Deficient Countries

Background  Advanced ultrasound, intraoperative magnetic resonance imaging (MRI), neuromonitoring, and aminolevulenic acid have improved the resection and safety of eloquent area gliomas. However, availability of these modern gadgets is a major concern in resource-deficient countries. A two-dimensional ultrasonography 2D USG is cheaper, provides real-time imaging, and is already established but underutilized instrument. Objective  Here, we revisited the principles of 2D USG and used it for eloquent-area glioma surgery. Materials and Methods  Fifty-eight patients with eloquent area gliomas were operated in last 2 years with the aid of 2D USG with 6-13 MHz curvilinear probe. Preoperative diagnosis was high-grade glioma in 38 and low-grade glioma (LGG) in 20 patients. Tumors were categorized as predominantly hyperechoic (27), uniformly hyperechoic (7), mixed echogenicity (21), and cystic (3). Results  Intraoperatively, 2D USG could define the tumor margins in 46 cases. Of these, USG suggested gross total excision in 38 patients and subtotal in 8 patients. The findings matched with follow-up MRI in 34 patients who showed hyperechogenicity (predominant/uniform). Injecting saline with air in to the resection cavity and insinuating through adjacent brain parenchyma helped in detecting residual lesion in three cystic gliomas and in two LGG where the tumor cavity collapsed. Conclusion  2D USG is a helpful tool in eloquent area glioma surgery, especially in resource-limited countries. Visualization through adjacent parenchyma and injection of saline-air mixture in to the resection cavity helped in delineating residual lesion. Extent of resection is best monitored by 2D USG when tumor appeared hyperechoic (predominant/uniform).

Spectrum of remote site extradural hematomas following decompressive craniectomy: Does fracture always co-exist?

Background

Remote-site extradural hematomas (EDHs) after decompressive-surgeries for traumatic brain injury (TBI) are rarely encountered. Typically, they form contralateral to the injured side, with an overlying fracture. We present a subset which developed EDH immediately after decompressive-hemi-craniectomy for TBI, most without an evidence of fracture, and not limited to contralateral location.

Methods

Nine such patients were retrospectively identified. Plausible mechanisms, management issues and outcomes have been discussed.

Results

All nine patients were victims of severe-TBI. Six did not have any skull-fractures. Eight showed hemispheric-injuries while one had bifrontal-contusions. In hemispheric-injuries, midline-shift was at least 8 mm except one with midline-shift of 6 mm. The EDH was straddling the midline in 2 (bifrontal-1, bi-occipital-1), and juxtaposed to the previous craniectomy in 1, apart from a contralateral-bleed in 6; all, except one, needed evacuation. In most patients, venous-source of bleed was identified. All had improved from their preoperative Glasgow coma scale (GCS) at follow-up.

Conclusion

A fracture need not always co-exist in EDH following decompressive craniectomy. However, an extra-caution is suggested in its presence. Given the need for surgical-evacuation in most patients and an inability to assess immediate postoperative-GCS in severely head-injured, a routine postoperative-computed tomography is recommended to avoid overlooking such potentially treatable condition.

C2 Nerve Root Preservation During Posterior Fixation for Instability Secondary to Congenital Craniovertebral Junction Anomalies: Feasibility Factors and Related Outcomes

OBJECTIVE

Patients with instability because of congenital craniovertebral anomalies often have complex C1-C2 osseovascular anomalies. C2 nerve root sacrifice has been described to address such difficult anatomy during posterior C1-C2 fixation and has its own downsides. Its preservation as a recent alternative poses greater surgical challenge, and the considerations differ from other causes of craniovertebral junctional instability; the pertaining outcomes have been scarcely studied. The objective of this study was to prospectively determine the feasibility and outcomes related to C2 nerve root preservation in patients with congenital atlantoaxial dislocation (CAAD) after posterior C1-C2 fixation.

METHODS

In this observational study, 63 patients (126 nerve roots) with CAAD after posterior fixation were prospectively assessed. Underlying osseovascular anomalies affecting the feasibility of C2 nerve root preservation, and C2 nerve-related dysfunction at 12 months follow-up were analyzed.

RESULTS

The overall C2 nerve root preservation rate was 89.7%. Even in the presence of extreme joint obliquity/spondyloptosis and anomalous vertebral artery, it was feasible in about three fourths. After preservation, 28.3% patients developed new-onset C2 nerve root dysfunction: neuralgia in 2, dysesthesia in 6, and hypoesthesia/paresthesia in 9. The symptoms were not disabling in most patients.

CONCLUSIONS

In most patients with CAAD, C2 nerve root preservation is feasible despite an aberrant bony and vascular anatomy. A few patients after nerve root preservation develop related symptoms that are conservatively manageable, with no significant adverse consequences. Given the controversy in the literature on C2 nerve sacrifice-related outcomes, we favor an attempt at C2 nerve root preservation.

Head injury care in a low- and middle-income country tertiary trauma center: epidemiology, systemic lacunae, and possible leads

BACKGROUND

Although head injury (HI) from low- and middle-income countries (LMIC) heavily contributes to the global disease burden, studies are disproportionately less from this part of the world. Knowing the different epidemiological characteristics from high-income nations can target appropriate prevention strategies. This study aims to provide a comprehensive overview of the clinico-epidemiological data of HI patients, focusing on the existing challenges with possible solutions from a developing nation's perspective.

METHODS

This is a prospective, registry-based, observational study of HI in an Indian tertiary trauma-care center over 4 years. Various clinico-epidemiological parameters, risk factors, and imaging spectrum were analyzed in a multivariate model to identify the challenges faced by LMIC and discuss pragmatic solutions.

RESULTS

The study included a large-volume cohort of 14,888 patients. Notably, half of these patients belonged to mild HI, despite most were referred (90.3%) cases. Only one-third (30.8%) had severe HI. Less than a third reached us within 6 h of injury. Road traffic accidents (RTA) accounted for most injuries (61.1%), especially in the young (70.9%). Higher age, males, RTA, helmet non-usage, drunken driving, systemic injuries, and specific imaging features had an independent association with injury severity.

CONCLUSIONS

The study represents the much-needed, large-volume, epidemiological profile of HI from an LMIC, highlighting the suboptimal utilization of peripheral healthcare systems. Strengthening and integrating these facilities with the tertiary centers in a hub and enhanced spoke model, task sharing design, and efficient back-referrals promise effective neurotrauma care while avoiding overburden in the tertiary centers. Better implementation of road safety laws also has the potential to reduce the burden of HI.

Intracranial Textiloma: Imaging Features and Literature Review

Background and Importance Intracranial textilomas are retained surgical sponges presenting as pseudomass lesions in postoperative patients usually with surrounding inflammatory reaction. Though rare, these are commonly misdiagnosed as postoperative hemorrhagic collections, abscesses, radionecrosis, or residual/recurrent mass lesions. We describe the imaging findings of intracranial textilomas diagnosed in four patients on follow-up postoperative imaging along with their characteristic imaging findings to help radiologists/neurosurgeons make accurate diagnosis.

Clinical Presentation One patient had chronic headache without any focal neurological deficits. Rest of the patients were asymptomatic at the time of presentation

Conclusion In postoperative scans, possibility of textilomas should be considered apart from residual/recurrent lesions, postoperative abscesses, or radionecrosis. Correct and timely diagnosis is important for further treatment planning and patient care.

Feasibility of Conducting a Virtual Exit Exam in Neurosurgery During the SARS-COV19 Pandemic

Background

Skills assessment forms an integral part of the exit examination in neurosurgical training programs. The established method of evaluating trainees for their clinical knowledge and surgical proficiency in the operating room is not feasible in the current time of SARS-COV19 pandemic.

Objective

The feasibility of conducting such an assessment using case modules on an online meeting platform is discussed.

Methods

Six candidates were evaluated on two consecutive days with two internal examiners located at the examination site and two external examiners situated at their own institutions elsewhere in the country. Clinical details, including images and videos of patients managed at our institute were recorded and provided to the candidates as case modules. Four sessions were conducted in the form of long and short cases, operative neurosurgery, neuroradiology, and neuropathology and a general viva-voce using "Zoom" (Zoom-Video-Communications, Inc. USA) platform. Feedback from the examinee and the examiners were obtained for any modification in the current format.

Result

The online platform worked well without any interruption except for slight lag in the audio-visual system and occasional difficulty in using microphone and screen simultaneously. Trainees were able to interpret the clinical details and rated this format close to actual clinical evaluation. The examiners uniformly agreed that the online format for assessment was satisfactory and made some suggestions for improvement.

Conclusion

Clinical and surgical skill evaluation is feasible using case modules and online meeting platforms. Use of original patient's data, images, videos demonstrating clinical signs, and operative procedures makes this assessment more objective.

Convergence Weakness with Intact Medial Rectus Function in Proptosis due to Orbital Tumors

Background

The pathway underlying ocular convergence is less clear. Convergence weakness is usually a clinical sign of dorsal midbrain pathology. An orbital tumor causing such phenomenon is unknown. We describe its occurrence in patients with proptosis due to orbital tumors.

Materials and Methods

Series of six patients with axial proptosis secondary to orbital tumors that demonstrated varying forms of convergence weakness (deficiency to complete failure).

Results

Three had weakness of convergence with drifting away of proptosed eyeball on attempted near vision, while the other three had failure. One of these had convergence weakness in nonproptosed eye. MRI excluded a central etiology in all.

Conclusions

The article highlights an interesting phenomenon of deficient convergence in the presence of intact medial rectus function in patients with proptosis. The symmetry of orbital contents possibly plays a significant role in the process of convergence.

Customising the surgical management for intraventricular meningiomas - 'one size doesn't fit all'

BACKGROUND

Intraventricular meningiomas are uncommon and gross total resection is the recommended treatment. However, total resection may not always be possible, especially in locations in which the lesions are adherent to veins and neural structures. We share our experience with intraventricular meningiomas, focusing on the management strategies and outcomes.

PATIENTS AND METHODS

We describe the data of 7 patients with intraventricular meningiomas operated at our institute over the last 9 years. Three patients had a third ventricular tumor of which two had lesions straddling across the foramen of Monro. The remaining 4 patients had trigonal mass. The clinico-radiological features, management strategies and outcomes have been elaborated with a mean follow-up of 57 months.

RESULTS

The common clinical presentations were raised intracranial pressure symptoms, visual field defects and memory deficits. One patient had multiple meningiomas. Total excision was achieved in all except in 2 patients in whom the lesion straddled across the foramen of Monro with dense adhesions to veins and neural structures. Staged resection was required in one patient with a large trigonal mass. All patients had a low-grade lesion. The tumor recurred in one patient (post-pregnancy) after partial resection. All the patients improved neurologically, and none had added deficits.

CONCLUSIONS

Gross total resection of intraventricular meningiomas although desirable may not be possible in certain cases in which the risks outweigh the benefits. These tumors often are of low histological grade and the treatment strategies should be individualized. Regular follow-up is warranted as these tumors may recur despite a low histological grade.

The enigma of acute worsening after a latent interval in post-operative patients of craniovertebral junction instability

OBJECTIVE

For reasons that are poorly understood and still undocumented, few patients of craniovertebral junction (CVJ) anomalies with instability/atlantoaxial dislocation (AAD) in our practice have been seen to suffer unprecedented acute neurological deterioration with respiratory compromise about 48-72 h post-surgery. This has been specifically observed after an uneventful, stable clinical condition in the immediate postoperative period. This study attempts to elucidate the factors and outcomes related to such latent worsening.

PATIENTS AND METHODS

The 4-year surgical data of 268-patients with CVJ instability (AAD/basilar-invagination) who underwent C1-C2 fixation were retrospectively studied. The relevant factors of 17 patients who showed such deterioration were compared with that of the remaining in a multivariate model.

RESULTS

Seventeen patients had acute neurological worsening with respiratory arrest after a latent period. Ten improved at follow-up. Contrary to the general expectation, poor preoperative neurological score or severe dislocation that needed considerable manipulation did not influence such worsening. Dural injury in patients with associated Chiari malformation and vertebral arterial (VA) injury emerged as independent factors (p < 0.01) associated with this pattern of delayed neurological decline.

CONCLUSIONS

We report our management and outcomes of a unique subset of AAD with neurological worsening in the postoperative period after 48-72 h. Such a subgroup was not previously identified in literature. Dural lacerations in AAD with Chiari, and VA injury seem to predispose to such complications and should be prevented at best. Close observation, and caution regarding early extubation (<72 h) is recommended in this subset despite an apparently uneventful immediate postoperative neurological status.

Co-existent epidermoid and dermoid in a child with spinal dysraphism

Both spinal epidermoids and dermoids, given their common embryological origin, are referred as a single entity under the category of spinal inclusion tumors. Many theories, although speculative, have been proposed in relevance to their development. We present a unique case of dual pathology consisting of both epidermoid and dermoid components in a child with spinal dysraphism and succinctly touch upon the related embryological aspects and plausible pathogenesis. To the best of our knowledge, such co-existent entity has not been observed in the pediatric spine. The report adds to the gamut of the diverse observations of spinal dysraphic anomalies.

Clinicopathological characteristics and outcomes in embryonal tumor with multilayered rosettes: A decade long experience from a tertiary care centre in North India

BACKGROUND

Embryonal tumor with multilayered rosettes (ETMR) are a heterogenous group clinically, pathologically and topographically. Due to limited cases, data regarding its molecular genetics, pathology and prognostic factors is evolving. We retrospectively analysed our cohort of ETMR over last decade in order to study their clinicopathological characteristics and outcome.

METHODS

Our cohort consisted of patients diagnosed with Embryonal tumor with abundant neuropil and true rosettes (ETANTR)/Ependymoblastoma (EBL)/ Medulloepithelioma (MEPL) over the past decade. Clinical details, including outcome and imaging data was retrieved. Histological analysis including immunohistochemical work-up was performed.

RESULTS

Cohort included 15 patients with age range between 1 and 28 years and M:F ratio of 1.5:1. Supratentorial location predominated in comparison to tumors arising in posterior fossa. ETANTR and EBL patterns were equally distributed (40% each), followed by one case each of mixed pattern (EBL + ETANTR), MEPL and embryonal tumor, unclassified. All tumors readily expressed LIN 28A and INI-1 was retained. Recurrence with evidence of glial and rhabdoid differentiation was noted in a single patient 9 months following resection. Follow-up period ranged from 1 to 31 months, with overall median survival of 6.4 months. Eight patients were planned for adjuvant treatment following surgery, of which only four could complete it. All patients, except for one, succumbed to the disease.

CONCLUSIONS

ETMR have a heterogenous morphology and gathers ETANTR, EBL, MEPL within its spectrum. Following treatment, the recurrent tumor may feature glial/rhabdoid differentiation. LIN28A is expressed in all cases, however should be interpreted in context of histology. Prognosis of ETMR remains dismal despite multimodal therapy.

Intraoperative consultation in the diagnosis of posterior fossa brain tumors following the 2016 WHO update

OBJECTIVE

Intraoperative crush/squash smear or frozen section consultation is routinely performed at several centers and offers rapid onsite assessment of tumor type and provides invaluable information to the neurosurgeons. The WHO classification of central nervous system neoplasms underwent a paradigm shift in 2016 with the incorporation of molecular data with the morphological features, such that several new entities came to be distinctly defined. With this paper, we present our experience at intraoperative consultation of brain tumors arising in posterior fossa and aim to apprise the pathologists with the spectrum of cytomorphologic appearances that can occur during such consultation and highlight the diagnostic dilemmas and pitfalls encountered in this setting.

METHODS

This is a retrospective observational study illustrating the salient morphological features of commonly encountered brain tumors arising in the posterior fossa (prototype example of each type) reported at our institute over a period of seven years. Both squash smears and rapid snap frozen section were prepared and stained with Toluidine blue and rapid hematoxylin and eosin (H&E) stains.

RESULTS AND CONCLUSIONS

While the majority of tumors at this location comprise of pilocytic astrocytoma, ependymoma, and medulloblastoma, some rare examples may also arise; common differentials must be considered and prudently excluded to arrive at the diagnosis which is crucial in guiding the neurosurgeon. Both squash smears and rapid frozen section should be prepared and complement each other for rapid on-site evaluation.

Fiberoptic bronchoscopy versus video laryngoscopy guided intubation in patients with craniovertebral junction instability: A cinefluroscopic comparison

Background:

Manipulation during endotracheal intubation in patients with craniovertebral junction (CVJ) anomalies may cause neurological deterioration due to underlying instability. Fiberoptic-bronchoscopy (FOB) is better than video laryngoscope (VL) for minimizing cervical spine movement during intubation. However, evidence suggesting superiority of FOB in patients with CVJ instability is lacking. We prospectively compared dynamic movements of the upper cervical spine during intubation using FOB with VL in patients with CVJ anomalies.

Methods:

A prospective, randomized, and clinical trial was conducted in 62 patients of American Society of Anaesthesiologist Grade I-II aged between 12 and 65 years with CVJ anomalies. Patients were randomized for intubation under general anesthesia with either VL or FOB. The intubation process was done with application of skeletal traction and recorded cinefluroscopically. The dynamic interrelationship of bony landmarks (horizontal, vertical, and diagonal distances between fixed points on posterior C1 and C2) was analyzed to indirectly calculate alteration of the upper cervical spinal canal diameter (at CVJ). Atlanto-dental interval (ADI) was calculated wherever possible.

Results:

The alteration in canal diameter (using bony landmarks) at CVJ during intubation was not significant with the use of either VL or FOB (P > 0.05). In 41 patients, where ADI could be measured, ADI was reduced (increased spinal canal diameter) in a greater number of patients in VL group when compared to FOB group (P < 0.05).

Conclusion:

Using rigid skull traction, intubation under general anesthesia with VL offers similar advantage as FOB in terms of the spinal kinematics in patients with CVJ anomalies/instability. Nevertheless, greater number of patients intubated with VL may have an advantage of increased cervical spinal canal diameter when compared to FOB.