Neuroimaging of pediatric infratentorial tumors and the value of diffusion-weighted imaging (DWI) in determining tumor grade.

BACKGROUND: Diffusion-weighted imaging (DWI) provides information about the cellular density of tumors. This feature is useful in grading and identifying different tumor types. PURPOSE: To assess the value of diffusion restriction and apparent diffusion coefficient (ADC) values in differentiating pediatric infratentorial tumors. MATERIAL AND METHODS: This was a retrospective review of the magnetic resonance imaging (MRI) of 82 children (age range 1-16 years) with infratentorial tumors. Histopathological grading after surgical excision/biopsy was categorized as low grade (WHO grades I and II) (n = 31; 29 pilocytic astrocytomas, 2 ependymomas) and high grade (WHO grade III and IV) (n = 51; 40 medulloblastomas, 8 anaplastic ependymomas, 1 anaplastic astrocytoma, 2 atypical rhabdoid teratoid tumors [ATRT]). MRI features and ADC values were compared among tumor types and grades using a two-tailed t test, Mann-Whitney U test for continuous data and Chi-square test for categorical variables. RESULTS: Diffusion restriction and low ADC value was a feature of high-grade tumors (P<0.001). The mean ADC values of the low-grade and high-grade tumors were 1.567 × 10-3mm2/s and 0.661 × 10-3mm2/s, respectively. Using 0.9 × 10-3mm2/s as the cut-off value, the sensitivity, specificity, positive and negative predictive values for differentiating the grades was 87%, 100%, 100%, and 81.8%, respectively. Significant differences were found between the mean ADC values of the individual tumor types (P<0.05), except between medulloblastoma and ATRT. CONCLUSION: ADC values and visual assessment of diffusion restriction are useful in tumor grading. The individual tumor types can be identified by an algorithmic approach, using DWI in conjunction with other described MRI features.

Dynamic imaging of the craniovertebral junction is mandatory in patients with posterior circulation strokes.

INTRODUCTION: The course of the vertebral artery after exiting from the C1 foramen transversarium and prior to entering the dura lends itself to compression in C1-2 instability. However, atlantoaxial dislocation presenting with vertebrobasilar insufficiency and posterior circulation stroke (PCS) is rare. METHODS: In this retrospective study, we identified 96 patients with PCS who had complete radiological data. Ten (10.4%) patients had craniovertebral junction (CVJ) anomalies, of which six underwent surgery and four were managed conservatively. The clinical and functional outcomes were measured in the two groups. RESULTS: Left-sided strokes were seen in 7/10 patients, the majority of whom had left dominant vertebral arteries. The mean age at presentation in those with CVJ anomalies was 27.2 ± 12.8 years that was significantly lower than those without CVJ anomalies, 52.2 ± 14.5 years (p ≤ 0.001). The etiologies of PCS in those < 50 years were CVJ anomalies (30%), atherosclerosis (30%) and vasculitis (27%); however, the overwhelming majority of strokes in the > 50 year age group was atherosclerosis (91%). Postoperatively, there were no recurrent strokes in the operated patients, who also obtained significant clinical improvement on the modified Rankin Scale, Nurick Scale and modified McCormick Scale as compared to those who did not undergo surgery. CONCLUSION: Early diagnosis and surgical treatment of CVJ instability prevent recurrent strokes and improve outcomes in patients with PCS. Physicians and spine surgeons need to be sensitized regarding CVJ anomalies as a cause of PCS enabling early diagnosis with dynamic imaging particularly in the younger age group. These slides can be retrieved under Electronic Supplementary Material.

Imaging Spectrum of Cavernous Sinus Lesions with Histopathologic Correlation.

Cavernous sinuses are paired interconnected venous plexuses situated in the floor of the middle cranial fossa on either side of the sella turcica and sphenoid sinus. They are lined by dura mater and consist of multiple venous channels within. The cavernous sinuses are intimately related to the internal carotid artery and its associated sympathetic plexus, the oculomotor nerve, the trochlear nerve, the abducens nerve, and the ophthalmic nerve. Cavernous sinuses are connected to the orbit, the pterygopalatine fossa, the infratemporal fossa, the nasopharynx, and the posterior cranial fossa by various foramina, fissures, and canals in the skull base. A multitude of structures in close relation to the cavernous sinus give rise to a myriad of possible pathologic conditions that can be broadly classified into (a) neoplastic, (b) vascular, (c) infective or inflammatory, or (d) miscellaneous lesions. These pathologic conditions can have overlapping clinical manifestations. Hence, imaging plays a crucial role in identifying the disease, assessing its extent, providing a pertinent differential diagnosis to guide further management, and suggesting a site or route for biopsy. MRI is the modality of choice to depict the cavernous sinuses, with CT and digital subtraction angiography playing supplementary roles in certain situations. In this article, the cavernous sinus lesions encountered in our institution during a 10-year period are reviewed. The purpose of the article is to (a) describe the anatomy of the cavernous sinus; (b) demonstrate the multimodality imaging spectrum of a wide variety of pathologic conditions involving the cavernous sinus, correlating with the histopathologic findings; (c) highlight important imaging clues for differential diagnosis; and (d) help the reader overcome potential pitfalls in interpretation. Online supplemental material is available for this article. ©RSNA, 2019.

An Unusual Cause of Chronic Headache in an Adolescent Boy: A Case Report.

Spontaneous intracranial hypotension (SIH) is an under-diagnosed cause of headache in children and adolescents. SIH results from cerebrospinal fluid (CSF) leak due to breach in the dura mater and the etiology for dural breach is often diverse. We report an adolescent boy who presented with chronic episodic headache that later progressed to daily headache. There was a typical history of worsening of headache on upright position and relief of headache on lying down. He was treated with migraine prophylaxis in another hospital but there was no response. Marfanoid features and brisk deep tendon reflexes were observed on clinical examination. Brain magnetic resonance imaging (MRI) revealed sagging of the brain stem, pachymeningeal enhancement, and tonsillar herniation. MRI of spine myelogram confirmed multiple levels of CSF leak. He was initially managed with supportive measures and fluoroscopic-guided fibrin glue injection. Although child remained symptom-free for the next 6 months, he again developed headache. MRI and computed tomography spine myelogram revealed a meningeal diverticulum in the lumbar spine. He was managed with an autologous epidural blood patch and he has been well since then. In this report, we highlight the clinical and radiological pointers to the presence of SIH in children with recurrent headache.

A review of extraaxial developmental venous anomalies of the brain involving dural venous flow or sinuses: persistent embryonic sinuses, sinus pericranii, venous varices or aneurysmal malformations, and enlarged emissary veins.

This paper is a narrative review of extraaxial developmental venous anomalies (eDVAs) of the brain involving dural venous flow or sinuses: persistent embryonic sinuses, sinus pericranii, enlarged emissary veins, and venous varices or aneurysmal malformations. The article highlights the natural history, anatomy, embryology, imaging, clinical implications, and neurosurgical significance of these lesions, which the authors believe represent a continuum, with different entities characterized by distinct embryopathologic features. The indications and surgical management options are discussed for these individual intracranial pathologies with relevant illustrations, and a novel classification is proposed for persistent falcine sinus (PFS). The role of neurointervention and/or microsurgery in specific cases such as sinus pericranii and enlarged emissary veins of the skull is highlighted. A better understanding of the pathophysiology and developmental anatomy of these lesions can reduce treatment morbidity and mortality. Some patients, including those with vein of Galen malformations (VOGMs), can present with the added systemic morbidity of a high-output cardiac failure. Although VOGM is the most studied and classified of the above-mentioned eDVAs, the authors believe that grouping the former with the other venous anomalies/abnormalities listed above would enable the clinician to convey the exact morphophysiological configuration of these lesions, predict their natural history with respect to evolving venous hypertension or stroke, and extrapolate invaluable insights from VOGM treatment to the treatment of other eDVAs. In recent years, many of these symptomatic venous malformations have been treated with endovascular interventions, although these techniques are still being refined. The authors highlight the broad concept of eDVAs and hope that this work will serve as a basis for future studies investigating the role of evolving focal venous hypertension/global intracranial hypertension and possibilities of fetal surgical intervention in these cases.

A randomized controlled trial to determine the role of intraoperative lumbar cerebrospinal fluid drainage in patients undergoing endoscopic transsphenoidal surgery for pituitary adenomas.

BACKGROUND: Intraoperative cerebrospinal fluid (CSF) leaks are a frequent cause of morbidity in patients undergoing transsphenoidal surgery. This prospective study was performed to examine the impact of intraoperative lumbar subarachnoid drainage (LSAD) on the incidence of this complication and on the extent of resection in patients undergoing endoscopic transsphenoidal surgery for pituitary adenomas. MATERIALS AND METHODS: This prospective study was conducted in a single large academic medical center. All patients with pituitary adenomas who had not undergone prior transsphenoidal surgery were eligible for inclusion in the study. Patients were randomly assigned to undergo transsphenoidal surgery with intraoperative lumbar drain insertion (LSAD group) or no lumbar drain insertion (no LSAD group). An otolaryngologist independently determined the occurrence of an intraoperative CSF leak. Extent of tumor resection was determined by volumetric analysis of postoperative magnetic resonance images in patients with nonfunctional tumors or functional adenomas with a large suprasellar component. RESULTS: Sixty patients were eligible for inclusion, of which 30 were assigned to the LSAD group and 30 to the no LSAD group. There were no statistically significant differences in patient demographics, tumor pathology, or radiology between the two groups. The LSAD catheter was successfully inserted in all patients in the LSAD group. Intraoperative CSF drainage significantly reduced the incidence of CSF leak from 46.7% in the no LSAD group to 3.3% in the LSAD group (P < 0.001). However, there were no statistically significant differences in the incidence of postoperative CSF rhinorrhea between the two groups. There were no major catheter-related complications. There was no statistically significant difference in the extent of resection between the two groups. CONCLUSIONS: Controlled intraoperative CSF drainage significantly reduces the incidence of intraoperative CSF leakage in patients undergoing endoscopic transsphenoidal surgery for pituitary adenomas.

Three-dimensional computed tomography angiographic study of the vertebral artery in patients with congenital craniovertebral junction anomalies.

PURPOSE: To describe vertebral artery (VA) course at the C0-C1-C2 complex in patients with congenital bony craniovertebral junction (CVJ) anomalies. METHODS: We studied the course of 169 VAs in 86 patients with congenital bony CVJ anomalies [basilar invagination (42), os odontoideum (33), and irreducible atlantoaxial dislocation (11)]. Occipitalized atlas occurred in 41 patients (30 complete and 11 partial). Using axial, coronal and sagittal three-dimensional computed tomography (3D-CT) angiograms, we traced the VA bilaterally at the CVJ and correlated the course to the presence or absence of occipitalization of the atlas. RESULTS: Of the 73 arteries associated with occipitalization of atlas, all had an abnormal course-58 (78.4 %) coursed through a canal within the C0-C1 fused complex and 15 (20.3 %) coursed below the C1 posterior arch, and it was absent unilaterally in one patient. There were 96 arteries associated with a non-occipitalized atlas and only 15 (15.3 %) were abnormal-eight coursed below the C1 posterior arch, four coursed above the C1 arch in the absence of a C1 foramen transversarium, one passed through a canal in C0-C1 and two arteries were absent unilaterally. Sixty vertebral arteries (34 on the right and 26 on the left side) had a redundant loop situated at a distance of ≥5 mm from the C1 lateral mass in patients with os odontoideum and irreducible atlantoaxial dislocation. CONCLUSIONS: In occipitalization of the atlas, the VA course is usually abnormal-typically passing through a canal within the C0-C1 fused complex or below the C1 arch. A redundant VA loop is more likely to be seen in os odontoideum and irreducible atlantoaxial dislocation. Careful study of the vertebral artery course with 3D CT angiography is mandatory while contemplating CVJ realignment surgery in congenital anomalies of the CVJ.

Sonothrombolysis for acute ischemic stroke - Break on through to the other side.

BACKGROUND: Intravenous (IV) tissue plasminogen activator (tPA) infusion combined with transcranial low-frequency ultrasound waves targeted on the occluded arterial segment (sonothrombolysis) can increase recanalization in large artery-acute ischemic stroke (LA-AIS). AIMS: To evaluate the benefits of sonothrombolysis in LA-AIS. SETTINGS AND DESIGNS: An open-labeled observational study done in a quaternary care teaching hospital. METHODOLOGY: Patients with LA-AIS within the window period (<4.5 h) with no contraindications for IV-recombinant tPA were sonothrombolysed. Recanalization was monitored and graded using the transcranial Doppler thrombolysis in brain ischemia (TIBI) flow criteria and also by time of flight magnetic resonance angiography using a modified thrombolysis in myocardial infarction score. Parenchymal changes were assessed using computed tomography (CT) or diffusion-weighted imaging-Alberta Stroke Programme Early CT Score. National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were used to assess the outcome. RESULTS: Eighteen patients underwent sonothrombolysis and the mean onset to needle time was 138 min (range 65-256). TIBI residual flow grade of ≥2 was seen in 15 of 18 patients (83%). Immediate dramatic improvement (NIHSS score ≤3 points or improvement by ≥10 points) was seen in 6 of 18 patients (30%) and in 9 of 18 patients (50%) within the next 24 h. Two patients (one with TIBI 0, another with re-occlusion) underwent mechanical thrombectomy post-sonothrombolysis. Symptomatic hemorrhage occurred in 5.5% of the patients. At 6 months, 2 of 18 patients (11%) died and 10 of 16 patients (63%) achieved mRS ≤2. CONCLUSIONS: Sonothrombolysis appears to be a safe way to augment the effect of tPA without increasing the door to needle time with the added advantage of observing flow through the occluded artery in real time.

Pure endoscopic transsphenoidal surgery for functional pituitary adenomas: outcomes with Cushing's disease.

BACKGROUND: This study was performed to examine patient outcomes following pure endoscopic transsphenoidal surgery (ETS) for Cushing's disease (CD). METHOD: We studied 64 consecutive patients who underwent 69 endoscopic transsphenoidal procedures. Radiological evaluation comprised detailed examination of preoperative magnetic resonance images (MRI), including positron emission tomography (PET) for select cases. Inferior petrosal sinus sampling (IPSS) was not performed for any patient. Remission was defined by the presence of hypocortisolemia with requirement for steroid replacement therapy or eucortisolemia with suppression to <1.8 µg/dl after 1 mg dexamethasone on evaluation at least 3 months after surgery. RESULTS: Preoperative MRI was abnormal in 87.5 % of cases and included 11 macroadenomas (17.2 %). PET was used to localize the adenoma in four cases. For microadenomas, operative procedures executed were as follows: selective adenomectomy (n = 15), enlarged adenomectomy (n = 21) and subtotal/hemihypophysectomy (n = 17). Overall, pathological confirmation of an adenoma was possible in 58 patients (90.6 %). Forty-nine patients (76.6 %) developed hypocortisolemia (<5 µg/dl) in the early postoperative period. Mean follow-up was 20 months (range 6-18 months). Remission was confirmed in 79.7 % of the 59 cases followed up for >3 months and was superior for microadenomas (86.4 %) versus macroadenomas (55.6 %) and equivocal MRI adenomas (66.7 %). Postoperative CSF rhinorrhea occurred in five patients, and new endocrine deficits were noted in 17.1 % patients. A nadir postoperative cortisol <2 µg/dl in the 1st week after surgery was highly predictive of remission (p = 0.001). CONCLUSION: ETS allows for enhanced intrasellar identification of adenomatous tissue, providing remission rates that are comparable to traditional microsurgery for CD. The best predictor of remission remains induction of profound hypocortisolemia in the early postoperative period.

Stuck with a drowsy patient, evoke the Percheron.

BACKGROUND: Strokes caused by normal variants of the cerebral circulation can be difficult to diagnose, hence a high index of suspicion is needed. This case series discusses the clinical and radiological aspects of one such stroke caused by occlusion of the artery of Percheron (AOP). MATERIALS AND METHODS: Computerized discharge summaries, outpatient records and imaging from picture archiving and communication system (PACS, GE), of patients with AOP infarction over a period of 12-years (2002-2014) were identified and their clinical and radiological features analyzed. RESULTS: Of 3589 strokes (both ischemic and hemorrhagic), 17 (0.47%) were due to AOP infarction. Their mean age was 50 years (range: 31-72 years). Disorders of consciousness (94%) were the most common presenting symptoms followed by gaze (53%) and memory impairment (24%). At follow-up, 2/17 (12%) patients developed extrapyramidal features. All patients had bilateral paramedian thalamic infarcts on magnetic resonance imaging (MRI). Associated anterior thalamic (5/17; 30%) and mid brain (10/17; 59%) infarcts were also seen. CT scan done in 11/17 patients prior to the MRI picked up only 6/11 (55%) of these infarcts. The most common etiological factors detected using the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria were cardio embolic (8/17; 47%) followed by small vessel occlusion (7/17; 41%). Mortality occurred in 2/17 (12%) patients. At 6 months, a modified Rankin score of 2 or less was seen in 8/17 (47%) patients. CONCLUSIONS: Artery of Percheron infarcts should be considered in the differential diagnosis of patients presenting with sudden alterations in consciousness. MRI should be the investigation of choice. An embolic etiology should be actively looked for.

Natural history of multiple sclerosis from the Indian perspective: Experience from a tertiary care hospital.

CONTEXT: Multiple sclerosis (MS) has a spectrum of heterogeneity, as seen in western and eastern hemispheres, in the clinical features, topography of involvement and differences in natural history. AIM: To study the clinical spectrum, imaging, and electrophysiological as well as cerebrospinal fluid (CSF) characteristics and correlate them with outcome. SETTINGS AND DESIGN: Retrospective analysis of MS patients during a period of 20 years. SUBJECTS AND METHODS: Cases were selected according to recent McDonald's criteria (2010), They were managed in the Department of Neurology, Christian Medical College, Vellore. STATISTICAL ANALYSIS USED: Chi-square and Fisher's exact tests were used for categorical variables. Multiple binary logistic regressions were done to assess significance. Kaplan-Meier curves were drawn to estimate the time to irreversible disability. RESULTS: A total of 157 patients with female preponderance (55%) were included. The inter quartile range duration of follow-up was 9.1 (8.2, 11) years for 114 patients, who were included for final outcome analysis. Relapsing remitting MS (RRMS) (54.1%) was the most common type of MS seen. RRMS had a significantly better outcome (odds ratio: 0.12, 95% confidence interval: 0.02-0.57, P = 0.008) compared to progressive form of MS (primary progressive, secondary progressive). The Expanded Disability Status Scale score of patients at presentation and at final follow-up was 4.4 ± 1.31 and 4.1 ± 2.31, respectively. During the first presentation, polysymptomatic manifestations like motor and sphincteric involvement, incomplete recovery from the first attack; and, during the disease course, bowel, bladder, cerebellar and pyramidal affliction, predicted a worse outcome. CONCLUSION: A high incidence of optico-spinal presentation, predominance of RRMS and a low yield on cerebrospinal fluid (CSF) studies are the major findings of our study. A notable feature was the analysis of prognostic markers of disability.

Surgical strategies in the management of aggressive spinal haemangiomas: Retrospective case series with literature review and a practical treatment algorithm.

Purpose: We studied the clinico-radiological features and treatment outcomes of patients with aggressive spinal haemangiomas. Methods: We undertook a retrospective review of 24 patients with aggressive spinal haemangiomas managed at our centre from 2004 to 2016. The cohort was divided into two groups. Group1 included patients managed from 2004 to 2009 while Group 2 was those treated between 2010 and 2016. Clinicoradiological features and treatment outcomes were studied. Results: Back pain (24/24) and myelopathy (18/24) were the most common presenting complaints. Over 80% (20/24) of patients, had involvement of the thoracic spine and more than 50% (13/24) had severe spasticity, being Nurick grade 4&5 at presentation. The various treatment modalities used were laminectomy with or without instrumented posterior fusion (10/24), corpectomy with instrumented fusion (10/24) and alcohol injection alone (4/24). Patients who were treated with surgery had significant clinical improvement at follow-up in both groups. Patients who underwent alcohol injection did not have any improvement in symptoms at follow-up. There was a change in our strategy in the later part of the series from a two staged anterior and posterior approach to a single staged posterior-only approach to address vertebral body disease with preoperative angioembolization. Conclusion: Haemangiomas are benign lesions with locally aggressive behavior in some cases. Results of conservative approaches such as alcohol injection in management of these lesions are discouraging. Aggressive surgical decompression combined with preoperative adjuncts such as angioembolization with or without stabilization reduces intra operative blood loss and results in good neurological recovery even in patients with severe myelopathy.

Decompressive craniectomy in cerebral venous thrombosis: a single centre experience.

BACKGROUND: Cerebral venous thrombosis (CVT) is an important cause for stroke in the young where the role for decompressive craniectomy is not well established. OBJECTIVE: To analyse the outcome of CVT patients treated with decompressive craniectomy. METHODS: Clinical and imaging features, preoperative findings and long-term outcome of patients with CVT who underwent decompressive craniectomy were analysed. RESULTS: Over 10 years (2002-2011), 44/587 (7.4%) patients with CVT underwent decompressive craniectomy. Diagnosis of CVT was based on magnetic resonance venography (MRV)/inferior vena cava (IVC). Decision for surgery was taken at admission in 19/44 (43%), within 12 h in 5/44 (11%), within first 48 h in 15/44 (34%) and beyond 48 h in 10/44 (22%). Presence of midline shift of ≥ 10 mm (p<0.0009) and large infarct volume (mean 146.63 ml; SD 52.459, p<0.001) on the baseline scan influenced the decision for immediate surgery. Hemicraniectomy was done in 38/44 (86%) and bifrontal craniectomy in 6/44 (13.6%). Mortality was 9/44 (20%). On multivariate analysis (5% level of significance) age <40 years and surgery within 12 h significantly increased survival. Mean follow-up was 25.5 months (range 3-66 months), 26/35 (74%) had 1 year follow-up. Modified Rankin Scale (mRs) continued to improve even after 6 months with 27/35 (77%) of survivors achieving mRs of ≤ 2. CONCLUSIONS: This is the largest series on decompressive craniectomy for CVT in literature to date. Decompressive craniotomy should be considered as a treatment option in large venous infarcts. Very good outcomes can be expected especially if done early and in those below 40 years.

The current role of transcranial surgery in the management of pituitary adenomas.

The aim of this study was to determine the factors influencing the use of a transcranial (TC) approach in pituitary adenomas and suggest a decision-making tree for the surgical strategy. The data for 23 (4.6%) patients who underwent TC surgery from amongst 494 pituitary adenomas were retrospectively analyzed. Eight factors on magnetic resonance imaging (MRI) that could predict a difficult transsphenoidal (TS) surgery were noted. Adverse findings at TS surgery leading to a 2nd stage TC surgery were documented. Eighteen of the 23 cases were giant adenomas. Thirteen patients underwent TC surgery alone or as an initial approach when combined with TS while 10 underwent 2nd stage TC surgery following a TS approach. Most cases in the first group had 3 or more radiological factors in combination with a small sella. The 2nd group had higher sellar tumor volumes and fewer unfavourable radiological factors that led to the initial use of the TS approach. A hard, fibrous consistency or a significant residue obscured from the surgeon's view, and difficulty in hemostasis were additional factors prompting the use of a TC approach. Tumor excision ≥90% could be achieved in 13 cases (56.5%). Post-operative RT was administered in 12 patients. There were 2 deaths (8.7%) and the major morbidity rate was 43 %. Despite advances in endoscopic surgery the TC approach may be required in 5% of cases. A study of the preoperative MRI for factors that predict difficulty with the TS approach might encourage the surgeon to consider a TC surgery either as an initial approach or combined with a TS surgery.

World Federation for Interventional Stroke Treatment (WIST) multispecialty training guidelines for endovascular stroke intervention.

Introduction: Today, endovascular treatment (EVT) is the therapy of choice for strokes due to acute large vessel occlusion, irrespective of prior thrombolysis. This necessitates fast, coordinated multi-specialty collaboration. Currently, in most countries, the number of physicians and centres with expertise in EVT is limited. Thus, only a small proportion of eligible patients receive this potentially life-saving therapy, often after significant delays. Hence, there is an unmet need to train a sufficient number of physicians and centres in acute stroke intervention in order to allow widespread and timely access to EVT. Aim: To provide multi-specialty training guidelines for competency, accreditation and certification of centres and physicians in EVT for acute large vessel occlusion strokes. Material and methods: The World Federation for Interventional Stroke Treatment (WIST) consists of experts in the field of endovascular stroke treatment. This interdisciplinary working group developed competency - rather than time-based - guidelines for operator training, taking into consideration trainees' previous skillsets and experience. Existing training concepts from mostly single specialty organizations were analysed and incorporated. Results: The WIST establishes an individualized approach to acquiring clinical knowledge and procedural skills to meet the competency requirements for certification of interventionalists of various disciplines and stroke centres in EVT. WIST guidelines encourage acquisition of skills using innovative training methods such as structured supervised high-fidelity simulation and procedural performance on human perfused cadaveric models. Conclusions: WIST multispecialty guidelines outline competency and quality standards for physicians and centres to perform safe and effective EVT. The role of quality control and quality assurance is highlighted.

World Federation for Interventional Stroke Treatment (WIST) Multispecialty Training Guidelines for Endovascular Stroke Intervention.

INTRODUCTION: Today, endovascular treatment (EVT) is the therapy of choice for strokes due to acute large vessel occlusion, irrespective of prior thrombolysis. This necessitates fast, coordinated multi-specialty collaboration. Currently, in most countries, the number of physicians and centres with expertise in EVT is limited. Thus, only a small proportion of eligible patients receive this potentially life-saving therapy, often after significant delays. Hence, there is an unmet need to train a sufficient number of physicians and centres in acute stroke intervention in order to allow widespread and timely access to EVT. AIM: To provide multi-specialty training guidelines for competency, accreditation and certification of centres and physicians in EVT for acute large vessel occlusion strokes. MATERIAL AND METHODS: The World Federation for Interventional Stroke Treatment (WIST) consists of experts in the field of endovascular stroke treatment. This interdisciplinary working group developed competency - rather than time-based - guidelines for operator training, taking into consideration trainees' previous skillsets and experience. Existing training concepts from mostly single specialty organizations were analysed and incorporated. RESULTS: The WIST establishes an individualized approach to acquiring clinical knowledge and procedural skills to meet the competency requirements for certification of interventionalists of various disciplines and stroke centres in EVT. WIST guidelines encourage acquisition of skills using innovative training methods such as structured supervised high-fidelity simulation and procedural performance on human perfused cadaveric models. CONCLUSIONS: WIST multispecialty guidelines outline competency and quality standards for physicians and centres to perform safe and effective EVT. The role of quality control and quality assurance is highlighted. SUMMARY: The World Federation for Interventional Stroke Treatment (WIST) establishes an individualized approach to acquiring clinical knowledge and procedural skills to meet the competency requirements for certification of interventionalists of various disciplines and stroke centres in endovascular treatment (EVT). WIST guidelines encourage acquisition of skills using innovative training methods such as structured supervised high-fidelity simulation and procedural performance on human perfused cadaveric models. WIST multispecialty guidelines outline competency and quality standards for physicians and centers to perform safe and effective EVT. The role of quality control and quality assurance is highlighted. SIMULTANEOUS PUBLICATION: The WIST 2023 Guidelines are published simultaneously in Europe (Adv Interv Cardiol 2023).

Leflunomide with low-dose everolimus for treatment of Kaposi's sarcoma in a renal allograft recipient.

Current treatment of Kaposi's sarcoma is reduction of immunosuppression with or without addition of mammalian target of rapamycin inhibitors (mTORi). Akt signalling plays a central role in oncogenesis of Kaposi's sarcoma. We describe a case of multifocal Kaposi's sarcoma in a renal allograft recipient, which showed unsatisfactory early response to immunosuppression reduction along with everolimus therapy but completely resolved after adding leflunomide. mTORi impair Kaposi's sarcoma oncogenesis by inhibiting mTOR downstream from the Akt signalling. Leflunomide inhibits Akt phosphorylation. This synergistic effect may be beneficial in treatment of Kaposi sarcoma and needs to be explored in trials.

Bone Marrow-Derived Mesenchymal Stem Cells Augment Regeneration of Intervertebral Disc in a Reproducible and Validated Mouse Intervertebral Disc Degeneration Model.

BACKGROUND: Back pain and radicular pain due to disc degeneration are probably the most common problems encountered in neurosurgical practice. The experience and results of stem cell therapy in animal disc degeneration model will help us while doing clinical trials. OBJECTIVE: To study the effect of bone marrow-derived mesenchymal stem cells in an established mouse disc degeneration model. METHODS: An easily reproducible mouse coccygeal (Co) 4-5 disc degenerated model by CT-guided percutaneous needle injury was established. The mesenchymal stem cells (MSCs) were cultured from mouse bone marrow and validated. By an established technique, 24 mice disc degenerative models were generated and divided equally into 3 groups (test, placebo, and control). The test group received MSCs with fibrin glue scaffold and placebo group received only scaffold after 6 weeks of degeneration. The control group did not receive any injection. The effects of MSCs were analyzed 8 weeks post injection. RESULTS: The test group showed a significant change in disc height index (%) in micro CT, whereas in the placebo and control groups, there was no change. The Safranin O staining showed an increase in glycosaminoglycan content and the polarized imaging of picrosirius red staining showed restoration of the collagen fibers in annulus fibrosus, which was statistically significant. CONCLUSION: Intradiscal MSC injection restored disc height and promoted regeneration in the discs at the end of 8 weeks. MSC's niche depends on the microenvironment of the host tissue. These findings will be helpful for clinical trials.

Development of a Unique Mouse Intervertebral Disc Degeneration Model Using a Simple Novel Tool.

STUDY DESIGN: Animal case control study. PURPOSE: To create a simple, reproducible disc degeneration model for mouse coccygeal vertebrae. OVERVIEW OF LITERATURE: Back pain due to disc degeneration is probably the most common problem encountered in neurosurgical practice. An easily reproducible animal model for disc degeneration will help in understanding its pathophysiology, and serve as a platform for examining various therapeutic options. METHODS: A total of 18 mice were divided into injured (n=12) and non-injured (n=6) groups. The disc height index (DHI%) at coccygeal 4-5 level was measured by computed tomography (CT) scan for all mice. Coccygeal 4-5 discs of the injury group were injured using a 32G needle fixed to a novel tool and confirmed by CT. The non-injury group underwent no procedure. DHI% was measured by CT at 2-, 4-, and 6-week post-injury, and all mice tails were sectioned for histopathology grading of disc degeneration at the respective time intervals. RESULTS: The injured group showed significant variation in DHI% at 2, 4, and 6 weeks, whereas there was no change in the noninjured group. Histopathologic evaluation with Safranin O stain showed a worsening of the disc degeneration score at 2, 4, and 6 weeks in the injured group, but in the non-injured group there was no change. Percutaneous needle injury technique with our novel tool provided 100% accuracy and uniform degeneration. CONCLUSIONS: A simple, easily reproducible mouse model for disc degeneration was created using a simple, cost-effective, novel tool and technique, its advantage being high precision and user friendly.