Clinical practice guideline on the management of vestibular schwannoma.

INTRODUCTION: Vestibular schwannoma (VS) is the most common tumour of the cerebellopontine angle. The greater accessibility to radiological tests has increased its diagnosis. Taking into account the characteristics of the tumour, the symptoms and the age of the patient, three therapeutic strategies have been proposed: observation, surgery or radiotherapy. Choosing the most appropriate for each patient is a frequent source of controversy. MATERIAL AND METHODS: This paper includes an exhaustive literature review of issues related to VS that can serve as a clinical guide in the management of patients with these lesions. The presentation has been oriented in the form of questions that the clinician usually asks himself and the answers have been written and/or reviewed by a panel of national and international experts consulted by the Otology Commission of the SEORL-CCC. RESULTS: A list has been compiled containing the 13 most controversial thematic blocks on the management of VS in the form of 50 questions, and answers to all of them have been sought through a systematic literature review (articles published on PubMed and Cochrane Library between 1992 and 2023 related to each thematic area). Thirty-three experts, led by the Otology Committee of SEORL-CCC, have analyzed and discussed all the answers. In Annex 1, 14 additional questions divided into 4 thematic areas can be found. CONCLUSIONS: This clinical practice guideline on the management of VS offers agreed answers to the most common questions that are asked about this tumour. The absence of sufficient prospective studies means that the levels of evidence on the subject are generally medium or low. This fact increases the interest of this type of clinical practice guidelines prepared by experts.

A new standardized nomenclature in neurosurgery: Criteria and quantitative and qualitative evaluation indicators of medical procedures.

PURPOSE: Update the list of medical acts in the specialty of Neurosurgery, eliminating obsolete acts and adding the new surgical techniques developed in recent years, so that they are faithfully adapted to the usual medical practice of our specialty, as well as establishing the general principles and defining the grading criteria, quantitative indicators and assessment scales. METHODS: The elaboration of the new nomenclator was divided into 3 phases: 1) identification and selection of medical acts, 2) establishment of the degree of difficulty of each of them based on the experience and the time necessary for their completion, as well as the percentage and severity of the possible complications and 3) consensus with the members of the SENEC through their individualized submission, making the necessary adjustments and subsequent approval in the general assembly of SENEC. RESULTS: The new nomenclator has 255 medical acts grouped into 4 groups: consultations and visits, therapeutic acts, diagnostic procedures and surgical interventions. 42 procedures included in the OMC nomenclator have been eliminated due to being obsolete, not related to the specialty or being too vague. New techniques have been included and medical acts have been more precisely defined. CONCLUSIONS: This nomenclator provides up-to-date terminology and will serve to offer the portfolio of services, measure and know the relative value of our activity and the approximate costs of the procedures, and additionally, to carry out longitudinal comparative studies. It should be a tool to improve patient care and minimise geographic variability in all healthcare settings.

Patients awaiting surgery for neurosurgical diseases during the first wave of the COVID-19 pandemic in Spain: a multicentre cohort study.

OBJECTIVES: The large number of infected patients requiring mechanical ventilation has led to the postponement of scheduled neurosurgical procedures during the first wave of the COVID-19 pandemic. The aims of this study were to investigate the factors that influence the decision to postpone scheduled neurosurgical procedures and to evaluate the effect of the restriction in scheduled surgery adopted to deal with the first outbreak of the COVID-19 pandemic in Spain on the outcome of patients awaiting surgery. DESIGN: This was an observational retrospective study. SETTINGS: A tertiary-level multicentre study of neurosurgery activity between 1 March and 30 June 2020. PARTICIPANTS: A total of 680 patients awaiting any scheduled neurosurgical procedure were enrolled. 470 patients (69.1%) were awaiting surgery because of spine degenerative disease, 86 patients (12.6%) due to functional disorders, 58 patients (8.5%) due to brain or spine tumours, 25 patients (3.7%) due to cerebrospinal fluid (CSF) disorders and 17 patients (2.5%) due to cerebrovascular disease. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was mortality due to any reason and any deterioration of the specific neurosurgical condition. Second, we analysed the rate of confirmed SARS-CoV-2 infection. RESULTS: More than one-quarter of patients experienced clinical or radiological deterioration. The rate of worsening was higher among patients with functional (39.5%) or CSF disorders (40%). Two patients died (0.4%) during the waiting period, both because of a concurrent disease. We performed a multivariate logistic regression analysis to determine independent covariates associated with maintaining the surgical indication. We found that community SARS-CoV-2 incidence (OR=1.011, p<0.001), degenerative spine (OR=0.296, p=0.027) and expedited indications (OR=6.095, p<0.001) were independent factors for being operated on during the pandemic. CONCLUSIONS: Patients awaiting neurosurgery experienced significant collateral damage even when they were considered for scheduled procedures.

Primary central nervous system angiosarcoma with recurrent acute subdural hematoma.

Angiosarcoma is an infrequent tumor among sarcomas, especially presenting as a primary tumor within the central nervous system, which can lead to a rapid neurological deterioration and death in few months. We present a 41-year old man with a right frontal enhancing hemorrhagic lesion. Surgery was performed with histopathological findings suggesting a primary central nervous system angiosarcoma. He was discharged uneventfully and received adjuvant chemotherapy and radiotherapy. At 5 months, the follow-up MRI showed two lesions with an acute subdural hematoma, suggesting a relapse. Surgery was again conducted finding tumoral membranes attached to the internal layer of the duramater around the right hemisphere. The patient died a few days later due to the recurrence of the subdural hematoma. This case report illustrates a rare and lethal complication of an unusual tumor. The literature reviewed shows that gross-total resection with adjuvant radiotherapy seems to be the best treatment of choice.

Impact of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients: a nationwide study in Spain.

OBJECTIVE: To assess the effect of the first wave of the SARS-CoV-2 pandemic on the outcome of neurosurgical patients in Spain. SETTINGS: The initial flood of COVID-19 patients overwhelmed an unprepared healthcare system. Different measures were taken to deal with this overburden. The effect of these measures on neurosurgical patients, as well as the effect of COVID-19 itself, has not been thoroughly studied. PARTICIPANTS: This was a multicentre, nationwide, observational retrospective study of patients who underwent any neurosurgical operation from March to July 2020. INTERVENTIONS: An exploratory factorial analysis was performed to select the most relevant variables of the sample. PRIMARY AND SECONDARY OUTCOME MEASURES: Univariate and multivariate analyses were performed to identify independent predictors of mortality and postoperative SARS-CoV-2 infection. RESULTS: Sixteen hospitals registered 1677 operated patients. The overall mortality was 6.4%, and 2.9% (44 patients) suffered a perioperative SARS-CoV-2 infection. Of those infections, 24 were diagnosed postoperatively. Age (OR 1.05), perioperative SARS-CoV-2 infection (OR 4.7), community COVID-19 incidence (cases/105 people/week) (OR 1.006), postoperative neurological worsening (OR 5.9), postoperative need for airway support (OR 5.38), ASA grade ≥3 (OR 2.5) and preoperative GCS 3-8 (OR 2.82) were independently associated with mortality. For SARS-CoV-2 postoperative infection, screening swab test <72 hours preoperatively (OR 0.76), community COVID-19 incidence (cases/105 people/week) (OR 1.011), preoperative cognitive impairment (OR 2.784), postoperative sepsis (OR 3.807) and an absence of postoperative complications (OR 0.188) were independently associated. CONCLUSIONS: Perioperative SARS-CoV-2 infection in neurosurgical patients was associated with an increase in mortality by almost fivefold. Community COVID-19 incidence (cases/105 people/week) was a statistically independent predictor of mortality. TRIAL REGISTRATION NUMBER: CEIM 20/217.

Effectiveness of Automatic Planning of Fronto-orbital Advancement for the Surgical Correction of Metopic Craniosynostosis.

BACKGROUND: The surgical correction of metopic craniosynostosis usually relies on the subjective judgment of surgeons to determine the configuration of the cranial bone fragments and the degree of overcorrection. This study evaluates the effectiveness of a new approach for automatic planning of fronto-orbital advancement based on statistical shape models and including overcorrection. METHODS: This study presents a planning software to automatically estimate osteotomies in the fronto-orbital region and calculate the optimal configuration of the bone fragments required to achieve an optimal postoperative shape. The optimal cranial shape is obtained using a statistical head shape model built from 201 healthy subjects (age 23 ± 20 months; 89 girls). Automatic virtual plans were computed for nine patients (age 10.68 ± 1.73 months; four girls) with different degrees of overcorrection, and compared with manual plans designed by experienced surgeons. RESULTS: Postoperative cranial shapes generated by automatic interventional plans present accurate matching with normative morphology and enable to reduce the malformations in the fronto-orbital region by 82.01 ± 6.07%. The system took on average 19.22 seconds to provide the automatic plan, and allows for personalized levels of overcorrection. The automatic plans with an overcorrection of 7 mm in minimal frontal breadth provided the closest match (no significant difference) to the manual plans. CONCLUSIONS: The automatic software technology effectively achieves correct cranial morphometrics and volumetrics with respect to normative cranial shapes. The automatic approach has the potential to reduce the duration of preoperative planning, reduce inter-surgeon variability, and provide consistent surgical outcomes.

Point-of-care manufacturing: a single university hospital's initial experience.

BACKGROUND: The integration of 3D printing technology in hospitals is evolving toward production models such as point-of-care manufacturing. This study aims to present the results of the integration of 3D printing technology in a manufacturing university hospital. METHODS: Observational, descriptive, retrospective, and monocentric study of 907 instances of 3D printing from November 2015 to March 2020. Variables such as product type, utility, time, or manufacturing materials were analyzed. RESULTS: Orthopedic Surgery and Traumatology, Oral and Maxillofacial Surgery, and Gynecology and Obstetrics are the medical specialties that have manufactured the largest number of processes. Working and printing time, as well as the amount of printing material, is different for different types of products and input data. The most common printing material was polylactic acid, although biocompatible resin was introduced to produce surgical guides. In addition, the hospital has worked on the co-design of custom-made implants with manufacturing companies and has also participated in tissue bio-printing projects. CONCLUSIONS: The integration of 3D printing in a university hospital allows identifying the conceptual evolution to "point-of-care manufacturing."

Primary central nervous system angiosarcoma with recurrent acute subdural hematoma.

Angiosarcoma is an infrequent tumor among sarcomas, especially presenting as a primary tumor within the central nervous system, which can lead to a rapid neurological deterioration and death in few months. We present a 41-year old man with a right frontal enhancing hemorrhagic lesion. Surgery was performed with histopathological findings suggesting a primary central nervous system angiosarcoma. He was discharged uneventfully and received adjuvant chemotherapy and radiotherapy. At 5 months, the follow-up MRI showed two lesions with an acute subdural hematoma, suggesting a relapse. Surgery was again conducted finding tumoral membranes attached to the internal layer of the duramater around the right hemisphere. The patient died a few days later due to the recurrence of the subdural hematoma. This case report illustrates a rare and lethal complication of an unusual tumor. The literature reviewed shows that gross-total resection with adjuvant radiotherapy seems to be the best treatment of choice.

Three-dimensional photography for intraoperative morphometric analysis in metopic craniosynostosis surgery.

PURPOSE: Surgical correction of metopic craniosynostosis typically involves open cranial vault remodeling. Accurate translation of the virtual surgical plan into the operating room is challenging due to the lack of tools for intraoperative analysis of the surgical outcome. This study aimed to evaluate the feasibility of using a hand-held 3D photography device for intraoperative evaluation and guidance during cranial vault surgical reconstruction. METHODS: A hand-held structured light scanner was used for intraoperative 3D photography during five craniosynostosis surgeries, obtaining 3D models of skin and bone surfaces before and after the remodeling. The accuracy of this device for 3D modeling and morphology quantification was evaluated using preoperative computed tomography imaging as gold-standard. In addition, the time required for intraoperative 3D photograph acquisition was measured. RESULTS: The average error of intraoperative 3D photography was 0.30 mm. Moreover, the interfrontal angle and the transverse forehead width were accurately measured in the 3D photographs with an average error of 0.72 degrees and 0.62 mm. Surgeon's feedback indicates that this technology can be integrated into the surgical workflow without substantially increasing surgical time. CONCLUSION: Hand-held 3D photography is an accurate technique for objective quantification of intraoperative cranial vault morphology and guidance during metopic craniosynostosis surgical reconstruction. This noninvasive technique does not substantially increase surgical time and does not require exposure to ionizing radiation, presenting a valuable alternative to computed tomography imaging. The proposed methodology can be integrated into the surgical workflow to assist during cranial vault remodeling and ensure optimal surgical outcomes.

DREZotomy in the treatment of deafferentation pain: review of results and analysis of predictive factors for success. / Drezotomía en el tratamiento del dolor por desaferentización: revisión de resultados y análisis de factores predictores de éxito.

BACKGROUND AND OBJECTIVES: The treatment of deafferentation pain by spinal DREZotomy is a proven therapeutic option in the literature. In recent years, use of DREZotomy has been relegated to second place due to the emergence of neuromodulation therapies. The objectives of this study are to demonstrate that DREZotomy continues to be an effective and safe treatment and to analyse predictive factors for success. PATIENTS AND METHODS: A retrospective study was conducted of all patients treated in our department with spinal DREZotomy from 1998 to 2018. Bulbar DREZotomy procedures were excluded. A visual analogue scale (VAS) and the reduction of routine medication were used as outcome variables. Demographic, clinical and operative variables were analysed as predictive factors for success. RESULTS: A total of 27 patients (51.9% female) with a mean age of 53.7 years underwent DREZotomy. The main cause of pain was brachial plexus injury (BPI) (55.6%) followed by neoplasms (18.5%). The mean time of pain evolution was 8.4 years with a mean intensity of 8.7 according to the VAS, even though 63% of the patients had previously received neurostimulation therapy. Favourable outcome (≥50% pain reduction in the VAS) was observed in 77.8% of patients during the postoperative period and remained in 59.3% of patients after 22 months average follow-up (mean reduction of 4.9 points). This allowed for a reduction in routine analgesic treatment in 70.4% of them. DREZotomy in BPI-related pain presented a significantly higher success rate (93%) than the other pathologies (41.7%) (p=.001). No association was observed between outcome and age, gender, DREZ technique, duration of pain or previous neurostimulation therapies. There were six neurological complications, four post-operative transient neurological deficits and two permanent deficits. CONCLUSION: Dorsal root entry zone surgery is effective and safe for treating patients with deafferentation pain, especially after brachial plexus injury. It can be considered an alternative treatment after failed neurostimulation techniques for pain control. However, its indication should be considered as the first therapeutic option after medical therapy failure due to its good long-term results.

Brain Arteriovenous Malformations: Impact of Neurologic Status, Bleeding, and Type of Treatment on Final Outcome.

BACKGROUND: Well-designed studies assessing the treatment outcome of brain arteriovenous malformations (AVMs) are infrequent and have not consistently included all of the available treatment modalities, making their results not completely generalizable. Moreover, the predictors of poor outcome are not well defined. METHODS: We performed an observational retrospective study of AVM patients. We included patients with clinical, radiologic, and outcome data, with a minimum follow-up of 1 year. Neurologic outcome was documented using the modified Rankin Scale (mRS) at the AVM diagnosis and 30 days after the treatment. RESULTS: There were 117 patients, with equal male/female proportion. The mean follow-up time was 51 months. Treatment distribution in the Spetzler-Martin grades I-III was as follows: 52 (54.6%) surgery, 31 (32.35%) radiosurgery, 2 (0.02%) embolization, and 11 (12%) conservative follow-up. Treatment distribution in Spetzler-Martin grades IV and V was as follows: 4 (20%) surgery, 7 (35%) radiosurgery, and 10 (45%) conservative follow-up. Poor neurologic outcome (mRS ≥ 3) was significantly associated with poor clinical status at diagnosis (Glasgow Coma Scale [GCS] score< 14; odds ratio [OR]: 0.20; 95% confidence interval [CI]: 0.001-0.396; p = 0.010). The rupture of the AVM was associated with poor neurologic outcome. The Lawton-Young Supplementary scale (LYSS) proved to be the most effective in predicting poor outcome. The existence of seizures, treatment-related complications, and conservative treatment was associated with the worsening of the mRS score, whereas the existence of hemorrhage was associated with the likelihood of disability. CONCLUSION: Our results suggest that poor neurologic status at diagnosis, AVM rupture, and conservative treatment were associated with worse outcome. Hemorrhage as initial presentation is related to disability, not with mRS worsening. The LYSS appeared to be the best method to predict outcome.

Imaging and Radiologic-Pathologic Correlation in Granular Cell Astrocytomas: Report of 2 Cases.

BACKGROUND: Granular cell astrocytoma is a rare and aggressive subtype of astrocytoma that is histopathologically well defined in the literature. It is formed by polygonal cells with granular cytoplasm mixed with neoplastic astrocytes and usually a perivascular infiltrate of lymphocytes. Despite its unusual histologic appearance, relevant radiologic features have not yet been described. CASE DESCRIPTION: We report 2 middle-aged patients with neurologic symptoms secondary to a newly diagnosed brain tumor. The absence of central tumor necrosis as well as the presence of an atypical pattern of enhancement and areas of intense diffusion restriction on magnetic resonance imaging in both cases led to the diagnosis of primary central nervous system lymphoma. Histopathologic findings in both tumors showed an aggressive astrocytoma with a prominent granular cell population and perivascular lymphocytic cuffing in tissue, corresponding to a granular cell astrocytoma. Despite the favorable prognostic factors, including World Health Organization grades II and III astrocytomas and IDH mutations, the outcome was poor. CONCLUSIONS: Granular cell astrocytomas can show unusual aggressive radiologic features that do not correspond to their histopathologic grade of malignancy. The presence of perivascular lymphocytic infiltrate may alter the typical radiologic appearance of common astrocytomas.

Craniosynostosis surgery: workflow based on virtual surgical planning, intraoperative navigation and 3D printed patient-specific guides and templates.

Craniosynostosis must often be corrected using surgery, by which the affected bone tissue is remodeled. Nowadays, surgical reconstruction relies mostly on the subjective judgement of the surgeon to best restore normal skull shape, since remodeled bone is manually placed and fixed. Slight variations can compromise the cosmetic outcome. The objective of this study was to describe and evaluate a novel workflow for patient-specific correction of craniosynostosis based on intraoperative navigation and 3D printing. The workflow was followed in five patients with craniosynostosis. Virtual surgical planning was performed, and patient-specific cutting guides and templates were designed and manufactured. These guides and templates were used to control osteotomies and bone remodeling. An intraoperative navigation system based on optical tracking made it possible to follow preoperative virtual planning in the operating room through real-time positioning and 3D visualization. Navigation accuracy was estimated using intraoperative surface scanning as the gold-standard. An average error of 0.62 mm and 0.64 mm was obtained in the remodeled frontal region and supraorbital bar, respectively. Intraoperative navigation is an accurate and reproducible technique for correction of craniosynostosis that enables optimal translation of the preoperative plan to the operating room.

Management of congenital midline nasofrontal dermoid cysts in two identical twins: Case report.

Midline dermoid cysts are uncommon lesions that can lead to severe complications when an intracranial extension exists. We report the cases of two twin sisters referred to surgery for removal of the masses and the intracranial extension. They represent an additional example of familial nasal dermoid cysts, providing further support for a genetic basis for the disorder.

Neurovascular Relations of the Trigeminal Nerve in Asymptomatic Individuals Studied with High-Resolution Three-Dimensional Magnetic Resonance Imaging.

Neurovascular compression (NVC) is considered the main cause of classic trigeminal neuralgia (TN) and may be surgically addressed with microvascular decompression (MVD). Preoperative high-resolution three-dimensional magnetic resonance has proven a reliable tool to diagnose NVC in patients with refractory TN undergoing MVD. However, there is still scarce data regarding the rate, degree, and characteristics of neurovascular compression in asymptomatic individuals. This article describes the vascular relations of the trigeminal nerve in the cerebellopontine angle (CPA) in 100 subjects without known TN studied with 3.0T FIESTA (Fast Imaging Employing Steady-state Acquisition) MRI sequence. A NVC was observed in 142 (71%) of the 200 nerves with a 75% rate of bilateral NVC. Of the nerves with NVC, 92.3% showed a mere contact (Grade 1) without distortion and 78% occurred at the cisternal segment. This most common vessel causing the NVC was a vein (66%) followed by the superior cerebellar artery (28%). No significant reduction in diameter suggesting atrophy was seen in the nerves with NVC. The results indicate a high rate of mild, distal and predominantly venous vascular contact with the trigeminal nerve at the CPA in asymptomatic individuals. This clearly contrasts with the usual pattern of NVC observed in TN that is generally a severe, proximal, and arterial compression. Knowledge about the frequent NVC in asymptomatic individuals and its features is essential for interpreting preoperative MRI in patients with refractory classical TN considered for surgery. Anat Rec, 302:639-645, 2019. © 2018 Wiley Periodicals, Inc.

Anatomical Variations of the Intrapetrous Portion of the Facial Nerve.

The intrapetrous facial nerve has the second longest intraosseous course of all cranial nerves, after the mandibular nerve. But it is by far the most complex considering the anatomical structures closely related to it. The auditory and vestibular portions of the inner ear, the dura of the middle fossa and posterior fossa, the sigmoid sinus and jugular bulb, and the internal carotid artery are close enough to merit attention. This article includes an anatomical study on 100 temporal bones with anatomical references as seen from the middle fossa and from the transmastoid approaches that may help identifying the facial nerve and protecting surrounding structures. Anatomical variability was present and noteworthy when considering the venous drainage system through the temporal bone and the mastoid pneumatization. The distance from the geniculate ganglion to the hiatus falopii offered the highest variability with a range of 0 to 7.75 mm and a mean of 3.30 mm. The geniculate ganglion was dehiscent in 20.8% of the specimens and the superior semicircular canal was spontaneously blue-lined in 27% of the cases. Through the transmastoid approach, the highest variability was found regarding the distance between the vertical portion of the facial nerve and the jugular bulb (range from 1.5 to 10.0 mm), the sigmoid sinus (range from 0 to 13.25 mm) and the internal carotid artery (range from 6.0 to 15.0 mm). This study highlights the importance of the relative variability of the facial nerve to other surrounding structures within the petrous portion of the temporal bone. Anat Rec, 302:588-598, 2019. © 2018 Wiley Periodicals, Inc.

Assessment of the impact of glioma diagnostic reclassification following the new 2016 WHO classification on a series of cases. / Evaluación del impacto del cambio diagnóstico de los gliomas aplicando la nueva clasificación de la OMS de 2016 sobre una serie de casos.

BACKGROUND AND OBJECTIVES: The aim of this project is to assess diagnostic reclassification based on molecular data over morphology in a series of glial tumours since the introduction of the 2016 WHO classification of brain tumours. MATERIALS AND METHODS: Retrospective review of glial tumours (oligodendrogliomas and astrocytomas) treated in our centre between January 2012 and June 2016 in which a review of diagnosis was performed when molecular studies were added. Statistical analysis included evaluation of variables of epidemiology, morphology and molecular data (mainly IDH mutation and 1p19q codeletion), diagnostic changes after new classification was considered, and clinical impact in cases of diagnostic reclassification. RESULTS: From a total of 147 glial tumours reviewed in our centre, molecular diagnosis was obtained in 74 cases (50.3%). Initial diagnosis changed in 23 cases (31%), and 20 (87%) of them had a prior histological diagnosis of oligodendroglioma (69.6% grade ii and 17.4% grade iii). Only 3 of these 23 cases diagnosis changed from astrocytoma to oligodendroglioma. Among reclassified tumours, there was a common molecular pattern, as findings showed mutant IDH in 16 cases (69.6%) and no codeletion in 20 cases (87%). According to the cell of origin, of the whole group of 27 oligodendrogliomas in our series (reclassified and non-reclassifed), 20 cases (74%) became astrocytomas, despite typical oligodendroglial morphology, due to absence of 1p19q codeletion. There was a trend for diagnosis reclassification in younger patients (<40 years), P=.065, mainly in those with a prior diagnosis of oligodendroglioma, with no statistical differences based on gender or clinical data. Besides, reclassification was more common among tumours with mutant IDH (69.6%), P=.003, than those with wild type IDH. In terms of survival, despite receiving different treatments, no significant changes were detected between reclassified and non-reclassified tumours after a mean follow-up of 16 months, partly related to lower grade of these lesions. CONCLUSIONS: Within the spectrum of the glial tumours treated in our institution, this new classification including molecular genetics over morphological data has provided marked diagnostic changes. These changes appear mainly in tumours previously diagnosed as oligodendrogliomas and in younger patients, with molecular patterns of mutant IDH and 1p19q codeletion. Although diagnosis reclassification may affect clinic, prognosis or therapeutic management of these tumours, deeper and prospective studies on these specific aspects are needed.

Multinodular and vacuolating neuronal tumor of the cerebrum. A rare entity. New case and review of the literature.

BACKGROUND: Multinodular and vacuolating neuronal tumor has been recently described and included in the World Health Organization Classification of Tumors of The Central Nervous System, even though its consideration as a true tumor is controversial. Patients with these lesions usually present with refractory seizures and inconclusive imaging findings that may be confused with other more common diagnoses such as dysembryoplastic neuroepithelial tumors or low-grade gliomas. Therefore, surgical resection is warranted to reach a pathologic diagnosis and seizure control. To the best of our knowledge, only 16 cases have been published in the English literature. CASE DESCRIPTION: We present the case of a 52-year-old male who presented at our institution with a 2-year-history of absence of seizures. Brain MRI showed a T2-hyperintense lesion with no contrast enhancement affecting his temporal lobe. Temporal craniotomy and microsurgical resection was scheduled. The procedure was uneventful and a grayish, gluey mass was sent for pathologic analysis. The tumor was formed by immature neuronal cells organized in nodules with a vacuolated matrix. A thorough immunohistochemical analysis showed positivity for: Protein Gene Product 9.5. ATRX. OLIG2. SOX10. p16. Nestin. Synaptophysin. The findings were consistent with multinodular and vacuolating neuronal tumor. The patient has been seizure-free after surgery and with no signs of tumor progression. CONCLUSION: We present a thorough review addressing this uncommon tumor along with a description of the 17th reported case of MVNT, a tumor that was described for the first time in 2013. Further studies and case studies are necessary to establish a well-defined morphological and immunohistochemical profile along with knowledge about its natural history.

Microvascular Decompression for Trigeminal Neuralgia Using a Novel Fenestrated Clip and Tentorial Flap Technique.

BACKGROUND: Microvascular decompression (MVD) for neurovascular compression syndromes, such as trigeminal neuralgia and hemifacial spasm, has been traditionally described as an interposing technique using Teflon. Some alternative interposing materials have been proposed. In addition, transposing techniques have been increasingly reported as an alternative with a potentially lower recurrence rate and fewer complications. OBJECTIVE: To describe our experience with a technique consisting of transposition of the superior cerebellar artery using a fenestrated clip and a tentorial flap in patients with trigeminal neuralgia. METHODS: We describe a novel transposing technique using a fenestrated clip and a tentorial flap in patients with neurovascular compression. An illustrative case is provided of an 83-year-old female patient who complained of a 4-year history of left trigeminal neuralgia caused by compression by the superior cerebellar artery who was treated with this technique. Furthermore, a thorough review of the literature is presented. RESULTS: The patient underwent the procedure with the proposed technique without complication. Both the surgery and the postoperative course were uneventful. The patient remains asymptomatic 1 year after the procedure. CONCLUSION: We propose a novel technique for the treatment of trigeminal neuralgia, eliminating the need for padding the vessel with a foreign body. This technique can be applied successfully in selected cases of neurovascular compression syndromes.

Neurological complications after gamma-knife radiosurgery for hypothalamic hamartoma.

BACKGROUND: The Gamma-knife technique is a safe and effective option for the treatment of hypothalamic hamartomas that produce epileptic seizures refractory to medical treatment and/or serious behavioral disorders. After this type of radiosurgery, an adequate symptomatic control is normally achieved, with notable decrease or even disappearance of the seizures. Radiological changes, such as a decrease in the size of the tumor or adjacent edema secondary to non-necrotizing radioinduced inflammatory reaction are unusual consequences. Side effects and neurological complications are also rare events. CASE PRESENTATION: This report describes an unusual case of complete radiological resolution of a hypothalamic hamartoma as well as neurological complications after Gamma-knife surgery (receiving 13 Gy to the 85% isodose line, 1 cm(3) of tumor volume) in a 8-year-old boy who suffered from severe refractory seizures. After radiosurgery, the patient experienced a notable improvement in his symptoms, achieving seizure cessation within 3 months. However, 4 months after the procedure he presented drowsiness, fever and decreased level of consciousness due to a direct effect on the hypothalamus with local and regional edema secondary to the radiosurgery that was performed. He was successfully treated with corticosteroids (with a total duration of 11 months), and twelve months after the surgery, complete disappearance of both the nodular lesion and the secondary edema was observed. The patient remains seizure-free in the last 16 months, with remarkable changes in his behavior. CONCLUSIONS: The present case shows that complete radiological resolution of a hypothalamic hamartoma after Gamma-knife technique is unusual but possible, without long-term neurological consequences. Nevertheless, despite its low incidence, if a patient presents neurological symptoms, primarily during the first year after intervention, possible complications of this type of surgery must be taken into account.