Transcranial Corticospinal Motor-Evoked Potentials in Cases of Ventral and Ventrolateral Intradural Extramedullary Cervical Spinal Cord Tumors.

Background and Objectives: We studied the clinical significance of an amplitude decrement and disappearance alarm criteria in transcranial motor-evoked potential (MEP) monitoring during surgeries on extramedullary tumors at the cervical spine with reference to postoperative morbidity. Material and Methods: We diagnosed and surgically treated fourteen patients with intradural extramedullary ventral or ventrolateral lesions to the cervical spinal cord in the Clinic of Neurosurgery at the University Hospital St Ivan Rilski from January 2018 to July 2022. Eight cases were diagnosed with schwannoma, and the remaining six had meningiomas. The follow-up period for neurological assessment was six months. Results: A decrease in the intraoperative transcranial MEPs of 50% or more compared to baseline in two cases (14.3%) resulted in an immediate postoperative motor deficit. One patient demonstrated full neurological recovery within six months, while the other exhibited only partial improvement. In six cases (42.9%) with preoperative motor deficits, tumor resection and decompression of the cervical spinal cord led directly to an increment of the transcranial MEPs by more than 20%. Postoperatively and at the 6-month follow-up, these patients showed recovery from the preoperative deficits. In the remaining cases, MEPs were stable during surgery with no clinical deterioration of the motor function. Conclusions: The decremented MEP criteria corresponded to postoperative motor deficit, whereas the improvement of the same parameters after decompression implied future recovery of preoperative motor deficits. The combination of different MEP criteria is likely to be helpful when tailored to a specific case of ventral or ventrolateral extramedullary lesions in the cervical spine.

Tumors of the nervous system and hearing loss: Beyond vestibular schwannomas.

Hearing loss is a common side effect of many tumor treatments. However, hearing loss can also occur as a direct result of certain tumors of the nervous system, the most common of which are the vestibular schwannomas (VS). These tumors arise from Schwann cells of the vestibulocochlear nerve and their main cause is the loss of function of NF2, with 95 % of cases being sporadic and 5 % being part of the rare neurofibromatosis type 2 (NF2)-related Schwannomatosis. Genetic variations in NF2 do not fully explain the clinical heterogeneity of VS, and interactions between Schwann cells and their microenvironment appear to be critical for tumor development. Preclinical in vitro and in vivo models of VS are needed to develop prognostic biomarkers and targeted therapies. In addition to VS, other tumors can affect hearing. Meningiomas and other masses in the cerebellopontine angle can compress the vestibulocochlear nerve due to their anatomic proximity. Gliomas can disrupt several neurological functions, including hearing; in fact, glioblastoma multiforme, the most aggressive subtype, may exhibit early symptoms of auditory alterations. Besides, treatments for high-grade tumors, including chemotherapy or radiotherapy, as well as incomplete resections, can induce long-term auditory dysfunction. Because hearing loss can have an irreversible and dramatic impact on quality of life, it should be considered in the clinical management plan of patients with tumors, and monitored throughout the course of the disease.

Cognitive brain activity before and after surgery in meningioma patients.

Neuropsychological studies have demonstrated that meningioma patients frequently exhibit cognitive deficits before surgery and show only limited improvement after surgery. Combining neuropsychological with functional imaging measurements can shed more light on the impact of surgery on cognitive brain function. We aimed to evaluate whether surgery affects cognitive brain activity in such a manner that it may mask possible changes in cognitive functioning measured by neuropsychological tests. Twenty-three meningioma patients participated in a fMRI measurement using a verbal working memory task as well as three neuropsychological tests focused on working memory, just before and 3 months after surgery. A region of interest based fMRI analysis was used to examine cognitive brain activity at these timepoints within the central executive network and default mode network. Neuropsychological assessment showed impaired cognitive functioning before as well as 3 months after surgery. Neuropsychological test scores, in-scanner task performance as well as brain activity within the central executive and default mode network were not significantly different between both timepoints. Our results indicate that surgery does not significantly affect cognitive brain activity in meningioma patients the first few months after surgery. Therefore, the lack of cognitive improvement after surgery is not likely the result of compensatory processes in the brain. Cognitive deficits that are already present before surgery appear to be persistent after surgery and a considerable recovery period. Our study shows potential leads that comprehensive cognitive evaluation can be of added value so that cognitive functioning may become a more prominent factor in clinical decision making.

Anestesia multimodal para ressecção de tumor cerebral com monitorização eletroneurofisiológica: relato de caso / Multimodal anesthesia for brain tumor resection with electroneurophysiological monitoring: case report

Introdução: O monitoramento neurofisiológico intraoperatório (MNIO) é uma técnica valiosa, empregada durante procedimentos neurocirúrgicos complexos. Ao monitorar continuamente as vias neurais, o MNIO fornece feedback em tempo real aos cirurgiões durante o procedimento, permitindo tomada de decisões críticas e redução do risco de déficits neurológicos. O papel do anestesiologista na identificação e correção dos fatores de risco modificáveis é fundamental para a prevenção de lesões neurológicas e otimização dos resultados. Sendo assim, a compreensão das limitações do MNIO e das evidências que orientam seu uso é de fundamental importância. Objetivo: Descrever o manejo de uma anestesia multimodal, realizada em conjunto com a equipe de neurofisiologia, para ressecção de um tumor cerebral recidivante e o seu desfecho clinico. Método: Trata-se de relato de caso atendido no Hospital do Servidor Público Municipal de São Paulo. Os dados para realização deste trabalho foram coletados durante a cirurgia, sendo a coleta autorizada pelo paciente por meio da assinatura de termo de consentimento livre e esclarecido. Relato do Caso: Paciente, sexo masculino, 64 anos, ASA II, hipertenso, com história prévia de meningioma atípico, submetido a neurocirurgia e radioterapia em 2021, em uso de anticonvulsivante oral para profilaxia de crises convulsivas. Apresenta lesão tumoral cerebral recidivante em região frontal bilateral. Após a indução anestésica, foi realizada passagem de acesso venoso central em veia jugular interna direita com auxílio de ultrassonografia, monitoração da pressão arterial invasiva após cateterização de artéria radial direita, sondagem vesical de demora, termômetro esofágico, otimização do posicionamento na mesa cirúrgica, índice bispectral e Scalp Block com 20 ml de ropicavaína a 0,375%. Realizou- se manutenção da anestesia com propofol (4-6 mg/kg/h) e remifentanil (0,1 mcg/kg/min) em infusão contínua associado a dexmedetomidina (0,2-0,6 mcg/kg/h) mantendo valores do índice bispectral entre 40-60. As respostas dos potenciais evocados foram obtidas nas extremidades superiores e inferiores durante todo o procedimento pela equipe de neurofisiologia. Durante a manipulação tumoral, foi detectada queda superior a 40% do potencial evocado motor em dimídio corporal esquerdo, e emitido o alerta à equipe cirúrgica. Nenhuma outra intercorrência foi registrada durante o procedimento. Conclusões: Propofol, dexmedetomidina, lidocaína, opioides e anestésicos voláteis potentes de baixa dosagem (menos de 0,5 CAM) associado a técnicas de bloqueios periféricos, fornecem condições compatíveis com monitoramento neurofisiológico intraoperatório. O MNIO contínuo é um complemento indispensável no período perioperatório para pacientes com alto risco de desenvolver complicações neurológicas. Os anestesistas devem fornecer um meio fisiológico e anestésico estável para facilitar a interpretação significativa das mudanças de sinal e precisa orientação cirúrgica. Palavras-chave: Adjuvantes Anestésicos. Potenciais Evocados. Neurocirurgia. Monitorização Neurofisiológica Intraoperatória.

Receptor Tyrosine Kinases as Candidate Prognostic Biomarkers and Therapeutic Targets in Meningioma.

Meningioma (MGM) is the most common type of intracranial tumor in adults. The validation of novel prognostic biomarkers to better inform tumor stratification and clinical prognosis is urgently needed. Many molecular and cellular alterations have been described in MGM tumors over the past few years, providing a rational basis for the identification of biomarkers and therapeutic targets. The role of receptor tyrosine kinases (RTKs) as oncogenes, including those of the ErbB family of receptors, has been well established in several cancer types. Here, we review histological, molecular, and clinical evidence suggesting that RTKs, including the epidermal growth factor receptor (EGFR, ErbB1), as well as other members of the ErbB family, may be useful as biomarkers and therapeutic targets in MGM.

Meningioma como causa poco común de hiposmia. A propósito de un caso / Meningioma as an infrequent cause of hyposmia. Case report

Resumen La afectación del sentido del olfato puede pasar desapercibida en gran parte de los pacientes, siendo únicamente valorada cuando la alteración es importante. Sin embargo, la hiposmia es un síntoma asociado a numerosas patologías, de menor a mayor gravedad. Este sentido está relacionado con nuestros recuerdos y puede alertarnos de potenciales amenazas. Como médicos especialistas en Otorrinolaringología debemos estar alerta ante determinados síntomas que orienten a posible etiología central. Presentamos el caso de una mujer de 39 años que acudió al Servicio de Otorrinolaringología del Hospital General Universitario Morales Meseguer derivada por hiposmia de un año de evolución con cervicalgia y cefalea occipital progresiva, sin otra sintomatología asociada. La exploración otorrinolaringológica resultó normal. Debido a la persistencia sintomática se solicitó una tomografía computarizada de senos paranasales con hallazgos de masa intracraneal extraaxial compatible con meningioma de fosa craneal anterior.

Abstract The affectation of smell can go unnoticed in a great part of the patients, being only valued when the alteration is important. However, this sense is related to our memories and can alert us to potential threats. As otolaryngologists we must be alert to certain symptoms that may lead to a possible central aetiology. We present the case of a 39-year-old woman who went to the otolaryngology service at Morales Meseguer General University Hospital due to one-year evolution of hyposmia with cervicalgia and progressive occipital headache, with no other symptoms associated. The otolaryngology examination was anodyne. In view of symptomatic persistence, a paranasal sinus computed tomography scan was requested with findings of extra-axial intracranial mass compatible with anterior cranial fossa meningioma.

Preserved arachnoid membrane acts as a predictor of postoperative visual improvement in clinoidal meningioma.

OBJECTIVES: Improvement of patient visual outcome is very important in the treatment of clinoidal meningioma (CLM). The purpose of this study is to determine the association between arachnoid preservation and visual outcome. PATIENTS: Fifteen patients with CLMs that caused visual impairment underwent surgery in our hospital. The patients included 4 men and 11 women, and the mean age was 53.3 years. METHODS: The clinical findings of these patients were retrospectively reviewed. We divided the patients into two groups based on the presence or absence of the arachnoid membrane. Group 1 comprised cases in which arachnoid preservation was intraoperatively confirmed. Group 2 comprised cases in which the arachnoid membrane was not preserved. The Landolt C chart was used to evaluate visual acuity, and dynamic visual field tests using Goldmann perimetry were used to evaluate the visual field. Results were compared before and after surgery. RESULTS: The visual acuity of the ipsilateral eye was significantly improved in Group 1 (p = 0.038). There were no other significant differences between the two groups in terms of tumor volume, patient age, and symptom duration. CONCLUSIONS: Patients in which arachnoid preservation could be intraoperatively confirmed had good improvement in visual acuity. Further research with an increased number of cases is needed to confirm these findings.

Delayed solitary mediastinal lymph node metastasis from a benign meningothelial meningioma six years after surgical resection of an intracranial tumor.

Meningiomas are common intracranial neoplasms with benign features, and extracranial metastases are very rare. There have been no previous reports of solitary mediastinal lymph node metastasis from benign meningiomas without pulmonary lesions. Here, we present a case of an 82-year-old female who visited our department for mediastinal lymphadenopathy with a history of meningioma treated with total surgical resection six years prior. Endobronchial ultrasound-guided transbronchial needle aspiration of the left lower paratracheal lymph node revealed a benign meningothelial meningioma. In patients with a history of meningioma, extracranial metastasis should be considered in the differential diagnosis of mediastinal lymphadenopathy.

How to predict the consistency and vascularity of meningiomas by MRI: an institutional experience.

OBJECTIVE: In surgery for meningiomas tumor location and extension is currently the only MRI characteristic used to predict the feasibility and difficulty of the resection. Key surgical tumor characteristics such as consistency and vascularity remain obscured until the tumor is exposed. We therefore aimed to identify MRI sequences able to predict these crucial meningioma features. METHODS: We retrospectively reviewed our imaging database on cranial meningiomas and correlated MRI T2W, T1W, and FLAIR images with the consistency and vascularity reported by the surgeon in the operative notes. The reported consistency was classified into three grades [°I (soft) to °III (hard)]. Vascularity was grouped into little (°I) versus strong (°II). MRI signal intensity (SI) ratios were calculated with ROIs in the meningioma, the buccinator muscle and the frontal white matter. RESULTS: Of the 172 reviewed patients, 44 met the strict inclusion criteria with respect to the quality of the OR notes. The included meningiomas were located at the convexity (11/44), falcine (3/44), skull base (14/44), and posterior fossa (16/44). Twenty-four meningiomas (54.5%) were classified as consistency grade (°)I, seven (15.9%) °II, and thirteen (29.5%) °III. The grade of vascularization was little in 12 and strong in 14. The higher the ratio on T2W images the softer (p = 0.020) and the more vascularized (p = 0.001) the tumor presented. DISCUSSION: T2W MR images may be helpful to characterize meningiomas with regard to the expected consistency and grade of vascularization.

Microsurgical Resection of Petroclival Meningioma via the Posterior Petrosal Approach: Three-Dimensional Operative Video.

Petroclival meningiomas are complex, deep-seated lesions related to many critical neurovascular structures. We present the case of a 44-year-old woman who had presented with a history of severe facial pain, hearing loss, and tinnitus on the left side, associated with left facial hypoesthesia (Video 1). Preoperative magnetic resonance imaging demonstrated a mass highly suggestive of a left petroclival meningioma. Considering the worsening symptoms and important mass effect, microsurgical resection using the posterior petrosal approach was performed. Mastoidectomy was performed first, followed by craniotomy encompassing both posterior and middle cranial fossae. The posterior fossa and middle fossa dural incisions were connected, coagulating and sectioning the superior petrosal sinus. Next, the tentorium was cut all the way toward the incisura, with care to preserve the fourth nerve in the last cut. After completion of the tentorium incision, the presigmoid space increased. The lesion was totally resected using microsurgical techniques, with the aid of an ultrasonic aspirator to debulk the mass and allow for its circumferential dissection. Postoperative magnetic resonance imaging demonstrated complete tumor resection. The patient presented with improvement of symptoms and no new neurological deficit during follow-up. Skull base approaches, such as the posterior petrosal approach, are useful for successfully treating challenging lesions such as the one presented, with low morbidity. Laboratory training is essential to be familiarized with the complex intraoperative neuroanatomical nuances. The patient provided written informed consent for the report of her case and operative video. The anatomical images were provided courtesy of the Rhoton Collection, American Association of Neurological Surgeons/Neurosurgical Research and Education Foundation.

A rare case of parasagittal meningioma causing isolated foot drop: case report and review of the literature.

Foot drop represents a very common reason for a neurologist referral and is often first seen in emergency departments or by a general practitioner. This condition is defined as weakness of ankle dorsiflexion (mainly through tibialis anterior muscle weakness). The most common causes include lower motor neuron lesion, with L4-L5 radiculopathy and peroneal neuropathy being the most frequent ones. Classical diagnostic pathway includes a thorough medical history, detailed neurological examination, radiological studies (MRI of the lumbosacral spine), EMG and nerve conduction studies, and a battery of laboratory tests. The absence of abnormal radiological and neurophysiological findings when searching for the most common causes of foot drop, should raise a red flag and broaden the diagnostic yield for central nervous system pathology (upper motor neuron, UMN) as a possible cause of foot drop. Central causes of isolated foot drop are very rare, with less than 20 cases reported in literature so far, and seven of them being a meningioma. We present a case of a 79-year-old female patient with an isolated foot drop (with no UMN signs on the initial examination) and parasagittal meningioma. Central causes of foot drop should be suspected when foot drop is associated with UMN signs on examination (hyperreflexia of the patellar or ankle jerk and extensor plantar reflex) and when standard diagnostic work-up (MRI of the lumbar spine, EMG and NCS, standard laboratory screening for most common causes of foot drop) is negative or inconclusive. Although very rare, central lesions present a far more serious cause of foot drop and require a more urgent diagnostic work up and a potential neurosurgical referral and treatment. Keeping in mind the possible central causes of foot drop would eliminate unnecessary diagnostic work up and avoid delayed diagnosis and treatment.

Electrophysiological predictors of hearing deterioration based on AEP monitoring during petroclival meningioma resection.

The objective of this study was to calculate the risk of postsurgical hearing deterioration as a function of changes in the amplitude and latency of the most stable components (waves III and V) of the auditory evoked potential (AEP) during petroclival meningioma resection surgery. We retrospectively analyzed intraoperative AEP monitoring results and pre- and postsurgical hearing status in 40 consecutive patients who were surgically treated for petroclival meningiomas. Statistical analyses were conducted to identify the most sensitive and specific way to predict hearing dysfunction after surgery. Patients' mean age was 59 ± 10 years, and 31 (77.5%) were women. Twelve (30%) patients presented with clinically detectable hearing impairment preoperatively. At the first postoperative assessment, four of those 12 patients reported subjective improvement, and eight reported hearing deterioration. Of those eight, four remained stable and four recovered hearing by the last assessment. Wave III latency reached its highest specificity (100%) and sensitivity (71.43%) at x = 143%. Wave V latency, on the other hand, reached its highest sensitivity (71%) and specificity (93%) at x = 124%. Finally, wave V amplitude reached its highest sensitivity (100%) and specificity (79%) at x = 74%. Intraoperative alterations of wave III latency and wave V amplitude seem to be highly sensitive and specific at predicting the risk of auditory dysfunction in patients undergoing petroclival meningioma resection and should be used to determine maximum resection with preservation of function.

Functional Outcomes and Temporal Profile of Recovery in Patients with Intradural Extramedullary Spinal Cord Tumors with Poor Nurick Grade.

BACKGROUND: Patients with spinal intradural extramedullary (IDEM) tumors usually have a good functional outcome after tumor excision. However, the literature is sparse on the functional outcome in patients with poor Nurick grade (NG 4 and 5). METHODS: A retrospective review of 81 patients with IDEM tumors presenting with a poor NG was performed to determine postoperative functional outcome and the temporal pattern of recovery. The following risk factors were analyzed: preoperative NG, duration of symptoms, tumor location, peritumoral edema, presence of syrinx, and tumor type. RESULTS: Neurologic function started recovering soon after surgery, with >80% of the patients improving by ≥1 grade at the end of 1 week after surgery. Of the 66 patients available for follow-up of >6 months after surgery, 63 (95.5%) improved to NG 0-2 and 51 (77.2%) became asymptomatic (NG 0 or 1). Three patients had a poor functional outcome on follow-up of >31 months; 2 had improved from NG 5 to NG 4, whereas 1 patient continued to be in NG 4. Factors associated with a poor outcome were an upper thoracic location (P = 0.025) and presence of a syrinx (P = 0.004). None of the patients had bladder dysfunction at follow-up of >6 months. CONCLUSIONS: After excision of spinal IDEM tumors, in patients who present with a poor neurologic function (NG 4 and 5), good functional outcome (NG 0-2) can be expected in >95% of patients. No recovery can be anticipated beyond 1 year after surgery.

Technique Nuances for Functional Preservation of Lower Cranial Nerves during Surgical Management of Ventral Foramen Magnum Meningiomas Via a Dorsal Lateral Approach.

BACKGROUND: This study established novel technique nuances in surgery for ventral foramen magnum meningiomas (vFMMs) via a dorsal lateral approach. METHODS: From July 2012 to July 2019, 37 patients with vFMMs underwent tumor resection surgery and were operated on with a dorsal lateral approach. Two safe zones were selected as the entrance of the surgical corridor. Safe zone I was located between the dural attachment of the first dental ligament (FDL) and the branches of C1; safe zone II lay between the dural attachment of the FDL and the jugular foramen. The tumor was debulked first through safe zone I and then through safe zone II. The tumor was removed through a trajectory from the caudal to cephalad to allow tumor debulking from below and downward delivery, away from the brainstem and lower cranial nerves. RESULTS: Thirty-three patients underwent gross total resection, and 4 patients underwent subtotal resection. Four patients transiently required a nasogastric feeding tube. All patients recovered within 3 months postoperatively. Three patients (8.1%) developed permanent mild hoarseness and dysphagia as a result of postoperative damage of cranial nerves IX and X. One patient underwent tracheotomy. No patient experienced tumor recurrence during the follow-up period. CONCLUSIONS: We established a minimal retraction principle, in which the selection of 2 safe zones as the entrance of the surgical corridor, tumor removal from the inferior to superior direction, and debulking followed by devascularization were the key elements to implement the minimal retraction principle in vFMM surgery.

Olfaction in Olfactory Groove Meningiomas.

BACKGROUND: Clinical examination, including pre- and postoperative assessment of olfaction, is essential in evaluating surgical outcomes in patients with olfactory groove meningiomas (OGMs). A review of a recent series revealed a lack of assessment of olfaction in most of the studies. Tests determining olfactory detection should be used to reveal olfactory dysfunction. Specialized examination techniques (e.g., electro-olfactography, olfactory evoked potentials, and functional magnetic resonance imaging) are currently used in research. METHODS: Prospective analysis of 13 patients who underwent surgical resection of OGMs from December 2013 to December 2017 was performed. Data on clinical presentation, pre- and postoperative neurologic examinations, complications, recurrences, adjuvant treatment, and follow-up outpatient examinations were recorded. Olfactory function was assessed using the Sniffin' Sticks odor identification test preoperatively, postoperatively, and 1 year after surgery. RESULTS: All the meningiomas were resected via unilateral craniotomy, and gross total resection was achieved in all cases. Surgery-related permanent morbidity was 7.7% and overall mortality 0%. For the eight patients with preoperative normosmia, five remained normosmic (62.5%), one deteriorated to hyposmia (12.5%), and two deteriorated to anosmia (25%). For the two patients with preoperative hyposmia, one remained hyposmic and one deteriorated to anosmia. For the three anosmic patients, two remained anosmic, and one improved to hyposmia.The intact olfactory function preoperatively was associated with a better olfactory outcome. Overall, 62.5% of these patients remained normosmic, and none of the hyposmic or anosmic patients normalized their olfaction.Higher meningioma volume is associated with worse olfactory function before surgery (normosmia in 16.7% versus 100.0% in less voluminous) and following the surgery (normosmia in 16.7% versus 57.1% less voluminous).The unilateral surgical approach enabled the anatomical preservation of the contralateral olfactory nerve in 76.9% of our patients. Functional normosmia was achieved in 50% and hyposmia in 30% of these cases. CONCLUSIONS: Assessment of olfactory function is both vital in preoperative decision making (surgical approach, radicality of resection) and when evaluating surgical outcome. Preoperative normosmia seems to be the most important prognostic factor for functional olfactory outcome. In normosmic patients the olfaction was preserved in 62.5% of cases. Moreover, higher meningioma volume is associated with worse olfactory function before and following the surgery. The greatest advantage of the unilateral surgical approach is anatomical preservation of the contralateral olfactory nerve with a satisfactory functional outcome. These results support a proactive approach, with early surgical resection using a unilateral approach even in cases with less voluminous OGMs that enables the preservation of olfactory function in a significant proportion of patients.

Meningioma in a patient with Werner syndrome.

Werner syndrome (WS), also known as adult progeria, is extremely rare, with about 1300 known cases in the world, with over 1000 of these in Japan. It occurs due to loss of function mutations in the WRN gene located on chromosome 8p12. WS is characterized by premature aging and increased risk of neoplasms, with meningiomas being the commonest intracranial tumor. We report the case of a 39-year-old male patient, who presented with occasional numbness in right arm for three weeks. The patient had developed signs and symptoms of premature aging which started in his adolescence. MRI brain done was suggestive of left frontal convexity extra-axial lesion, suggestive of meningioma. Genetic analysis performed has identified an autosomal recessive, apparently homozygous c.3383+3A>G mutation, a mutation not previously reported. As per the existing literature, this is the index case of meningioma in Werner syndrome from India. A new mutation has been identified.

Meningioma of the Fourth Ventricle: Literature Review

Meningiomas are among the most common central nervous system tumors, with an incidence that ranges from 15% to 40% of intracranial tumors. Of these, only 0.5% to 3% are intraventricular, and the rarest of them occurs in the fourth ventricle. Fourth-ventricle meningiomas originate generally fromthe choroid plexus and have no dural adhesions. Most often, they manifest in young patients, around 41 years of age, with a possible predominance in females, through intracranial hypertension and cerebellar syndromes. The treatment consists of surgical resection, which commonly presents good results due to the characteristics of the tumor. So, for better preoperative planning, the radiological differentiation of the most frequent tumors in this location is important. Themost common histologic subtypes are fibroblastic and meningothelial, both grade I according to the World Health Organization (WHO), although there are reports of tumors of grades II and III. We report a case ofmeningioma of the fourth ventricle operated in our institution, and we have conducted a literature review, through which we found that 57 cases have been reported so far, with the first one reported in 1938.

Chordoid Meningioma: Literature Review

Chordoid meningiomas (CMs) are a rare subgroup of tumors, accounting for 0.5% of all meningiomas. Chordoid meningioma tumors correspond to World Health Organization (WHO) Grade II lesions and behave aggressively, with an increased likelihood of recurrence. There are few genetic studies about CMs, but we understand that there is deletion at many chromosomal loci. Histologically, CMs are characterized by strands and cords of meningothelial cells arranged in a mucinous stroma. Morphologically, it can mimic other chondroid and myxoid tumors within the brain and its vicinity, thus posing a diagnostic challenge. Chordoid meningiomas have an aggressive clinical course and a propensity to recur compared with classical meningiomas. The goal of the treatment is surgery, with total resection of the tumor; however, due to its high degree of recurrence, radiotherapy is often necessary as an adjuvant treatment.

Neurofibromatosis tipos 1 y 2 / Neurofibromatosis type 1 and 2

La neurofibromatosis (NF) comprende un grupo de enfermedades genéticas de herencia autosómica dominante, que se clasifican de la siguiente manera: neurofibromatosis tipo 1 (NF1), neurofibromatosis tipo 2 (NF2) y schwannomatosis (también conocida como neurofibromatosis tipo 3). Esta última es una enfermedad muy infrecuente, con una prevalencia aproximada de 1/126 000 personas, por lo que solo profundizaremos las dos primeras. La NF1, también conocida como la enfermedad de Von Recklinghausen, es la más frecuente de las tres y afecta principalmente la piel y el sistema nervioso periférico. Se caracteriza por la presencia de máculas "café con leche", pecas axilares o inguinales, nódulos de Lisch (hamartomas en el iris) y neurofibromas (tumores de la vaina de nervios periféricos). Otras manifestaciones menos frecuentes, aunque de mayor gravedad, incluyen gliomas del nervio óptico, meningiomas, neurofibromas malignos, escoliosis y displasia de la tibia. Su diagnóstico se suele realizar al nacimiento o durante los primeros años de vida, y se estima que un 50% de quienes la padecen presenta dificultades cognitivas. No hay datos concluyentes sobre la mortalidad en los pacientes con NF1, aunque se sabe que la expectativa de vida es menor que en la población general. La NF2 tiene una prevalencia considerablemente menor que la NF1 y su inicio es más tardío, afectando principalmente a adultos jóvenes. La presentación clínica típica se caracteriza por acúfenos, hipoacusia y ataxia en contexto de la presencia de schwannomas vestibulares bilaterales. Otros hallazgos menos frecuentes incluyen schwannomas de nervios periféricos, meningiomas, ependimomas o astrocitomas. La esperanza de vida es de unos 36 años, con una supervivencia media desde el momento del diagnóstico de 15 años. (AU)

Neurofibromatosis (NF) includes a group of genetic diseases with an autosomal-dominant inheritance pattern, and they are classified as follows: Neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2) and Schwannomatosis (also known as neurofibromatosis type 3). This last one is a very rare disease, with an approximate prevalence of 1/126000, so we will only deepen in the first two. NF1, also known as von Recklinghausen disease, is the most frequent, and mainly affects the skin and peripheral nervous system. Its typical manifestations are the presence of café-au-lait macules, axillary or inguinal freckles, Lisch nodules (hamartomas in the iris) and neurofibromas (peripheral nerve sheath tumors). Less frequent manifestations, although more serious, include optic nerve gliomas, meningiomas, malignant neurofibromas, scoliosis and tibial dysplasia. The diagnosis is usually made at birth or during the first years of life, and approximately 50% of patients present cognitive difficulties. There is no conclusive data on mortality in patients with NF1, although it is known that life expectancy is lower than in general population. NF2 has a considerably lower prevalence than NF1, and its onset is later in life, mainly affecting young adults. Its typical clinical presentation is characterized by tinnitus, hearing loss and ataxia in the context in the presence of bilateral vestibular schwannomas. Less frequent findings include peripheral nerve schwannomas, meningiomas, ependymomas or astrocytomas. Life expectancy is about 36 years old, with a median survival from the moment of diagnosis of 15 years. (AU)

Prognostic Value of Ki-67/MIB-1 Expression in Meningioma Patients: A Meta-Analysis.

Ki-67/MIB-1 is the most widely used immumohistochemical marker to measure cell proliferation in recent years, and its high expression is significantly related to high malignancy and short survival cycle. This meta-analysis was conducted to confirm the prognostic value of Ki-67/MIB-1 in meningioma patients. A comprehensive search was carried out of mainstream electronic databases including Pubmed, EMBASE, Google Scholar, Web of Science, and Cochrane Library, and finally 10 studies containing 1,414 meningioma patients were included in the meta-analysis. The combined hazard ratio (HR) and its 95% confident intervals (CIs) were used to evaluate the association between Ki-67/MIB-1 expression and survival. High expression of Ki-67/MIB-1 was found to be significantly associated with low RFS (HR 3.31, 95% CI 1.62-6.78, P = 0.001, random effect) and PFS(HR 3.14, 95% CI 1.64-6.00, P = 0.001, fixed effect). Subgroup analysis was conducted to explore the potential heterogeneity. Results of the meta-analysis indicated that high expression of Ki-67/MIB-1 may serve as a useful biomarker for poor prognosis in meningioma patients.