Impact on natural history of atypical meningioma after changes in 2016 edition of the world health organization (WHO) classification of central nervous system tumors: a literature review.

Meningiomas and their WHO histological diagnostic criteria is complex, especially for grade 2 tumors presenting a interobserver discordance as high as 12.2%. The 2016 edition of the WHO Classification of CNS tumors recommended brain invasion as a stand-alone grading criterion for diagnosing an atypical grade 2 meningioma (AM). To provide an overview of the classification of 2016 WHO impact on the natural history of atypical meningioma (AM) relative to previous classification. To achieve this goal, we selected articles from the period 2017-2024 in Medline search on atypical meningiomas and analyzed them after following the following criteria: 1) reports with confirmed histopathological diagnosis according to WHO 2016 and or 2021 criteria; 2) series and case reports; 3) detailed and individualized clinical outcomes for AM; and 4) papers written in English; after that a total of 3445 patients reported in 67 manuscripts from worldwide centers from 2017 to March 2024 were analyzed. The patient's age at the time of surgery ranged from 1 month to 97 years (mean 52.28 ± 18.7 years). The most common tumor site was the convexity, accounting for 67.8%, followed by the skull base in 30.6%, ventricle in 1%, and spine in 0.6%; Gross total resection (GTR) was performed in 71.25% and subtotal resection (STR) in 28.75%; 1021 patients (29.63%) underwent adjuvant radiotherapy, and 22 patients (0.6%) were treated with adjuvant chemotherapy; tumor recurrence was reported in 1221 patients (35.44%) and 859 deaths (24.93%). 1) AM prevalence in females; 2) AM age distribution similar to the distribution of meningiomas in general; 3) AM recurrence rate of 35.44%, despite the high rate of GTR, which was higher than previously reported; 4) deepening knowledge in molecular mechanism of tumor progression will provide alternative therapeutic approaches for AM.

Natural history and neuro-oncological approach in spinal gangliogliomas: a systematic review.

To describe the natural history of spinal gangliogliomas (GG) in order to determine the most appropriate neuro-oncological management. A Medline search for relevant publications up to July 2023 using the key phrase "ganglioglioma spinal" and "ganglioglioma posterior fossa" led to the retrieval of 178 studies. This corpus provided the basis for the present review. As an initial selection step, the following inclusion criteria were adopted: (i) series and case reports on spinal GG; (ii) clinical outcomes were reported specifically for GG; (iii) GG was the only pathological diagnosis for the evaluation of the tumor; (iv) papers written only in English was evaluated; and (v) papers describing each case in the series were included. The World Health Organization (WHO) 2021 grading criteria for gangliogliomas were applied. A total of 107 tumors were evaluated (63 from male patients and 44 from female patients; 1.43 male/1.0 female ratio, mean age 18.34 ± 15.84 years). The most common site was the cervical spine, accounting for 43 cases (40.18%); GTR was performed in 35 cases (32.71%) and STR in 71 cases (66.35%), while this information was not reported in 1 case (0.94%). 8 deaths were reported (7.47%) involving 2 males (25%) and 6 females (75%) aged 4-78 years (mean 34.27 ± 18.22) years. GGs located on the spine displayed the same gender ratio as these tumors in general. The most frequent symptom was pain and motor impairment, while the most prevalent location was the cervical spinal cord. GTR of the tumor posed a challenge for neurosurgeons, due to the difficulty of resecting the lesion without damaging the spinal eloquent area, explaining the lower rate of cure for this tumor type.

Impact of a cell cycle and an extracellular matrix remodeling transcriptional signature on tumor progression and correlation with EZH2 expression in meningioma.

OBJECTIVE: The authors searched for genetic and transcriptional signatures associated with tumor progression and recurrence in their cohort of patients with meningiomas, combining the analysis of targeted exome, NF2-LOH, transcriptome, and protein expressions. METHODS: The authors included 91 patients who underwent resection of intracranial meningioma at their institution between June 2000 and November 2007. The search of somatic mutations was performed by Next Generation Sequencing through a customized panel and multiplex ligation-dependent probe amplification for NF2 loss of heterozygosity. The transcriptomic profile was analyzed by QuantSeq 3' mRNA-Seq. The differentially expressed genes of interest were validated at the protein level analysis by immunohistochemistry. RESULTS: The transcriptomic analysis identified an upregulated set of genes related to metabolism and cell cycle and downregulated genes related to immune response and extracellular matrix remodeling in grade 2 (atypical) meningiomas, with a significant difference in recurrent compared with nonrecurrent cases. EZH2 nuclear positivity associated with grade 2, particularly with recurrent tumors and EZH2 gene expression level, correlated positively with the expression of genes related to cell cycle and negatively to genes related to immune response and regulation of cell motility. CONCLUSIONS: The authors identified modules of dysregulated genes in grade 2 meningiomas related to the activation of oxidative metabolism, cell division, cell motility due to extracellular remodeling, and immune evasion that were predictive of survival and exhibited significant correlations with EZH2 expression.

Natural history of intraventricular meningiomas: systematic review.

Review the data published on the subject to create a more comprehensive natural history of intraventricular meningiomas (IVMs). A Medline search up to March 2018 using "intraventricular meningioma" returned 98 papers. As a first selection step, we adopted the following inclusion criteria: series and case reports about IVMs, as well as papers written in other languages, but abstracts written in English were evaluated. Six hundred eighty-one tumors were evaluated from 98 papers. The majority of the tumors were located in the lateral ventricles (602-88.4%), fourth ventricle (59-8.7%), and third ventricle (20-2.9%). These tumors accounted for a mortality rate of 4.0% (25 deaths) and a recurrence rate of 5.3% (26 recurrences). The majority of the tumors were grade I (89.8%) and consisted of the following subtypes: fibrous, 39.7% (n = 171); transitional, 22.0% (n = 95); meningothelial, 18.6% (n = 80); angiomatosus, 3.2% (n = 14); psammomatous, 2.6% (n = 11); and others, 13.9% (n = 60). Forty-five patients (7.4%) presented with grade II (GII) tumors, and 17 patients (2.8%) presented with grade III (GIII) tumors. These tumors follow the histopathological distribution of meningiomas in general, with the exception of the higher prevalence of the fibrous subtype, possibly due to its embryonic origin. Recurrence and mortality were lower than in other localizations likely due to a complete surgical resection rate than in the convexity and skull base, which suggests that GTR is the gold standard for the management of IVMs.

Impact of radiotherapy in atypical meningioma recurrence: literature review.

Evaluate whether radiotherapy (RT) after the neurosurgical treatment of atypical meningiomas (AM) has an impact on the reduction rate of recurrence. A Medline search through October 2017 using "atypical meningioma" returned 1277 papers for initial review. Inclusion criteria were as follows. We analyzed the database and included articles in which the anatomic pathological classification of atypical meningiomas was in accordance with WHO 2007 or WHO 2016 criteria, patients > 18 years of age, and there was postoperative external beam radiation to the tumor bed. Exclusion criteria were WHO grade I or III meningioma, patients who underwent whole-brain radiation, RT used as salvage therapy for recurrence, palliative dose of RT (< 45 Gy), recurrent AMs, and multiple AMs. Papers reporting outcomes in which atypical and anaplastic meningiomas were analyzed together were rejected, as were papers with small samples that may compromise evaluation. After filtering our initial selection, only 17 papers were selected. After reviewing the seventeen articles including a total of 1761 patients (972 female and 799 male; 1.21 female/1.0 male), the difference in proportion of tumor recurrence between patients with and without radiotherapy after neurosurgical procedure was 1.0448, 95% CI [0.8318 to 1.3125], p value = 0.7062. On the basis of this review, there is no evidence to suggest that RT decreases the rate of recurrence in patients with atypical meningiomas.

Atypical and Malignant Meningiomas: Neurooncologic Management in a Brazilian cohort.

OBJECTIVE: To analyze the surgical and oncologic treatment of a Brazilian cohort of patients with grade II and III meningioma at a follow-up time of 15 years to get an overview of these patients' outcomes. METHODS: Cross-sectional study of 43 patients (26 women, 17 men; age range 20 to 83 years; average 57.72 ± 14.54) operated on from 2000 to 2014 at a single institution, with the neuropathologic diagnosis of meningioma grade II (39 patients) and grade III (4 patients). RESULTS: Radiotherapy: 24 patients (55.81%) underwent radiotherapy; the time between the surgical procedure and the beginning of radiotherapy was 5 months; 7 patients with a diagnosis of AM underwent a new surgical procedure, albeit of adjuvant therapy, because of tumor recurrence, and only 3 of them underwent radiotherapy after the first resection. Mortality: in total, 19 deaths (44.18%) were identified in this sample: 15 (38.46%) with GII and 4 (100%) with GIII. The 10-year survival was expected in 35% of GII patients and 0% of GIII patients. CONCLUSION: Surgery is still the main form of treatment and the mainstay for prolonging survival. Radiotherapy is still controversial; however, we observed its positive impact on recurrence and progression-free survival.

Predictors of Outcome in Nontraumatic Spontaneous Acute Spinal Subdural Hematoma: Case Report and Literature Review.

OBJECTIVES: To analyze the clinical presentation and outcome of nontraumatic spontaneous acute spinal subdural hematoma by observing the predictors of outcome. METHODS/RESULTS: This study was based on a case report and systematic review of the international literature. Among the 151 patients, 80 were female and 65 were male (1.25 female/1.0 male). The age distribution ranged from 6 months to 87 years, with a small increase in incidence between the first and second decade of life and a major peak at age 60 years. The difference of proportion of good results between patients with and without established neurologic deficits was: 0.488, 95% confidence interval (95% CI) 0.237-0.648, P = 2.71e-08; coagulopathy was 0.335, 95% CI 0.163-0.508, P = 0.0002; SAH was 0.0539, 95% CI -0.119 to 0.226, P = 0.6529; lumbar puncture/associated diseases was 0.149 95% CI -0.032 to 0.330, P = 0.1171; surgery was 0.0593, 95% CI -0.114 to 0.233, P = 0.5838; and hematoma extension equal or longer than 5 levels was 0.010 95% CI -0.178 to 0.197, P = 1. CONCLUSIONS: Although mortality and morbidity associated with nontraumatic spontaneous acute spinal subdural hematoma has decreased during the last 2 decades, the disease still carries a mortality rate of approximately1.3% and a morbidity (permanent neurologic deficits) rate of 28%. The main factors affecting the outcome are neurologic status at presentation and coagulopathies.

Microsurgical treatment of tentorial meningiomas: Report of 30 patients.

BACKGROUND: Tentorial meningiomas represent about 5% of intracranial meningiomas. This article reviews our recent institutional series of patients with tentorial meningiomas, proposes a simplified classification and analyzes postoperative evolution, discussing the salient features in the management of these patients. METHODS: From 1998 to 2005, 30 patients (22 female and 8 male) with tentorial meningiomas were operated at our institution. Thirteen patients had tumor restricted to the infratentorial space; 12, to the supratentorial space; and in 5 cases, the tumor involved both compartments. Follow-up ranged from 1 to 8 years. A total of 35 surgical procedures were performed in 30 patients, where 26 procedures were performed through a single approach (2, ITSC; 10, RS; 5, SOIH; 5, ST; and 4, TT); and 9, through combined approaches (7, ITSC/ SOIH; and 2, RS/ST). RESULTS: Simpson I resection was achieved in 17 patients. Tumors involving both compartments, involving the petrous sinus, and attached to the torcula limited complete resection. Twenty-two out of 30 patients were able to return to their regular life with no or minimal neurological sequelae. Most frequent complications in our series were shunt dependence, CSF fistulae, diffuse brain injury and visual field defects. Overall, our series revealed 3% mortality and 23% morbidity. CONCLUSION: Tentorial meningiomas are associated with significant morbidity related to the nervous and vascular structures surrounding the tumor. Partial tumor removal may be necessary in some cases.

Stereotactic disconnection of hypothalamic hamartoma to control seizure and behavior disturbance: case report and literature review.

An 18-year-old boy with refractory epilepsy and aggressiveness associated to a hypothalamic hamartoma was submitted to a stereotactically guided lesion by thermocoagulation. The target was based on magnetic resonance (MR) images merged with computed tomography scan images taken on the day of surgery while patient was on a stereotactic frame. In order to reveal structures not discernible in MR images, the Schaltenbrand digital brain atlas was merged onto the patient's images. Target and trajectory of the depth electrode were chosen based on three-dimensional imaging reconstructions. A surgical plan was devised to disconnect the hypothalamic hamartoma from the hypothalamus, medial forebrain bundle, fasciculus princeps, and dorsal longitudinal fasciculus. Our target was placed at the inferior portion of the posterolateral component of the hamartoma, bordering the normal hypothalamus. The patient evolved with marked lessening of aggressiveness. Seizure frequency was reduced from several seizures per day to less than one tonic-clonic seizure during sleep per month and only two episodes suggestive of partial complex seizures during daytime. These results have remained consistent over a 24-month postoperative follow-up. Functional neuroanatomy of hypothalamic connections involved in seizure propagation and aggressive behavior was reviewed.

From lateral to mesial: the quest for a surgical cure for temporal lobe epilepsy.

PURPOSE: A gap of more than a hundred years occurred between the first accounts of mesial temporal sclerosis and recognition of its role in the pathogenesis of psychomotor seizures. This paper reviews how the understanding and surgical treatment of temporal lobe epilepsy developed, particularly from the work of Penfield, Jasper, and their associates at the Montreal Neurological Institute (MNI). METHODS: Publications on EEG and surgery for temporal lobe seizures from 1935 to 1953 were reviewed and charts of selected patients operated on at the MNI in the same period were examined. Attention was focused on the evolution of surgical techniques for temporal lobe epilepsy. RESULTS: In the late 1930s, some EEG findings suggested deep-lying disturbances originating in the temporal lobe. However, it took another two decades before the correlation of clinical, neurophysiological, and anatomical findings provided evidence for the involvement of the mesial structures in psychomotor or temporal lobe seizures. From 1949 and onward, Penfield and his associates applied this evidence to extend the surgical resections to include the uncus and the hippocampus. CONCLUSION: The collaborative work of a team led by Penfield and Jasper at the MNI helped to define the role of neurophysiological studies in epilepsy surgery. As a result, the importance of removing the mesial structures in order to obtain better seizure control in patients with temporal lobe epilepsy became firmly established.

Postoperative fever after hemispherectomy: the role of non-infectious factors.

Postoperative fever is a usual source of concern among caregivers and patients' family given that it may reflect a wide range of complications. The objective of this paper was to outline the expected postoperative temperature variation after hemispherectomies, and to establish factors that affect this curve. From 1987 to 2003, 30 patients were hemispherectomized in our institution. Among them, 24 patients without clinical diagnosis of infection were selected for this study. Postoperative axillary temperature from each patient was recorded over 10 days. Data was initially analyzed for all 24 patients and, later, for subgroups by (1) surgical technique (functional hemispherectomy, anatomical hemispherectomy, and hemispherotomy) and (2) hemispheric volume of the causative pathology (groups with large, moderately atrophic, and severely atrophic hemispheres). There was a trend of temperature elevation (p=0.06) over the first 4 days in all patients where 14 subjects recorded values over 38.5 degrees C, and 3 over 39.0 degrees C. Temperature curves from subgroups undergoing different techniques presented no statistical differences. However, the group including causative pathologies with larger hemispheres had a higher temperature curve when compared to patients with severely atrophic hemispheres (p<0.05). Our findings support the view that fever is an predictable event after hemispherectomies and causative pathologies with larger hemispheres present higher postoperative temperatures.

Efficacy of and morbidity associated with stereoelectroencephalography using computerized tomography--or magnetic resonance imaging-guided electrode implantation.

OBJECT: The purpose of this paper was to define the general efficacy of and morbidity associated with stereoelectroencephalography using modem methods of imaging and to particularize the risks related to specific lobes of the brain. METHODS: All patients admitted to the Montreal Neurological Institute who had undergone either computerized tomography- or magnetic resonance imaging-guided electrode implantation by one surgeon (A.O.) were reviewed. The procedure was considered efficient if the obtained information was sufficient to make a decision either in support of or against surgery. Two hundred seventeen patients underwent 224 implantations with 3022 electrodes. Complications related to each lobe were as follows: temporal lobe, two abscesses (0.54%); frontal lobe, one abscess and three hematomas (1.4%); and occipital lobe, one hypointense lesion found 1 week after electrode explantation (2.6%). Significant risk factors associated with hematomas were implantation in the frontal lobe (p < 0.05) and the use of four or more implanted electrodes (p < 0.025). General complications included the following: 26 patients, psychiatric symptoms during monitoring; one patient, meningitis; four patients, scalp cellulitis; and two patients, hemiparesis during angiography in the early 1980s. One of these latter patients maintained a mild hemiparesis and represents the only case of permanent neurological sequela in the entire series. Data obtained during recordings supported an indication for surgery in 178 patients (79.5%), excluded a surgical option in 37 patients (16.5%), and were unsatisfactory in nine patients (4%). Thus, the overall efficacy as defined previously was 96%. CONCLUSIONS: Stereoelectroencephalography is an efficient procedure with low associated morbidity. Bilateral exploration of the temporal lobes has a morbidity rate of approximately 1%. A higher risk of hematomas occurs with the implantation of four or more electrodes in the frontal lobes.

Hemispherectomy: a schematic review of the current techniques.

Anatomical hemispherectomy has been used for the treatment of seizures since 1938. However, it was almost abandoned in the 1960s after reports of postoperative fatalities caused by hydrocephalus, hemosiderosis, and trivial head traumas. Despite serious complications, the remarkable improvement of patients encouraged authors to carry out modifications on anatomical hemispherectomy in order to lessen its morbidity while preserving its efficacy. The effort to improve the technique generated several original procedures. This paper reviews current techniques of hemispherectomy and proposes a classification scheme based on their surgical characteristics. Techniques of hemispherectomy were sorted into two major groups: (1) those that remove completely the cortex from the hemisphere and (2) those that associate partial cortical removal and disconnection. Group 1 was subdivided into two subgroups based on the integrity of the ventricular cavity and group 2 was subdivided into three subgroups depending on the amount and location of the corticectomy. Grouping similar techniques may allow a better understanding of the distinctive features of each one and creates the possibility of comparing data from different authors.

The value of cranial computed tomography in high-risk, mildly head-injured patients.

BACKGROUND: The purpose of this article was to assess if high-risk, mildly head-injured patients with normal CT scan present an outcome similar to the group with "low-risk MHI." METHODS: A total of 379 hospital charts of inpatients with Glasgow Coma Scale scores of 13, 14, and 15 were reviewed. Information regarding age, fGCS, trauma mechanism, cranial CT scan findings, hospital course, and follow-up using the GOS were obtained from all patients. RESULTS: Patients were separated in 3 groups: fGCS 13 (46 patients), fGCS 14 (138 patients), and fGCS 15 (195 patients). The groups with different scores on fGCS did not differ regarding CT scan abnormalities, surgical treatment, or outcome. Patients were also separated in 2 groups based on CT scan findings: 266 patients had CT interpreted as abnormal and 113 had CT interpreted as normal. The 2 groups differed statistically regarding surgical treatment and scores on GOS (P < .05). There was no statistically significant difference between the 2 groups regarding sex, trauma mechanism, fGCS, or age. CONCLUSIONS: Our findings support the idea that a normal cranial CT scan in patients with fGCS scores of 13 or higher ascertain a low-risk MHI outcome and, therefore, such patients must be included in this category of traumatic brain injury. On the other hand, patients with cranial CT scan abnormalities should be included in the group with moderate head injury.

Factors of morbidity in hemispherectomies: surgical technique x pathology.

OBJECTIVE: The objective of this paper is to evaluate factors of surgical morbidity from different techniques of hemispherectomy with emphasis on causative pathology. PATIENTS AND METHODS: Thirty patients underwent hemispherectomy in our institution from 1987 to 2003, two presented with Sturge-Weber Syndrome (SWS), sixteen with Rasmussen's Syndrome (RS), eight with established hemispheric lesions (EHL), and four with cortical development malformations (CDM). Six surgeons operated on three patients using anatomical hemispherectomies (AH), 11 patients using functional hemispherectomy (FH), and 16 patients employing hemispherotomy (HT). Surgical technique and causative pathology were studied independently as factors of morbidity in hemispherectomy. RESULTS: Overall mean surgical time was 11:50+/-3:20 h and increased proportionately in pathologies with larger hemispheres. Blood transfusion was particularly influenced by the approach adopted by our team of anesthesiologists, independently of technique or pathology. Pathology was the most important factor related to hydrocephalus as two out of four patients with CDM needed ventriculoperitoneal shunt whilst none with EHL or SWS. Four patients undergoing HT and one FH presented residual bridges connecting the hemispheres, three were reoperated and are seizure free. Two patients with CDM did not improve their seizures worthwhile with surgery and other two (one with RS and other with CDM) were waiting a second procedure due to incomplete inter-hemispheric disconnection. Five patients presented infection and one died after developing meningoencephalitis. CONCLUSION: Hemispherectomies are procedures where pathology and surgical technique interact narrowly. Therefore, in order to study surgical morbidity or outcome, both pathology and technique have to be analyzed independently.

The early years of hemispherectomy.

Today, hemispherectomy is a well-established procedure for the treatment of some sorts of catastrophic epilepsies. This, however, has not always been the case. The technique was developed to deal with brain tumors; however, the initial results were not remarkable. Moreover, when its morbidity became evident, it was almost abandoned. Had it not been for a shift in its use, with a huge increase in operations on patients with infantile hemiplegia, this surgery would certainly have disappeared. This paper focuses on the facts that surrounded these early years.