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Hemispherotomy is a surgical procedure aimed at the treatment of hemispheric epilepsy. Hemispherotomy disconnects the commissural fibers, projecting fibers, and limbic system while preserving most of the brain parenchyma, unlike conventional hemispherectomy. 1 Hemispherotomy is one of most complicated operations currently used in epilepsy surgery and requires a high-level understanding of the intrinsic neuroanatomy. Generally, 2 main techniques are applied in hemispherotomy: lateral hemispherotomy and vertical hemispherotomy. 2,3 Vertical hemispherotomy was developed after the lateral technique. Despite a deeper, narrower surgical corridor, vertical hemispherotomy requires a smaller craniotomy and a shorter disconnection line and allows easier disconnection of the insula than the lateral approach. 1 In performing vertical hemispherotomy, 2 options are available: the interhemispheric approach 4 and the parasagittal approach. 3 With the parasagittal approach, the lateral ventricle is opened and entered via superior frontal gyrus. To ease the surgery and minimize the operation time, we apply "partial superior frontal gyrus removal." This procedure is useful to widen a shallower surgical field while skipping the need for interhemispheric dissection. Total callosotomy is then performed via the lateral ventricle. To disconnect limbic system, we used the technique following the falx and tentorial edge as a landmark. 5 Here, we present our surgical steps for parasagittal hemispherotomy in a 5-month-old girl diagnosed as hemimegalencephaly (Figures 1-8). [ABSTRACT FROM AUTHOR]

• Parasagittal meningiomas have a relatively high rate of recurrence. • Salvage therapy is associated with several histological and radiographic factors. • Superior sagittal sinus invasion and WHO grade independently predict salvage. • Treatment modality (surgery, radiation, or both) does not affect progression. Parasagittal meningiomas (PM) are treated with primary microsurgery, radiosurgery (SRS), or surgery with adjuvant radiation. We investigated predictors of tumor progression requiring salvage surgery or radiation treatment. We sought to determine whether primary treatment modality, or radiologic, histologic, and clinical variables were associated with tumor progression requiring salvage treatment. Retrospective study of 109 consecutive patients with PMs treated with primary surgery, radiation (RT), or surgery plus adjuvant RT (2000–2017) and minimum 5 years follow-up. Patient, radiologic, histologic, and treatment data were analyzed using standard statistical methods. Median follow up was 8.5 years. Primary treatment for PM was surgery in 76 patients, radiation in 16 patients, and surgery plus adjuvant radiation in 17 patients. Forty percent of parasagittal meningiomas in our cohort required some form of salvage treatment. On univariate analysis, brain invasion (OR: 6.93, p < 0.01), WHO grade 2/3 (OR: 4.54, p < 0.01), peritumoral edema (OR: 2.81, p = 0.01), sagittal sinus invasion (OR: 6.36, p < 0.01), sagittal sinus occlusion (OR: 4.86, p < 0.01), and non-spherical shape (OR: 3.89, p < 0.01) were significantly associated with receiving salvage treatment. On multivariate analysis, superior sagittal sinus invasion (OR: 8.22, p = 0.01) and WHO grade 2&3 (OR: 7.58, p < 0.01) were independently associated with receiving salvage treatment. There was no difference in time to salvage therapy (p = 0.11) or time to progression (p = 0.43) between patients receiving primary surgery alone, RT alone, or surgery plus adjuvant RT. Patients who had initial surgery were more likely to have peritumoral edema on preoperative imaging (p = 0.01). Median tumor volume was 19.0 cm3 in patients receiving primary surgery, 5.3 cm3 for RT, and 24.4 cm3 for surgery plus adjuvant RT (p < 0.01). Superior sagittal sinus invasion and WHO grade 2/3 are independently associated with PM progression requiring salvage therapy regardless of extent of resection or primary treatment modality. Parasagittal meningiomas have a high rate of recurrence with 80.0% of patients with WHO grade 2/3 tumors with sinus invasion requiring salvage treatment whereas only 13.6% of the WHO grade 1 tumors without sinus invasion required salvage treatment. This information is useful when counseling patients about disease management and setting expectations. [ABSTRACT FROM AUTHOR]

Background: Solitary fibrous tumor/meningeal hemangiopericytoma (SFT/M-HPC) is a rare neoplasm which accounts for around 1% of the intracranial masses. This pathology has a high risk for recurrence and metastasis to distant locations such as the liver, lungs, and bones. Precise diagnosis necessitates detailed histopathological examination. Case Description: We present two case reports of SFT/M-HPC. The first case is a 44-year-old female who presented with headache, nausea, vomiting, and frontal ataxia for several months. Imaging findings showed a large parasagittal extra-axial mass with compression of the frontal horns of both lateral ventricles. She underwent gross total resection with an uncomplicated postoperative period. The patient had no recurrent tumors or distal metastases in the follow-up period of 5 years. The second case is a 48-year-old male who presented with right-sided hemianopsia and hemiparesis. Computed tomography (CT) scans revealed a large parieto-occipital extra-axial mass with superior sagittal sinus engulfment and dislocation of the interhemispheric fissure. He underwent gross total resection with an uncomplicated postoperative period. Six years later, he presented with right-sided weakness. CT scan showed a multifocal recurrent mass at the previous location. He underwent subtotal resection with an uncomplicated postoperative period. Conclusion: SFT/M-HPC should be considered when presented with a meningioma-like tumor mass on preoperative imaging. Immunohistochemical study is crucial for the correct diagnosis. Strict long-term follow-up examinations and regular magnetic resonance imaging scans are key to preventing the appearance of metastases and large recurrent masses. [ABSTRACT FROM AUTHOR]

Purpose: Owing to their vicinity near the superior sagittal sinus, parasagittal and parafalcine meningiomas are challenging tumors to surgically resect. In this study, we investigate key factors that portend increased risk of recurrence after surgery. Methods: This is a retrospective study of patients who underwent resection of parasagittal and parafalcine meningiomas at our institution between 2012 and 2018. Relevant clinical, radiographic, and histopathological variables were selected for analysis as predictors of tumor recurrence. Results: A total of 110 consecutive subjects (mean age: 59.4 ± 15.2 years, 67.3% female) with 74 parasagittal and 36 parafalcine meningiomas (92 WHO grade 1, 18 WHO grade 2/3), are included in the study. A total of 37 patients (33.6%) exhibited recurrence with median follow-up of 42 months (IQR: 10–71). In the overall cohort, parasagittal meningiomas exhibited shorter progression-free survival compared to parafalcine meningiomas (Kaplan–Meier log-rank p = 0.045). On univariate analysis, predictors of recurrence include WHO grade 2/3 vs. grade 1 tumors (p < 0.001), higher Ki-67 indices (p < 0.001), partial (p = 0.04) or complete sinus invasion (p < 0.001), and subtotal resection (p < 0.001). Multivariable Cox regression analysis revealed high-grade meningiomas (HR: 3.62, 95% CI: 1.60–8.22; p = 0.002), complete sinus invasion (HR: 3.00, 95% CI: 1.16–7.79; p = 0.024), and subtotal resection (HR: 3.10, 95% CI: 1.38–6.96; p = 0.006) as independent factors that portend shorter time to recurrence. Conclusion: This study identifies several pertinent factors that confer increased risk of recurrence after resection of parasagittal and parafalcine meningiomas, which can be used to devise appropriate surgical strategy to achieve improved patient outcomes. [ABSTRACT FROM AUTHOR]

Abstract The clearance pathways of brain waste products in humans are still under debate in part due to the lack of noninvasive imaging techniques for meningeal lymphatic vessels (mLVs). In this study, we propose a new noninvasive mLVs imaging technique based on an inter-slice blood perfusion MRI called alternate ascending/descending directional navigation (ALADDIN). ALADDIN with inversion recovery (IR) at single inversion time of 2300 ms (single-TI IR-ALADDIN) clearly demonstrated parasagittal mLVs around the human superior sagittal sinus (SSS) with better detectability and specificity than the previously suggested noninvasive imaging techniques. While in many studies it has been difficult to detect mLVs and confirm their signal source noninvasively, the detection of mLVs in this study was confirmed by their posterior to anterior flow direction and their velocities and morphological features, which were consistent with those from the literature. In addition, IR-ALADDIN was compared with contrast-enhanced black blood imaging to confirm the detection of mLVs and its similarity. For the quantification of flow velocity of mLVs, IR-ALADDIN was performed at three inversion times of 2000, 2300, and 2600 ms (three-TI IR-ALADDIN) for both a flow phantom and humans. For this preliminary result, the flow velocity of the dorsal mLVs in humans ranged between 2.2 and 2.7 mm/s. Overall, (i) the single-TI IR-ALADDIN can be used as a novel non-invasive method to visualize mLVs in the whole brain with scan time of ~ 17 min and (ii) the multi-TI IR-ALADDIN can be used as a way to quantify the flow velocity of mLVs with a scan time of ~ 10 min (or shorter) in a limited coverage. Accordingly, the suggested approach can be applied to noninvasively studying meningeal lymphatic flows in general and also understanding the clearance pathways of waste production through mLVs in humans, which warrants further investigation.

Objective: Meningiomas of the rolandic region are associated to high risk of postoperative motor deficits. This study discusses the factors affecting motor outcome and recurrences from the analysis of a monoinstitutional case series and eight studies from a literature review. Methods: Data of 75 patients who underwent surgery for meningioma of the rolandic region were retrospectively reviewed. The analyzed factors included tumor location and size, clinical presentation, magnetic resonance imaging (MRI) and surgical findings, brain-tumor interface, extent of resection, postoperative outcome and recurrence. Eight studies from literature on rolandic meningiomas treated with or without intraoperative monitoring (IOM) were reviewed with the aim to define the impact of IOM on the extent of resection and motor outcome. Results: Among the 75 patients of the personal series, the meningioma was on the brain convexity in 34 (46%), at the parasagittal region in 28 (37%) and at the falx in 13 (17%). The brain-tumor interface was preserved in 53 cases (71%) at MRI and in 56 (75%) at surgical exploration. Simpson grade I resection was obtained in 43% of patients, grade II in 33%, grade III in 15% and grade IV in 9%. The motor function worsened postoperatively in 9 among 32 cases with preoperative deficit (28%) and in 5 among 43 with no preoperative deficit (11.5%); definitive motor deficit was evidenced in overall series at follow-up in 7 (9.3%). Patients with meningioma with lost arachnoid interface had significant higher rates of worsened postoperative motor deficit (p = 0.01) and seizures (p = 0.033). Recurrence occurred in 8 patients (11%). The analysis of the 8 reviewed studies (4 with and 4 without IOM) shows in the group without IOM higher rates of Simpson grades I and II resection (p = 0.02) and lower rates of grades IV resection (p = 0.002); no significant differences in postoperative immediate and long-term motor deficits were evidenced between the two groups. Conclusions: Data from literature review show that the use of IOM does not affect the postoperative motor deficit Therefore, its role in rolandic meningiomas resection remains to be determined and will be defined in further studies. [ABSTRACT FROM AUTHOR]

The clearance pathways of brain waste products in humans are still under debate in part due to the lack of noninvasive imaging techniques for meningeal lymphatic vessels (mLVs). In this study, we propose a new noninvasive mLVs imaging technique based on an inter-slice blood perfusion MRI called alternate ascending/descending directional navigation (ALADDIN). ALADDIN with inversion recovery (IR) at single inversion time of 2300 ms (single-TI IR-ALADDIN) clearly demonstrated parasagittal mLVs around the human superior sagittal sinus (SSS) with better detectability and specificity than the previously suggested noninvasive imaging techniques. While in many studies it has been difficult to detect mLVs and confirm their signal source noninvasively, the detection of mLVs in this study was confirmed by their posterior to anterior flow direction and their velocities and morphological features, which were consistent with those from the literature. In addition, IR-ALADDIN was compared with contrast-enhanced black blood imaging to confirm the detection of mLVs and its similarity. For the quantification of flow velocity of mLVs, IR-ALADDIN was performed at three inversion times of 2000, 2300, and 2600 ms (three-TI IR-ALADDIN) for both a flow phantom and humans. For this preliminary result, the flow velocity of the dorsal mLVs in humans ranged between 2.2 and 2.7 mm/s. Overall, (i) the single-TI IR-ALADDIN can be used as a novel non-invasive method to visualize mLVs in the whole brain with scan time of ~ 17 min and (ii) the multi-TI IR-ALADDIN can be used as a way to quantify the flow velocity of mLVs with a scan time of ~ 10 min (or shorter) in a limited coverage. Accordingly, the suggested approach can be applied to noninvasively studying meningeal lymphatic flows in general and also understanding the clearance pathways of waste production through mLVs in humans, which warrants further investigation. [ABSTRACT FROM AUTHOR]

Background: Brachial plexus block is a key technique in anesthesiologist’s practice. Ropivacaine is a long acting local anaesthetic, Dexmedetomidine has been included as an adjuvant to enhance block duration. Aim: To elucidate the effect of addition of Dexmedetomidine to Ropivacaine in ultrasound guided parasagittal supraclavicular brachial plexus approach with respect to duration of analgesia, onset and duration of sensorimotor blockade. Methods: A randomized single blinded prospective clinical study was conducted among Forty patients of 20-50yrs, ASA Grade I and II, weighing >60kgs scheduled for elective upper limb orthopedic surgeries. Group RN received 25ml of 0.75% ropivacaine with 1ml normal saline, Group RD received 25ml of 0.75% ropivacaine with 1mcg/kg dexmedetomidine diluted to 1ml. Analgesic efficacy, sensorimotor blockade was determined. Statistical Analysis: Demographic and hemodynamic data was analyzed using student t-test. Unpaired t-test was used to analyze onset, duration of sensorimotor blockade and analgesic duration. Results were statistically significant if p-value

Background and purpose: Although the cerebellar tonsils are parasagittal structures, the extent of tonsillar herniation (ETH) in Chiari I malformation (CMI) is currently measured in the midsagittal plane. We measured the ETH of each cerebellar tonsil in the parasagittal plane and assessed their diagnostic utility by comparing them to the midsagittal ETH measurements in predicting cough-associated headache (CAH), an indicator of clinically significant disease in CMI. Methods: Eighty-five CMI patients with 3D-MPRAGE images were included. Neurosurgeons determined the presence of CAH. Sagittal images were used to measure ETH in the midsagittal (MS_ETH) and parasagittal planes (by locating tonsillar tips on each side on reformatted coronal images). Given the parasagittal ETH (PS_ETH) asymmetry in the majority of cases, they were considered Smaller_PS_ETH or Larger_PS_ETH. The accuracy of ETH measurements was assessed by the receiver operating characteristic (ROC) curve. Results: Of 85 patients, 46 reported CAH. ROC analysis showed an area under the curve (AUC) of 0.78 for Smaller_PS_ETH significantly better than 0.65 for MS-ETH in predicting CAH (p = 0.001). An AUC of 0.68 for Larger_PS_ETH was not significantly different from MS_ETH. The sensitivity and specificity of predicting CAH were 87% and 28% for MS_ETH >6 mm versus 90% and 46% for Smaller_PS_ETH >6 mm, and 52% and 67% for MS_ETH >9 mm versus 48% and 87% for Smaller_PS_ETH >9 mm. At ETH >15 mm, no differences were seen between the measurements. Conclusions: Diagnostic utility of ETH measurements in detecting clinically significant CMI can be improved by parasagittal measurements of the cerebellar tonsillar herniation. [ABSTRACT FROM AUTHOR]

Objective: To assess the inter-method agreement between midsagittal (msAoP) and parasagittal (psAoP) measurements of the angle of progression (AoP) during labor. In addition, we aimed to evaluate the correlation between AoP measurements by both midsagittal and parasagittal approaches with the mode of delivery.Methods: We recruited a nonconsecutive series of women in active labor with a singleton uncomplicated term pregnancy with fetuses in vertex presentation. Women underwent transperineal ultrasound in the absence of uterine contractions or maternal pushing to measure both msAoP and psAoP. The inter-method agreement between the two acquisitions was then assessed. Lastly, both measurements were compared between women who had a vaginal delivery versus those who underwent cesarean section (CS).Results: Overall, 151 women were included in the study. We found an excellent agreement between msAoP and psAoP (ICC 0.935; 95% CI 0.912-0.953, p < .001). On the other hand, psAoP overestimated the measurements in comparison with msAoP (101.2 ± 15.6 versus 98.2 ± 16.0, p < .001). There was a significant correlation between both methods of AoP assessment and duration of the active second stage of labor and AoP measured by either method was significantly wider in patients who delivered vaginally compared to those who had a CS.Conclusions: Our data showed a significant difference in the measured angle between the psAoP and the originally described msAoP. The automated measurements of AoP that have been introduced are designed using the parasagittal visualization of the more echogenic pubic arch, rather than the hypoechogenic pubic symphysis. We think that in the light of our data, care should be taken before applying data from midsagittal measurement in centers using the parasagittal automated approach. [ABSTRACT FROM AUTHOR]

Purpose: There is no study exploring the cortical veins (CVs) and connecting bridging veins (BVs) with neuroimaging modalities. The present study aimed to characterize these veins of the upper cerebral convexity. Methods: A total of 89 patients with intact cerebral hemispheres and covering meninges underwent thin-sliced, contrast magnetic resonance imaging (MRI). In addition, three injected specimens were dissected in this study. Results: In cadaver dissection, the BVs were observed to course in the arachnoid sheaths, suspended from the dura mater. The medial parts of the BVs, located near the superior sagittal sinus (SSS)-BV junction site, were occasionally exposed subdurally. The CVs were formed by venous channels arising from the cerebral gyri and those emerging from the sulci. On MRI, the CVs and connecting BVs were identified in the medial and latera convexity areas and medial surface of the cerebrum. These veins were highly variable in number, thickness, length, course, and distribution. In the medial convexity area, the CVs arising from the gyri were identified in 58% of patients, while they were found only in 11% of patients in the lateral convexity area. Conclusion: In the medial convexity area, involving the parasagittal region, the CVs connect more densely with the BVs that may predispose to injury during neurosurgical procedures. Mechanical impact exerted the area, diameter of the veins in the craniocaudal direction, and number of venous afferences may affect the SSS–BV junctional region in an indirect manner and lead to the development of acute subdural hematoma. [ABSTRACT FROM AUTHOR]

Lagerpeton chanarensis is an early avemetatarsalian from the lower Carnian (lowermost Upper Triassic) levels of the Chañares Formation, La Rioja Province, Argentina. Lagerpeton and its kin were traditionally interpreted as dinosaur precursors of cursorial habits, with a bipedal posture and parasagittal gait. Some authors also speculated saltatorial capabilities for this genus. Recent analyses indicate that lagerpetids are early-diverging pterosauromorphs, a hypothesis that invites a review of most aspects of their anatomy and function. A revision of available specimens and additional preparation of previously known individuals indicate that Lagerpeton lacked a parasagittal gait and was probably a sprawling archosaur. This latter inference is based on the femoral head articulation with the acetabulum. The acetabular rim has a strongly laterally projected posteroventral antitrochanteric corner, which results in a position of the legs that recalls that of sprawling living reptiles, such as lizards, and departs from the parasagittally positioned limbs of dinosaurs. This may indicate that early pterosauromorphs had a sprawling posture of their hindlegs, casting doubts on the significance of bipedal posture and parasagittal gait for the radiation of early ornithodirans, given that both traits have been regarded as key features that triggered the ecological and evolutionary success of the clade. Our results bolster recent claims of a high ecomorphological diversity among early avemetatarsalians., (© 2024 American Association for Anatomy.)

We describe an unusual case of delayed onset acute cerebral venous infarct that developed after an uneventful parasagittal meningioma excision. While the acute and chronic venous infarct are well known entities, there is dearth of literature regarding delayed onset acute form, which may prove to be fatal.

Background & Aim: The treatment of Parasagittal Meningioma (PSM) is always a challenge, especially when the tumor has already invaded the critical structures like venous sinuses. This study aims at evaluating the outcomes of Gamma Knife Radiosurgery (GKRS) in patients with PSM. Methods and Materials/Patients: In this descriptive retrospective study, we reviewed the medical records of 61 patients with PSM, who had undergone GKRS from 2003 to 2013. We reviewed their demographic characteristics, medical history, radiotherapy history, tumor volume, and the characteristics of radiosurgery. We also evaluated radiological tumor control following the treatment during the follow-up period. Results: In this study, 32(52.5%) patients were men, and 29(47.5%) were women. Of 61 patients, 45 had a history of operation or and radiotherapy. Their Mean±SD tumor volume was 11.35±9.20 mL (range: 1-37.9mL). The Mean±SD follow-up time was 30.28±27.48 months, and during this time, five patients died. Radiologic tumor control was achieved in (91.8%) of the patients, in whom the tumor volume decreased in 30(49.2%) patients and remained unchanged in 26(42.6%) ones. The tumor volume increased in five (8.2%) patients. Overall, the progression-free survival of the patients was (98.6%) during 12 months, and their Mean±SD percentage was 67.04±13.4% during 60 months. The edema incidence rate was (18%). There was no significant difference in GKRS characteristics, tumor volume, the history of operation, and radiotherapy among the patients, whose tumors were controlled and the patients, who experienced an increase in the tumor volume. Conclusion: Our study suggests that GKRS can be the first or second choice of treatment to control PSM. There was no association between the treatment outcome, tumor characteristics, and radiosurgery parameters. As radiosurgery management in PSMs has some limitations, a long-term follow-up is recommended to diagnose life-threatening complications, including brain edema.

Background: For decades, half of the electrodes used in traditional electroencephalography (EEG) have been dedicated to midline and parasagittal coverage. Recently, newer EEG devices have used fewer electrodes without direct coverage over the midline or parasagittal regions. However, no systematic study to date has explored the prevalence of midline parasagittal seizures, and as such the risk of missing such seizures with only ten electrodes remains unknown.Methods: We reviewed retrospective EEG data from a cohort of 300 patients at Stanford University Medical Center and determined the frequency of seizures localized to the midline parasagittal regions. We then compiled previously reported EEG cohorts that reported the prevalence of midline parasagittal seizures to validate our findings.Results: In our cohort, only two EEGs (0.66%) were identified with a midline or parasagittal seizure focus. In a subsequent study, we compiled literature evidence from 169510 EEGs and found that the prevalence of midline or parasagittal epileptic spikes/seizures was similarly less than 1%.Conclusions: Our study serves as the first to systematically explore the scope of EEG abnormalities captured exclusively by midline or parasagittal electrodes and document their very low prevalence. [ABSTRACT FROM AUTHOR]

In the management of meningiomas invading the major venous sinuses, balance between tumor control and complication prevention is desirable. The aim of this study was to describe an institutional experience in management of meningiomas involving major venous sinuses. A retrospective study was carried out over 18 years, between 1999 and 2017, in patients with meningiomas involving major venous sinuses. Clinical features, operative strategy, histology, postoperative complications, adjuvant therapy, and long-term follow-up were studied. The study included 84 patients. Neurologic deficits were seen in 26 (31%) patients at presentation. The recurrence rates in Simpson grade I, II, and III excision were 7.6%, 25%, and 29.4% at a mean follow-up of 45.4 months (range, 1–192 months). No intervention of the involved sinus was done in 64 (76%) cases, venotomy was done in 3 (3.5%) cases, sinus resection without graft was done in 14 (16.6%) cases, and sinus reconstruction with patch was done in 3 (3.5%) cases. There were 53 (67.0%) patients with World Health Organization grade I histology and 25 (31.6%) patients with World Health Organization grade II histology. Fifteen recurrences were treated with Gamma Knife radiosurgery. In univariate analysis using Cox proportional hazards model, World Health Organization grade (P = 0.036, hazard ratio 2.90, 95% confidence interval = 1.07–7.87) and Simpson grade (P = 0.017, hazard ratio 2.90, 95% confidence interval = 1.18–5.29) were found to be significant factors to predict tumor recurrence. Management of meningiomas involving major venous sinus with microsurgical techniques and adjuvant Gamma Knife radiosurgery achieves a good tumor control rate with an acceptable complication rate. [ABSTRACT FROM AUTHOR]

Background Parasagittal and parafalcine (PSPF) meningiomas recur more frequently than other intracranial meningiomas owing to the difficulty in achieving gross total resection. The present study investigated the preoperative magnetic resonance imaging (MRI) features for the prediction of progression/recurrence (P/R) in benign PSPF meningiomas with an emphasis on the apparent diffusion coefficient (ADC) values. Methods We retrospectively investigated the preoperative MRI features for the prediction of P/R in benign (World Health Organization grade I) PSPF meningiomas. Only patients who had undergone preoperative and postoperative MRI follow-up studies for ≥1 year were included. From October 2006 to December 2015, 48 patients with a diagnosis of benign PSPF meningioma were included (median follow-up period, 42.5 months). Of these 48 patients, 12 (25%) developed P/R (median time to P/R, 23 months). Results PSPF meningiomas in male patients, subtotal resection, large tumor diameter, high diffusion-weighted imaging signal, and lower ADC values or ratios were significantly associated with P/R (P < 0.05). The cutoff points of the ADC value and ADC ratio for the prediction of P/R were 0.83 × 10–3 mm2/second and 0.99, with an area under the curve of 0.82 and 0.83, respectively (P = 0.001). On multivariate Cox proportional hazards analysis, male sex and low ADC values (<0.83 × 10–3 mm2/second) were high-risk factors for P/R, with a hazard ratio of 12.37 and 30.2, respectively (P < 0.05). Kaplan-Meier analysis showed that lower ADC values and ratios predicted for significantly shorter progression-free survival (P < 0.05). Conclusions The preoperative ADC values and ratios for the prediction of P/R offer additional valuable information for the treatment planning for PSPF meningiomas. [ABSTRACT FROM AUTHOR]

Background: meningioma in parasagittal location represent between 20%-30% of meningioma in the cranial cavity. The close relation of it with Superior Sagittal Sinus make its surgical resection is a great challenge to the surgeon to get a good result. Patients & method: we collected 23 cases of Parasagittal Meningioma cases medical records (including pre-& postoperative clinical pictures, images plus operative details and complications post operatively) who admitted to neurosurgery dept., Mansoura University Hospital and underwent surgical resection in the period that began in 2010 and ended in 2016. We followed up the cases at least for 6 months. Results: the patient’s age varied between 64-35 years. 16 female & 7 males. The presenting symptoms was headache (11 patients), fits (6 patients), motor weakness (5 cases), abnormal gait (1 patient) and dizziness (1 case). 15 cases had gross total tumor excision while 8 cases showed partial tumor removal. Recurrence rat was in 4 cases (17.4%) plus two mortality cases. Conclusion: through our series we could detect cardinal factors in prognosis of these cases which included: tumor size, histology, preoperative identification of the venous collateral and preservation of it in the surgical maneuver. The meticulous microscopic surgical technique can augment this goal.

Background: meningioma in parasagittal location represent between 20%-30% of meningioma in the cranial cavity. The close relation of it with Superior Sagittal Sinus make its surgical resection is a great challenge to the surgeon to get a good result. Patients & method: we collected 23 cases of Parasagittal Meningioma cases medical records (including pre-& postoperative clinical pictures, images plus operative details and complications post operatively) who admitted to neurosurgery dept., Mansoura University Hospital and underwent surgical resection in the period that began in 2010 and ended in 2016. We followed up the cases at least for 6 months. Results: the patient's age varied between 64-35 years. 16 female & 7 males. The presenting symptoms was headache (11 patients), fits (6 patients), motor weakness (5 cases), abnormal gait (1 patient) and dizziness (1 case). 15 cases had gross total tumor excision while 8 cases showed partial tumor removal. Recurrence rat was in 4 cases (17.4%) plus two mortality cases. Conclusion: through our series we could detect cardinal factors in prognosis of these cases which included: tumor size, histology, preoperative identification of the venous collateral and preservation of it in the surgical maneuver. The meticulous microscopic surgical technique can augment this goal. [ABSTRACT FROM AUTHOR]

Background: Resection within the supplementary motor area (SMA) may be accompanied by dramatic motor deficits and speech arrest when the dominant hemisphere is involved, termed the SMA syndrome. Typically, the muscle tone of the paralyzed extremities is preserved, and in most cases, a complete or near complete recovery is seen within a few months. The SMA syndrome has not been recognized for extra-axial tumor surgery in approximation of the SMA.Methods: We observed the SMA syndrome in a patient operated for a parasagittal meningioma in the posterior frontal region, and this observation intrigued us to prospectively collect similar cases.Results: In the period from January 2010 to December 2015, we observed five patients who developed a partial SMA syndrome after surgery for frontal parasagittal meningiomas. The muscle tone was preserved in the affected extremities. All patients experienced improvement in motor function within a few days, and on follow-up, three out of five patients had recovered completely. Three of the patients had meningioma WHO grade II.Conclusions: Surgically induced SMA syndrome can easily be confused with pyramidal weakness. This series of cases demonstrate that the syndrome may also develop after removal of extra-axial tumors and is probably underdiagnosed and underreported. The good functional prognosis is helpful in the preoperative counseling and follow-up of these patients. [ABSTRACT FROM AUTHOR]

Falx and parasagittal meningiomas are common locations for meningiomas of the cranial vault. Many of these tumors are now discovered incidentally during cranial imaging for other reasons. Therefore, in the calculation of the risks and benefits of surgery it behooves the surgeon to do all he/she can to avoid surgical complications. This is a heavily experience based article based off the senior author's experience with over 1200 intracranial meningiomas. We present three cases to illustrate some of the decision-making and techniques used to reduce complications in the management of these cases treated with an open operation. [ABSTRACT FROM AUTHOR]

There are various approaches to the treatment of patients with parasagittal meningiomas., Objective: To optimize treatment strategy for meningiomas invading the superior sagittal sinus., Material and Methods: The study included 87 patients with benign parasagittal meningiomas between 2010 and 2012. Of these, 34 patients underwent surgery alone, 27 - radiotherapy, 26 - surgery and subsequent radiotherapy. Both groups were comparable in male-to-female ratio, age and localization of tumors in relation to superior sagittal sinus. The follow-up period was at least 5 years. We analyzed the effect of treatment on neurological status, Karnofsky score and tumor growth control., Results: Mean volume of tumors was 43.3 cm 3 in patients undergoing surgery and 6.7 cm 3 in the radiotherapy group. In the combined treatment group, mean volume was 65.8 cm 3 before surgery and 8.8 cm 3 before irradiation. General cerebral symptoms (84%), epileptic seizures (37%) and movement disorders (31%) prevailed. Surgery provided the best results in patients with small meningiomas (<14 cm 3 ) causing focal neurological symptoms. Isolated radiotherapy was the most effective in asymptomatic patients. Large tumors required surgery with adjuvant irradiation., Conclusion: Benign parasagittal meningiomas followed by focal neurological symptoms require surgical intervention regarding the best functional outcomes and tumor growth control. Radiotherapy without surgery is advisable for progressive asymptomatic tumors. Resection followed by irradiation is preferable if total resection without the risk of damage to veins and cortex is impossible.

Abstract: Intracranial chondrosarcomas are primary cartilaginous neoplasms that represent 6% of all skull base tumors. Intracranial extraskeletal chondrosarcomas are more rare, often arising from the meninges at the falx, tentorium, or cerebral convexity. They are generally characterized as classical or mesenchymal, with the latter associated with worse outcomes. We present our institutional series of falcine and parasagittal chondrosarcomas along with a review of the literature. Although skull base chondrosarcomas pose significant challenges due to their invasive biology and proximity to vital brainstem structures and cranial nerves, intracranial extraskeletal chondrosarcomas are generally associated with a good prognosis. Our review of the literature identified 29 patients with falcine and parasagittal chondrosarcomas. There were six recurrences, five among patients with the mesenchymal subtype and one in a patient with the classical subtype. All deaths occurred in patients with the mesenchymal subtype. Management of skull base chondrosarcomas is controversial but extraskeletal intracranial tumors can generally be managed by surgical resection alone. Treatment should be tailored to the biology of the tumor, with radiation therapy reserved for patients with the mesenchymal subtype. [Copyright &y& Elsevier]

Meningomas is usually a benign, encapsulated tumor with a predominance in women. Parasagittal Meningomas is a common type of these tumors and with clinical manifestation like Cereberovascular diseases. This is a report on 80-year-old female patient with acut presentations of a parasagittal meningiomas with apoplexy of tumor and subcoma and righthemiplegia, that resected totally in the Behshar Imam Khomeini Hospital (August 2011). [ABSTRACT FROM AUTHOR]

Summary: Video-electroencephalographic (EEG) ictal recordings play an important role in the pre-surgical evaluation of patients with medically refractory focal epilepsy. Paradoxical lateralization of the scalp EEG ictal onset patterns, consistently contralateral to the side of the proven epileptogenic lesion is rare but important to recognize, with possible implications on patient management. We searched the database of the University of Munich Epilepsy Monitoring Unit for patients with extratemporal epilepsies, with scalp EEG ictal patterns consistently contralateral to the proven epileptogenic zone. All available clinical, EEG and imaging data were reviewed. Dipole source analysis of EEG seizure onset was performed where possible. Four patients were identified, who had proven paradoxical lateralization of scalp EEG ictal patterns, demonstrated by seizure freedom after epilepsy surgery, data from invasive electroencephalography, or imaging and seizure semiology. Parasagittal lesions on MRI brain scan were found in three cases. Invasive recordings with subdural electrodes were performed in one patient. Dipole source analysis of EEG seizure onset was possible in two patients, helping to correctly lateralize the ictal EEG pattern in one patient. Patients with midline or near midline neocortical seizure foci may show paradoxical lateralization of the ictal EEG, likely due to the spatial orientation of the cortical generators in the medial regions of the cerebral hemispheres. These patients may have excellent surgical outcome despite the apparently discordant EEG findings, making this an important phenomenon to be recognized in clinical practice. [ABSTRACT FROM AUTHOR]

Of the intracranial epidermoids, interhemispheric epidermoids are extremely rare and only about 19 cases have been reported. This is a retrospective study of 15 patients with interhemispheric epidermoids surgically treated over a 13-year period. The age at the time of presentation varied between 17 and 45 years and there were 9 males. The presenting feature was seizures (focal with secondary generalization) in 12 patients, hemiparesis in 5 and features of raised intracranial pressure in 3. On computerized tomography scan the lesions were hypodense in the interhemispheric region. On magnetic resonance imaging, the lesions were located in the interhemispheric region with heterogenous signal intensities. Restricted diffusion was evident on diffusion-weighted images and apparent diffusion co-efficient images. All the lesions were predominantly located in the anterior interhemispheric region, with either basal or parietal extension along the interhemispheric fissure. Eleven patients underwent frontal or fronto-parietal craniotomies, 3 underwent bifrontal craniotomies and 1 patient underwent supra-orbital craniotomy and endoscopic procedure. Total excision could be achieved in 11 patients; near-total, in 3; and partial excision, in 1 patient. Follow-up was available in 10 patients. Three patients had recurrence of lesion at 5½, 8 and 10 years, respectively. [ABSTRACT FROM AUTHOR]

Background: Intracranial cause of isolated unilateral foot drop is very rare. There may be a delay in the diagnosis of the cause of central foot drop or patients with such lesions might be misdiagnosed and subjected to unnecessary interventions. One of the reasons for the diagnostic uncertainty might be the absence of upper motor neuron (UMN) signs in the initial examination of such patients. Case Description: We present a very rare case of a 78-year-old woman who had presented with a five-year progressive right-sided unilateral isolated foot drop from a left-sided parasagittal tumor. Previously, she had undergone biopsy of an abnormality on the right C7/T1 facet, which was found to be benign. On examination of the patient, she had UMN signs in the ipsilateral foot. On magnetic resonance imaging scan of her head, a 3-cm left parasagittal lesion, consistent with it being a meningioma, was noted. The patient had significant medical history and declined to undergo surgical removal of the lesion. Conclusion: We review the literature on central foot drop from various intracranial pathologies and discern its clinical features. Patients with central foot drop often have UMN signs; however, these may be absent causing diagnostic uncertainty, and physicians should be vigilant of these variations in the presentation. [ABSTRACT FROM AUTHOR]

Surgery for parasagittal and falcine meningiomas requires meticulous preservation of the cortical veins that surround the tumour; thus, knowledge of the relevant venous anatomy would be extremely helpful during surgery. This study utilises virtual reality technology to determine the number, size and disposition of the veins in relation to the tumour in 8 patients with parasagittal and falcine meningiomas. The same data were also collected from the scans of 8 normal subjects and compared with the data from the meningioma patients. Our results show that the average number of veins is comparable in the tumour and control groups, and that the number of veins on either side does not differ significantly for both groups. On measurement, the size of the veins is approximately the same on either side of the superior sagittal sinus for both the control and the tumour groups. It was also observed that regardless of size, most of the parasagittal and falcine meningiomas demonstrated no significant anatomical distortion effects on the adjacent venous structures, with the exception of one parasagittal meningioma with invasion of the superior sagittal sinus and concomitant engulfment of the draining veins. Data from a larger population would have to be collected in order to determine the effect of the growth of these tumours on the surrounding venous anatomy. With virtual reality technology, the parasagittal veins are clearly discerned, and knowing their location and relationship to the tumour would contribute towards safe and effective surgery. [ABSTRACT FROM AUTHOR]

Abstract: Parasagittal or off-midsagittal structures of the interhemispheric fiber tracts, i.e., the corpus callosum (CC), have a tendency to form structures which diverge from the midsagittal CC (mCC). This has led to mild inconsistencies in terms of defining parasagittal structures as region of interest for diffusion tensor imaging (DTI) analysis. Moreover, it is a labor-intensive work with potential inconsistencies and inaccuracies to define the parasagittal structure slice by slice using currently available methods. In the present study, to better cope with these problems, a new method was developed to construct the extended parasagittal structure of the CC using diffusion tensor tractography-guided (TGI) parameterization methods based on tract-length-based and parasagittal plane-based extensions. Using extended ROIs, fractional anisotropy (FA) values, as the indicators of fiber integrity in DTI, were compared between normal 14 male (25.7±4.7 years) and 17 female (25.9±4.6 years) groups for investigating the gender difference. Both TGI parameterization methods showed that men have significantly higher regional FA values than women for global CC structure areas in parasagittal and midsagittal space. In contrast, women showed significantly higher FA values in the partial areas of the rostrum, genu and splenium. Our findings based on TGI statistics (TGIS) of fiber integrity could serve as a frame of reference for assessing the group differences of the CCs in finer scale and in more extended space or parasagittal space. [Copyright &y& Elsevier]

The Purkinje cells of both the adult and the developing cerebellar cortex are organized into parasagittal stripes or ‘segments’ expressing a variety of biochemical markers. We show that in the developing mouse cerebellar cortex, members of the Eph receptor gene family are expressed in mediolaterally alternating Purkinje cell segments. Since members of the Eph receptors family have been shown to play a role in hindbrain segmentation and boundary formation (Philos. Trans. R. Soc. Lond. B: Biol. Sci. 355 (2000) 993), we analyzed the effect of a null mutation of the EphA4 gene on Purkinje cell compartmentation. Using well characterized markers of Purkinje cell compartmentation in both the developing and the adult cerebellum, we observed no significant alteration in the banding pattern of these markers between the EphA4 knockout mice and their wild type controls. The ribboned pattern of migrating granule cells in the developing cerebellum also appears unaltered. The expression of other members of this gene family, including ephrin-B2, EphA2, and ephrin-A1, in a compartmentalized pattern within the Purkinje cell layer suggests a possible redundancy and/or a compensation of EphA4 function in the segmental patterning of cerebellar Purkinje cells. [Copyright &y& Elsevier]

The authors present the case of a 62-year-old woman with rapid enlargement of a meningioma following radiosurgery (RS). Previous slow growth of the tumor over a 3-year period and the radiological signs of benign meningioma had been confirmed by successive MR scans. Histopathological examination performed after successful surgical removal revealed an atypical, infiltrating meningioma. [ABSTRACT FROM AUTHOR]

Background: Cervical epidural steroid injections (ESI) are performed either by interlaminar (IL) or transforaminal (TF) approaches; however, there is controversy over which is better for safety and efficacy., Objectives: This clinical trial aimed to compare the effectiveness of the parasagittal IL and TF approaches for cervical ESI in patients who were suffering from cervical radicular pain., Study Design: A prospective randomized assessor-blind study., Setting: The study took place at a single pain clinic within a tertiary medical center in Seoul, Republic of Korea., Methods: This prospective randomized, assessor-blind trial included 80 patients with cervical radicular pain. We randomly assigned patients to the TF or parasagittal IL approach for cervical ESI. The effectiveness of the 2 groups was compared based on pain intensity using the Numeric Rating Scale (NRS-11) at 1 and 3 months. The Neck Disability Index (NDI), Medication Quantification Scale (MQS), and responders at 1 and 3 months between the 2 groups were compared., Results: The pain intensity of both groups significantly reduced after 1 and 3 months after each procedure (P < 0.001). Two-way repeated measures of analysis of variance showed no significant interaction between group and time for cervical radicular pain (P = 0.266), although NRS-11 pain score was lower in the TF group than the parasagittal IL group after 1 month (P = 0.010). NDI, MQS, and successful responders were not different between the 2 groups at 1 and 3 months after the procedure. We observed 7 cases (18.4%) of vascular visualization in the TF group, although no serious complications were found in either group., Limitations: This study had no placebo control group and limited follow-up time., Conclusions: Parasagittal IL ESI may be recommended over the TF ESI in reducing cervical radicular pain, considering both clinical effectiveness and safety.

The contralateral interhemispheric approach is utilized to provide the surgeon with a favorable trajectory for approaching lesions projecting contralaterally from the midline falcine dura. The contralateral approach also requires a less rigid retraction than other approaches, which is paramount when manipulating the eloquent cortex of the paracentral lobule. This patient had a large laterally projecting falcine meningioma. This case demonstrates well the effect that gravity has on the tumor, pulling the tumor medially into the surgeon's view and making the surgical approach ideal for this lesion. The lesion was removed en bloc with the falcine dura, and postoperative imaging demonstrated a gross total resection. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Parasagittal meningiomas are defined as meningiomas that grow into at least one wall of the superior sagittal sinus. Long- and short-term morbidity is, in addition to cortical function, related to management of venous structures and flow. Clinical management needs to address the extent of removal in the sinus wall and to address relations to the adjacent cortex, which is highly eloquent in the Rolandic and calcarine areas., (Copyright © 2020 Elsevier B.V. All rights reserved.)

For many years, radical surgery was considered the only effective method for treating meningiomas, including parasagittal meningiomas (PSM). However, accumulated experience makes it evident that extensive resections in the parasagittal region lead to impaired venous outflow and involve high rates of disability and mortality. In recent decades, stereotactic radiotherapy has been developed and widely implemented in practical neurosurgery, its role in the treatment of PSM patients is discussed in this work., Material and Methods: A sample of publications in the PubMed search system was taken using the following keywords: meningioma, parasagittal, superior sagittal sinus, stereotactic radiosurgery, stereotactic radiation therapy. No publications of evidence levels 1 and 2 have been found. Out of 123 works, 32 most relevant were selected., Results and Discussion: Currently, both neurosurgeons and radiologists are involved in the treatment of PSM. An analytical review of the literature on the treatment of PSM is presented. Both surgical treatment and radiation therapy have their pros and cons. No general approach to the treatment of these tumours has been developed to date. A comprehensive treatment is considered to be effective - the maximum possible removal of the tumor without damaging functionally significant structures, including venous outflow pathways, followed by radiotherapy for tumor residues., Conclusion: In the existing literature, it was not possible to identify a single decision-making algorithm for the tactics of multimodality therapy for PSM patients, including the one for manipulations on the superior sagittal sinus and with regard to the role of ir irradiation radiation methods.