Olfactory Groove Meningiomas Research Articles

Neuropsychological Outcomes after Surgery for Olfactory Groove Meningiomas.

Simple SummaryOlfactory groove meningiomas account for 9% of all meningiomas, present with unique molecular characteristics and are standardly treated by surgical removal. Due to their location (in direct contact with cortical structures exerting key-role functions in cognition), olfactory groove meningiomas might negatively impact cognitive abilities. However, little is known about the effects of both their presence and surgical removal on patients’ neuropsychological functions. In this retrospective study, we analyze the evolution of neuropsychological abilities in 17 patients benefitting from surgical removal of an olfactory groove meningioma. We observed that those patients already presented with preoperative deficits in pre-frontal cortex cognitive functions, more pronounced in the domain of cognitive flexibility, followed by attention. After an initial postoperative worsening, patients tended to improve in the majority of cognitive aspects, with attention and flexibility remaining impaired at one-year follow-up.Background: In recent years, several studies have reported abnormal pre- and postoperative neuropsychological functioning in patients with meningiomas located in the prefrontal cortex (notably the ventromedial region). In the case of olfactory groove meningiomas, the tumor is in direct contact with the inferior aspect of the prefrontal cortex, a cortical region with crucial roles in decision-making, cognition and memory functions, potentially negatively impacting neuropsychological functions. Materials and Methods: We retrospectively compared pre- and post-operative neuropsychological testing of 17 patients undergoing surgical removal of olfactory groove meningiomas in our institution between January 2013 and December 2018. Neuropsychological results were obtained from the patients’ medical history and normalized as z-scores of their respective cognitive functions. Results: Assessment of cognitive follow-up showed an important heterogeneity among patients. Pre-operative cognitive impairment was observed in most patients, particularly in cognitive flexibility (mean z-score: −1.35). Immediate post-operative cognitive status showed an overall impairment in all domains of cognition, significant for the domains of attention (p = 0.0273) and flexibility (p = 0.0234) and almost significant for the domain of language (p = 0.0547). The late follow-up at one year showed a trend towards general improvement, although attention and flexibility remained impaired. Discussion: Olfactory groove meningiomas impact pre-frontal cortex cognitive functions, particularly in the domain of cognitive flexibility. After an initial postoperative worsening, patients tended to improve in most aspects after one year, aside from cognitive flexibility and attention.

795 Trends in Cerebrospinal Fluid Leak Rates Following the Extended Endoscopic Endonasal Approach for Anterior Skull Base Meningioma: A Meta-Analysis Over the Last 20 Years

Abstract Introduction The extended endoscopic approach (EEA) provides direct access for resection of tuberculum sellae (TSM) and olfactory groove meningiomas (OGM) but is associated with cerebrospinal fluid (CSF) leak in up to 25% of patients. To evaluate the impact of improved skull base reconstructive techniques, we assessed published CSF leak percentages in EEA over the last two decades. Method Random-effects meta-analyses were performed for studies published between 2004-2020. Outcomes assessed were CSF leak, gross total resection, visual improvement, intraoperative arterial injury and 30-day mortality. For the main analyses, publications were pragmatically grouped based on publication year in three categories: 2004-2010, 2011-2015, and 2016-2020. Results We included 29 studies describing 540 TSM and 115 OGM patients. CSF leak incidence dropped over time from 22% (95% CI: 6-43%) in studies published between 2004 and 2010, to 16% (95% CI: 11-23%) between 2011 and 2015, and 4% (95% CI: 1-9%) between 2016 and 2020. Outcomes of gross total resection, visual improvement, intraoperative arterial injury, and 30-day mortality remained stable over time Conclusions We report a noticeable decrease in CSF leak over time, which might be attributed to the development of reconstructive techniques (e.g., hadad bassagasteguy flap, and gasket seal), refined multilayer repair protocols, and selected lumbar drain usage.

Keyhole Superior Interhemispheric Approach to Midline Meningiomas of the Far Frontal Region of the Anterior Skull Base: Cadaveric Study and Illustrative Cases

Unique challenges can present in the treatment of small to mid-sized meningiomas that arise from the region of the anterior most aspect of the falx cerebri including its junction with the anterior skull base, what we call the far frontal region. Although this region of the anterior skull base is considered in the surgical approach of olfactory groove meningiomas invading this space, important differences exist between these tumors and those of the far frontal region. Toward refining surgical selection, our cadaveric study details a minimally invasive keyhole superior interhemispheric approach to the far frontal region and 2 illustrative cases show the feasibility of this approach. Our cadaveric study defines 5 steps of the approach from the incision, craniectomy, dural opening, approaching the skull base and ipsilateral exposure, and finally falcine resection and bilateral skull base exposure. Two illustrative cases with the approach confirmed visualization of the full extent of tumor and gross total resection with preservation of the unaffected olfactory bulb. To the best of our knowledge, our anatomic study is distinctively unique in quantifying the working distance of the keyhole superior interhemispheric exposure and refining visualization of the far frontal region. We discuss these benefits and limitations (i.e., substantial involvement of tumor beyond midline) and differences with large meningiomas of the olfactory groove and far frontal region with significant posterior or lateral extension for which conventional exposures are appropriate.

Neuropsychiatric symptoms as first manifestation of olfactory groove meningioma - importance of neuroimaging evaluation

IntroductionNeuropsychiatric symptoms may be the first and only manifestation of brain tumours, while classic neurological symptoms and signs may be minimal or absent at first. These patients will often receive psychiatric treatments for prolonged periods before correct diagnosis.ObjectivesTo report the case of a patient with olfactory groove meningioma presenting with neuropsychiatric symptoms as a basis for discussion.MethodsRetrospective review of clinical notes, neuroimaging results and house photos. Literature review.ResultsA 66-year-old woman was brought by police to the psychiatric emergency department Her neighbours had notified authorities of a bad smell, and police found the house was loaded with garbage. The patients reported depressive symptoms in the last 6 months, including apathy, anhedonia, social isolation, decreased appetite and insomnia; loss of basic skills such as cooking or cleaning; she also reported dizziness and two episodes of urinary and faecal incontinence in public. The patient had a history of being medicated for depression between 2000 and 2006. Currently she was taking only alprazolam 1 mg daily. During evaluation she was conscious, oriented and cooperative, with evident hypomimia, psychomotor inhibition and indifferent attitude. Cranial nerve function was preserved except for anosmia. Cranial CT and MRI showed a solid extra-axial tumour of 5.2x3.5x4.9 centimetres compatible with meningioma of the olfactory groove, and she was referred to Neurosurgery for surgical intervention.ConclusionsThis case illustrates the importance of a thorough organic evaluation, including neuroimaging, in the differential diagnosis of patients with atypical symptoms before making a psychiatric diagnosis and instituting treatment.

A Case of Foster Kennedy Syndrome in a Pregnant Lady Presenting with Unilateral Deterioration of Vision

Foster Kennedy syndrome is a rare neurological entity that includes ipsilateral optic atrophy, contralateral papilledema, and sometimes anosmia. The syndrome has been described in association with a variety of intracranial pathologies such as a large frontal lobe tumor, olfactory groove meningioma, or medial third sphenoidal wing meningioma. In this report, we present a case of sphenoidal wing meningioma with Foster Kennedy syndrome in a 25-year-old pregnant female.

Optical coherence tomography analysis of eyes in patients with chronic chiasmal compression: A case report

Introduction. Olfactory groove meningiomas cause progressive compression of the frontal lobes with posterior projection towards the sella turcica. If large enough, these tumors may cause optic nerve compression and optic chiasm. The aim of this study was to determine whether optical coherence tomography, as a method that objectively measures the thickness of retinal nerve fiber layer and retinal ganglion cell complex thickness, provides a realistic assessment of the postoperative visual outcome in chronic chiasmal compression caused by olfactory groove meningioma. Case Report. A 55-year-old woman presented with an eight month history of malaise, weakness, frontal headaches, anosmia, and blurred vision in both eyes. Magnetic resonance imaging of the endocranium revealed a large olfactory groove meningioma extending into the prechiasmal portion of the optic nerves and optic chiasm with a marked compressive effect. The mean preoperative retinal nerve fibre layer thickness was 65 ?m in the right eye and 63 ?m in the left eye. Ten months after surgery, the mean retinal nerve fibre layer thickness was 67 ?m in the right eye and 63 ?m in the left eye. The mean preoperative ganglion cell complex thickness was 57 ?m in the right eye, while it could not be measured in the left eye due to loss of fixation. Ten months after surgery, the mean ganglion cell complex thickness was 56 ?m in the right eye and 48 ?m in the left eye. The obtained values were significantly lower than the physiologic thickness values. Conclusion. Retinal nerve fibre layer thickness and ganglion cell complex thickness measured by optical coherence tomography represent a valid prognostic indicator of visual outcome and recovery after surgical decompression of the optic chiasm.

A Case of Olfactory Groove Meningioma Diagnosed from Anosmia

A Case of Olfactory Groove Meningioma Diagnosed from Anosmia

Endoscopic endonasal surgery for anterior cranial fossa meningiomas.

Meningiomas along the anterior skull base arise from the midline but have historically been resected via open cranial approaches with lateral to medial trajectories. The endoscopic endonasal approach (EEA) offers a direct, inferomedial approach which has demonstrated several superior qualities for their resection. These meningiomas include tuberculum sellae, planum sphenoidale, and olfactory groove meningiomas. While early gross total resection (GTR) was lower than open approaches, EEA has currently achieved comparable rates of GTR and significantly improved postoperative visual outcomes. Rate of cerebrospinal fluid (CSF) leak was one of the early complicating features preventing widespread use of EEA. However, CSF leak rates have dramatically fallen into a tolerable range with introduction of the vascularized nasoseptal flap. Olfactory groove meningiomas often present with anosmia which is persistent after endonasal approach. Rates of other complications have proven similar between EEA and open approaches and include: vascular injury, infection, morbidity, and mortality. With the appropriate team and experience, EEA for anterior skull base meningiomas is increasingly becoming the standard for resection of these lesions. However, there are certain anatomic considerations, patient features, and other aspects which may favor the open approach over EEA, and vice versa; these must be carefully and judiciously evaluated preoperatively. Overall, resection and recurrence rates are comparable, complication rates fall within a very acceptable range, and patients experience superior cosmesis and improved visual outcome with this approach.

Detailed Arterial Anatomy and Its Anastomoses of the Sphenoid Ridge and Olfactory Groove Meningiomas with Special Reference to the Recurrent Branches from the Ophthalmic Artery.

Detailed arterial anatomy of the sphenoid ridge and olfactory groove meningiomas is complicated due to the fine angioarchitecture and anastomoses between each feeder. Herein, we present details of the arterial anatomy and the relationships of feeders in these lesions. This study included 20 patients admitted to our department between April 2015 and March 2020. Conditions of subjects consisted of 16 sphenoid ridge meningiomas and 4 olfactory groove meningiomas. We mainly analyzed arterial anatomy using 3D rotational angiography and slab MIP images of these lesions. We also analyzed the anastomoses of each feeder. We found that 19 (95%), 15 (75%), and 15 (75%) lesions had feeders from the ophthalmic, internal carotid, and external carotid arteries, respectively. As feeders from the ophthalmic artery, recurrent meningeal arteries were involved in 18 lesions (90%). Fifteen lesions (75%) had anastomoses between each feeder. Most of the meningiomas in the sphenoid ridge and olfactory groove had feeders from the ophthalmic and internal carotid arteries. There were various anastomoses between each feeder. This is the first report to demonstrate the detailed arterial anatomy and frequency of recurrent branches from the ophthalmic artery and their anastomoses using detailed imaging techniques.

Endoscopic Endonasal Resection-Olfactory Groove Meningioma: 2-Dimensional Operative Video.

Olfactory groove meningiomas can represent a surgical challenge, and controversy persists in regard to the optimal approach corridor.1,2 This video exemplifies the endoscopic endonasal resection of a voluminous olfactory groove meningioma. Focus is given on the key aspects of the procedure, complication avoidance, nuances of the technique, and advantages pertaining to this approach.3-6 The patient consented for the conception and publication of this video.

Microsurgical Excision of Olfactory Groove Meningiomas, Comparative Studies of Different Surgical Approaches

Introduction: To review the surgical approaches, techniques, outcomes and recurrence rates in a series of 11 olfactory groove meningioma (OGM) patients operated from January 2010 to April 2019. Methods: Eleven patients underwent craniotomy and micro-neurosurgical removal of olfactory groove meningioma. Tumor diameter varied from 5 to 8.5 cm among 11 cases, 2 cases underwent Transglabellar/ Subcranial approach, 3 cases by bifrontal approach, 1 case unifrontal approach, 2 extended endonasal and 3 cases fronto-lateral approach. Result: Total removal was possible in all cases except 2 cases. Histopathology revealed typical meningioma (WHO grade 1). There was 1 operative mortality and no permanent focal neurological deficit except anosmia. 3 patients developed CSF leak and two cases meningitis which were resolved by lumber drain and antibiotic therapy. Conclusion: Extended endonasal approach or transglabellar/ subcranial approach were sufficient for gross total removal of OGM which is associated with bony hyperostosis, paranasal extension and optic canal. Bang. J Neurosurgery 2020; 10(1): 9-19

Cost-effectiveness of endoscopic endonasal vs transcranial approaches for olfactory groove meningioma.

Endoscopic endonasal approaches (EEAs) have been adopted as an alternative to standard transcranial approaches for olfactory groove meningiomas (OGMs). However, the relative cost-effectiveness remains controversial. Cost-utility analysis from a societal perspective comparing EEA vs transcranial approaches for OGM was used in this study. Surgical treatment was modeled using decision analysis, and a Markov model was adopted over a 20-year horizon. Parameters were obtained from literature review. Costs were expressed in 2017 Canadian dollars. In the base case, EEA was cost-effective compared with transcranial surgery with an incremental cost-effectiveness ratio of $33 523 ($30 475 USD)/QALY. There was a 55% likelihood that EEA was cost-effective at a willingness-to-pay of $50 000/QALY. EEA remained cost-effective at a cerebrospinal fluid leak rate below 60%, gross total resection rate above 25%, and base cost less than $66 174 ($60 158 USD). EEA may be a cost-effective alternative to transcranial approaches for selected OGM.

Eyebrow supraorbital keyhole craniotomy for olfactory groove meningiomas with endoscope assistance: case series and systematic review of extent of resection, quantification of postoperative frontal lobe injury, anosmia, and recurrence.

Olfactory groove meningiomas (OGMs) are commonly treated with open craniotomy. Endonasal approaches have also been described. To present clinical and radiographic outcomes for the minimally invasive eyebrow incision supraorbital keyhole approach with endoscopic assistance for OGMs. We performed a retrospective single-center cohort study and a systematic literature review. Fifteen patients were identified, all with Grade I meningiomas. Radiographic gross total resection of enhancing tumor was achieved in all patients. Mean frontal lobe fluid-attenuated inversion recovery volume decreased from 11.1 ± 18.3cm3 preoperatively to 9.9 ± 11.4cm3 immediately postoperatively, and there was minimal new restricted diffusion (3.2 ± 2.2cm3; max 7.5cm3). Median length of stay was 3days (range 2-8). Vision was improved in 4 (80%) and stable in 1 (20%) of 5 patients with a preoperative deficit. New postoperative anosmia occurred in 3 (23%) of 13 patients with any preoperative olfaction. All patients were satisfied with their cosmetic result at 3months. After a median follow-up of 32.2months, there were 2 (13.3%) asymptomatic radiographic recurrences, 1 treated with radiosurgery and the other with endoscopic endonasal approach (EEA). No patients required further craniotomy. Systematic review revealed the present series to be the largest to date reporting disaggregated outcomes for the eyebrow approach to OGM. The eyebrow incision supraorbital keyhole craniotomy with endoscopic assistance is a safe and effective approach to OGM with tumor control rates similar to more invasive open approaches and better than the endonasal approach. Rates of frontal lobe injury, CSF leak and anosmia are comparatively low.

Use of endoscopic transorbital and endonasal approaches for 360° circumferential access to orbital tumors.

Orbital tumors are often surgically challenging because they require an extensive fronto-temporo-orbital zygomatic approach (FTOZ) and a multidisciplinary team approach to provide the best outcomes. Recently, minimally invasive endoscopic techniques via a transorbital superior eyelid approach (ETOA) or endoscopic endonasal approach (EEA) have been proposed as viable alternatives to transcranial approaches for orbital tumors. In this study, the authors investigated the feasibility of 360° circumferential access to orbital tumors via both ETOA and EEA. Between April 2014 and June 2019, 16 patients with orbital tumors underwent either ETOA or EEA at the authors' institution. Based on the neuro-topographic "four-zone model" of the orbit with its tumor epicenter around the optic nerve in the coronal plane, ETOA (n = 10, 62.5%) was performed for tumors located predominantly superolateral to the nerve and EEA (n = 6, 37.5%) for those located predominantly inferomedial to the nerve. Eight patients (50%) presented with intraconal tumors and 8 (50%) with extraconal ones. The orbital tumors included orbital schwannoma (n = 6), cavernous hemangioma (n = 2), olfactory groove meningioma (n = 1), sphenoorbital meningioma (n = 1), chondrosarcoma (n = 1), trigeminal schwannoma (n = 1), metastatic osteosarcoma (n = 1), mature cystic teratoma (n = 1), sebaceous carcinoma (n = 1), and ethmoid sinus osteoma (n = 1). The clinical outcomes and details of surgical techniques were reviewed. Gross-total resection was achieved in 12 patients (75%), near-total resection in 3 (18.8%), and subtotal resection in 1 (6.2%). Eight (88.9%) of the 9 patients with preoperative proptosis showed improvement after surgery, and 4 (66.7%) of the 6 patients with visual symptoms demonstrated improvement. Four (40%) of the 10 patients treated with ETOA experienced partial third nerve palsy immediately after surgery (3 transient and 1 persistent). There have been no postoperative CSF leaks or infections in this series. Without transcranial approaches requiring temporalis muscle dissection and orbitozygomatic osteotomy, the selection of ETOA or EEA based on a concept of a four-zone model with its epicenter around the optic nerve successfully provides a minimally invasive 360° circumferential access to the entire orbit with acceptable morbidity.

Giant Olfactory Groove Meningioma in Pregnancy

Introduction: Meningioma is slow growing neoplasm cells that comes from arachnoid cap most common benign intracranial tumours. Olfactory groove meningiomas (OGM) account for 8–13% of all intracranial meningiomas. Intracranial tumors on pregnancy is a rare event, with few reports. Case Presentation: A 36-year-old- female (G11P9A1) 34 gestational week presented to the Adam Malik General Hospital with smelling disturbances for 6 months and lossing smelling sense in the past 1 month. Slowly progression of vision disturbances for 3 months without improvement in using glasses, progressive loss of vision in both eyes for the past 1 month. CT scan and MRI revealead a solid mass lesion, with 6.3 x 4.2 x 3.1 cm. It was a supratentorial in frontal region, olfactory groove mass. The Craniotomy tumor removal was performed in this patient. Discussion: Meningiomas are mostly silent brain tumors with slow growth, however may get detected and mostly become symptomatic during pregnancy and luteal phase of menstrual cycle due to increase in size secondary to either water retention, enhanced vascularity or progesterones are possible etiologies. The majority of meningiomas express progesterone reseptor, which can be detected also by immunohistochemistry. In fact, tumour growth when progesterone concentrations are higher, shows the role of sex hormones in the mechanism. Regardless of the status of pregnancy, symptomatic and large meningiomas require surgical resection. Conclusion: Changes of plasma concentration hormones during pregnancy and their effect on meningioma growth in the second and third trimester are crucial and critical. The management of brain lesions during pregnancy required professional collaboration between neurosurgeons, obstetricians and anesthesiologists.

The Role of 3D Tractography in Skull Base Surgery: Technological Advances, Feasibility, and Early Clinical Assessment with Anterior Skull Base Meningiomas.

Objective The aim of this study is to determine feasibility of incorporating three-dimensional (3D) tractography into routine skull base surgery planning and analyze our early clinical experience in a subset of anterior cranial base meningiomas (ACM). Methods Ninety-nine skull base endonasal and transcranial procedures were planned in 94 patients and retrospectively reviewed with a further analysis of the ACM subset. Main Outcome Measures (1) Automated generation of 3D tractography; (2) co-registration 3D tractography with computed tomography (CT), CT angiography (CTA), and magnetic resonance imaging (MRI); and (3) demonstration of real-time manipulation of 3D tractography intraoperatively. ACM subset: (1) pre- and postoperative cranial nerve function, (2) qualitative assessment of white matter tract preservation, and (3) frontal lobe fluid-attenuated inversion recovery (FLAIR) signal abnormality. Results Automated 3D tractography, with MRI, CT, and CTA overlay, was produced in all cases and was available intraoperatively. ACM subset : 8 (44%) procedures were performed via a ventral endoscopic endonasal approach (EEA) corridor and 12 (56%) via a dorsal anteromedial (DAM) transcranial corridor. Four cases (olfactory groove meningiomas) were managed with a combined, staged approach using ventral EEA and dorsal transcranial corridors. Average tumor volume reduction was 90.3 ± 15.0. Average FLAIR signal change was -30.9% ± 58.6. 11/12 (92%) patients (DAM subgroup) demonstrated preservation of, or improvement in, inferior fronto-occipital fasciculus volume. Functional cranial nerve recovery was 89% (all cases). Conclusion It is feasible to incorporate 3D tractography into the skull base surgical armamentarium. The utility of this tool in improving outcomes will require further study.

Temporo-parietal muscle pedicle flap for reconstruction of the anterior skull base after resection of recurrent olfactory groove meningioma: a technical note

Reconstruction becomes the main issue in surgery for tumours penetrating the anterior skull base because it faces the nasal cavity. Vascularized flaps are desirable for preventing infection, but in re-opening surgery, tissue availability is limited. We report a case of recurrent olfactory groove meningioma in which the anterior skull base defect was reconstructed using a temporo-parietal muscle (TPM) pedicle flap. A 65-year-old woman presented with recurrent olfactory groove meningioma penetrating the anterior skull base. Because the frontal pericranium had been used in the initial surgery, the temporal fascia was harvested with a TPM pedicle flap from behind the initial bicoronal incision. After removal of the tumour, the pedicle flap reached the sphenoid planum easily and was sutured to the surrounding structures. The fascia lata was sutured as an inlay. The postoperative course was uneventful, and no cerebrospinal fluid leakage was observed. In re-opening surgery, a TPM pedicle flap can be an option for reconstruction of the anterior skull base.

Olfaction in Olfactory Groove Meningiomas.

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. 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. 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. 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.

Amelioration of anosmia after removal of an olfactory groove meningioma via pterional approach

Anosmia is one of the early symptoms of olfactory groove meningiomas (OGM) and the postoperative recovery of anosmia is accepted to be unexpected. A 42-year-old female patient presented with bilateral anosmia, and visual field field defects. Radiological examination revealed a large OGM with significant peritumoral edema. The tumor was totally resected through the pterional approach, with the meticulous preservation of the left olfactory nerve. Visual field disturbances improved in the early postoperative period. Furthermore, olfaction recovered in the left nostril at the 6-month follow-up. Despite the common belief that anosmia persists after OGM surgery, with preservation of ofactory nerves, olfaction can be recovered in rare cases.

The extended pterional approach for midline anterior skull base meningiomas

Background: Various surgical approaches for the management of midline anterior skull base meningiomas exist in the literature. The main surgeon target is proper selection the appropriate approach that achieves total removal of the lesion without causing morbidity or mortality and facilitates safe effective removal of the tumour.
 Objectives: To evaluate the role of the extended pterional approach for excision of midline anterior skull base meningiomas as regarding the effectiveness, extent of resection and surgical outcome.
 Patients and methods: This retrospective study involved 23 cases with midline anterior skull base meningiomas resected through the extended pterional approach. Patients' clinical data, operative notes, imaging studies and clinical follow-up data were analyzed and evaluated.
 Results: Tumors studied were 9 olfactory groove meningiomas, 8 tuberculum Sellae meningiomas, 4 planum sphenoidale meningiomas and 2 diaphragma sellae meningiomas. Gross total resection tumour excision in 15 cases (64.5%), subtotal excision in 5 cases (21.5%) and partial excision in 3 cases (14%). Complications were diabetes insipidus (2 cases 8.6%), CSF rhinorrhea (3 cases 12.9%) and visual deterioration (3 cases 12.9%). We had two cases of mortality.
 Conclusion: The extended pterional approach allows safe and effective removal of midline anterior skull base meningiomas. It expands the exposure offered by the classic pterional approach and minimizing the necessity for applying fixed brain retraction with good cosmetic outcome and less approach-related morbidities in comparison with the extensive skull base approaches.