Cognitive brain activity before and after surgery in meningioma patients.

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

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

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

[Diagnostic Value of Locally Produced Tumor Markers and Blood Brain Barrier
Integrity in Lung Cancer Patients with Leptomeningeal Metastasis].

BACKGROUND: Tumor markers (TM) in cerebrospinal fluid (CSF) are useful for diagnosing leptomeningeal metastasis (LM). It has not been fully exploited the diagnostic possibilities of the CSF levels since the basic fact that the TM concentration of CSF depends strongly upon the serum levels as well as upon the condition of the blood brain barrier (BBB). To analyze the intrathecal TM synthesis and evaluate the integrity of BBB can be helpful for the definitive diagnosis of LM. Therefore, the aim of this study was to further explore the clinical value of intrathecal TM synthesis and BBB in the diagnosis for the lung cancer patients with LM. METHODS: Twenty-five lung cancer patients with LM and 57 patients with nonmalignant neurological diseases (NMNDs) admitted to Nanjing Drum Tower Hospital from December 2016 to March 2020 were included. We compared the integrity of BBB and intrathecal TM synthesis between two groups, analyzed the correlation of CSF TM between the detection and intrathecal synthesis, and evaluated serial CSF cytology, the integrity of BBB and intrathecal TM synthesis when intrathecal chemotherapy for one patient. RESULTS: Ninety-four percent LM patients showed the dysfunction of BBB, and all LM patients showed at least one intrathecal synthesized TM in CSF. In one patient, the CSF cytology was negative for the first time, but LM was eventually diagnosed based on the the intrathecal TM synthesis and positive CSF cytology of repeated lumbar puncture. In LM group, no correlation was observed between the detection and intrathecal synthesized TM in CSF. In the control group, only 3.5% (2/57) NMNDs patients had the dysfunction of BBB and no patients had intrathecal TM synthesis, both the differences of which were statistically significant (P<0.05). Finally, evaluating the CSF cytology, integrity of BBB and intrathecal TM synthesis can be used to assess the intracranial treatment effect. Moreover, intrathecal TM synthesis changes earlier than cytology. CONCLUSIONS: The evaluation of intrathecal TM synthesis and integrity of BBB are novel clinical diagnostic tools. In addition, serial measurement of intrathecal synthesized TM may play an important role in monitoring efficacy of lung cancer patients with LM, which is worthy of further promotion and clinical application.

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

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

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

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

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

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

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

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

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

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

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

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

Intravenous analgesia with ultra-high-dose morphine for the treatment of headache and successful withdrawal of morphine: A case report and literature review.

RATIONALE: Pain is the fifth vital sign of human beings. Morphine is the first choice for relieving moderate to severe cancer pain. Most of the previous studies merely focused on the analgesic effect of high-dose or ultra-high-dose morphine in patients with advanced cancers but did not report any cases related to successful morphine withdrawal. PATIENT CONCERNS: A 42-year-old woman was admitted to our hospital in March 2019. DIAGNOSIS: She was diagnosed with progressive aggravation of headache for 1 month, which was meningeal metastasis of lung cancer. INTERVENTIONS: Symptomatic treatments like dehydration, hormone, intrathecal injection chemotherapy and an increased dose of osimertinib to 160 mg/day were applied but showed poor curative effects. The patient refused whole-brain radiotherapy. Pain intensity level was re-evaluated and the patient scored 9 based on numerical rating scale, which suggested that the patient suffered from severer cancerous pain. Thus, the patient started to receive morphine for treating headache. OUTCOMES: The patient's headache was alleviated after receiving high-dose morphine treatment, and she continued to undergo anti-cancer treatment. After tumor remission, the patient's morphine dose gradually decreased and eventually stopped, without any withdrawal symptoms. In addition, the quality of life of the patient was greatly improved with performance status scored 2 and limb muscle strength increased from Grade 2 to Grade 5. LESSONS: For patients with advanced cancers, the application of ultra-high-dose morphine may significantly relieve cancerous pain, improve survival and quality of life, and overcome their fear for death and desperation, which contributes to the establishment of a basis for subsequent anticancer treatments. Thus, timely effective pain management and routine anticancer treatments are the key to addressing the cancer pain problem.

Olfaction in Olfactory Groove Meningiomas.

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

Meningioma in a patient with Werner syndrome.

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

Higher expression of beclin 1 in human meningiomas is related to better clinical outcome and pathological grade.

Meningiomas are common intracranial tumors, and most exhibit optimal prognosis; however, some meningiomas still recur and even develop malignant transformation in the following years, regardless of initial pathological grade. During these years, autophagy raises its significance in tumorigenesis and tumor suppression, both important for tumor development. The aim of this study was to elucidate the relationship between two autophagy markers, LC3B and beclin 1, with clinical and pathological parameters in patients with meningiomas. A total of 77 thin-sectioned slides, retrospectively collected from meningioma patients, were analyzed and correlated with clinicopathological parameters. We found that expression of beclin 1 rather than LC3B correlated to better prognosis, lower pathological grade, and longer survival. Furthermore, intensity of beclin 1 was also found to be significantly related to the pathological grade. These findings indicated that beclin 1 as a protective factor predicts better prognosis and plays the role of tumor suppression in meningiomas.

Spinal Accessory Nerve Meningioma at the Foramen Magnum with Medullar Compression: A Case Report and Literature Review.

BACKGROUND: Meningiomas that arise from the cranial nerve are rare. We present a case with an intradural extramedullary tumor at the foramen magnum originating from the spinal accessory nerve. CASE DESCRIPTION: The patient was a 69-year-old woman with dizziness and pain in the bilateral shoulder for 2 years. Neurologic examination revealed spinal accessory nerve palsy (difficult in raising the shoulder, deficit of 3/5) on the left side without further deficits. Magnetic resonance imaging showed medullar compression because of a left intradural extramedullary foramen magnum lesion dorsolateral to the medulla. Surgical exposure via a midline suboccipital approach with C1 laminectomy revealed that the lesion arises from the left accessory nerve without dural attachment. The tumor was resected without injury to the spinal accessory nerve, and histologic examination revealed that it was a meningothelial meningioma. The spinal accessory nerve palsy improved to 4 of 5 after 3 months after surgery. CONCLUSIONS: To our knowledge, this is the first report of an accessory nerve meningioma at the foramen magnum in which the spinal accessory nerve palsy appeared before operation and improved after tumor resection.

Clinical Outcome of Operated Intracranial Meningiomas: An Ethiopian Experience.

BACKGROUND: Intracranial meningioma is the most common brain tumor operated in the 2 teaching hospitals in Ethiopia. This study reviews the clinical outcome of intracranial meningiomas in a resource-limited setup. METHODS: This is a retrospective study undertaken at 2 neurosurgical teaching hospitals: Black Lion Specialized Hospital and Myungsung Christian Medical Center. It includes all operated patients with intracranial meningioma during the time period January 2009 to December 2013. Patient data regarding sociodemographics, presenting complaint, focal neurologic deficit, preoperative imaging, postoperative neurologic findings, intraoperative findings, and histopathologic results were collected and analyzed. RESULTS: A total of 91 patients were enrolled in the study. Tumor size was estimated in 79 cases (86.8%). Fifty-one tumors (64.6%) were >5 cm in diameter, whereas 28 (35.4%) were ≤5 cm. Only 4 patients had tumors <3 cm (5.1%). Tumor size was shown to be related to postoperative functional outcome (P = 0.032). The surgical mortality rate, which was defined as death within 1 month, was 14.3%. Among 88 patients with a postoperative Karnofsky Performance Status Scale score, 43% achieved a postoperative score ≥70. CONCLUSIONS: Meningioma size determines the outcome of the patients. It was shown that the functional outcome of patients is encouraging even though further improvement on neurosurgical care is needed.

Leptomeningeal leukaemia misdiagnosed as tubercular meningitis.

Chronic meningitis is a common syndrome with multiple aetiological causes. It can be associated with visionproblems as well as multifocal involvement of the central nervous system. Often it presents with constitutional symptoms as well. The intervention commonly practised in a tropical country like India is starting antitubercular therapy with corticosteroids. This practice though may be correct in a majority of situations, may lead to diagnostic delay and may be fatal.

Perioperative olfactory dysfunction in patients with meningiomas of the anteromedial skull base.

Olfactory dysfunction represents a main symptom in olfactory groove meningiomas (OGM). Besides this, olfactory function has been sparsely investigated in patients suffering from supratentorial meningiomas. Here, the authors explore pre- and postoperative variables associated with olfactory dysfunction in supratentorial meningioma patients. This is a retrospective study on supratentorial meningioma patients who underwent meningioma resection between January 2015 and January 2016. Preoperative and postoperative olfactory performance was quantified using a lateralized sniffin' stick odor identification test. Meningiomas affecting the olfactory system (n = 23) were compared to meningiomas in other locations among the control group (n = 40). Meningiomas that affected the olfactory system had odds of 3.6 and 3.7 in being associated with ipsilateral (lesional) and bilateral anosmia, respectively. Subgroup analysis revealed that meningiomas causing a midline shift across the frontal base and older age represented risk factors for preoperative anosmia. The odds of experiencing acquired postoperative ipsilateral anosmia were significantly increased in olfactory system affecting meningiomas (OR 11.1). Subgroup analysis highlighted OGMs to represent the predominant location associated with deterioration. General surgical complications predisposed patients to loss of contralateral (OR 12.3) and bilateral olfactory function (OR 27.8). Older age and meningiomas causing a midline shift across the frontal base predispose patients to preoperative olfactory dysfunction. Resection of OGMs and surgical complications are risk factors for postoperative olfactory deterioration to anosmia. Likely, olfactory dysfunction is underrecognized even in OGMs. In OGM surgery, however, preoperative lateralized testing might be critical to selecting an appropriate surgical route to preserve olfactory function. Clin. Anat. 32:524-533, 2019. © 2019 Wiley Periodicals, Inc.

Endoscopic Endonasal Removal of Primary/Recurrent Meningiomas in the Medial Optic Canal: Surgical Technique and Long-Term Visual Outcome.

BACKGROUND: Tuberculum sellae meningiomas frequently extend into the optic canals, which leads to a progressive longitudinal visual loss. Therefore, in addition to tumor removal, unroofing and exploration inside the optic canal are important procedures. OBJECTIVE: To perform endoscopic endonasal tumor removal with optic canal decompression for small primary or recurrent meningiomas associated with a progressive visual loss at the inferior-medial optic canal, which corresponded to a blind corner in the ipsilateral pterional/subfrontal approach. METHODS: We retrospectively reviewed 2 cases of primary meningiomas that arose in the inferior-medial optic canal and 4 recurrent cases from the remnant inside the medial optic canal that had previously undergone craniotomy for tuberculum sellae meningiomas, and were treated by the endoscopic endonasal approach. RESULTS: All tumors were detectable and could be removed without manipulation of the affected optic nerve. The average maximum diameter of the tumor was 8.4 mm (range: 5-12 mm). Two patients who had a long history of progressive visual disturbance and papillary atrophy did not recover from severe visual disturbances postoperatively. However, others showed considerable improvement, maintaining postoperative visual function during follow-up. There were no postoperative complications. CONCLUSION: Endoscopic endonasal approach has several advantages for meningiomas in the medial optic canal and associated with progressive visual disturbance. In surgery of tuberculum sellae meningiomas, optic canal decompression and exploration inside the optic canal are important procedures to avoid symptomatic recurrence, which may be facilitated by the endoscopic endonasal approach. Papillary atrophy and duration of visual deterioration are predictive factors for postoperative visual outcomes.