Bilateral infraoptic origin of the anterior cerebral artery: illustrative case.

BACKGROUND: A bilateral infraoptic origin of the anterior cerebral arteries (ACAs) is a rare anatomical variant that can be encountered during anterior skull base surgery. The ACAs arise from the internal carotid artery (ICA) at the level of the ophthalmic artery and course medially, traveling inferior to the ipsilateral optic nerves. Herein, the authors discuss the different configurations of the anatomical variant, its prevalence, and hypotheses leading to the variable configuration of this anomaly. OBSERVATIONS: A 67-year-old woman presented with worsening dizziness over a week-long period and was found to have a large left sphenocavernous meningioma with optic, cavernous, and suprasellar extension. The tumor incorporated the left supraclinoid ICA and its branches. She underwent a left modified orbitozygomatic craniotomy for tumor resection. Early identification of the aberrant ACA anatomy was crucial in avoiding vascular injury. LESSONS: While this variant is typically encountered during the treatment of vascular pathologies-namely, intracranial aneurysms-its existence should be kept in mind during the treatment of any anterior skull base pathology. Failure to account for the presence of this variant may lead to potential intraoperative complications.

Surgery for acromegaly: Indications and goals.

Acromegaly is a disease that occurs secondary to high levels of GH, most often from a hormone-secreting pituitary adenoma, with multisystem adverse effects. Diagnosis includes serum GH and IGF-1 levels, and obtaining an MRI pituitary protocol to assess for a functional pituitary adenoma. Attempted gross total resection of the GH-secreting adenoma is the gold standard in treatment for patients with acromegaly for a goal of biochemical remission. Medical and radiation therapies are available when patients do not achieve biochemical cure after surgical therapy.

Adjuvant Radiotherapy in Grade II, Atypical Meningioma of the Skull Base.

Introduction Atypical meningiomas (AM) are meningiomas that are more aggressive than their grade-I counterparts and have a higher rate of recurrence. The effect of adjuvant radiotherapy (ART) on AM of the skull base is not defined. Methods A retrospective review of all AM's of the skull base primarily resected at our institution from 1996 to 2018 was completed. ART was defined as radiotherapy (RT) that occurred within 6 months of initial resection, regardless of Simpson's grade. Minimum time length of follow-up after resection was 2 years. Statistical analysis was performed using SAS. Results There were a total of 59 skull base-located (SBL) AMs resected at our institution from 1996 to 2018. The average age of our cohort was 53.2 years. Gross total resection, defined as Simpson's grades I to III resection, was achieved in 36 (61%) of cases. Thirty-five of 59 (59%) patients received ART. Recurrence was observed in 14 patients (24%), and mean time to recurrence was 63.8 months. Patients who received ART had a lower observed rate of recurrence (8 vs. 46%); however, time to recurrence was not significantly different between the two populations. Conclusion We observe that AM in the skull base location have higher recurrence rates than we would expect from grade-I meningioma. These data suggest that ART may offer benefit to the overall observed frequency of recurrence of SBL AM; however, the time to recurrence between patients who received ART and those who did not was not statistically significant in survival analysis.

Adjuvant Radiotherapy Versus Watchful Waiting for World Health Organization Grade II Atypical Meningioma: A Single-Institution Experience.

BACKGROUND: Atypical meningiomas (AMs) are meningiomas that have a higher rate of recurrence than grade I meningioma. Due to the higher risk of recurrence, adjuvant radiotherapy (RT) after resection of AM has been employed. At our institution, some neurosurgeons employ adjuvant RT on all primarily resected AMs, while others employ watchful waiting with serial imaging. OBJECTIVE: To study the effect of adjuvant RT on newly resected AMs. METHODS: A retrospective review of all AMs primarily resected at our institution from 1996 to 2018 was completed. Data on patient demographics, radiographic findings, use of adjuvant RT, time of follow-up, and recurrences were collected. Adjuvant RT was defined as RT that occurred within 6 mo of initial resection. RESULTS: A total of 162 patients met the inclusion criteria. Gross total resection was achieved in 73% of cases. Average time until recurrence in the cohort was 37 mo. A total of 108 patients had adjuvant RT, while 54 patients did not. On multivariate survival analysis, sex, Simpson grade resection, and use of adjuvant RT were independent predictors of recurrence. Mean time to recurrence in patients who received adjuvant RT was 43.7 mo versus 34.7 mo for those who did not receive adjuvant RT. CONCLUSION: This study includes the largest retrospective cohort of patients who have received adjuvant RT after primary resection of AM. Our results suggest that the use of adjuvant RT is independently associated with a lower chance of recurrence. These data suggest that practitioners can consider the use of adjuvant RT for newly resected AMs, regardless of Simpson grade resection.

Endoscopic-assisted parieto-occipital interhemispheric precuneal transtentorial approach for microsurgical resection of vermian arteriovenous malformation: operative video and technical nuances.

In this illustrative video, the authors demonstrate resection of a superior vermian arteriovenous malformation (AVM) using the endoscopic-assisted parieto-occipital interhemispheric precuneal transtentorial approach. Lateral positioning allows for gravity-assisted access to the interhemispheric fissure without retractors. The parieto-occipital trajectory is useful in patients who have a steep tentorial angle and avoids manipulation of the occipital lobe and visual cortex. In addition, the authors utilize an angled endoscope, which allows full inspection of the resection bed after AVM removal to visualize areas hidden from the microsurgical view to minimize the chance of residual disease in a deep corridor with multiple visual obstructions. The video can be found here: https://youtu.be/hk9nIIdtqbI.

A phase 0 analysis of ixazomib in patients with glioblastoma.

Improving overall survival in recurrent glioblastoma remains a challenge, and drugs acting by unique mechanisms are urgently required. Ixazomib is an orally-administered proteasome inhibitor used in combination with lenalidomide and dexamethasone to treat patients with multiple myeloma who have received at least one prior therapy. However, ixazomib's ability to reach brain tumors has not been studied during its development. The aim of the present study (ClinicalTrials.gov, NCT02630030) was to establish and quantify ixazomib's presence in glioblastoma. The present study investigated 3 patients with recurrent glioblastoma after administration of oral ixazomib citrate (MLN 9708) at a fixed 4.0 mg dose within a 3-hpreoperative window. A total of 2 blood samples were taken from each patient at the time of incision, tumor sampling and closure. Brain tumor samples were collected during tumor resection. These samples were then used to measure the plasma and brain tumor tissue concentration of the biologically-active form of ixazomib (MLN 2238). Patient 1 had plasma concentrations of ixazomib averaging 26.2, 21.8 and 15.3 ng/ml at incision, tumor sampling and closure, respectively. The brain tumor tissue concentration was 7.88 ng/g. Patient 2 had the same interval and brain tumor tissue measurements of 19.0, 18.0 and 8.93 ng/ml, and 2.03 ng/g. Patient 3 had plasma concentration interval measurements of 25.6, 36.2 and 28.7 ng/ml. Multiple brain tumor tissue samples were taken in patient 3, with an average tissue ixazomib concentration of 3.37 ng/g. Ixazomib was found at plasma concentrations commensurate with its previously established pharmacokinetic profile without clinically relevant drug-related adverse events. Ixazomib reaches glioblastoma tissues at measurable concentrations at the time of tumor resection, confirming target tissue delivery. This justifies the phase I study of ixazomib in recurrent glioblastoma currently in development.

Status of Pituitary Surgery During the COVID-19 Pandemic.

Even in ideal circumstances, the performance of safe and effective endoscopic transsphenoidal pituitary surgery requires complicated orchestration of care amongst multiple medical and surgical teams in the preoperative, intraoperative, and postoperative settings. The current COVID-19 pandemic further complicates this highly orchestrated effort. Healthcare systems around the globe are working to adapt to the rapidly changing healthcare landscape as information about the SARS-CoV-2 virus is discovered and disseminated. The nature of the transsphenoidal corridor exposes the pituitary surgery team to increased risk of virus exposure.

Completely Dehiscent Posterior Sphenoid Sinus Wall During Endoscopic Pituitary Surgery.

A 53-year-old man presented with a 1-week history of headache and double vision. On examination, he was found to have right cranial nerve III palsy. Computed tomography and magnetic resonance imaging of the brain showed a sellar mass with right cavernous sinus invasion. There was no evidence of anterior visual pathway compression on formal neuro-ophthalmologic examination. An elective endoscopic transsphenoidal adenectomy was performed. On access to the sphenoid sinus, he was noted to have a completely dehiscent posterior bony wall of sphenoid sinus with only a thin mucous membrane covering the sella, optic nerves, carotid arteries, and clivus (Figure 1). A focal area of mucosa was subsequently stripped from the posterior sphenoid sinus wall, and a micro-Doppler was used to localize the carotid arteries before sharp dural opening. The tumor was subsequently resected without complication. Failure to appreciate this uncommon anatomic variant (Figures 2 and 3) could result in disastrous irreversible carotid artery or optic nerve injury.

Occult tumors presenting with negative imaging: analysis of the literature.

OBJECT: Some patients presenting with neurological symptoms and normal findings on imaging studies may harbor occult brain tumors that are undetectable on initial imaging. The purpose of this study was to analyze the cases of occult brain tumors reported in the literature and to determine their modes of presentation and time to diagnosis on imaging studies. METHODS: A review of the literature was performed using PubMed. The authors found 15 articles reporting on a total of 60 patients with occult tumors (including the authors' illustrative case). RESULTS: Seizures were the mode of initial presentation in a majority (61.7%) of patients. The initial imaging was CT scanning in 55% and MRI in 45%. The mean time to diagnosis for occult brain tumors was 10.3 months (median 4 months). The time to diagnosis (mean 7.5 months, median 3.2 months) was shorter (p = 0.046) among patients with seizures. Glioblastoma multiforme (GBM) was found more frequently among patients with seizures (67.6% vs 34.8%, p = 0.013). The average time to diagnosis of GBM was shorter than the time to diagnosis of other tumors; the median time to diagnosis was 3.2 months for GBM and 6 months for other tumors (p = 0.04). There was no predilection for side or location of occult tumors. In adult patients, seizures may be predictive of left-sided tumors (p = 0.04). CONCLUSIONS: Based on the results of this study, the authors found that in patients with occult brain tumors, the time to diagnosis is shorter among patients with seizures and also among those with GBM.

Metastatic prostate mass to the intradural foramen magnum region: a case report.

Intradural metastatic tumors of the foramen magnum region are extremely rare tumors. We report a 73-year-old patient that presented with right hemiparesis and a recent history of prostate biopsy for an enlarged prostate. Imaging revealed an anterolateral intradural foramen magnum mass with compression of the medulla. A right far lateral approach with condyle preservation was used to resect the mass. Pathological examination revealed the tumor as a metastatic prostate mass. The patient had a significant recovery of motor function and was given adjuvant external beam radiation. At the time of last follow-up, the patient had good clinical relief from the preoperative symptoms. To our knowledge, this is the first reported case of an intradural foramen magnum prostate tumor metastasis. We report on multimodal management of this rare, yet morbid presentation of a common tumor.

Phosphoinositide 3-kinase-gamma expression is upregulated in brain microglia and contributes to ischemia-induced microglial activation in acute experimental stroke.

Microglia, the resident microphages of the CNS, are rapidly activated after ischemic stroke. Inhibition of microglial activation may protect the brain by attenuating blood-brain barrier damage and neuronal apoptosis after ischemic stroke. However, the mechanisms by which microglia is activated following cerebral ischemia is not well defined. In this study, we investigated the expression of PI3Kgamma in normal and ischemic brains and found that PI3Kgamma mRNA and protein are constitutively expressed in normal brain microvessels, but significantly upregulated in postischemic brain primarily in activated microglia following cerebral ischemia. In vitro, the expression of PI3Kgamma mRNA and protein was verified in mouse brain endothelial and microglial cell lines. Importantly, absence of PI3Kgamma blocked the early microglia activation (at 4h) and subsequent expansion (at 24-72 h) in PI3Kgamma knockout mice. The results suggest that PI3Kgamma is an ischemia-responsive gene in brain microglia and contributes to ischemia-induced microglial activation and expansion.