Multiple craniotomies for the resection of symptomatic multifocal intracranial metastatic cardiac myxoma: A case report.

Background: Myxomas, rare benign mesenchymal lesions, are the most common cardiac tumors. Patients may rarely develop hematogenous metastasis to the brain, which can present as new-onset neurological deficits that correlate with multifocal hemorrhagic lesions on imaging. Limited guidelines presently exist for the treatment of such lesions. This report outlines a unique case involving three craniotomies and failed radiation therapy in the treatment of metastatic cardiac myxoma. Case Description: A 63-year-old woman presented with a right middle cerebral artery embolic stroke secondary to a left atrial myxoma and multifocal hemorrhagic lesions consistent with intracranial metastasis. She had a right frontal craniotomy for tumor resection, followed by stereotactic radiosurgery, though this did not arrest disease progression. She later had a left occipital craniotomy for a symptomatic lesion. More than two years after her initial presentation, she returned with acute-onset symptoms correlating to growth in a left frontal lesion requiring another resection. Following this third craniotomy, imaging has not revealed the progression of metastatic intracranial disease. She is pursuing further treatment through primary cardiac tumor resection. Conclusion: Although rare, hematogenous seeding with subsequent formation of hemorrhagic metastasis is a possible complication of atrial myxoma. While surgical resection, radiation therapy, and chemotherapy have historically been used, no standard of care currently exists. This case demonstrates repeat tumor resection as effective for managing symptomatic intracranial metastatic myxoma in a patient with poor response to radiation therapy and multiple recurrences, with follow-up showing improvement in neurological symptoms and mass effect and absence of recurrence on imaging.

Cerebrospinal fluid liver pseudocyst: A bizarre long-term complication of ventriculoperitoneal shunt: A case report.

BACKGROUND: Ventriculoperitoneal (VP) shunt placement has become a standard of care procedure in managing hydrocephalus for drainage and absorption of cerebrospinal fluid (CSF) into the peritoneum. Abdominal pseudocysts containing CSF are the common long-term complication of this frequently performed procedure, mainly because VP shunts have significantly prolonged survival. Of these, liver CSF pseudocysts are rare entities that may cause shunt dysfunction, affect normal organ function, and therefore pose therapeutic challenges. CASE SUMMARY: A 49-year-old man with history of congenital hydrocephalus status post bilateral VP shunt placement presented with progressively worsening dyspnea on exertion, abdominal discomfort/distention. Abdominal computed tomography (CT) scan revealed a large CSF pseudocyst in the right hepatic lobe with the tip of VP shunt catheter into the hepatic cyst cavity. Patient underwent robotic laparoscopic cyst fenestration with a partial hepatectomy, and repositioning of VP shunt catheter to the right lower quadrant of the abdomen. Follow-up CT demonstrated a significant reduction in hepatic CSF pseudocyst. CONCLUSION: A high index of clinical suspicion is required for early detection of liver CSF pseudocysts since their presentation is often asymptomatic and cunning early in the course. Late-stage liver CSF pseudocysts could have adverse outcomes on the treatment course of hydrocephalus as well as on hepatobiliary dysfunction. There is paucity of data to define the management of liver CSF pseudocyst in current guidelines due to rare nature of this entity. The reported occurrences have been managed by laparotomy with debridement, paracentesis, radiological imaging guided fluid aspiration and laparoscopic-associated cyst fenestration. Robotic surgery is an additional minimally invasive option in the management of hepatic CSF pseudocyst; however, its use is limited by lack of widespread availability and cost of surgery.

Microsurgical resection of previously embolized recurrent cerebellopontine angle AVM.

This is the case of a ruptured Spetzler-Martin grade II arteriovenous malformation (AVM) located in the cerebellopontine angle and draining into the transverse sinus. The AVM was initially treated with staged embolization using Onyx (ev3 Neurovascular). However, recurrence was noted and treatment with microsurgical resection was undertaken. The authors present technical nuances of the approach and strategies for microsurgical resection of a previously embolized recurrent AVM with the aid of intraoperative indocyanine green angiography. Follow-up after endovascular treatment is critical, and curative treatment with microsurgical resection can be achieved with low morbidity in such AVMs as demonstrated by this case. The video can be found here: https://youtu.be/LMpz_YTFC0g.

Update on Trigeminal Neuralgia.

PURPOSE OF REVIEW: To review current treatments for trigeminal neuralgia, with an emphasis on determining which patients may benefit from neurosurgical procedures. RECENT FINDINGS: A detailed history is the most helpful tool for diagnosing trigeminal neuralgia (TN) and predicting response to neurosurgical treatments. Patients with classic trigeminal neuralgia will describe severe, unilateral, intermittent facial pain that is triggered by innocuous sensory stimuli. In most cases, pain is caused by compression of the trigeminal nerve by a blood vessel near the brainstem. Magnetic resonance imaging is necessary to rule out TN secondary to multiple sclerosis or tumor. Modern high-resolution T2 images may demonstrate neurovascular contact, particularly when analyzed by a neurosurgeon with expertise in TN. Initial management involves a trial of medication, usually carbamazepine or oxcarbazepine. Microvascular decompression (MVD) is safe and effective surgery, for patients with classic TN related to neurovascular compression. For patients with TN secondary to multiple sclerosis, and for patients who are otherwise poor candidates for MVD, neurosurgical options include percutaneous trigeminal rhizotomy and radiosurgery. Neurosurgical procedures are less effective in relieving atypical facial pain. In the clinical evaluation of a patient with facial pain, it is important to distinguish classic trigeminal neuralgia from atypical facial pain. A patient with classic trigeminal neuralgia would benefit from neurosurgical consultation. The advent of high-resolution MRI and MRA sequences now allows a neurosurgeon to detect when neurovascular compression is likely, and select the optimal procedure for treatment.

Real-Time Evaluation of Anterior Choroidal Artery Patency During Aneurysm Clipping.

Inadvertent occlusion of the anterior choroidal artery during aneurysm clipping can cause a disabling stroke in minutes. We evaluate the clinical utility of direct cortical motor evoked potential (MEP) monitoring during aneurysm clipping, as a real-time assessment of arterial patency, prior to performing indocyanine green videoangiography.   Direct cortical MEPs were recorded in seven patients undergoing surgery for aneurysms that involved or abutted the anterior choroidal artery. The aneurysms clipped in those seven patients included four anterior choroidal artery aneurysms and six posterior communicating artery aneurysms. Serial MEP recordings were performed during the intradural dissection, aneurysm exposure, and clip placement. A significant change in MEPs after clip placement would prompt immediate inspection and removal or repositioning of the clip. If the clip placement appeared satisfactory and MEP recordings were stable, then an intraoperative indocyanine green videoangiogram was performed to confirm obliteration of the aneurysm and patency of the arteries.  Seven patients underwent successful clipping of anterior choroidal artery aneurysms and posterior communicating artery aneurysms using direct cortical MEP monitoring, with good clinical and radiographic outcomes. In six patients, no changes in MEP amplitudes were observed following permanent clip placement. In one patient, a profound decrease in MEP amplitude occurred 220 seconds after placement of a permanent clip on a large posterior communicating aneurysm. An inspection revealed that the anterior choroidal artery was kinked. The clip was immediately removed, and the MEP signals returned to baseline shortly thereafter. A clip was then optimally placed, and the patient awoke without neurologic deficit.  Direct cortical MEPs are a useful adjunct to standard electrophysiologic monitoring in aneurysm surgery, particularly when the anterior choroidal artery or lenticulostriate arteries are at risk. When these arteries are occluded, infarction may occur before the occlusion is detected by indocyanine green videoangiography or intraoperative angiography. The use of MEPs allows real-time detection of ischemia to subcortical motor pathways.

Five-fraction stereotactic radiosurgery (SRS) for single inoperable high-risk non-small cell lung cancer (NSCLC) brain metastases.

BACKGROUND: Achieving durable local control while limiting normal tissue toxicity with definitive radiation therapy in the management of high-risk brain metastases remains a radiobiological challenge. The objective of this study was to examine the local control and toxicity of a 5-fraction stereotactic radiosurgical approach for treatment of patients with inoperable single high-risk NSCLC brain metastases. METHODS: This retrospective analysis examines 20 patients who were deemed to have "high-risk" brain metastases. High-risk tumors were defined as those with a maximum diameter greater than 2 cm and/or those located within an eloquent cortex. Patients were evaluated by a neurosurgeon prior to treatment and determined to be inoperable due to tumor or patient characteristics. Patients were treated using the CyberKnife® SRS system in 5 fractions to a total dose of 30 Gy, 35 Gy, or 40 Gy. RESULTS: Twenty patients with a median age of 65.5 years were treated from April 2010 to August 2014 in 5 fractions to a median total dose of 35 Gy. At a median follow up of 11.3 months local tumor control was observed in 18 of 20 metastases (90 %). Both local failures were observed in patients receiving a lower dose of 30 Gy. Median pre-treatment dexamethasone dose was 10 mg/day and median post-treatment nadir dose was 0 mg/day. Salvage intracranial therapy was required in 45 % of patients. Symptomatic radionecrosis was observed in 4 of 20 patients (20 %), two of which were treated to 40 Gy and the remainder to 35 Gy. Kaplan-Meier 1-year, 2-year, and median survival were calculated to be 45 %, 20 %, and 13.2 months, respectively. CONCLUSIONS: Five-fraction SRS to a total dose of 35 Gy appears to be a safe and effective management strategy for single high-risk NSCLC brain metastases, while a total dose of 40 Gy leads to an excess risk of neurotoxicity.

Cerebral aneurysms with intrasellar extension: a systematic review of clinical, anatomical, and treatment characteristics.

OBJECT: Intrasellar aneurysms are rare lesions that often mimic pituitary tumors, potentially resulting in catastrophic outcomes if they are not appropriately recognized. The authors aimed to characterize the clinical and anatomical details of this poorly defined entity in the modern era of neuroimaging and open/endovascular neurosurgery. METHODS: A PubMed literature review was conducted to identify all studies reporting noniatrogenic aneurysms with intrasellar extension, as confirmed by CT or MR imaging and angiography. Clinical, anatomical, and treatment characteristics were analyzed. RESULTS: Thirty-one studies reporting 40 cases of intrasellar aneurysms were identified. Six patients (15%) presented with aneurysmal rupture. Patients with unruptured aneurysms presented with the following signs and symptoms: headache (61%), visual field cuts/decreased visual acuity (61%), endocrinopathy (57%), symptomatic hyponatremia (21%), and cranial nerve paresis (other than optic nerve) (18%). The most common endocrine abnormalities were hyperprolactinemia and hypogonadism. Eight aneurysms (20%) were diagnosed in conjunction with a pituitary adenoma. Aneurysms could be categorized into 2 primary anatomical groups as follows: 1) cavernous/clinoid segment internal carotid artery (ICA) (infradiaphragmatic) aneurysms with medial extension into the sella; and 2) suprasellar (supradiaphragmatic) aneurysms originating from the ophthalmic segment of the ICA or from the anterior communicating artery, with inferomedial extension into the sella. The mean diameters of infradiaphragmatic and supradiaphragmatic aneurysms were 14.5 and 21.8 mm, respectively. Infradiaphragmatic aneurysms were much more likely to present with endocrinopathy, whereas supradiaphragmatic ones presented more commonly with visual disturbances. Aneurysms with infradiaphragmatic growth were generally treated using either endovascular techniques or surgical trapping and bypass, while supradiaphragmatic aneurysms were more often treated by surgical clipping. CONCLUSIONS: Aneurysms with intrasellar extension typically present due to mass effect on surrounding structures, and they can be classified as infradiaphragmatic cavernous or clinoid segment ICA aneurysms, or supradiaphragmatic ophthalmic ICA or anterior communicating artery aneurysms. Varying approaches exist for treating these complex aneurysms, and intervention strategies depend substantially on the anatomical subtype.

A novel technique for planning surgical approaches to the pineal region by using external cranial landmarks.

OBJECT: The infratentorial supracerebellar approach to the pineal region presents special challenges during patient positioning. The head must be flexed and the body positioned to allow an operative trajectory under the straight sinus. Image guidance is not useful during positioning because registration and navigation take place after the head is fixed in its final position. Therefore, a reliable method of positioning based on external, easily identifiable landmarks to estimate the surgical trajectory along the straight sinus toward the pineal region is needed. Based on observation, the authors hypothesized that a line between 2 palpable external landmarks, the inion and the bregma, often approximates the surgical trajectory along the straight sinus. They tested this hypothesis by quantifying the relationship between the straight sinus and the bregma, and describe a method for estimating the working angle during patient positioning. METHODS: The midsagittal, Gd-enhanced, T1-weighted MR images of 102 patients were analyzed. Demographic data and the presence or absence of tentorial pathological entities was recorded. The slant of the straight sinus was classified as common, high, or low, based on a previously described classification system. A line along the bottom of the straight sinus (that is, the straight-sinus line) was extended superiorly to its intersection with the calvaria, and the distance from this intersection point to the bregma was measured. RESULTS: The intersection point of the straight-sinus line and the calvaria was on average 2 ± 8.2 mm (these values are expressed as the mean ± SD throughout) anterior to the bregma (range 19.9 mm anterior to 19.1 mm posterior). The distance from the intersection point to the bregma was not statistically significantly different in younger or older patients, or in patients with or without tumors involving the pineal region. In patients with a low slant of the straight sinus, the intersection point was 5.3 ± 6.3 mm anterior to the bregma, whereas in patients with a high slant of the straight sinus, the intersection point was 0.21 ± 9.1 mm posterior to the bregma (p = 0.015). CONCLUSIONS: The straight-sinus line, which defines the working angle for the supracerebellar infratentorial approach, intersects the calvaria very close to the bregma in the majority of patients. Therefore, ideal patient positioning can be achieved by flexing the patient's head to optimize the working angle defined by an imaginary line connecting the torcula (inion) to the bregma.

Surgical approaches to meningiomas of the lateral ventricles.

BACKGROUND: Intraventricular meningiomas account for 0.5-3% of all intracranial meningiomas. The majority occur in the atrium of the lateral ventricle. Surgical experience with intraventricular meningiomas is rare in the literature, and several surgical approaches exist. METHODS: Between 1987 and 2007, 13 patients underwent resection of intraventricular meningiomas. All patients had tumors of the lateral ventricles. These patients were retrospectively identified and their records reviewed. RESULTS: Eleven tumors were found in the atrium, one in the frontal horn, and one in the body of the lateral ventricle. In 9 of 13 cases, the tumor occurred in the left lateral ventricle. Patients commonly presented with headache and cognitive difficulties. A visual field deficit was noted preoperatively in one patient. Four patients underwent preoperative angiography, but no patients underwent embolization. Gross total resection was achieved in all cases: 6 via a middle temporal gyrus approach, 5 via a superior parietal lobule approach, and 2 via a transcallosal approach. Image-guided stereotaxis was used in 6 cases. Pathology was benign in 12 of 13 cases; atypical features were identified in one case. There was no operative mortality, and no patients showed evidence of recurrence. Postoperatively, 3 patients developed new cognitive-linguistic deficits that subsequently resolved. One of these patients developed a new visual field deficit after surgery. CONCLUSIONS: Several approaches are available for the surgical treatment of intraventricular meningiomas. Tumor location, extension, and laterality drive the selection algorithm for these approaches. Preoperative angiography is rarely useful, and surgical cure is the rule.

Transtubular microendoscopic approach for resection of a choroidal arteriovenous malformation.

The authors describe the novel use of a table-mounted tubular retractor system (MetRx) originally designed for minimally invasive spine surgery, in the resection of an intraventricular arteriovenous malformation (AVM) in a 12-year-old child. The tubular retractor system may have several advantages over traditional Greenberg or Leyla retractors in selected intracranial procedures. In our case, the low-profile 4x22-mm tube and fixed table attachment offered excellent exposure of the trigone of the lateral ventricle where the choroidal AVM was located and from which it was completely resected. Immediate postoperative cerebral angiography confirmed that the entire AVM had been resected. The patient suffered no new neurological deficits as a result of the retractor system or the exposure that it afforded. Although the good clinical results of a single case cannot be directly compared with those obtained using other open techniques of intracranial surgery in larger series, microendoscopic surgery of the brain is an alternative to the other techniques and may be recommended as a time-saving, trauma-reducing procedure with the potential to improve postoperative outcomes.

Preservation of visual fields with the inferior temporal gyrus approach to the atrium.

Various transcortical approaches have been described for the resection of tumors that lie in the atrium of the lateral ventricle. An approach through the middle temporal gyrus has a short trajectory to the atrium and can grant early access to the tumor's blood supply, but it typically results in damage to the optic radiations that course lateral to the atrium. Anatomical studies have suggested that an approach inferior to the inferior temporal sulcus would avoid traversing through the optic radiations. The authors describe 2 cases of meningioma in the atrium that were exposed and resected through an incision in the inferior temporal gyrus. They provide data from neuroophthalmological testing that shows full preservation of the visual fields with this approach.

Neuronavigation applied to epilepsy monitoring with subdural electrodes.

Accurate localization of the epileptogenic zone is of paramount importance in epilepsy surgery. Despite the availability of noninvasive structural and functional neuroimaging techniques, invasive monitoring with subdural electrodes is still often indicated in the management of intractable epilepsy. Neuronavigation is widely used to enhance the accuracy of subdural grid placement. It allows accurate implantation of the subdural electrodes based on hypotheses formed as a result of the presurgical workup, and can serve as a helpful tool for resection of the epileptic focus at the time of grid explantation. The authors describe 2 additional simple and practical techniques that extend the usefulness of neuronavigation in patients with epilepsy undergoing monitoring with subdural electrodes. One technique involves using the neuronavigation workstation to merge preimplantation MR images with a postimplantation CT scan to create useful images for accurate localization of electrode locations after implantation. A second technique involves 4 holes drilled at the margins of the craniotomy at the time of grid implantation; these are used as fiducial markers to realign the navigation system to the original registration and allow navigation with the merged image sets at the time of reoperation for grid removal and resection of the epileptic focus. These techniques use widely available commercial navigation systems and do not require additional devices, software, or computer skills. The pitfalls and advantages of these techniques compared to alternatives are discussed.