Endoscopic Transventricular Transaqueductal Excision of Fourth Ventricular Neurocysticercosis: 2-Dimensional Endoscopic Video: 2-Dimensional Operative Video.

Ventricular neurocysticercosis is a challenging disease that may cause obstructive hydrocephalus and require surgical intervention.1,2 Cysts of the lateral and third ventricle can be addressed by neuroendoscopy and removal of the cyst, when feasible. Surgical excision of cysts from the fourth ventricle can be achieved through endoscopic or microsurgical techniques, depending on the experience of the surgeon and characteristics of the cyst. Unresectable cysts causing hydrocephalus require cerebrospinal fluid diversion through a ventriculoperitoneal shunt.1-8 Medical therapy consisting of antiparasitic and anti-inflammatory agents should be limited to patients where surgery is a poor option or in cases, where there are residual cysts in the body. Medical therapy can cause an inflammatory response resulting in adherence of the cyst to the ventricular wall, which increases the surgical complication rate. Therefore, surgical cyst excision should always precede medical therapy.2 The endoscopic transventricular transaqueductal approach has been described in the literature as a safe route to resect nonadherent cysts when performed by an experienced neuroendoscopist.1-5 Although descriptions of the procedure exist in the literature, no video outlines its detailed operative steps and relevant anatomy. In this video, we present a case of a 42-year-old woman who presented with obstructive hydrocephalus caused by a third ventricular cestode that migrated into the fourth ventricle during her hospitalization. The patient underwent an endoscopic transventricular transaqueductal excision of a fourth ventricular cyst with complete neurological recovery and without requiring ventricular shunting. The patient consented to the procedure and to the publication of her video and images. Institutional Review Board review is not required for a single case report.

A Survey Assessment of Neurosurgeons' Interest in Osteopathic Medicine and Its Integration Into Their Practice.

INTRODUCTION: Osteopathic manipulative medicine (OMM) encompasses techniques guided by the tenets of osteopathy aimed at facilitating the body's natural self-healing capabilities as a treatment option for injury or illness. This approach recognizes the interrelationship of structure and function in promoting overall health. The clinical applications of OMM have been highly researched throughout different subspecialties of medicine; however, there is a notable lack of osteopathic-based research targeted toward neurosurgical patient populations. METHODS: This cross-sectional descriptive study was conducted via a survey generated using SurveyMonkey (SurveyMonkey, San Mateo, CA, USA; accessed at www.surveymonkey.com). Subjects for this survey were gathered using a convenience sampling method in which emails of all neurosurgeons listed in the "Member Directory" on the American Association of Neurological Surgeons website were compiled into a mailing list. The survey was sent to all 6,503 emails collected, and the responses were recorded over the next month. The responses for each survey question were averaged and, when appropriate, compared using a two-tailed T-test, with statistical significance defined as a p<0.05. Where applicable, simple linear regression analysis was used to assess correlations between survey data. The measured outcomes included neurosurgeons' (1) knowledge of and (2) attitudes toward OMM. RESULTS: Both MD and DO neurosurgeons reported using OMM (or referring their patients for OMM) less than once per year. In comparison to their MD colleagues, neurosurgeons carrying a DO degree ranked their familiarity with the tenets of osteopathic medicine (p<0.0001) and their knowledge of the applications of OMM in their practice (p=0.0018) significantly higher. Greater reported familiarity with the tenets of osteopathic medicine and applications of OMM showed a positive correlation with neurosurgeons' comfort in recommending OMM as a nonsurgical, preoperative treatment option, as a post-surgical, rehabilitative treatment option, and as a pain management option (p<0.0001 for all). There was a clear interest in seeing further osteopathic-based neurosurgery research by both MD and DO neurosurgeons, as well as a trend of interest in incorporating OMM into their practice if shown to be clinically beneficial. CONCLUSIONS: Both MD and DO neurosurgeons are interested in seeing more research into the applications of OMM in their patient populations and, most importantly, are likely to integrate OMM into their practice if presented with research detailing clinical benefits to their patients. This study highlights the clinical interest of neurosurgeons in further research into the applications of OMM specific to the field of neurosurgery.

Combining Endovascular Coiling and Open Evacuation for a Delayed-Onset Ruptured Post-traumatic Pseudoaneurysm of the Distal Paracentral Pericallosal Artery Branch.

Cerebrovascular pseudoaneurysm development and rupture is a rare, delayed sequelae of trauma. We present a case of a female patient in her sixties who presented after a fall without evidence of vascular injury on imaging. However, after one week, repeat imaging due to an abrupt change in mental status revealed a ruptured pseudoaneurysm, which was treated with a combination of coil embolization and open surgical evacuation of associated intracranial hematoma. This case illustrates the importance of continued surveillance beyond the acute traumatic period to identify late-onset complications in trauma patients requiring emergent treatment.

Stereotactic Radiosurgery for Brain Metastases in Patients With Small Cell Lung Cancer.

Purpose: Treatment of small cell lung cancer (SCLC) with brain metastatic disease has traditionally involved whole brain radiation therapy (WBRT). The role of stereotactic radiosurgery (SRS) is unclear. Methods and Materials: Our study was a retrospective review of an SRS database evaluating patients with SCLC who received SRS. A total of 70 patients and 337 treated brain metastases (BM) were analyzed. Forty-five patients had previous WBRT. The median number of treated BM was 4 (range, 1-29). Results: Median survival was 4.9 months (range, 0.70-23.9). The number of treated BM was correlated with survival; patients with fewer BM had improved overall survival (P < .021). The number of treated BM was associated with different brain failure rates; 1-year central nervous system control rates were 39.2% for 1 to 2 BM, 27.6% for 3 to 5 BM, and 0% for >5 treated BM. Patients with previous WBRT had worse brain failure rates (P < .040). For patients without previous WBRT, the 1-year distant brain failure rate was 48%, and median time to distant failure was 15.3 months. Conclusions: SRS for SCLC in patients with <5 BM appears to offer acceptable control rates. Patients with >5 BM have high rates of subsequent brain failure and are not ideal candidates for SRS.

Tension pneumocephalus following bariatric surgery: case report.

Bariatric surgery is an effective treatment for patients with idiopathic intracranial hypertension (IIH), a condition that is associated with skull base defects. A 55-year-old woman presented with symptoms of intractable nausea and vomiting, followed by headache and confusion two weeks after an elective laparoscopic vertical sleeve gastrectomy procedure. She had a presumed diagnosis of IIH and a remote history of CSF oto/rhinorrhea treated with a lumbar peritoneal (LP) shunt. Computed tomography (CT) scan of the head revealed tension pneumocephalus with midline shift and dehiscence of the tegmen. The patient underwent emergent craniotomy for decompression of the air-filled temporal lobe, clamping of the LP shunt, and repair of the skull base defect. Caution should be exercised in obese patients with a history of CSF leak secondary to a middle fossa skull base defect when being evaluated for bariatric surgery.

Merkel cell carcinoma brain metastasis with radiological findings mimicking primary CNS lymphoma: illustrative case.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine tumor with a high likelihood of distant metastasis. Approximately 30 cases of MCC brain metastasis have been reported. The authors report a case of MCC brain metastasis with imaging findings mimicking primary central nervous system lymphoma. OBSERVATIONS: A 69-year-old asymptomatic White female with a past medical history of rheumatoid arthritis and MCC of the right cheek with no known regional or distant spread presented with a right frontal lobe lesion discovered incidentally on a surveillance scan. Brain magnetic resonance imaging revealed a vividly enhancing homogeneous lesion with restricted diffusion on diffusion-weighted imaging and corresponding apparent diffusion coefficient maps. Imaging characteristics suggested a highly cellular mass consistent with primary central nervous system lymphoma; however, given the likelihood of metastasis, resection was recommended. An intraoperative frozen section suggested lymphoma. However, further examination revealed positive cytokeratin 20 staining for a tumor, and a final diagnosis of MCC brain metastasis was made. LESSONS: Imaging characteristics of MCC brain metastasis can vary widely. A high level of suspicion should be maintained in a patient with a known history of MCC. Aggressive resection is recommended, regardless of appearance on scans or pathology of frozen sections, because MCC can mimic other intracranial pathologies.

Evaluating the impact of prescription isodose line on plan quality using Gamma Knife inverse planning.

The impact of selection of prescription isodose line (IDL) on plan quality has not been well evaluated during inverse planning (IP). In this study, a total of 180 IP plans at five levels of IDL were generated for 30 brain metastases (BMs). For each BM, one round of IP was performed with typical IP settings, followed by a quick fine-tuning to ensure the same target coverage and comparable conformality index. The impact of the IDL on the quality metrics (selectivity, gradient index [GI], and treatment time) was evaluated. The decrease of selectivity and increase of GI meant inferior target dose conformality and more dose spillage. Additionally, a metric directly correlated to the treatment time was proposed. For all cases, the mean GI decreased monotonically as IDL decreased from 70% to 30%, and the decreasing rate was significantly different based on tumor size. The mean selectivity and number of shots decreased monotonically as IDL decreased for all the tumors. From 70% to 30% IDL, the decreasing rate of the mean selectivity was 2.8% (p = 0.020), 7.7% (p = 0.005), and 15.4% (p = 0.020) and that of the number of shots was 75.4% (p = 0.001), 73.2% (p = 0.001), and 50.7% (p = 0.009), for the large, medium, and small tumors, respectively. For the medium and small tumor groups, the mean treatment time increased monotonically when IDLs decreased (increasing rate was 80.0% [p = 0.002] for medium tumors [p = 0.001] and 130.8% [p = 0.001] for small tumors from 70% to 30%). For the large tumors, the mean treatment time was the shortest at 50% IDL (59.0 min) and higher at 70% (65.9 min) and 30% (71.9 min). Overall, the GammaPlan chose smaller sectors for plans with lower IDLs except for the large size group.

Tuning-Target-Guided Inverse Planning of Brain Tumors With Abutting Organs at Risk During Gamma Knife Stereotactic Radiosurgery.

Purpose We proposed a planning strategy that utilized tuning targets to guide GammaKnife (GK) Inverse Planning (IP) to deliver higher dose to the tumor, while keeping acceptable dose to the abutting organ at risk (OAR). Methods Ten patients with a large portion of brain tumor abutting the OAR previously treated with GK stereotactic radiosurgery (SRS) were selected. For each patient, multiple tuning targets were created by cropping the target contour from three-dimensional (3D) expansions of the OAR. The number of the tuning targets depended on the complexity of the planning process. To demonstrate dose sparing effect, an IP plan was generated for each tuning target after one round of optimization without shot fine-tuning. In the dose enhancement study, a more aggressive target dose was prescribed to the tuning target with a larger margin and one to two shots were filled in the region with missing dose. The resulting plans were compared to the previously approved clinical plans. Results For all 10 patients, a dose sparing effect was observed, i.e. both target coverage and dose to the OARs decreased when the margins of 3D expansion increased. For one patient, a margin of 6 mm was needed to decrease the maximum dose to the optical chiasm and optical nerve by 44.3% and 28.4%, respectively. For the other nine patients, the mean dropping rate of V12Gyto brain stem were 28.2% and 59.5% for tuning targets of 1 and 2 mm margins, respectively. In the dose enhancement study, the tuning-target-guided plans were hotter than the approved treatment plans, while keeping similar dose to the OARs. The mean of the treatment and enhancement dose was 15.6 ± 2.2 Gy and 18.5 ± 3.2 Gy, respectively. The mean coverage of the target by prescription dose was slightly higher in the enhancement plans (96.9 ± 2.6% vs 96.3 ± 3.6%), whereas the mean coverage of the enhancement dose was 20.1% higher in the enhancement plans (89.6 ± 9.0% vs 74.6 ± 19.9%). Conclusions We demonstrated that an inverse planning strategy could facilitate target dose enhancement for challenging GK cases while keeping acceptable OAR dose.

Dosimetric comparison of inverse and forward planning for Gamma Knife stereotactic radiosurgery of brain metastases.

The Leksell GammaPlan (LGP) with an inverse planning (IP) tool has been upgraded to version 11.1 since its launch in 2010. We evaluated its IP planning performance by re-planning 16 targets that had been planned using forward planning (FP). The FP and IP plans were compared. A planning guideline for IP process was developed aiming for an unbiased comparison. Sixteen brain metastases (BMs) without nearby critical structures were included in the study (size > 1 cm for all targets). All prior FP were re-planned in the LGP using IP and maintaining the same beam-on time and coverage. The dose to all the targets was scaled to 20 Gy in a single fraction at 50% isodose line (IDL) for FP and IP comparison purpose. The coverage and beam-on time were nearly the same for both the FP and IP plans. For all the IP plans, the mean selectivity was 0.85 ± 0.04 (vs 0.83 ± 0.04 in FP plans, p = 0.02), the mean GI was 2.92 ± 0.21 (vs 3.18 ± 0.60 in FP plans, p = 0.047), the mean V12Gy was 8.18 ± 8.57 cc (vs 9.09 ± 9.08 cc in FP plans, p = 0.001), the mean V8Gy was 14.63 ± 15.14 cc (vs 16.34 ± 16.17 cc in FP plans, p = 0.001), and the mean V5Gy was 29.01 ± 28.77 cc (vs 32.77 ± 31.41 cc in FP plans, p = 0.001). The number of shots was higher in IP plans (means of 16.69 ± 8.11 vs 10.81 ± 6.87 in FP plans, p = 0.001). We retrospectively re-planned 16 FP plans using the IP tool while meeting the quality limiting factors for the FP plans. The dosimetry parameters from the IP plans outperformed the treated FP plans and the IP tool should be preferred for tumors with size > 1 cm.

Epithelioid glioblastoma presenting as aphasia in a young adult with ovarian cancer: A case report.

Our patient's clinical history and preoperative radiographic evaluation suggested central nervous system (CNS) metastatic disease. Ultimately, final pathology revealed epithelioid glioblastoma (eGBM), a newly classified CNS primary tumor. This reinforces the importance of direct tissue sampling and including eGBM on the differential for young patients with histories of systemic cancer presenting with new CNS lesions.

Fluorescence-guided stereotactic biopsy: a proof-of-concept study.

OBJECTIVEAccurate histopathological diagnoses are often necessary for treating neuro-oncology patients. However, stereotactic biopsy (STB), a common method for obtaining suspicious tissue from deep or eloquent brain regions, fails to yield diagnostic tissue in some cases. Failure to obtain diagnostic tissue can delay initiation of treatment and may result in further invasive procedures for patients. In this study, the authors sought to determine if the coupling of in vivo optical imaging with an STB system is an effective method for identification of diagnostic tissue at the time of biopsy.METHODSA minimally invasive fiber optic imaging system was developed by coupling a 0.65-mm-diameter coherent fiber optic fluorescence microendoscope to an STB system. Human U251 glioma cells were transduced for stable expression of blue fluorescent protein (BFP) to produce U251-BFP cells that were utilized for in vitro and in vivo experiments. In vitro, blue fluorescence was confirmed, and tumor cell delineation by fluorescein sodium (FNa) was quantified with fluorescence microscopy. In vivo, transgenic athymic rats implanted with U251-BFP cells (n = 4) were utilized for experiments. Five weeks postimplantation, the rats received 5-10 mg/kg intravenous FNa and underwent craniotomies overlying the tumor implantation site and contralateral normal brain. A clinical STB needle containing our 0.65-mm imaging fiber was passed through each craniotomy and images were collected. Fluorescence images from regions of interest ipsilateral and contralateral to tumor implantation were obtained and quantified.RESULTSLive-cell fluorescence imaging confirmed blue fluorescence from transduced tumor cells and revealed a strong correlation between tumor cells quantified by blue fluorescence and FNa contrast (R2 = 0.91, p < 0.001). Normalized to background, in vivo FNa-mediated fluorescence intensity was significantly greater from tumor regions, verified by blue fluorescence, compared to contralateral brain in all animals (301.7 ± 34.18 relative fluorescence units, p < 0.001). Fluorescence intensity measured from the tumor margin was not significantly greater than that from normal brain (p = 0.89). Biopsies obtained from regions of strong fluorescein contrast were histologically consistent with tumor.CONCLUSIONSThe authors found that in vivo fluorescence imaging with an STB needle containing a submillimeter-diameter fiber optic fluorescence microendoscope provided direct visualization of neoplastic tissue in an animal brain tumor model prior to biopsy. These results were confirmed in vivo with positive control cells and by post hoc histological assessment. In vivo fluorescence guidance may improve the diagnostic yield of stereotactic biopsies.

Liposclerosing Myxofibrous Tumor of the Cranial Vault: A Case Report.

BACKGROUND AND IMPORTANCE: Liposclerosing myxofibrous tumors (LSMFTs) are rare benign fibro-osseous tumors most frequently occurring in the proximal femur. We report the first case of this rare tumor occurring within the calvarium. CLINICAL PRESENTATION: Our patient presented with a 2-yr history of enlarging, painless, fixed mass over the left forehead. She underwent surgical resection and the mass was histologically confirmed to be a LSMFT. CONCLUSION: LSMFT is a rare tumor that should remain on the differential for lesions of the calvarium. When diagnosed, this lesion can be removed with the goal of gross total resection and excellent cosmesis can be achieved.

Improved Dose Conformity for Adjacent Targets: A Novel Planning Technique for Gamma Knife Stereotactic Radiosurgery.

Purpose In the current Gamma Knife (GK) planning system (GammaPlan, version 10.2, Elekta AB, Stockholm, Sweden), multiple adjacent brain metastasis (BMs) had to be planned sequentially if BMs were drawn separately, leading to less conformal target dose in the composite plan due to inter-target dose contribution and fine-tuning of the shots being quite tedious. We proposed a method to improve target dose conformality and planning efficiency for such cases. Methods and Materials Fifteen patients with multiple BMs treated on the Leksell GK Perfexion system were retrospectively replanned in the Institutional Review Board (IRB) approved study. The recruitment criterion was all the BMs should be entirely encompassed within the maximum dose grid allowed in the GammaPlan. The BMs were first planned sequentially as routine clinic cases. The contours of the BMs were then exported to the VelocityAI (Varian, CA, USA) to generate a composite contour after a union operation, and all the BMs were planned again simultaneously using this composite contour in the GammaPlan. The inverse planning (IP) was employed in both methods with the same treatment time allowed for a fair plan comparison. Dose evaluation was performed in the VelocityAI with all planning magnetic resonance (MR) images, structure set and dose were exported to the VelocityAI. The dosimetery parameters, including conformality index (CI), V20Gy, V16Gy, V12Gy, and V5Gy, were compared between the two methods. Results The planning results from both methods were reviewed qualitatively and quantitatively. The proposed method exhibited superior CI, except for an outlier case with very tiny BMs. The mean and standard deviation (std.) of the Paddick CI for all patients were 0.76±0.11 for the proposed method, comparing to 0.69±0.13 for the sequential method. The V20Gy, V16Gy, V12Gy, and V5Gy for the proposed method were 10.9±0.9%, 9.5±10.2%, 6.2±16.4% and 3.3±21.8%, all lower than those from the sequential method. Conclusions The proposed method showed improved target dose conformality for all cases except for very tiny BMs. Planning efficiency is considerably better with the combined target technique. The improved dose conformality will be beneficial to patients in long term with lowered risk of radiation necrosis after GK stereotactic radiosurgery (SRS).

Optic Nerve Sheath Diameter Assessment in Patients with Intracranial Pressure Monitoring.

Background Optic nerve sheath diameter (ONSD) has been found to have good correlation with intracranial pressure (ICP) measurements. Here, we aim to determine if the correlation between ONSD and ICP persists throughout the acute phase of neurologic injury through the evaluation of patients with ICP monitoring. We also aim to determine if the ONSD assessments at different depths (3, 6, or 9 mm) and a ratio of the ONSD and eyeball transverse diameter (ETD) are better correlated with ICP than the well-studied ONSD assessment at 3 mm beyond the globe.  Methods This retrospective study included 68 patients more than 18 years of age with ICP monitors with both traumatic and spontaneous intracranial injuries. Head computed tomography (CT) scans were reviewed by a radiology resident for assessment of the ETD and ONSD at depths of 3, 6 and 9 mm beyond the globe, and the readings were confirmed by a neuroradiologist. The mean ICP recordings two hours before and after a CT scan were used for assessing the correlation. Results We found that ONSD expansions during the acute phase of neurologic injury were seen even without ICP elevations. This lack of correlation persisted even when different depths of the ONSD assessment or ONSD/ETD ratios were studied. Conclusion This study suggests that ONSD assessment throughout the acute phase may not be a reliable method to monitor ICP. ONSD expansion can persist even after ICP control, and this may be the reason for ONSD expansions seen in our study even with normal ICPs. Further larger size studies are needed to confirm these findings.

Proposed Diagnostic Criteria, Classification Schema, and Review of Literature of Notochord-Derived Ecchordosis Physaliphora.

Ecchordosis physaliphora (EP) is a benign notochordal remnant derived from ectopic nests found along the craniospinal axis. It typically presents asymptomatically and is diagnosed using classic radiologic features, particularly location, T1-hypointensity, T2-hyperintensity, and lack of enhancement following gadolinium (Gd) contrast administration. Distinguishing EP from its malignant counterpart, chordoma, is of paramount importance, given the aggressive nature of the latter. Advances in imaging and immunohistochemistry have aided in diagnosis to an extent but, to our knowledge, identification of the genetic fingerprint of EP has yet to take place. Further cytological analysis of these lesions in search of a genetic link is warranted. We propose here a set of diagnostic criteria based on features consistently cited in the literature. In this literature review, 23 case reports were identified and collated into a summary of symptomatic cases of ecchordosis physaliphora. An illustrative case report of two patients was also included.

Stereotactic Radiosurgery for Poor Performance Status Patients.

PURPOSE: Patients with poor performance status (PS), usually defined as a Karnofsky Performance Status of 60 or less, were not eligible for randomized stereotactic radiosurgery (SRS) studies, and many guidelines suggest that whole-brain radiation therapy (WBRT) is the most appropriate treatment for poor PS patients. METHODS AND MATERIALS: In this retrospective review of our SRS database, we identified 36 patients with PS of 60 or less treated with SRS for central nervous system (CNS) metastatic disease. PS, as defined by the Karnofsky Performance Status, was 60 (27 patients), 50 (8 patients), or 40 (1 patient). The median number of CNS lesions treated was 3. RESULTS: Median overall survival (OS) was 7.2 months (range, 0.73-25.6 months). Fifteen patients (41%) were alive at 6 months, and 6 patients (16.6%) were alive at 1 year. There was no difference in OS in patients who underwent previous WBRT. There were no local failures or cases of radiation toxicity. Distant CNS failures were seen in 9 patients (25%). CONCLUSIONS: Our patients with poor PS had reasonable median OS and relatively low distant CNS failure rates. Patients in this patient population may be ideal candidates for SRS compared with WBRT given the low incidence of distant failure over their remaining lives and the favorable logistics of single-fraction treatment for these patients with debility and their caregivers.

Traumatic coagulopathy: the effect of brain injury.

Traumatic coagulopathy has several possible mechanisms. In traumatic brain injury (TBI), the principal process involves the release of tissue factor (TF). There is no agreement how common this mechanism is following general trauma. Furthermore, when TF-induced coagulopathy occurs, it is unknown whether the source of TF (TBI or extracranial trauma) influences the course of coagulopathy. We undertook this investigation to address both questions. The temporal course of prothrombin times (PTs) were recorded in a group (n = 441) with isolated TBI (head Abbreviated Injury Scale [AIS] >or= 3, non-head AIS < 3) and a group (n = 101) with extracranial trauma (non-TBI; non-head AIS >or= 3; head AIS < 3). Data were arranged according to preset time intervals after injury. The PT values in both groups were elevated and not significantly different for the first 12 h after trauma. Values then fell to normal in TBI patients, but remained elevated in non-TBI injury. Traumatic coagulopathy can be explained at least in part by TF release into the general circulation with activation of the coagulation cascade in both TBI and non-TBI. We hypothesize that the different time courses of coagulopathy represented by PT values in these populations were due to reconstitution of the blood-brain barrier, although further investigation is warranted. Peripheral hematologic studies may not reflect persistent coagulopathy in cerebral circulation.