[Show abstract][Hide abstract] ABSTRACT: The supracerebellar transtentorial approach via a suboccipital craniotomy provides a corridor to reach lesions of the tentorial incisura and supratentorial lesions of the posterior medial basal temporal lobe, such as lesions of the posterior parahippocampal and fusiform gyri. The supracerebellar transtentorial approach obviates the need for either retraction of eloquent cortex or a transcortical route to reach lesions in this region. We present three cases that demonstrate the utility of this approach: a left-sided tentorial meningioma with superior projection, a left-sided posterior parahippocampal cavernous malformation, and a left-sided posterior parahippocampal grade 2 oligodendroglioma. The video can be found here: https://youtu.be/OLnzUGZfUqk .
Full-text · Article · Jan 2016 · Neurosurgical FOCUS
[Show abstract][Hide abstract] ABSTRACT: Osteopetrosis (OP) is hereditary X-linked, autosomal recessive (ARO), or autosomal dominant (ADO) skeletal disease. ARO has two subtypes, which are infantile malignant and intermediate type. ARO and X-linked OP have poor clinical outcome. ADO is called adult benign type because of the normal life expectancy, which has type I and type II. Here, the authors present an ADO patient with Chiari type I. Concomitant ADO with Chiari type I malformation is an extremely rare condition. Literature research yielded only one case report to date.
[Show abstract][Hide abstract] ABSTRACT: Diagnostic tools for evaluating the supraorbital rim in preparation for nerve decompression surgery in patients with chronic headaches are currently limited. We evaluated the use of sonography to diagnose the presence of a supraorbital notch or foramen in 11 cadaver orbits. Sonographic findings were assessed by dissecting cadaver orbits to determine whether a notch or foramen was present. Sonography correctly diagnosed the presence of a supraorbital notch in 7 of 7 cases and correctly diagnosed a supraorbital foramen in 4 of 4 cases. We found that sonography had 100% sensitivity in diagnosing a supraorbital notch and foramen. This tool may therefore be helpful in characterizing the supraorbital rim preoperatively and may influence the decision to use a transpalpebral or endoscopic approach for supraorbital nerve decompression as well as the decision to use local or general anesthesia.
No preview · Article · Oct 2015 · Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine
[Show abstract][Hide abstract] ABSTRACT: One paradigmatic example of "irrational" bias in human economic decision-making-known as the "reflection effect"-is a tendency to prefer sure amounts over risky gambles in situations involving potential gain, but to prefer risky gambles over sure amounts in situations involving potential loss. To date, there is no causal evidence regarding the neural basis of the reflection effect. The ventromedial prefrontal cortex (vmPFC) is believed to play a critical role in mediating value-based decision-making. In this study, we administered a behavioral test of the reflection effect to three groups of subjects: neurosurgical patients with focal bilateral vmPFC lesions, neurosurgical patients with lesions outside vmPFC, and neurologically healthy adults. Subjects made a series of choices between a sure amount (e.g., gain of $50) and a gamble (e.g., 50% chance of gaining $100, 50% chance of gaining $0). Half the trials featured potential gains while the other half featured potential losses. The sure amounts varied across trials. Relative to the two comparison groups, the vmPFC lesion patients exhibited a significantly greater reflection effect; more gambles selected in the loss condition and fewer gambles selected in the gain condition. This finding demonstrates a critical role for vmPFC in governing susceptibility to bias in decision-making.
[Show abstract][Hide abstract] ABSTRACT: Giant posterior circulation aneurysms pose a significant challenge to neurovascular surgeons. Among various treatment methods that have been applied individually or in combination, clipping under hypothermic circulatory arrest (HCA) is rarely used. We present a 62-year-old man who initially underwent coil occlusion of the right vertebral artery (VA) for a 2.5 cm giant vertebrobasilar junction (VBJ) aneurysm. His neurological condition had declined gradually and the aneurysm grew to 4 cm in size. The patient underwent clip reconstruction of giant VBJ aneurysm under HCA. His postoperative course was prolonged due to his preexisting neurological deficits. His preoperative Modified Rankin Score was 5, and improved postoperatively to 3 at three and six months, and to 2 at one year. The video can be found here: http://youtu.be/L53SiLV8eJY .
[Show abstract][Hide abstract] ABSTRACT: Giant distal anterior cerebral artery aneurysms are rare. Their treatment is most challenging, due to the complexities of the aneurysm neck and branches involved, as well as their relatively deep locations. Various strategies can be used in the treatment of these complex aneurysms, including endovascular coiling, flow-diverting stents, surgical trapping, microsurgical clip reconstruction, and a wide spectrum of bypass techniques.
[Show abstract][Hide abstract] ABSTRACT: Intracranial pseudoaneurysms (IP) represent about 1% of all patients presenting with an intracranial aneurysm. In true intracranial aneurysms, the intima, internal elastic lamina, and media are disrupted, but the adventitia is intact. In pseudoaneurysms, there is disruption of all three layers of the arterial wall, thus resulting in higher rates of re-hemorrhage and thrombus formation. Patients with IP commonly present with subarachnoid hemorrhage or thromboembolic complications. Until now, no specific guidelines have been established for the ideal treatment of pseudoaneurysms. Although IP have higher rates of morbidity and mortality compared to true intracranial aneurysms, surgical treatment can prevent catastrophic hemorrhagic and thrombotic complications. Despite recent advances in endovascular techniques that allow safe approaches to complicated intracranial vascular pathologies, vascular trapping and bypass remains the definitive and safe treatment for IP. Based on our experience and related literature, we consider the latter treatment in experienced hands as an effective and decisive treatment modality to prevent the devastating complications of IP. In this article, we discuss the surgical management of iatrogenic intracranial internal carotid artery pseudoaneurysms by trapping, and extracranial-intracranial bypass through a case illustration in which the technique is demonstrated via a video presentation.
Full-text · Article · May 2015 · Turkish neurosurgery
[Show abstract][Hide abstract] ABSTRACT: The role of postoperative radiation (RT) in atypical meningioma remains controversial.
We report a retrospective review of outcomes and prognostic factor analysis in 158 patients treated between 2000 and 2010, and extensively review the literature.
Following resection, 23 patients received immediate RT, whereas 135 did not. Median progression-free survival (PFS) with and without RT was 59 (range 43-86) and 88 (range 64-123) months. For Simpson grade (G) 1-3 resection, with and without RT, median PFS was 48 (2-80) versus 96 (88-123) months and for Simpson G4, it was 59 (6-86) versus 47 (15-104) months (P = 0.4). The rate of 5-year overall survival (OS) with and without RT was 89% and 83%, respectively. On univariate analysis, Simpson G4 (HR 3.2, P = 0.0006) and brain invasion (HR 2.2, P = 0.03) were significantly associated with progression, whereas age >60 years (HR 9.7, P = 0.002), mitoses >5 per 10 high-power field (0.2, P = 0.0056), and Simpson G4 (HR 2.4, P = 0.07) were associated with higher risk of death. We summarized 22 additional reports, which provide very divergent results regarding the benefit of RT.
In our series, adjuvant RT is surprisingly associated with worse PFS and OS, and this is more likely to be due to selection bias of referring tumors with more aggressive characteristics such as elevated Ki-67 and brain invasion for adjuvant RT, rather than a direct causal effect of adjuvant RT. Although there is a trend toward improved PFS with adjuvant RT after subtotal resection, no improvement was noted in OS. Multivariate analysis did not yield statistical significance for any of the factors including Simpson grades of resection, adjuvant RT, or six pathological defining features. The relatively divergent results in the literature are most likely explained by patient selection variability; therefore, randomized trials to adequately address this question are clearly necessary.
Full-text · Article · Apr 2015 · Journal of cancer research and therapeutics
[Show abstract][Hide abstract] ABSTRACT: Klippel-Trenaunay-Weber syndrome (KTWS) is a rare syndrome in which patients usually present with cutaneous hemangiomas, venous varicosities, and bone and soft tissue hypertrophy of the affected limb. Intracranial lesions in patients with KTWS are extremely rare, and are generally reported as single cases in the literature. We describe a rare case, where a patient with KTWS was found with a hemorrhagic grade IV astrocytoma. Although central nervous system abnormalities such as intracranial aneurysms and cerebral and spinal cord cavernomas have been described in patients with KTWS, to the best of our knowledge, this is the first report of an association between glioblastoma multiforme (grade IV astrocytoma) and KTWS in the English-language medical literature.
A 61-year-old white Caucasian man with a history of KTWS presented with seizures. Left upper and lower extremity hypertrophy, left foot, leg and ear gigantism and left-sided abdominal capillary hemangiomas were noted in the physical examination. Cranial computed tomography (CT) and magnetic resonance imaging (MRI) were obtained, showing a heterogeneous lesion in the cingulate gyrus, with peripheral and central areas of T1 hyperintensity and layering T2 hypointensity consistent with a hemorrhage. A right parasagittal frontal craniotomy was performed with an interhemispheric approach. We had difficulty controlling the bleeding with bipolar electrocautery during surgery and finally were able to stop the bleeding using surgicel and gelfoam. Postoperative cranial CT and MRI scans showed intraparenchymal hemorrhage centered within the medial right frontal lobe. There was no increase in hematoma size in consecutive CT scans.
Co-occurrence of vascular abnormalities with KWTS should be taken into consideration to avoid perilous preoperative and postoperative complications.
Full-text · Article · Apr 2015 · Journal of Medical Case Reports
[Show abstract][Hide abstract] ABSTRACT: The ventromedial prefrontal cortex (vmPFC) plays a key role in modulating emotional responses, yet the precise neural mechanisms underlying this function remain unclear. vmPFC interacts with a number of subcortical structures involved in affective processing, including the amygdala, hypothalamus, periaqueductal gray, ventral striatum, and bed nucleus of stria terminalis (BNST). While a previous study of non-human primates shows that vmPFC lesions reduce BNST activity and anxious behavior, no such causal evidence exists in humans. In this study, we used a novel application of magnetic resonance imaging (MRI) in neurosurgical patients with focal, bilateral vmPFC damage to determine whether vmPFC is indeed critical for modulating BNST function in humans. Relative to neurologically healthy subjects, who exhibited robust rest-state functional connectivity between vmPFC and BNST, the vmPFC lesion patients had significantly lower resting-state perfusion of the right BNST. No such perfusion differences were observed for the amygdala, striatum, hypothalamus, or periaqueductal gray. This study thus provides unique data on the relationship between vmPFC and BNST, suggesting that vmPFC serves to promote BNST activity in humans. This finding is relevant for neural circuitry models of mood and anxiety disorders.
[Show abstract][Hide abstract] ABSTRACT: The angioarchitectural features of an arteriovenous malformation (AVM) provide key information regarding natural history and treatment planning. Because of rapid filling and vascular overlap, two-dimensional (2D) and three-dimensional (3D) digital subtraction angiography (DSA) are often suboptimal for evaluation of these features. We have developed an algorithm that derives a series of fully time-resolved 3D DSA volumes (four-dimensional (4D) DSA) at up to 30 frames/s from a conventional 3D DSA. The temporal/spatial resolution of 4D reconstructions is significantly higher than that provided by current MR angiography and CT angiography techniques. 4D reconstruction allows viewing of an AVM from any angle at any time during its opacification. This feasibility study investigated the potential of 4D DSA to improve the ability to analyze angioarchitectural features compared with conventional 2D and 3D DSA.
2D, 3D, and 4D DSA reconstructions of angiographic studies of six AVMs were evaluated by three cerebrovascular neurosurgeons and one interventional neuroradiologist. These observers evaluated the ability of each modality to visualize the angioarchitectural features of the AVMs. They also compared the information provided using the combination of 2D and 3D DSA with that provided by a 4D DSA reconstruction.
By consensus, 4D DSA provided the best ability to visualize the internal features of the AVM including intranidal aneurysms, fistulae, venous obstructions, and sequence of filling and draining. 2D and 3D images in comparison were limited because of overlap of the vasculature.
In this small series, 4D DSA provided better ability to visualize the angioarchitecture of an AVM than conventional methods. Further experience is required to determine the ultimate utility of this technique.
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Preview · Article · Jan 2015 · Journal of Neurointerventional Surgery
[Show abstract][Hide abstract] ABSTRACT: Thrombosed giant intracranial aneurysms usually present with symptoms and signs from their mass effect. Although multiple treatment options are available, direct clip reconstruction with thromboendarterectomy remains the gold standard. Here we present a 66-year-old man with seizure, aphasia and hemiparesis. Work-up revealed a giant partially thrombosed aneurysm of the internal carotid artery bifurcation with surrounding vasogenic edema. He underwent clip reconstruction of the aneurysm via a cranio-orbital approach. Although we prepared for bypass with the radial artery and/or the superficial temporal artery, we were able to clip-reconstruct the aneurysm without bypass. The patient improved upon his pre-morbid state after surgery and made an excellent recovery. The video can be found here: http://youtu.be/P_10hRQFuPo .
Full-text · Article · Jan 2015 · Neurosurgical FOCUS
[Show abstract][Hide abstract] ABSTRACT: Background and Study Aim To enhance the visualization of the intracranial vasculature of cadavers under gross examination with a combination of imaging modalities. Material and Methods A total of 20 cadaver heads were used to test two different perfusion techniques. First, fixed cadaver heads were perfused with water; second, fresh cadavers were perfused with saline and 10% formalin. Subsequently, brains were removed and fixed. The compounds used were silicone rubber, silicone rubber mixed with powdered barium sulfate, and silicone rubber mixed with tantalum dioxide prepared by the first perfusion technique and gelatin mixed with liquid barium prepared with the second technique. Conventional X-ray imaging, computed tomography (CT), dynamic computed tomography (dCT), and postprocessing three-dimensional (3D) images were used to evaluate all the heads. Results Gelatinized barium was better visualized when compared with tantalum dioxide in conventional X-ray images. The blood vessels injected with either tantalum dioxide or gelatinized barium demonstrated a higher enhancement than the surrounding soft tissues with CT or dCT. The quality of the 3D reconstruction of the intracranial vasculature was significantly better in the CT images obtained from the gelatinized barium group. Conclusions Radiologic examinations of the heads injected with gelatinized barium facilitates the 3D understanding of cerebrovascular anatomy as an important tool for neuroanatomy training.
Full-text · Article · Dec 2014 · Journal of Neurological Surgery, Part B: Skull Base