Navjot Chaudhary

Transcortical Venous Approach for Direct Embolization of a Cavernous Sinus Dural Arteriovenous Fistula: Technical Case Report

BACKGROUND AND IMPORTANCE: Dural arteriovenous fistulas (dAVFs) represent 10% to 15% of all intracranial arteriovenous malformations. Most often, embolization is accomplished with transfemoral catheter techniques. We present a case in which embolization of a cavernous sinus dAVF was made possible through transcranial cannulation of a cortical draining vein. CLINICAL PRESENTATION: An 82-year-old woman presented with diplopia, left sixth cranial nerve palsy, intraocular hypertension, and bilateral chemosis. Angiography revealed a complex cavernous dAVF with cortical venous reflux, supplied by both external carotid arteries and the left meningohypophyseal trunk. Percutaneous transvenous access failed, and only partial occlusion was achieved by transarterial embolization. A frontotemporal craniotomy was performed to access the superficial middle cerebral vein in the left sylvian fissure. Under fluoroscopic guidance, a microcatheter was advanced through this vein to the floor of the middle cranial fossa and into the dAVF, permitting coil occlusion. CONCLUSION: This transcranial vein technique may be a useful adjunct in dAVF therapy when percutaneous transarterial or transvenous approaches fail or are not possible. ABBREVIATIONS: CVD, cortical venous drainage dAVF, dural arteriovenous fistula ECA, external carotid artery

Magnetic resonance perfusion image features uncover an angiogenic subgroup of glioblastoma patients with poor survival and better response to antiangiogenic treatment

Background In previous clinical trials, antiangiogenic therapies such as bevacizumab did not show efficacy in patients with newly diagnosed glioblastoma (GBM). This may be a result of the heterogeneity of GBM, which has a variety of imaging-based phenotypes and gene expression patterns. In this study, we sought to identify a phenotypic subtype of GBM patients who have distinct tumor-image features and molecular activities and who may benefit from antiangiogenic therapies. Methods Quantitative image features characterizing subregions of tumors and the whole tumor were extracted from preoperative and pretherapy perfusion magnetic resonance (MR) images of 117 GBM patients in 2 independent cohorts. Unsupervised consensus clustering was performed to identify robust clusters of GBM in each cohort. Cox survival and gene set enrichment analyses were conducted to characterize the clinical significance and molecular pathway activities of the clusters. The differential treatment efficacy of antiangiogenic therapy between the clusters was evaluated. Results A subgroup of patients with elevated perfusion features was identified and was significantly associated with poor patient survival after accounting for other clinical covariates (P values <.01; hazard ratios > 3) consistently found in both cohorts. Angiogenesis and hypoxia pathways were enriched in this subgroup of patients, suggesting the potential efficacy of antiangiogenic therapy. Patients of the angiogenic subgroups pooled from both cohorts, who had chemotherapy information available, had significantly longer survival when treated with antiangiogenic therapy (log-rank P=.022). Conclusions Our findings suggest that an angiogenic subtype of GBM patients may benefit from antiangiogenic therapy with improved overall survival.

Craniosynostosis involving the squamous temporal sutures: a rare and possibly underreported etiology for cranial vault asymmetry.

Craniosynostosis is a condition in which 1 or more cranial sutures fuse prematurely, often secondary to a fibroblast growth factor receptor (FGFR) mutation, typically involving FGFR2 or FGFR3. This mutation may occur sporadically or in the setting of a genetic syndrome and typically presents within the first few days of life or in early infancy. Most commonly, the sagittal and coronal sutures are involved, although involvement of the lambdoidal and/or metopic sutures is not uncommon. Surgical correction is undertaken both for cosmetic purposes and to relieve raised intracranial pressure, both of which can be severe, depending on the sutures involved. We report on 2 children who presented in their first year of life with synostosis involving: in one instance, a single squamous temporal suture, and in the other, both squamous temporal sutures. The initial presentation and clinical courses of these 2 patients are highly distinct from one another, although both ultimately did quite well after extensive cranial remodeling. To the best of our knowledge, only a handful of patients with squamous synostosis have been reported in the medical literature.

Evidence for Use of Teriparatide in Spinal Fusion Surgery in Osteoporotic Patients

BACKGROUND Osteoporosis is defined as bone mineral density. METHODS A PubMed literature review was performed to review preclinical and clinical evidence for the use of teriparatide in osteoporotic patients undergoing spine fusion surgery. RESULTS Preclinical studies in animal models show that teriparatide increases spinal fusion rates. Early clinical studies show that teriparatide both increases spinal fusion rates and decreases hardware loosening in the setting of postmenopausal osteoporosis. CONCLUSION Ongoing additional trials will help formulate preoperative screening recommendations, determine the optimal duration of preoperative and postoperative teriparatide treatment, and investigate its utility in men.

Familial syndromes associated with intracranial tumours: a review

BackgroundMost cancers of the central nervous system (CNS) occur sporadically in the absence of any known underlying familial disorder or multi-systemic syndrome. Several syndromes are associated with CNS malignancies, however, and their recognition has significant implications for patient management and prognosis. Patients with syndrome-associated CNS malignancies often have multiple tumours (either confined to one region or distributed throughout the body), with similar or different histology.ObjectiveThis review examines syndromes that are strongly associated with CNS cancers: the phakomatosis syndromes, familial syndromes such as Li–Fraumeni and familial polyposis syndromes and dyschondroplasia.

Stereotactic radiosurgery for metastasis to the craniovertebral junction preserves spine stability and offers symptomatic relief

OBJECT Metastatic disease to the craniovertebral junction (CVJ) is rare but presents unique management challenges. To date, studies on using stereotactic radiosurgery (SRS) for CVJ metastases have been limited to case reports and small case series. The aim of this analysis was to evaluate the utility of SRS in the management of these secondary lesions. METHODS Clinical and radiological information from the charts of 25 patients with metastatic disease of the CVJ who were treated with SRS between 2005 and 2013 at the Stanford CyberKnife Center were retrospectively reviewed. RESULTS Seven male and 18 female patients with a median age of 58 years (range 34-94 years) were identified. The most common primary tumors were breast cancer (n = 5) and non-small cell lung cancer (n = 5), and the most frequent symptom was neck pain (n = 17). The average tumor volume treated was 15.9 cm3 (range 0.16-54.1 cm3), with a mean marginal radiation dose of 20.3 Gy (range 15-25.5 Gy). The median follow-up was 18 months (range 1-81 months), though 1 patient was lost to follow-up. SRS provided radiographic tumor stability in over 80% of patients, offered pain alleviation in nearly two-thirds of patients, and produced no serious complications. Moreover, SRS preserved spinal stability in all but 1 patient, in whom pre-SRS stability was established. There was no evidence of radiation toxicity in the patient population. Median survival was 28 months (range 2-81 months), with survival of 13.3% at 5 years. CONCLUSIONS In the absence of unstable pathological fracture and spinal cord compression, metastatic tumors of the CVJ can be safely and effectively treated with SRS. This treatment option offers palliative pain relief and can halt tumor progression with only a low risk of complications or spinal instability.

A rare case of atlantooccipital dissociation in the context of occipitalization of the atlas, with a 2-year follow-up: case report.

Atlantooccipital dislocation (AOD) is a rare and often fatal injury. In cases of survival, residual deficits are severe and often include cranial nerve palsy, quadriplegia, or respiratory issues. Occipitalization is defined as partial or complete congenital fusion of the occiput to the atlas and is exceptionally rare. The authors present a rare case of AOD superimposed on a congenital occipitalization of the atlas. This 39-year-old man had AOD following a motor vehicle collision. On examination, his overall motor score on the American Spinal Injury Association scale was 5/100, and his rectal tone was absent. Computed tomography demonstrated AOD in an area of occipitalization. Magnetic resonance imaging revealed ligamentous injury leading to C1-2 instability. Intervention included occipital cervical instrumentation fusion from the occiput to C-3. Six months postoperatively, imaging revealed fusion of the graft and consolidation of the fractured occipitalization. At the 2-year follow-up, the patients strength was 3/5 for wrist extension and handgrip on the right side and full strength in the rest of the myotomes. Bladder and bowel function was also normalized. A high-velocity collision led to disruption of the atlantooccipital ligaments and fracture of the occipitalized lateral masses in this patient. Internal fixation and fusion led to good fusion postoperatively. Occipitalization probably led to abnormal joint mechanics at the C1-occiput junction, which might have altered the amount of force required to fracture the occipitalization and produce AOD. This difference may partially account for the favorable neurological outcome in the featured patient compared with traditional cases of AOD.

Quantitative analysis of the safety and efficacy of microvascular decompression for patients with trigeminal neuralgia above and below 65 years of age

For medically-refractory trigeminal neuralgia (TN), microvascular decompression (MVD) is the first-line treatment, and has demonstrated the greatest efficacy and durability. However, due to potential surgical complications, a bias may exist against performing MVD in elderly patients. We sought to determine through a quantitative analysis whether MVD in the elderly is a safe and effective procedure for TN. We completed a Pubmed/SCOPUS literature search up to 12/2016 for eligible studies on MVD for TN. Only research articles with age stratification of results were included. In this quantitative analysis, we analyzed the data for the six articles identified in the literature comparing MVD for a group of patients ≥65 years with an elderly group <65 years. A total of 1483 were included. 455 patients were ≥65 years (mean 70.8 years, range 65-89 years) and 1028 patients were <65 years (mean 53.4 years, range 19-64 years). Composite mean follow-up time was 51.6 months for the elderly group, and 55.1 months for the young group. Following MVD, each group had 1 mortality (p = 0.43). There were 21 serious morbidities in the elderly group (4.62%) and 32 in the young group (3.11%) (p = 0.11). In addition, 15 patients (1.46%) in the elderly group and 24 patients (1.62%) in the young group experienced a cerebrospinal fluid leak (p = 0.23). TN recurrence rates 9.23% in the young group and 13.33% in the elderly group (p = 0.070). In conclusion, for properly-selected surgical candidates, MVD should not be ruled out on the basis of age ≥65 years.

Gold Nanoparticles for Brain Tumor Imaging: A Systematic Review

Background Demarcation of malignant brain tumor boundaries is critical to achieve complete resection and to improve patient survival. Contrast-enhanced brain magnetic resonance imaging (MRI) is the gold standard for diagnosis and pre-surgical planning, despite limitations of gadolinium (Gd)-based contrast agents to depict tumor margins. Recently, solid metal-based nanoparticles (NPs) have shown potential as diagnostic probes for brain tumors. Gold nanoparticles (GNPs) emerged among those, because of their unique physical and chemical properties and biocompatibility. The aim of the present study is to review the application of GNPs for in vitro and in vivo brain tumor diagnosis. Methods We performed a PubMed search of reports exploring the application of GNPs in the diagnosis of brain tumors in biological models including cells, animals, primates, and humans. The search words were “gold” AND “NP” AND “brain tumor.” Two reviewers performed eligibility assessment independently in an unblinded standardized manner. The following data were extracted from each paper: first author, year of publication, animal/cellular model, GNP geometry, GNP size, GNP coating [i.e., polyethylene glycol (PEG) and Gd], blood-brain barrier (BBB) crossing aids, imaging modalities, and therapeutic agents conjugated to the GNPs. Results The PubMed search provided 100 items. A total of 16 studies, published between the 2011 and 2017, were included in our review. No studies on humans were found. Thirteen studies were conducted in vivo on rodent models. The most common shape was a nanosphere (12 studies). The size of GNPs ranged between 20 and 120 nm. In eight studies, the GNPs were covered in PEG. The BBB penetration was increased by surface molecules (nine studies) or by means of external energy sources (in two studies). The most commonly used imaging modalities were MRI (four studies), surface-enhanced Raman scattering (three studies), and fluorescent microscopy (three studies). In two studies, the GNPs were conjugated with therapeutic agents. Conclusion Experimental studies demonstrated that GNPs might be versatile, persistent, and safe contrast agents for multimodality imaging, thus enhancing the tumor edges pre-, intra-, and post-operatively improving microscopic precision. The diagnostic GNPs might also be used for multiple therapeutic approaches, namely as “theranostic” NPs.