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PURPOSE: Rasmussen encephalitis (RE) is a very rare chronic neurological disorder of unilateral inflammation of the cerebral cortex. Hemispherotomy provides the best chance at achieving seizure freedom in RE patients, but with significant risks and variable long-term outcomes. The goal of this study is to utilize our multicenter pediatric cohort to characterize if differences in pathology and/or imaging characterization of RE may provide a window into post-operative seizure outcomes, which in turn could guide decision-making for parents and healthcare providers. METHODS: This multi-institutional retrospective review of medical record, imaging, and pathology samples was approved by each individual institution's review board. Data was collected from all known pediatric cases of peri-insular functional hemispherotomy from the earliest available electronic medical records. Mean follow-up time was 4.9 years. Clinical outcomes were measured by last follow-up visit using both Engel and ILAE scoring systems. Relationships between categorical and continuous variables were analyzed with Pearson correlation values. RESULTS: Twenty-seven patients met study criteria. No statistically significant correlations existed between patient imaging and pathology data. Pathology stage, MRI brain imaging stages, and a combined assessment of pathology and imaging stages showed no statistically significant correlation to post-operative seizure freedom rates. Hemispherectomy Outcome Prediction Scale scoring demonstrated seizure freedom in only 71% of patients receiving a score of 1 and 36% of patients receiving a score of 2 which were substantially lower than predicted. CONCLUSIONS: Our analysis did not find evidence for either independent or combined analysis of imaging and pathology staging being predictive for post peri-insular hemispherotomy seizure outcomes, prompting the need for other biomarkers to be explored. Our data stands in contrast to the recently proposed Hemispherectomy Outcome Prediction Scale and does not externally validate this metric for an RE cohort.

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BACKGROUND: Herein, the authors describe the successful utilization of 5-aminolevulinic acid (5-ALA) and the first case of GammaTile cesium-131 therapy in a pediatric patient with recurrent high-grade glioma. 5-ALA was utilized to optimize gross-total resection prior to GammaTile implantation. After conversion to an equivalent dose in 2-Gy fractions (EQD2), a composite was made of the GammaTile dose with the initial external beam radiotherapy. Two hypothetical plans consisting of a standard hypofractionated strategy for glioma reirradiation and a CyberKnife plan using GammaTile's planning target volume were developed and likewise underwent EQD2 conversion and composite plan generation with the initial radiotherapy. OBSERVATIONS: 5-ALA was useful in achieving gross-total resection with no acute toxicity from the surgery or GammaTile irradiation. When compared with the hypothetical composite doses, GammaTile's composite, axium point dose (D0.03cc) to the brainstem was 32.9 Gy less than the hypofractionated and the CyberKnife composite plans at 38.7 Gy and 40.2 Gy, respectively. The right hippocampus demonstrated a substantially reduced composite plan dose with GammaTile with a D0.03cc of 62.4 Gy versus 71.7 and 80.7 Gy for the hypofractionated and CyberKnife composite plans, respectively. LESSONS: Utilization of 5-ALA and GammaTile therapy yielded clinically superior tumor debulking and effective radiotherapy dose localization with sparing of organs at risk, respectively.

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We present a case in which a retrocondylar far-lateral approach was utilized to resect a hemangioblastoma at the craniocervical junction. The patient was a 33-year-old man presenting with 2 months of symptoms referable to compression at the craniocervical junction (i.e., dizziness and gait instability). Though neurologically intact on exam, his imaging demonstrated a highly vascular cystic lesion dorsolateral to the medulla on the left consistent with a hemangioblastoma. Virtual reality software was critical to visualize the patient's lesion in relationship to the vertebral artery and draining vein ( Fig. 1 ). A far-lateral retrocondylar suboccipital craniectomy with a C1 hemilamiectomy permitted resection of this lesion. The operative strategy was to address the lesion similar to an arteriovenous malformation by detaching the lesion from its arterial feeders first, and then addressing the lesion's draining vein ( Fig. 2 ). Postoperative imaging demonstrated a gross-total resection and the patient had an uncomplicated postoperative course. This case demonstrates not only the lateral reach of a retrocondylar far-lateral approach; but also, clearly demonstrates an effective dissection strategy when approaching a hemangioblastoma. The link to the video can be found at: https://youtu.be/M0szMOdhjfE .

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BACKGROUND: Aortic pseudoaneurysms are a rare cause of chronic back pain, usually resulting from compression of the adjacent neurovasculature. It is uncommon for patients with pseudoaneurysms of the abdominal aorta to present in a delayed fashion after initial traumatic injury. CASE DESCRIPTION: We describe an unusual case of delayed pseudoaneurysm formation with subsequent erosion into the adjacent L1 vertebral body. This pseudoaneurysm was secondary to a gunshot wound with retained ballistic fragment that had occurred 27 years previously. Herein, we discuss the patient's presenting symptoms, imaging, and overall treatment. In this particular case, we used a combined surgical and endovascular (hybrid) approach after the patient experienced recurrent low back pain, weeks after a primary endovascular treatment was performed. We additionally review the current literature on the management of aortic pseudoaneurysms causing vertebral body erosion and back pain. CONCLUSIONS: In our patient, a combined surgical and endovascular (hybrid) approach led to the complete resolution of his back pain symptoms and to complete exclusion of the pseudoaneurysm on follow-up imaging. Endovascular management of aortic pseudoaneurysms may be a reasonable alternative to open surgery in high-risk patients; however, this approach may result in a higher recurrence of pseudoaneurysm and initial presenting symptoms. Further investigation is needed to elucidate the efficacy of endovascular treatment of these lesions.

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BACKGROUND: Stereotactic biopsy is an important and minimally invasive technique used for a variety of indications in neurosurgery. Initially, this technique required a frame, but recently there have been a number of newer, less cumbersome approaches to biopsy including robotic arms, fixed arms, and, more recently, skull-mounted miniframes. Miniframes are attractive because they are disposable and low profile. However, the relatively limited degree of freedom offered by currently available devices necessitates a preplanned burr hole, which in turn limits flexibility and multiple trajectories. The AXiiiS device is a skull-mounted, magnetic resonance imaging-compatible miniframe that provides a similar degree of freedom with a frame while maintaining a low-profile, disposable platform. OBJECTIVE: To assess the image-guided trajectory alignment accuracy using AXiiiS stereotactic miniframe biopsy of intracranial lesions. The accuracy of the AXiiiS device is compared with the Navigus Trajectory Guide as platforms. METHODS: After approval by our institutional review board, medical records of 10 neurosurgical patients with intracranial pathologies were chosen for AXiiiS stereotactic miniframe biopsy, and histological correlation was obtained. RESULTS: Ten reported cases demonstrate the precision and ease of using the AXiiiS stereotactic miniframe for biopsy of intracranial lesions in conjunction with preoperative magnetic resonance imaging. Multiple trajectories and angles have been used with precision and safety. CONCLUSION: The AXiiiS stereotactic miniframe is a feasible, safe, and disposable platform for multitrajectory intracranial biopsies. Compared with existing platforms, this novel device provides a more stable base and wider limits of trajectory angles with comparable accuracy and precision.

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OBJECTIVE: Transcatheter aortic valve replacement (TAVR) is performed as a stand-alone procedure in patients that are not suitable for surgical aortic valve replacement. However, a significant proportion of patients with severe aortic stenosis have coexisting coronary artery disease (CAD). We report concomitant TAVR and percutaneous coronary intervention (PCI) as a single procedure in such patients. METHODS: Three patients with severe aortic stenosis and CAD that were high risk for conventional surgery had concomitant alternative approach TAVR and PCI performed. Two patients had PCI and stent placement immediately after the deployment of the transapical transcatheter aortic valve, and one patient had a coronary artery stent placed just prior to the deployment of the transaortic transcatheter aortic valve. RESULTS: Two male patients and one female (age range 68-91 years) had 100% procedural success with resolution of symptoms and zero residual stenosis. There were no complications related to neurologic events, worsening renal function, or myocardial infarction. In-hospital and 30-day mortality was zero. All three patients were discharged home with a median hospital stay of eight days. CONCLUSIONS: In our small series of patients presented we demonstrate that PCI and TAVR performed concurrently in the hybrid operating room is a feasible option in patients undergoing TAVR with coexisting CAD. Furthermore, we propose this single-stage approach in such high-risk patients as it decreases the number of procedures performed and may theoretically lower cost and hospital stay.

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BACKGROUND CONTEXT: There are few reported cases of failed axial lumbar interbody fusion (AxiaLIF) in the existing neurosurgical literature, and an anecdotal case of open paramedian retroperitoneal approach to L5-S1 level for retrieval of AxiaLIF rod has been published. PURPOSE: The object of this study is to illustrate a minimally invasive presacral rod retrieval technique in cases with failed AxiaLIF causing lumbosacral instability. STUDY DESIGN/SETTING: Retrospective case series. METHODS: A retrospective analysis of the initial 26 cases of AxiaLIF done at our institution was performed; two cases of failed AxiaLIF that required rod removal were identified for detailed study. Available literature on the minimally invasive presacral techniques for rod retrieval was researched, and the use of a novel rod retrieval device with an expanding hex tip is discussed. RESULTS: Using a minimally invasive presacral approach through the previous surgical corridor, the authors were able to retrieve the AxiaLIF rod implant and then proceed with an alternative fusion technique. Both patients improved clinically and radiographically after revision. Removal of the presacral rod was not associated with vascular or bowel complications and required minimal operating room time with minimal blood loss. CONCLUSIONS: To the authors' knowledge, this is the first report demonstrating the safety and efficacy of minimally invasive presacral approach for removal of AxiaLIF rods in patients with failed AxiaLIF. As the AxiaLIF procedure is rapidly gaining acceptance among spine surgeons, we can expect to see increasing numbers of failed procedures as well. Understanding options for revision strategies is important for surgeons considering the use of this technique.

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The authors present the first report of spinal congenital dermal sinus with paramedian dual ostia leading to 2 intradural epidermoid cysts. This 7-year-old girl had a history of recurrent left paramedian lumbosacral subcutaneous abscesses, with no chemical or pyogenic meningitis. Admission MRI studies demonstrated bilateral lumbar dermal sinus tracts and a tethered spinal cord. At surgery to release the tethered spinal cord the authors encountered paramedian dermal sinus tracts with dual ostia, as well as 2 intradural epidermoid cysts that were not readily apparent on MRI studies. Congenital dermal sinus should be considered in the differential diagnosis of lumbar subcutaneous abscesses, even if the neurocutaneous signatures are located off the midline.

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A highly conserved region of 21 amino acids flanked by cysteine residues, contained within a larger repeated domain, has been proposed to be the antibody-binding site in the ovarian cancer biomarker CA125 (MUC16). In this study solid-phase peptide synthesis with Fmoc protection chemistry was used to assemble a 21-mer peptide corresponding to the most frequently occurring antibody binding sequence in CA125. Potentially significant sequence variants were also synthesized. Peptide secondary structure was investigated using Fourier transform infrared spectroscopy, revealing the consensus sequence peptide to be largely unstructured at physiological pH whether the cysteine residues were reduced or were oxidized to form an intramolecular disulfide bond. Substitution of serine for proline at position 8 (P8S) results in ß-sheet formation in peptides involved in intramolecular disulfide bonds. This ß-sheet structure does not persist in peptides incapable of intramolecular disulfide bonding because of sequence nor in peptides treated with the reducing agent dithiothreitol. In CA125, P8S is predicted to occur in ∼25% of repeat domains, suggesting that this structural motif is a non-negligible contributor to overall structure and function. These findings suggest that future structural characterization efforts of CA125 should be especially mindful of the amino acid sequence and oxidation state of the protein.

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Therapy for human immunodeficiency virus (HIV)-infected patients requires chronic multidrug administration. The eventual failure of therapy in some patients has brought into question the tissue concentration of the drugs. With an appropriately radiolabeled compound, we could utilize positron emission tomography to provide quantitative time-activity curves for various tissues. We have developed a fluorine-18 labeled analog of Tenofovir, the active metabolite of Tenofovir DF, a commonly prescribed component of multidrug therapy. Because (1-(6-amino-9H-purin-9-yl)-3-fluoropropan-2-yloxy)methylphosphonic acid (FPMPA) has a chiral center, we prepared both enantiomers and confirmed that the S-isomer exhibited significantly higher antiviral activity than the R-isomer. In viral replication inhibition assays in human MT4 cells infected with SHIV(DH12R), S-FPMPA had an IC(50) of 1.85 muM (95% CI; 0.8-5.53), while the R-isomer was inactive. An appropriate chiral precursor was prepared to allow the incorporation of fluorine-18. The [(18)F]FPMPA in racemic, R, or S form was prepared in a 50 min synthesis in 38+/-5% yield (n = 23, corrected for decay). The product was of high radiochemical and enantiomeric purity. The specific activity of the final product was 4.0+/-1.8 Ci/mumol at EOB (end of bombardment). This product may provide information about drug tissue distribution in animal models under chronic drug treatment.