Pre-operative Embolization of a Cerebellar Hemangioblastoma Using Polyvinyl Alcohol (PVA) and Target Tetra 360 Detachable Coil.

Due to its hypervascularity, hemangioblastoma, a rare primary central nervous system intracranial tumor, has been treated with pre-operative embolization prior to surgical resection. Here, we describe a case treated as such. A 37-year-old male presented with worsening chronic headache and right ear tinnitus was found to have a hypervascular, heterogeneous right cerebellar lesion suspicious for arteriovenous malformation or hemangioblastoma. He underwent polyvinyl alcohol (PVA) and Target Tetra 360 (Fremont, CA: Stryker Neurovascular) detachable coil embolization followed by complete tumor resection. Pathology was consistent with hemangioblastoma. He presented with complete resolution of his symptoms immediately post-operatively and at a two-week follow-up. Our case highlighted the importance of pre-operative embolization to help achieve complete tumor resection which is considered curative in the treatment of hypervascular hemangioblastoma. The Target Tetra 360 detachable coil embolization is another material that can be considered.

Identification of novel blood biomarker panels to detect ischemic stroke in patients and their responsiveness to therapeutic intervention.

The use of blood biomarkers for stroke has been long considered an excellent method to determine the occurrence, timing, subtype, and severity of stroke. In this study, venous blood was obtained from ischemic stroke patients after stroke onset and compared with age and sex-matched controls. We used a multiplex panel of 37 inflammatory molecules, analyzed using Luminex MagPix technology, to identify the changes in plasma proteins after ischemic stroke. We identified eight key molecules that were altered within the blood of stroke patients as compared to controls. Plasma levels of interleukin 6 signal transducer (sIL-6Rß/gp130), matrix metalloproteinase-2 (MMP-2), osteopontin, sTNF-R1 and sTNF-R2 were significantly higher in stroke patients compared to controls. Interferon-ß, interleukin-28, and thymic stromal lymphopoietin (TSLP) were decreased in plasma from stroke patients. No other immunological markers were significantly different between patient groups. When stroke patients were treated with tissue plasminogen activator (t-PA), plasma levels of interferon-α2 significantly increased while interleukin-2 and pentraxin-3 decreased. The discriminatory power of the molecules was evaluated by receiver operating characteristic (ROC) analysis. According to ROC analysis, the best markers for distinguishing stroke occurrence were MMP-2 (AUC = 0.76, sensitivity 62.5%, specificity 88.5%), sTNF-R2 (AUC = 0.75, sensitivity 83.3%, specificity 65.3%) and TSLP (AUC = 0.81, sensitivity 66.7%, specificity 96.2%). Multivariate logistic regression, used to evaluate the combination of proteins, identified a biomarker panel with high specificity and sensitivity (AUC = 0.96, sensitivity 87.5%, specificity 96.2%). These results indicate a novel set of blood biomarkers that could be used in a panel to identify stroke patients and their responsiveness to therapeutic intervention.

Cerebral arterial fenestrations.

Arterial fenestrations are an anatomic variant with indeterminate significance. Given the controversy surrounding fenestrations we sought their prevalence within our practice along with their association with other cerebrovascular anomalies. We retrospectively reviewed 10,927 patients undergoing digital subtraction angiography between 1992 and 2011. Dictated reports were searched for the terms "fenestration" or "fenestrated" with images reviewed for relevance, yielding 228 unique cases. A Medline database search from February 1964 to January 2013 generated 304 citations, 127 cases of which were selected for analysis. Cerebral arterial fenestrations were identified in 228 patients (2.1%). At least one aneurysm was noted in 60.5% of patients, with an aneurysm arising from the fenestration in 19.6% of patients. Aneurysmal subarachnoid hemorrhage or non-aneurysmal subarachnoid hemorrhage were present in 60.1% and 15.8%, respectively. For the subset of patients with an aneurysm arising directly from a fenestration relative to those patients with an aneurysm not immediately associated with a fenestration, the prevalence of aneurysmal subarachnoid hemorrhage was 66.7% vs. 58.6% (p = 0.58). Fenestrations were more often within the posterior circulation (73.2%) than the anterior circulation (24.6%), though there was no difference in the prevalence of aneurysms within these groups (61.1% vs. 60.7%, p = 1.0). Cerebral arterial fenestrations are an anatomic variant more often manifesting at the anterior communicating arterial complex and basilar artery and with no definite pathological relationship with aneurysms.

Radiation dose reduction in intra-arterial chemotherapy infusion for intraocular retinoblastoma.

BACKGROUND AND PURPOSE: Retinoblastoma (RB) is a rare malignancy affecting the pediatric population. Intravenous chemotherapy is the longstanding delivery method, although intra-arterial (IA) chemotherapy is gaining popularity given the reduced side effects compared with systemic chemotherapy administration. Given the sensitivity of the target organ, patient age, and secondary tumor susceptibility, a premium has been placed on minimizing procedural related radiation exposure. MATERIALS AND METHODS: To reduce patient x-ray dose during the IA infusion procedure, customized surgical methods and fluoroscopic techniques were employed. The routine fluoroscopic settings were changed from the standard 7.5 pulses/s and dose level to the detector of 36 nGy/pulse, to a pulse rate of 4 pulses/s and detector dose to 23 nGy/pulse. The angiographic dose indicators (reference point air kerma (Ka) and fluoroscopy time) for a cohort of 10 consecutive patients (12 eyes, 30 infusions) were analyzed. An additional four cases (five eyes, five infusions) were analyzed using dosimeters placed at anatomic locations to reflect scalp, eye, and thyroid dose. RESULTS: The mean Ka per treated eye was 20.1±11.9 mGy with a mean fluoroscopic time of 8.5±4.6 min. Dosimetric measurements demonstrated minimal dose to the lens (0.18±0.10 mGy). Measured entrance skin doses varied from 0.7 to 7.0 mGy and were 73.4±19.7% less than the indicated Ka value. CONCLUSIONS: Ophthalmic arterial melphalan infusion is a safe and effective means to treat RB. Modification to contemporary fluoroscopic systems combined with parsimonious fluoroscopy can minimize radiation exposure.

Serial angiographic appearance of segmental arterial mediolysis manifesting as vertebral, internal mammary and intra-abdominal visceral artery aneurysms in a patient presenting with subarachnoid hemorrhage and review of the literature.

Segmental arterial mediolysis (SAM) is a rare, non-inflammatory, non-atherosclerotic vasculopathy typically affecting the abdominal arteries although it may also affect the great vessels and cerebral vasculature. Diseased vessels manifest with aneurysms and/or dissections, often presenting clinically with catastrophic thromboembolic injury and less frequently with subarachnoid hemorrhage (SAH). The etiology of SAM remains indeterminate although there is evidence it may be an endogenous pathological response to vasospasm. The SAM literature is reviewed and a case of SAH related to a ruptured dissecting-type vertebral artery aneurysm is described. In addition to furthering awareness of SAM, this unique case offers insight into the acute phase of the disease and the potential role of vasospastic induction.

Intercellular calcium signaling in astrocytes via ATP release through connexin hemichannels.

Astrocytes are capable of widespread intercellular communication via propagated increases in intracellular Ca(2+) concentration. We have used patch clamp, dye flux, ATP assay, and Ca(2+) imaging techniques to show that one mechanism for this intercellular Ca(2+) signaling in astrocytes is the release of ATP through connexin channels ("hemichannels") in individual cells. Astrocytes showed low Ca(2+)-activated whole-cell currents consistent with connexin hemichannel currents that were inhibited by the connexin channel inhibitor flufenamic acid (FFA). Astrocytes also showed molecular weight-specific influx and release of dyes, consistent with flux through connexin hemichannels. Transmembrane dye flux evoked by mechanical stimulation was potentiated by low Ca(2+) and was inhibited by FFA and Gd(3+). Mechanical stimulation also evoked release of ATP that was potentiated by low Ca(2+) and inhibited by FFA and Gd(3+). Similar whole-cell currents, transmembrane dye flux, and ATP release were observed in C6 glioma cells expressing connexin43 but were not observed in parent C6 cells. The connexin hemichannel activator quinine evoked ATP release and Ca(2+) signaling in astrocytes and in C6 cells expressing connexin43. The propagation of intercellular Ca(2+) waves in astrocytes was also potentiated by quinine and inhibited by FFA and Gd(3+). Release of ATP through connexin hemichannels represents a novel signaling pathway for intercellular communication in astrocytes and other non-excitable cells.