Journal of neurosurgery
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Journal of neurosurgery · Sep 2011
Minimally invasive evacuation of spontaneous intracerebral hemorrhage using sonothrombolysis.
Catheter-based evacuation is a novel surgical approach for the treatment of brain hemorrhage. The object of this study was to evaluate the safety and efficacy of ultrasound in combination with recombinant tissue plasminogen activator (rt-PA) delivered through a microcatheter directly into spontaneous intraventricular (IVH) or intracerebral (ICH) hemorrhage in humans. ⋯ Lysis and drainage of spontaneous ICH and IVH with a reduction in mass effect can be accomplished rapidly and safely through sonothrombolysis using stereotactically delivered drainage and ultrasound catheters via a bur hole. A larger clinical trial with catheters specifically designed for brain blood clot removal is warranted.
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Cerebrospinal fluid hypotension, or "brain sag," is a recently described phenomenon most commonly seen following craniotomy for the clipping of ruptured aneurysms along with preoperative lumbar drain placement. The clinical features and CT findings have been previously described. Clinical presentation can be similar to and often mistaken for cerebral vasospasm. In this study, the authors report on the angiographic findings in patients with brain sag. ⋯ Brain sag appears to be associated with characteristic angiographic features. Recognizing these features may help to diagnose brain sag as the cause of neurological deterioration in this patient population.
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Journal of neurosurgery · Sep 2011
Tracking accuracy of T2- and diffusion-weighted magnetic resonance imaging for infusate distribution by convection-enhanced delivery.
Because convection-enhanced delivery relies on bulk flow of fluid in the interstitial spaces, MR imaging techniques that detect extracellular fluid and fluid movement may be useful for tracking convective drug distribution. To determine the tracking accuracy of T2-weighted and diffusion-weighted MR imaging sequences, the authors followed convective distribution of radiolabeled compounds using these imaging sequences in nonhuman primates. ⋯ Real-time T2- and diffusion-weighted MR imaging significantly underestimate tissue Vd during convection-enhanced delivery over a wide range of molecular sizes. Application of these imaging modalities may lead to inaccurate estimation of convective drug distribution.
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Journal of neurosurgery · Sep 2011
Notch receptor and effector expression in von Hippel-Lindau disease-associated central nervous system hemangioblastomas.
Central nervous system hemangioblastomas are the most common manifestation of von Hippel-Lindau (VHL) disease, an autosomal dominant tumor suppressor syndrome that results in loss of VHL protein function and continuous upregulation of hypoxia-inducible factors. These tumors are composed of neoplastic stromal cells and abundant vasculature. Stromal cells express markers consistent with multipotent embryonically arrested hemangioblasts, which are precursors for hematopoietic and vascular lineages. Notch receptors are transmembrane signaling molecules that regulate multiple developmental processes including hematopoiesis and vasculogenesis. To investigate the importance of notch signaling in the development of VHL disease-associated CNS hemangioblastomas, the authors examined the presence of the four notch receptors and downstream notch effectors in this setting. ⋯ The presence of all four notch receptors and downstream effector molecules suggests that the notch signaling pathway plays a critical role in the maintenance of the undifferentiated pluripotent phenotype of these tumors and in the associated vascular response. Moreover, the prominent expression of notch receptors in VHL-associated CNS hemangioblastomas reveals a new and possibly potent therapeutic target.
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Posttraumatic vasospasm (PTV) is an underrecognized cause of ischemic damage after severe traumatic brain injury (TBI) that independently predicts poor outcome. There are, however, no guidelines for PTV screening and management, partly due to limited understanding of its pathogenesis and risk factors. ⋯ Independent risk factors for PTV include parenchymal contusions and fever. These results suggest that diffuse mechanical injury and activation of inflammatory pathways may be underlying mechanisms for the development of PTV, and that a subset of patients with these risk factors may be an appropriate population for aggressive screening. Further studies are needed to determine if treatments targeting fever and inflammation may be effective in reducing the incidence of vasospasm following severe TBI.