No abstract

The purpose of this study was to determine if exercise could induce expression of vascular endothelial growth factor (VEGF) and angiopoietin 1 and 2, in association with angiogenesis; and if angiogenic changes correlated with reduced brain injury in stroke. Adult male Sprague Dawley rats (3 month old, n=44) were exercised on a treadmill 30 minutes each day for 1, 3 or 6 weeks, or housed as non-exercised controls for 3 weeks. Some 3 week-exercised rats were then housed for an additional 3 weeks. Exercise significantly (p<0.01) increased mRNA (determined by real-time reverse transcriptase-polymerase chain reaction) expression of angiopoietin 1 and 2 as early as 1 week, with further increases occurring at 3 weeks. A mild increase after 1 week and a robust increase after 3 weeks of exercise in four isoforms (120, 144, 164, 188) of VEGF mRNA levels were significantly (p<0.01) observed, with VEGF(144) being more markedly up-regulated. Overexpression of the mRNAs decreased upon withdrawal of exercise. A significant increase (p<0.01) in the density of microvessels (determined by laminin-immunocytochemistry) was found at 3 weeks of exercise and this continued after exercise was withdrawn. In exercising rats subjected to 2-h MCA occlusion followed by 48-h reperfusion, neurological deficits and infarct volume were significantly reduced. Neuroprotection continued after 3 weeks of rest. This study indicates that pre-ischemic exercise reduces brain injury in stroke. The reduced damage is associated with angiogenesis, possibly induced by angiogenic factors following exercise. Physical exercise up-regulates mRNA levels of the angiopoietin family and VEGF.

The microvascular anatomy of the proximal segments (M1 and M2) of the middle cerebral artery (MCA) was studied in 70 unfixed brain hemispheres from 35 cadavers. The arteries were injected with a tinted polyester resin and dissected under magnification by microsurgical techniques. The authors studied the outer diameter (OD), length, site of origin, and pattern of branching of the main trunk, secondary trunks, and the initial insular portion of the cortical branches of the MCA. The degree of mobilization of the arteries lying over the insular cortex was also assessed. The main trunk of the MCA, which had an OD of 3 +/- 0.1 mm bilaterally and a length of 15 +/- 1.1 mm in the right hemisphere and 15.7 +/- 1.3 mm in the left hemisphere, could be divided into four groups: Group I: absence of a main division (that is, a single-trunk type of MCA) (in 6% of cases); Group II: bifurcation (64%); Group III: trifurcation (29%); and Group IV: quadrifurcation (1%). The secondary trunks resulting from the division of the main trunk of the MCA had a mean OD ranging from 1.4 to 2.3 mm and a mean length that varied from 12.1 to 14.9 mm. The mean OD of the cortical branches measured near their origin in the main and secondary trunks indicated that the angular artery was the largest vessel, with a mean OD of 1.5 mm on both sides of the brain. The temporopolar artery was the smallest, with a mean OD of 0.8 mm in the right hemisphere and 0.9 mm in the left hemisphere. The authors also describe the patterns of origin of the cortical vessels from the main trunk (early branches) and from the secondary trunks, as well as their branching pattern at the site of origin (single vessels and common stems). These anatomical data indicate that it is possible to perform microvascular reconstructive procedures, such as anastomosis, grafting, and reimplantation of branches in the insular area. The advantages of using unfixed specimens, intravascular injections, and magnification to reproduce in vivo conditions as closely as possible are also discussed.

The NeuroMatetrade mark robot system (Integrated Surgical Systems, Davis, CA) is a commercially available, image-guided, robotic-assisted system used for stereotactic procedures in neurosurgery. In this article, we present a quantitative comparison of the application accuracy of the NeuroMate with that of standard frame-based and frameless stereotactic techniques. The article discusses a five-way application accuracy comparison study. The variables of our comparison and their mean errors are as follows: (1) with the robot in a frame-based configuration, the RMS was 0.86 +/- 0.32 mm; (2) with the robot in the frameless configuration, the RMS was 1.95 +/- 0.44 mm; (3) in a standard stereotactic (ZD) frame-based approach, the RMS was 1.17 +/- 0.25 mm; (4) with an infrared tracking system using the frame for fiducial registration, the RMS was 1.47 +/- 0.45 mm; (5) with an infrared tracking system using screw markers for registration, the RMS was 0.68 +/- 0.26 mm. The study was performed with 2-mm sections of CT scans. These results show that the application accuracy of the frame-based NeuroMate robot is comparable to that of standard localizing systems, whether they are frame-based or infrared tracked.

With the advent of newer devices for measuring intracranial pressure (ICP) and cerebral metabolism, more alternatives continue to rise aiming to control ICP. This manuscript presents a proposed analysis of different ICP monitoring devices in order to make appropriate selection of them in our clinical setting including general and pediatric applications. A systematic review of the literature was made analyzing the technical advances in ICP monitoring. The recent in vitro and in vivo tests as well as mathematical/computer models were reviewed. Practical applications of principles were discussed and compared based on the mode of pressure transformation. A ventricular catheter connected to an external strain gauge transducer or catheter tip pressure transducer device is considered to be the most accurate method of monitoring ICP and enables therapeutic CSF drainage. The significant infections or hemorrhage associated with ICP devices causing patients morbidity are clinically rare and should not deter the decision to monitor ICP. Parenchymal catheter tip pressure transducer devices are advantageous when ventricular ICP cannot be obtained or if there is an obstruction in the fluid couple, though they have the potential for significant measurement differences and drift due to the inability to recalibrate. Subarachnoid or subdural fluid-coupled devices and epidural ICP devices are currently less accurate. With an increasing miniaturization of the transducers, fiberoptic systems have been developed, however, there is a problem of measurement accuracy during the period of patient monitoring and external calibration should be performed frequently to ensure constant accuracy. Ventriculostomies continue to have a pivotal role in ICP control. With a rational understanding of the applications and limitations of the different ICP monitoring devices, the outcome for critically ill neurological patients is optimized.

Background and Purpose-Small case series have reported potential benefit from thrombolysis after spontaneous intraventricular hemorrhage (IVH). Our objective was to review our experience using intraventricular urokinase (UK) in treating selected patients with IVH. Methods-Using medical records, we identified all patients who received ventriculostomies for CT-confirmed nonaneurysmal nontraumatic spontaneous IVH from December 1992 through November 1996. We reviewed charts and CT images and examined the data for associations with specific outcomes. Results-We identified 40 patients, 18 treated with ventriculostomy alone and 22 receiving adjunctive intraventricular UK.The initial Glasgow Coma Scale (GCS) scores of the two groups were similar (Pϭ0.5). While there was a trend for patients with any intraparenchymal hemorrhage (IPH) to receive UK (Pϭ0.07), the mean size of IPH in those who received ventriculostomy alone was larger than in those who received adjunctive UK (Pϭ0.002). There was lower mortality in the group treated with UK (31.8 versus 66.7%; Pϭ0.03), but there was only a trend toward an increase in favorable outcome (22.2% versus 36.4%; Pϭ0.3). Overall, the most significant association with outcome was neurological condition at presentation (GCS Ͼ5 versus Յ5; Pϭ0.003). Receiving UK did not increase the occurrence of complications or hospital length of stay for survivors (Pϭ0.5). Conclusions-Intraventricular UK remains a safe and potentially beneficial intervention. While it appeared to lower mortality, a randomized, placebo-controlled trial is needed to explore whether the therapy can increase the incidence of favorable outcomes.

Eighty-three patients underwent 85 intracranial to extracranial pedicle bypass anastomosis procedures to the posterior circulation. There were 15 patients with occipital artery (OA) to posterior inferior cerebellar artery (PICA) anastomosis, 20 patients with OA to anterior inferior cerebellar artery (AICA) anastomosis, and 50 patients with superficial temporal artery (STA) to superior cerebellar artery (SCA) anastomosis. All patients had transient ischemic attacks (TIA's) suggestive of vertebrobasilar ischemia. Twenty-seven patients had crescendo TIA's or stroke in evolution and were considered to be clinically unstable. All patients had severe bilateral distal vertebral artery or basilar artery disease. Twenty-two patients had bilateral vertebral artery occlusion and three had basilar artery occlusion. In this series, 69% had complete resolution of symptoms; the mortality rate was 8.4% and the morbidity rate 13.3%. Clinically stable patients did better than unstable patients. The STA-SCA anastomosis was well tolerated and technically less demanding than the OA-PICA or OA-AICA anastomosis procedures. Patients with symptomatic severe bilateral vertebral or basilar artery disease have a grave prognosis and the option of a surgical arterial pedicle revascularization procedure should be offered to them.

Local prereperfusion infusion effectively induced hypothermia and ameliorated brain injury from stroke. Clinically, this procedure could be used in acute stroke treatment, possibly in combination with intra-arterial thrombolysis or mechanical disruption of clot by means of a microcatheter.