Neurological research
-
Neurological research · Oct 2006
ReviewDysfunction of nitric oxide synthases as a cause and therapeutic target in delayed cerebral vasospasm after SAH.
Nitric oxide (NO), also known as endothelium-derived relaxing factor, is produced by endothelial nitric oxide synthase (eNOS) in the intima and by neuronal nitric oxide synthase (nNOS) in the adventitia of cerebral vessels. It dilates the arteries in response to shear stress, metabolic demands, pterygopalatine ganglion stimulation and chemoregulation. Subarachnoid hemorrhage (SAH) interrupts this regulation of cerebral blood flow. ⋯ CSF ADMA levels are closely associated with the degree and time course of vasospasm; when CSF ADMA levels decrease, vasospasm resolves. Thus, exogenous delivery of NO, inhibiting the L-arginine-methylating enzyme or stimulating DDAH II, may provide new therapeutic modalities to prevent and treat vasospasm. This paper will present results of pre-clinical studies supporting the NO-based hypothesis of delayed cerebral vasospasm development and its prevention by increased NO availability.
-
Symptomatic vasospasm leading to delayed ischemia and neurological deficits is one of the most serious complications after aneurysmal subarachnoid hemorrhage (SAH). Reliable and early detection of symptomatic vasospasm is one of the major goals in the management of patients with SAH. In awake patients, the close clinical neurological examination still remains the most important diagnostic measure. ⋯ Therefore, a large panel of new monitoring techniques for the assessment of regional cerebral perfusion has been recently introduced into the clinical management of SAH patients. This article briefly reviews the most relevant methods for monitoring cerebral perfusion and discusses their clinical predictive value for the diagnosis of vasospasm. On the basis of the currently available monitoring technologies, an algorithm for the diagnosis of vasospasm is presented.
-
To review the historical development and current status of endovascular techniques used in the treatment of symptomatic vasospasm following aneurysmal subarachnoid hemorrhage. ⋯ Neurointerventional treatment of vasospasm following aneurysmal hemorrhage has been proven to be a safe and successful technique for those patients suffering symptomatic vasospasm refractory to medical management. The techniques contunue to undergo refinement as endovascular technology advances. We currently favor the use of balloon angioplasty over intraarterial antispasmotics due to the increased durability and long-lasting effects of the former and lower risk profile.
-
Neurological research · Jul 2006
Intraoperative visualization for resection of gliomas: the role of functional neuronavigation and intraoperative 1.5 T MRI.
To investigate how functional neuronavigation and intraoperative high-field magnetic resonance imaging (MRI) influence glioma resection. ⋯ The combination of intraoperative MRI and functional navigation allows safe extended resections in glioma surgery. However, despite extended resections, still in the majority of the grade III and IV gliomas no gross total resection could be achieved owing to the extension of the tumor into eloquent brain areas. Intraoperative MRI data can be used to localize the tumor remnants reliably and compensate for the effects of brain shift.
-
Neurological research · Jun 2006
ReviewMagnesium therapy within 48 hours of an aneurysmal subarachnoid hemorrhage: neuro-panacea.
Whereas advances in neurosurgical treatment and intensive care management improve the results from many of the devastating complications associated with aneurysmal subarachnoid hemorrhage, cerebral vasospasm remains a major cause of neurological morbidity and mortality. Experimental studies suggested that MgSO(4) inhibits excitatory amino acid release, blocks N-methyl-D-aspartate (NMDA) receptors and prevents calcium entry into the cell. Magnesium also increases red blood cell deformability. ⋯ Our group is currently hosting the intravenous magnesium sulfate to improve outcome after aneurysmal subarachnoid hemorrhage (IMASH) trial, which is a randomized, placebo-controlled, double-blinded, multicentered trial to evaluate the effect of magnesium sulfate infusion on the clinical outcome of patients with aneurysmal subarachnoid hemorrhage since 2002. The pilot result showed a trend towards decreased clinical vasospasm and better patient outcome. Magnesium sulfate infusion may prove to be an effective and inexpensive way to reduce the morbidity and mortality associated with aneurysmal subarachnoid hemorrhage, which is a major breakthrough in the current management.