Acta neurochirurgica. Supplement
-
Acta Neurochir. Suppl. · Jan 2008
Noninvasive estimation of intracranial compliance in idiopathic NPH using MRI.
The pathophysiology of idiopathic normal pressure hydrocephalus (I-NPH) is still unclear and the diagnosis is sometimes difficult. The aim of this study was to assess the biophysics of I-NPH by measuring intracranial compliance using cine MRI. ⋯ It is possible to estimate intracranial compliance as CI non-invasively using cine MRI. CI could become a useful method for the diagnosis of I-NPH.
-
Acta Neurochir. Suppl. · Jan 2008
Biomechanical modeling of decompressive craniectomy in traumatic brain injury.
Decompressive craniectomy is the final phase in the graded scheme of critical care management of refractory raised intracranial pressure following severe traumatic brain injury. We aim to define the optimal size for decompressive craniectomy so that a good balance is achieved between reduction of raised ICP and the extent of trans-calvarial herniation. Provision of such quantitative data will also allow for improved data comparison in clinical trials addressing the surgical management of severe head injury. ⋯ Finite element mesh modeling in the scenario of reafractory raised intracranial pressure following severe head injury may be able to guide the optimal conduct of decompressive surgery so as to effect a reduction in intracranial pressure whilst minimizing trans-calvarial brain herniation.
-
Approximately 15% of all strokes are due to intracerebral hemorrhage, and of these, 5 to 9% will occur in the pons, with mortality approximately 60% of the time. However, there is not an adequate animal model to fully address this important clinical problem. To this end, pontine hemorrhage was induced in rats using stereotaxic injection of 0.15 units of collagenase. ⋯ All tested parameters were significantly increased, compared to sham, without any differences between time points. Furthermore, the extent of brainstem edema was highly correlated with neurological score, inclined plane, and body temperature. This new pontine hemorrhage rat model demonstrated brain edema and neurological deficits, and can be used to test treatment strategies for pontine hemorrhage.
-
Acta Neurochir. Suppl. · Jan 2008
Hyperbaric oxygen preconditioning protects against traumatic brain injury at high altitude.
Recent studies have shown that preconditioning with hyperbaric oxygen (HBO) can reduce ischemic and hemorrhagic brain injury. We investigated effects of HBO preconditioning on traumatic brain injury (TBI) at high altitude and examined the role of matrix metalloproteinase-9 (MMP-9) in such protection. ⋯ HBO preconditioning attenuates TBI in rats at high altitude. Decline in MMP-9 expression may contribute to HBO preconditioning-induced protection of brain tissue against TBI.
-
Acta Neurochir. Suppl. · Jan 2008
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 haemorrhage (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, the exogenous delivery of NO, inhibiting the L-arginine-methylating enzyme (IPRMT3) or stimulating DDAH II, may provide new therapeutic modalities to prevent and treat vasospasm. This paper will present results of preclinical studies supporting the NO-based hypothesis of delayed cerebral vasospasm development and its prevention by increased NO availability.