Journal of neurosurgery
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Journal of neurosurgery · Nov 2002
Transcorneal stimulation of trigeminal nerve afferents to increase cerebral blood flow in rats with cerebral vasospasm: a noninvasive method to activate the trigeminovascular reflex.
The goal of this study was to investigate whether stimulation of trigeminal afferents in the cornea could enhance cerebral blood flow (CBF) in rats after they have been subjected to experimental subarachnoid hemorrhage (SAH). Cerebral vasospasm following SAH may compromise CBF and increase the risks of morbidity and mortality. Currently, there is no effective treatment for SAH-induced vasospasm. Direct stimulation of the trigeminal nerve has been shown to dilate constricted cerebral arteries after SAH; however, a noninvasive method to activate this nerve would be preferable for human applications. The authors hypothesized that stimulation of free nerve endings of trigeminal sensory fibers in the face might be as effective as direct stimulation of the trigeminal nerve. ⋯ Data from the present study demonstrate that transcorneal stimulation of trigeminal nerve endings induces vasodilation and a robust increase in CBF. The vasodilatory response of cerebral vessels to trigeminal activation is retained after SAH-induced vasospasm.
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Journal of neurosurgery · Nov 2002
Use of a resorbable sheet in iliac crest reconstruction in a sheep model.
Iliac crest bone graft harvesting can result in major complications, the rates of which range from approximately 6 to 8%. The objective of this study was to evaluate the postoperative regeneration of iliac crest donor defects in an animal model after harvesting a full-thickness tricortical graft. ⋯ Based on the results of the present study, MacroPore resorbable Protective Sheeting can improve bone regeneration significantly within the donor site following tricortical iliac crest graft harvesting.
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Journal of neurosurgery · Oct 2002
Case Reports Clinical TrialMagnetoencephalography-directed surgery in patients with neocortical epilepsy.
Magnetoencephalography (MEG) and magnetic source (MS) imaging are techniques that have been increasingly used for preoperative localization of epileptic foci and areas of eloquent cortex. The use of MEG examinations must be carefully balanced against the high cost and technological investments required to perform these studies, particularly when less expensive alternative localization methods are available. To help elucidate the value of MEG, the authors have critically reviewed their experience with whole-head MEG in the case management of patients undergoing epilepsy surgery. ⋯ Magnetic source imaging can provide unique localization information that is not available when other noninvasive methods are used. Magnetic source imaging appears most useful for cases of neocortical epilepsy. In particular, when an MS imaging study revealed six or more interictal spikes that were densely clustered in a single anatomical location, the MS image was highly correlated with the zone of seizure origin identified by ECoG. In these cases the MS imaging data may be useful to guide placement of intracranial electrodes.
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Journal of neurosurgery · Oct 2002
Randomized Controlled Trial Clinical TrialImmediate administration of tranexamic acid and reduced incidence of early rebleeding after aneurysmal subarachnoid hemorrhage: a prospective randomized study.
By pursuing a policy of very early aneurysm treatment in neurosurgical centers, in-hospital rebleeds can be virtually eliminated. Nonetheless, as many as 15% of patients with aneurysm rupture suffer ultraearly rebleeding with high mortality rates, and these individuals are beyond the reach of even the most ambitious protocol for diagnosis and referral. Only drugs given immediately after the diagnosis of subarachnoid hemorrhage (SAH) has been established at the local hospital level can, in theory, contribute to the minimization of such ultraearly rebleeding. The object of this randomized, prospective, multicenter study was to assess the efficacy of short-term antifibrinolytic treatment with tranexamic acid in preventing rebleeding. ⋯ More than 90% of patients reached the neurosurgical center within 12 hours of their first hospital admission after SAH; 70% of all aneurysms were clipped or coils were inserted within 24 hours of the first hospital admission. Given the protocol, only one rebleed occurred later than 24 hours after the first hospital admission. Despite this strong emphasis on early intervention, however, a cluster of 27 very early rebleeds still occurred in the control group within hours of randomization into the study, and 13 of these patients died. In the tranexamic acid group, six patients rebled and two died. A reduction in the rebleeding rate from 10.8 to 2.4% and an 80% reduction in the mortality rate from early rebleeding with tranexamic acid treatment can therefore be inferred. Favorable outcome according to the GOS increased from 70.5 to 74.8%. According to TCD measurements and clinical findings, there were no indications of increased risk of either ischemic clinical manifestations or vasospasm that could be linked to tranexamic acid treatment. Neurosurgical guidelines for aneurysm rupture should extend also into the preneurosurgical phase to guarantee protection from ultraearly rebleeds. Currently available antifibrinolytic drugs can provide such protection, and at low cost. The number of potentially saved lives exceeds those lost to vasospasm.
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Journal of neurosurgery · Oct 2002
Randomized Controlled Trial Clinical TrialTreatment of chronic pain by using intrathecal drug therapy compared with conventional pain therapies: a cost-effectiveness analysis.
The object of this study was to compare the cost-effectiveness of intrathecal drug therapy (IDT) with that of conventional pain therapy (CPT) in patients suffering from chronic low back pain caused by failed back syndrome. In this study, the authors tabulated actual costs, in Canadian dollars, in a consecutive series of patients undergoing IDT within the Canadian health care system and have compared them with costs in a control group in the same environment. The influence of these treatments on the quality of life (QOL) was also analyzed. ⋯ In patients who respond to this treatment, IDT is cost effective in the long term despite high initial costs of implantable devices.