Journal of neurosurgery
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Journal of neurosurgery · Sep 2004
Variability of intraoperative electrocortical stimulation mapping parameters across and within individuals.
Electrocortical stimulation mapping is regarded as the gold standard of intraoperative mapping for predicting functional outcomes. Nevertheless, methodologies across institutions are inconsistent. Although many vary and maximize stimulation currents at each cortical site, some use a single current level to map the entire exposed cortex. The former comes at the cost of possibly inducing additional afterdischarge activity. The authors retrospectively reviewed their eperience with intraoperative electrocortical stimulation mapping to characterize variability of both mapping and afterdischarge thresholds. ⋯ To maximize identification of eloquent cortices in some clinical situations, it may be advantageous to maximize currents at each cortical site regardless of adjacent afterdischarge threshold rather than to map the entire exposed cortex at a single current level. Moreover, the current findings highlight the need for electrocorticography during electrocortical stimulation mapping, both to identify when afterdischarges occur and to verify stimulation by recording stimu lation artifacts. The advantages and limitations of maximizing currents at each cortical site as well as mapping at a single current level are discussed.
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Journal of neurosurgery · Sep 2004
Multicenter Study Comparative StudySurgical repair of brachial plexus injury: a multinational survey of experienced peripheral nerve surgeons.
Brachial plexus injuries (BPIs) are often devastating events that lead to upper-extremity paralysis, rendering the limb a painful extraneous appendage. Fortunately, there are several nerve repair techniques that provide restoration of some function. Although there is general agreement in the medical community concerning which patients may benefit from surgical intervention, the actual repair technique for a given lesion is less clear. The authors sought to identify and better define areas of agreement and disagreement among experienced peripheral nerve surgeons as to the management of BPIs. ⋯ Experienced peripheral nerve surgeons disagree in important ways as to the management of BPI. The decisions made by the various treating physicians underscore the many areas of disagreement regarding the treatment of BPI, including the diagnostic approach to defining the injury, timing of and indications for surgical intervention in birth-related palsy, the treatment of neuroma-in-continuity, the choice of nerve transfers to achieve elbow flexion and shoulder abduction, the use of intra- or extraplexal donors for neurotization, and the use of distal or proximal coaptation during nerve transfer.
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Journal of neurosurgery · Sep 2004
Normobaric hyperoxia--induced improvement in cerebral metabolism and reduction in intracranial pressure in patients with severe head injury: a prospective historical cohort-matched study.
The effect of normobaric hyperoxia (fraction of inspired O2 [FIO2] concentration 100%) in the treatment of patients with traumatic brain injury (TBI) remains controversial. The aim of this study was to investigate the effects of normobaric hyperoxia on five cerebral metabolic indices, which have putative prognostic significance following TBI in humans. ⋯ The results of the study support the hypothesis that normobaric hyperoxia in patients with severe TBI improves the indices of brain oxidative metabolism. Based on these data further mechanistic studies and a prospective randomized controlled trial are warranted.
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Journal of neurosurgery · Sep 2004
Endotracheal tube electrodes to map and monitor activities of the vagus nerve intraoperatively. Technical note.
Difficulty swallowing due to damage of the vagus nerve is one of the most devastating complications of surgery in and around the medulla oblongata; therefore, intraoperative anatomical and functional evaluation of this nerve is crucial. The authors applied endotracheal tube surface electrodes to record electromyography (EMG) activity from vocal cords innervated by the vagus nerve. The vagal nucleus or rootlet was electrically stimulated during surgery and vocalis muscle EMG activities were displayed by auditory and visual signals. ⋯ The advantages of this method compared with the use of needle electrodes include safe simple electrode placement and stable recording during surgery. In cases involving a pontine cavernoma pressing the nucleus or a jugular foramen tumor encircling the rootlet, this method would be particularly valuable. Additional studies with a larger number of patients are needed to estimate the significance of this method as a means of functional monitoring to predict clinical function.
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Journal of neurosurgery · Sep 2004
Relationship between intracranial pressure and other clinical variables in patients with aneurysmal subarachnoid hemorrhage.
Increased intracranial pressure (ICP) is well known to affect adversely patients with head injury. In contrast, the variables associated with ICP following aneurysmal subarachnoid hemorrhage (SAH) and their impact on outcome have been less intensely studied. ⋯ Increased ICP is common after SAH, even in patients with a good clinical grade. Elevated ICP post-SAH is associated with a worse patient outcome, particularly if ICP does not respond to treatment. This association, however, may depend more on the overall severity of the SAH than on ICP alone.