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Significant changes in topographic quantitative EEG (QEEG) features were documented during induction and emergence from anaesthesia induced by the systematic administration of sevoflurane and propofol in combination with remifentanil. The goal was to identify those changes that were sensitive to alterations in the state of consciousness but independent of(More)
The perception of a visual stimulus can be inhibited by occipital transcranial magnetic stimulation. This visual suppression effect has been attributed to disruption in the cortical gray matter of primary visual cortex or in the fiber tracts leading to V1 from the thalamus. However, others have suggested that the visual suppression effect is caused by(More)
We describe a method for mapping the functional regions of the brain using a tran-scranial magnetic stimulation (TMS) device. This device, when placed on a subject's scalp, stimulates the underlying neurons by generating focused magnetic eld pulses. A brain mapping is then generated by measuring responses of diierent motor and sensory functions to this(More)
OBJECTIVE Resection or even biopsy of an intra-axial mass lesion in close relationship to eloquent cortex carries a major risk of neurological deficit. We have assessed the safety and effectiveness of craniotomy under local anesthesia and monitored conscious sedation for the resection of tumors involving eloquent cortex. METHODS We have performed a(More)
OBJECTIVE Craniotomy and brain mapping performed with the patient under local anesthesia and monitored sedation is an important technique to allow optimal resection of brain tumors or other lesions in close apposition to eloquent cortex. The subjective experience of patients undergoing this procedure has not been addressed in the literature. METHODS This(More)
INTRODUCTION AND METHODS Compound muscle action potentials (CMAPs) elicited by transcranial magnetic stimulation (TMS) are characterized by enormous variability, even when attempts are made to stimulate the same scalp location. This report describes the results of a comparison of the spatial errors in coil placement and resulting CMAP characteristics using(More)
Hypomagnesemia is a common disorder in noncardiac surgical patients in the postoperative period, but the effect of cardiac surgery on serum magnesium concentrations remains unclear. The authors hypothesized that cardiac surgery is associated with hypomagnesemia, and prospectively studied 101 subjects (60 +/- 13.1 years of age) undergoing coronary artery(More)
Electroencephalographic monitoring has been performed since the early days of cardiopulmonary bypass. Despite this long experience, the technology has never been widely used for cardiac operations. This review examines the reasons for the limited use and describes technological advances that may alter this pattern.
One week after surgery neuropsychological (NP) deficits were quite common, occurring in 40.6% of the patients, with QEEG abnormality developing or increasing in the majority of patients. This change in the QEEG was an accurate predictor of NP performance 1 week after surgery. Two to three months after surgery evidence of continued NP performance deficits(More)
BACKGROUND Brachial plexus injury may occur without obvious cause in patients undergoing cardiac surgery. To determine whether such peripheral nerve injury can be predicted intraoperatively, we monitored somatosensory evoked potentials (SEPs) from bilateral median and ulnar nerves in 30 patients undergoing coronary artery bypass surgery. METHODS SEPs were(More)