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OBJECT The early pathophysiological features of traumatic brain injury observed in the intensive care unit (ICU) have been described in terms of altered cerebral blood flow, altered brain metabolism, and neurochemical excitotoxicity. Seizures occur in animal models of brain injury and in human brain injury. Previous studies of posttraumatic seizures in(More)
Intracranial EEG was analyzed from 16 pharmaco-resistant epilepsy patients. Subjects participated in memory tasks for faces and/or words. Face-selective coherence increases were found between the fusiform gyrus and temporal, parietal, and frontal cortices at 160-230 ms poststimulus onset. Word stimuli elicited weak or negligible response at the same(More)
The neurologic morbidity of delayed ischemic deficits from vasospasm following aneurysmal subarachnoid hemorrhage (SAH) continues to be the most debilitating complication from this devastating illness. Neurologic critical care is focused on recognition and treatment of these secondary insults but often the treatment is withheld until an irreversible deficit(More)
OBJECTIVE To characterize ventral occipitotemporal and prefrontal EEG during cognitive processing. METHODS Depth probes were implanted for seizure localization in 16 pharmaco-resistant epileptics. Probes penetrated from middle temporal through fusiform to lingual gyrus, and from inferior frontal to anterior cingulate gyrus. Event-related potentials (ERPs)(More)
Magnetic resonance (MR) imaging has recently been used to demonstrate physiological activation of the human brain. This development is of considerable interest to the neurosurgeon planning procedures near brain regions involving specific functions. In the present study, rolandic and visual cortices were imaged with a conventional 1.5-tesla clinical MR(More)
Early post-traumatic seizures occur commonly and may have adverse clinical consequences. In order to determine the significance of post-traumatic seizures, we performed a prospective assessment of the consequences of epileptic activity by assessing the change in extracellular glycerol levels. Glycerol is a marker of cellular membrane breakdown. Thirteen(More)
Evoked potentials (EPs) measure synaptic current flows that propagate from brain to scalp, Alternatively, positron emission tomography (PET) using fluoro-deoxyglucose (FDG) can measure the increased glucose metabolism supporting this synaptic activation. It is difficult to localize the brain activity-generating EPs from their scalp distribution, because(More)
Local cerebral glucose metabolic rate was measured using F18-DG/PET in 11 normal righthanded male volunteers performing two versions of a visual lexical decision task differing only with respect to whether the stimuli were all novel and shown only once, or whether they were all repeated many times. Each subject was also scanned in a resting state (eyes open(More)
A network model with some general properties of hippocampal area CA3, and the results of its simulation on a massively parallel processor, are described. This network performs the tasks of recent declarative memory including recovery of complete traces from partial cues and recognition of familiarity. Immediate recurrent inhibition is essential for(More)