Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society
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J Clin Neurophysiol · Feb 2013
Noninvasive predictors of subdural grid seizure localization in children with nonlesional focal epilepsy.
Subdural grid evaluation (SDE) in refractory focal epilepsy aims to precisely define the ictal onset zone and map eloquent cortex. In a small but significant proportion of children, SDE shows multifocal or diffuse, rather than focal, seizure onset. Resective epilepsy surgery is denied, or is unsuccessful, in the majority of such patients. The authors investigated whether the noninvasive data could be abstracted to predict subsequent SDE electrographic outcome (focal vs. multifocal/diffuse ictal onset). ⋯ (1) Diffuse or multifocal ictal onsets on SDE are almost three times as likely in nonlesional patients as in those with a single definite MRI brain lesion. (ii) The noninvasive data of children with nonlesional brain MRI may be summarized by a score that rewards localizing information and intermodality concordance: low-scoring patients are more likely to exhibit diffuse or multifocal ictal onset on subsequent SDE. (iii) Bayesian likelihood ratios predictive of ictal focality on SDE are highly favorable for concordant scalp interictal-ictal EEG combinations. (iv) Decision-theoretic methods of this type may find use in the selection of nonlesional pediatric presurgical candidates offered SDE.
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Patients with parietal lobe epilepsy (PLE) exhibit an electroclinical epilepsy syndrome that is rarely seen even at large epilepsy centers. Clinically, most patients with PLE exhibit a somatosensory aura that may include painful dysesthesias, though vertigo, aphasia, disturbances of one's body image also occur, when ictal propagation occurs from the parietal lobe to the supplementary motor area, hypermotor manifestations are noted. When temporolimbic propagation occurs, complex visual or auditory hallucinations and automatisms may appear. ⋯ Combined EEG and functional magnetic resonance imaging (EEG-fMRI) may be useful for patients with PLE to refine the localization in patients undergoing a presurgical evaluation. High-frequency oscillations (HFOs) are more concentrated inside the seizure onset zone (SOZ), indicating that they may be used as interictal scalp EEG biomarker for the SOZ. When medical therapy fails, resective epilepsy surgery can result in seizure freedom or significant reduction especially when a lesion is present.
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J Clin Neurophysiol · Aug 2012
Unmasking of periodic limb movements with the resolution of obstructive sleep apnea during continuous positive airway pressure application.
Periodic limb movements (PLMs) and obstructive sleep apnea (OSA) may present as overlapping conditions. This study investigated the occurrence of PLM during continuous positive airway pressure (CPAP) titration, with the hypothesis that the presence of PLM during CPAP represented "unmasking" of a coexisting sleep disorder. ⋯ These findings suggest that PLM seen during CPAP titration may be related to a concurrent sleep disorder because of "unmasking" in patients with treated OSA.
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J Clin Neurophysiol · Aug 2012
The utility of routine EEG in the diagnosis of sleep disordered breathing.
Sleep disordered breathing (SDB) is a common medical condition. Its manifestations of snoring, nocturnal choking, arousals, and sleep fragmentation can lead to excessive daytime sleepiness, neuropsychological slowing, lapses of consciousness, and accidents that can be misinterpreted as epileptic phenomena. Moreover, patients with documented epilepsy commonly exhibit similar symptomatology because of the undiagnosed coexistence of sleep apnea. ⋯ It can therefore serve as a valuable, adjunctive tool for the diagnosis of SDB. Our data highlight that potential but unveil its decreased use in the neurology community. Increased awareness is required by the EEG technologists, interpreting neurologists, and referring physicians, regarding reporting and using sleep apnea features on the EEG.
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J Clin Neurophysiol · Aug 2012
Interval neurophysiological changes in non septic critically ill mechanically ventilated patients.
Peripheral nerve changes in critically ill patients are common, sepsis being the most important risk factor. The aim of our study is to investigate interval neurophysiological changes in non septic mechanically ventilated critically ill patients, a group who has not been the focus of previous studies. Consecutive non septic mechanically ventilated critically ill patients were included. ⋯ In conclusion, interval changes in peripheral nerves can exist in critically ill mechanically ventilated non septic patients. The pattern is similar to critically ill patients with sepsis. Theories of possible pathophysiology of critical illness neuropathy should not merely depend on the presence of sepsis as a trigger and other mechanisms should be investigated.