Epilepsia
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Psychogenic nonepileptic seizures (PNES) continue to represent a serious diagnostic challenge for neurologists. Video-electroencephalography (EEG) studies have provided detailed knowledge of the spectrum of visible PNES manifestations. However, little is known about how patients or seizure witnesses experience PNES, although many diagnoses in seizure clinics are made on the basis of self-reported information rather than video-EEG observations. This study describes the range of PNES manifestations as they are reported by patients or seizure witnesses. ⋯ These findings based on the self-report of patients with well-characterized PNES and witnesses of their seizures demonstrate why it can be difficult to distinguish descriptions of PNES from those of epilepsy on the basis of factual items. The differences between patient and witness reports suggest that clinicians have to take note of the source of information they use in their diagnostic considerations. The intra- and interindividual variability of reported PNES manifestations demonstrates the clinical heterogeneity of PNES disorders. The positive correlation of symptoms of dissociation and anxiety in these patients may reflect psychopathologic differences between subgroups of PNES patients.
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Tonic seizures and the tonic phase of tonic-clonic epileptic seizures are defined as "sustained tonic" muscle contraction lasting a few seconds to minutes. Visual inspection of the surface electromyogram (EMG) during seizures contributed considerably to a better understanding and accurate diagnosis of several seizure types. However, quantitative analysis of the surface EMG during the epileptic seizures has received surprisingly little attention until now. The aim of our study was to elucidate the pathomechanism of the tonic muscle activation during epileptic seizures. ⋯ Our results indicate that the mechanism of muscle activation during epileptic seizures is different from the physiologic one. Furthermore the sustained muscle activation during the tonic phase of tonic-clonic seizures is different from that during tonic seizures: The tonic phase of tonic-clonic seizures is characterized by increased amplitude of the signal, whereas tonic seizures are produced by a significant increase in the frequency of the signal.
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Continuous electroencephalography (EEG) monitoring is a valuable tool for the detection of seizures among critically ill children, in particular when these seizures occur without clinical signs: termed nonconvulsive seizures. Continuous EEG monitoring is a limited resource in many centers. We sought to identify which critically ill children most frequently experience nonconvulsive seizures, and thus may particularly benefit from continuous EEG monitoring. ⋯ Seizures are common among critically ill children undergoing diagnostic cEEG monitoring. The great majority of these seizures are nonconvulsive, requiring EEG for their detection. Predictors of nonconvulsive seizures include acute epilepsy, acute structural brain injury, prior in-hospital convulsive seizures, and interictal epileptiform abnormalities on EEG. These findings can help inform future allocation of limited cEEG monitoring resources to those patients at greatest risk for nonconvulsive seizures.
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To evaluate morning dream recall frequency and content in patients with temporal lobe epilepsy (TLE). ⋯ Onirical activity of patients with TLE is different from that of healthy subjects. Our results support the role of mesial and neocortical temporal structures in dream experience. The selective activation of dysfunctional mesial structures may be responsible for some of the observed variability. However, dream content changes can also mirror social and psychological comorbidities of patients with epilepsy.
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There is significant variability and controversy regarding the interpretation, nomenclature, and clinical implications of many EEG patterns seen in encephalopathic patients. The American Clinical Neurophysiology Society has attempted to create well-defined, objective rules for naming these patterns in order to allow scientific investigation into their significance. ⋯ A perfect system for describing complex wave forms with words will never be perfect; scalp EEG itself has substantial limitations, as intracranial recordings in neurocritical care patients have shown. The latest version of the nomenclature is available at http://www.acns.org.