Epilepsia
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Takotsubo cardiomyopathy is characterized by chest pain, dyspnea, electrocardiographic changes resembling an acute coronary syndrome, and transient wall-motion abnormalities without identifiable coronary culprit lesion explaining the wall-motion abnormality. Takotsubo cardiomyopathy occurs frequently after emotional or physical stress. Seizures have been reported as triggers of takotsubo cardiomyopathy. ⋯ Compared with 974 patients reported in takotsubo cardiomyopathy -series, patients with seizure-associated takotsubo cardiomyopathy were younger (61.5 vs. 68.5 years, p < 0.0001), more frequently males (17 vs. 9%, p = 0.004), had less frequent chest pain (6 vs.76%, p < 0.005), more frequent cardiogenic shock (25 vs. 8%, p = 0.003), and more frequent recurrency (14 vs. 3%, p = 0.004). Seizure-associated takotsubo cardiomyopathy manifests frequently as sudden hemodynamic deterioration, which could result in death in the absence of adequate help. Probably some cases of sudden unexpected death in epilepsy are attributable to takotsubo cardiomyopathy.
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Cardiac arrhythmias and respiratory disturbances have been proposed as likely causes for sudden unexpected death in epilepsy. Oxygen desaturation occurs in one-third of patients with localization-related epilepsy (LRE) undergoing inpatient video-electroencephalography (EEG) telemetry (VET) as part of their presurgical workup. Ictal-related oxygen desaturation is accompanied by hypercapnia. Both abnormal lengthening and shortening of the corrected QT interval (QTc) on electrocardiography (ECG) have been reported with seizures. QTc abnormalities are associated with increased risk of sudden cardiac death. We hypothesized that there may be an association between ictal hypoxemia and cardiac repolarization abnormalities. ⋯ We have shown that the likelihood of abnormal QTcH prolongation is increased 4.3-fold with seizures that are associated with oxygen desaturation when compared with seizures that are not accompanied with oxygen desaturation. The likelihood of abnormally shortened QTcH increases with seizures that are accompanied by oxygen desaturation with an odds ratio of 2.13 compared with that in seizures without desaturations. There is a significant association between the depth and duration of oxygen desaturation and QTr increase. These findings may be related to the pathophysiology of SUDEP.
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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.