Background and PurposeThe present study was designed to investigate whether 24 h of SD negatively affects the attention and working memory and increases the serum concentrations of stress hormones, glucose, and inflammatory markers.MethodsThe acute effects of sleep deprivation (SD) on cognition and the stress hormones were evaluated in six healthy volunteers (all men, age 23-27 years). All were good sleepers, had no history of medical or neuropsychiatric diseases, and were not taking any kind of medication. All of the volunteers were subjected to the Continuous Performance Test (CPT) for attention and working memory of cognition and blood tests both before and after 24 h of SD. Electroencephalographic monitoring was performed during the study to confirm the wakefulness of the subjects.ResultsSD significantly elevated the serum concentrations of stress hormones (cortisol, epinephrine, and norepinephrine), but serum levels of glucose and inflammatory markers were not changed compared to baseline. For easier steps of the CPT the subjects performed well in giving correct responses after SD; the correct response scores decreased only at the most difficult step of the CPT. However, the subjects performed consistently poor for the error responses at all steps after SD. There was no correlation between the CPT scores and stress hormone levels.ConclusionsThe 24 h of SD significantly heightened the levels of stress hormones and lowered attention and working memory. The acute SD condition seems to render the subject more susceptible to making errors.

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Background and Purpose:To investigate the duration of seizures and its relationship to seizure type, epilepsy syndrome, and seizure clustering.Methods:We examined 1,251 seizures from 152 patients who underwent video-electrocorticographic monitoring with subdural electrodes. Their seizure duration, seizure types, epilepsy syndromes, and seizure clusters were analyzed.Results:The median seizure duration was 91.5s (4–1016s). There were 34 (2.7%) seizures lasting > 5 minutes in 20 (13.2%) patients. There was a significant difference in seizure duration according to seizure types (p < 0.0001), but not to epilepsy syndromes. There were 99 seizure clusters in 67 (44.1%) patients. The first seizure in a cluster of seizures tended to last longer than non-cluster seizures (median 98s versus 89s, p = 0.033). Seizure duration was significantly longer in mesial temporal lobe epilepsy than in neocortical lobe epilepsy (median 103s versus 87s, p = 0.041). Rate of seizure cluster was lower in mTLE (38.0%) than in NLE (47.1%), but this difference was not significant.Conclusions:Seizure durations were different among seizure types. Seizure clustering also differ between patients with mTLE and those with NLE, which suggests different seizure generation and propagation among different epileptogenic foci. This study has implications for the identification of abnormally prolonged seizures.