Showing papers on "Delta wave published in 1988"
TL;DR: A new interval histogram method for automatic, all-night sleep stage scoring, simulated on a digital computer, is described and the profile of the elementary parameters of the EEG signals clearly illustrated the cyclic nature of these activities throughout the night.
72 citations
TL;DR: The findings indicate a relationship between the chromosomal constitution 45,X and EEG background activity and suggest the presence of functional brain disturbance in the thalamus and in the ascending reticular activating system, which tends to disturb theThalamo-cortical circuit.
Abstract: A qualitative and quantitative analysis was performed on the EEG background activity in 62 Danish girls and women with Turner's syndrome (30 with karyotype 45,X and 32 with other karyotypes) whose ages ranged from 6 to 47 years (87% were aged 15 years or more) and age-matched controls. The pooled data and a case-control study showed characteristic features in Turner subjects, including: (1) more rapid frequency, larger amplitude and lower amount of alpha waves, (2) higher amount of theta waves, (3) larger amplitude and higher amount of delta waves and (4) larger amplitude and higher amount of beta waves than in controls. These findings in Turner subjects were more pronounced in the left hemisphere, and more typical, except for the amplitude in alpha waves, in Turner subjects with 45,X than in those with other karyotypes. The effects of advancing age on the EEG background activity observed in controls — including more rapid frequency, decreased amplitude and amount of alpha waves, increased amount of theta and delta waves, and increased amount of beta waves, particularly after 35 years of age — were found in some Turner subjects. Hemispheric differences with higher activity (i.e. more rapid frequency, larger amplitude and higher amount of alpha waves, particularly at Fp1 and F3, and, inversely, lower amount of theta or delta waves) at P3, T3, T5 and O2 than at the opposite side were found in many Turner subjects. However, these findings were not specific for Turner subiects, since the same hemispheric differences were also observed much more markedly in controls. These topographic distributions with hemispheric differences did not provide evidence for hypofunction in the temporo-parieto-occipital tertiary area of the right hemisphere in Turner subjects, though this had been expected on the basis of neuropsychological examinations. Our findings, including transiently appearing brain hypofunction at the parietal, temporal and occipital areas, most often in the right hemisphere, indicate a relationship between the chromosomal constitution 45,X and EEG background activity. They suggest the presence of functional brain disturbance in the thalamus and in the ascending reticular activating system, which tends to disturb the thalamo-cortical circuit. Further studies, including topographic and sequential power spectrum analysis of EEG background activity, 24-h continuous EEG recording, blood flow studies (positron computerized tomography) and neuropathological examination, may be needed.
13 citations
TL;DR: In this article, the authors showed that the hippocampus and its monoamine-reactive systems participate in the central mechanisms of the phasic type of paradoxical sleep, and that large doses of serotonin in the stage of slow-wave sleep induced somnambulistic behavior, sometimes turning into true awakening.
Abstract: 1.
Microapplication of serotonin into the dorsal hippocampus induced a change in the time indices of slow-wave and paradoxical sleep and increased the number of phasic reactions on the EEG and on the periphery. In the state of paradoxical sleep, serotonin increased the probability of recording of a theta rhythm at the frequency 6.5 Hz. Large doses of serotonin in the stage of slow-wave sleep induced somnambulistic behavior, sometimes turning into true awakening.
2.
Microapplication of norepinephrine into the dorsal hippocampus of cats changed the time indices of the slow-wave and paradoxical sleep and inhibited the phase type of paradoxical sleep. In low doses it increased the probability of recording of a theta rhythm at the frequency 4–5 Hz in the phase of paradoxical sleep; in large doses it induced episodes of delta waves.
3.
The data obtained showed that the hippocampus and its monoamine-reactive systems participate in the central mechanisms of the phasic type of paradoxical sleep.
2 citations
TL;DR: Natural sleep and sleep deprived EEGs are an appropriate combination in the evaluation of refractory seizures and may facilitate the appearance of generalized seizures or epilepti-form discharges, while sleep deprivation may accentuate the yield of EEG abnormalities in partial epilepsy.
Abstract: Sleep and sleep deprivation are often used for EEG activation in epilepsy. We compared postprandial naps and day-long sleep deprived EEGs in 36 patients with generalized seizures, 57 complex partial seizure patients, and 7 individuals with mixed seizure disorders. Ten of 36 generalized seizure patients had normal sleep and sleep deprived EEGs, while both were normal in 16 of 57 partial seizure patients. Both were abnormal in 18 of 36 generalized and 22 of 57 partial epileptics. Seven generalized seizure patients had epileptiform discharges or seizures during afternoon naps but normal sleep deprived EEGs. No partial seizure patients had normal sleep deprived EEGs and abnormal nap, but 29 of 57 had abnormalities or seizures only with sleep deprivation. All 7 mixed seizure patients had abnormal sleep and sleep deprived studies, and 6 had seizures, 4 on both studies. Natural sleep may facilitate the appearance of generalized seizures or epilepti-form discharges, while sleep deprivation may accentuate the yield of EEG abnormality in partial epilepsy. Either is likely to be abnormal in patients with mixed seizures and encephalopathy. Natural sleep and sleep deprived EEGs are an appropriate combination in the evaluation of refractory seizures.
2 citations