PubMed · 14929643
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
H H JASPER. 1952. Electroencephalography.. https://pubmed.ncbi.nlm.nih.gov/14929643/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Adaptive time-frequency approximations of signals have proven to be a valuable tool in electroencephalogram (EEG) analysis and research, where it is believed that oscillatory phenomena play a crucial role in the brain's information processing. This paper extends this paradigm to the nonoscillating structures such as the epileptic EEG spikes, and presents the advantages of their parametrization in general terms such as amplitude and half-width. A simple detector of epileptic spikes in the space of these parameters, tested on a limited data set, gives very promising results. It also provides a direct distinction between randomly occurring spikes or spike/wave complexes and rhythmic discharges.
The nogo potentials (N2/P3) were studied in a precuing auditory reaction time task in human subjects who had to either perform a button-press response (Press condition) or imagine they were performing it (Imagine condition). In the full precue condition (the subjects knew in advance which response they had to perform/imagine), in 25% of the trials, a nogo signal instructed the subject not to perform or not to imagine the prepared action. Clear N2/P3 components were obtained on nogo trials on the Press trials, but also on the Imagine ones: the N2 was of similar amplitude in both conditions, whereas the P3 was of smaller amplitude in the Imagine condition. The presence of nogo potential in motor imagery is discussed in terms of the functional significance of the N2/P3 complex.
OBJECTIVES: To define the clinical and polysomnographic features of a distinct variant of obstructive sleep-disordered breathing that is remarkably mild during rapid eye movement (REM) sleep. DESIGN: Observational study and evaluation of polysomnographic and clinical records. SETTING: American Academy of Sleep Medicine-accredited multidisciplinary sleep disorders center and laboratory. PATIENTS: 35 medication-free subjects with clinical and polysomnographic severe obstructive sleep-disordered breathing selected for dominance of 1 of 2 disordered breathing patterns. INTERVENTIONS: Positive airway pressure titration. MEASUREMENTS AND RESULTS: Nasal pressure was used to score respiratory events. Sleep was scored by both the standard criteria and cyclic alternating pattern (CAP), and the distribution of respiratory events was tabulated and analyzed. A distinct clinical and polysomnographic syndrome emerged, CAP-dominant sleep-disordered breathing, characterized by severe relatively short cycle obstructive events during non-REM sleep that were mild in REM sleep. Characteristics include lower body mass index, fewer apneas, and a lower hypoxic burden as reflected by frequency and severity of nocturnal oxygen saturation. During positive pressure titration, a remarkable respiratory instability emerged selectively during CAP, in contrast to stability during REM sleep. This partial treatment failure was associated with persistent clinical symptoms. CONCLUSIONS: This variant of sleep apnea may reflect a dominant component of respiratory instability and periodic breathing coupled with upper-airway obstruction. Its existence questions the conventional practice of calculating global respiratory indexes. Besides positive airway pressure, measures to treat periodic breathing may be required.