{"title":"EEG as an Indicator of Cerebral Functioning in Postanoxic Coma.","authors":"E. Juan, P. Kaplan, M. Oddo, A. Rossetti","doi":"10.1097/WNP.0000000000000199","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000199","url":null,"abstract":"Postanoxic coma after cardiac arrest is one of the most serious acute cerebral conditions and a frequent cause of admission to critical care units. Given substantial improvement of outcome over the recent years, a reliable and timely assessment of clinical evolution and prognosis is essential in this context, but may be challenging. In addition to the classic neurologic examination, EEG is increasingly emerging as an important tool to assess cerebral functions noninvasively. Although targeted temperature management and related sedation may delay clinical assessment, EEG provides accurate prognostic information in the early phase of coma. Here, the most frequently encountered EEG patterns in postanoxic coma are summarized and their relations with outcome prediction are discussed. This article also addresses the influence of targeted temperature management on brain signals and the implication of the evolution of EEG patterns over time. Finally, the article ends with a view of the future prospects for EEG in postanoxic management and prognostication.","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133352815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Periodic lateralized epileptiform discharges after complex partial status epilepticus associated with increased focal cerebral blood flow.","authors":"I. Ali, N. Pirzada, B. Vaughn","doi":"10.1097/00004691-200111000-00007","DOIUrl":"https://doi.org/10.1097/00004691-200111000-00007","url":null,"abstract":"Periodic lateralized epileptiform discharges (PLEDs) are typically associated with encephalitis, cerebral abscess, cerebral infarct, and status epilepticus. There is considerable debate as to whether this pattern is ictal or interictal when seen in association with status epilepticus. We present a patient with complex partial status epilepticus who developed PLEDs and remained comatose despite optimal drug therapy. Technetium 99m single-photon emission computed tomography (SPECT) showed hyperperfusion that resolved with further aggressive antiepileptic drug therapy, indicating that this pattern may indeed be ictal. Further studies are needed to define the significance of PLEDs in patients with status epilepticus. The role of SPECT in differentiating PLEDs as an interictal or ictal pattern also requires further study.","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132239036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Vagus nerve stimulation for refractory epilepsy.","authors":"P. Boon","doi":"10.1097/00004691-200109000-00001","DOIUrl":"https://doi.org/10.1097/00004691-200109000-00001","url":null,"abstract":"","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117345684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multiplicity of the alpha rhythm in normal humans.","authors":"V. Feshchenko, R. Reinsel, R. Veselis","doi":"10.1097/00004691-200107000-00005","DOIUrl":"https://doi.org/10.1097/00004691-200107000-00005","url":null,"abstract":"Previous analyses of the alpha rhythm in a given single derivation have shown that it is a result of narrowband filtration of a broadband process. As many as three distinct alpha rhythms within each hemisphere could be differentiated in 65 resting, awake subjects by considering the spatial properties of these rhythms along with their dynamics. The analysis was based on cross-correlation measurements of rhythmic and broadband processes, and comparison of the dynamic characteristics of oscillatory systems underlying the alpha rhythms. Five-minute epochs of the EEG were recorded to provide 10% precision of the statistical estimates of the variables measured. A frontal alpha rhythm independent of occipital rhythmic activity was present in 20% of subjects. This third rhythm is distinct from the more familiar alpha and mu rhythms described in the literature, and is attenuated when the eyes are open. The authors demonstrate that the dynamic characteristics of the oscillatory systems underlying the alpha rhythm, as well as intrahemispheric coefficients of cross-correlation, are reproducible over time in a single subject. These parameters can form the basis for reliable individual EEG characteristics in the description of the \"normal\" EEG. The high correlation of the alpha rhythm in symmetric derivations could be explained by symmetric afferent impulse flows rather than by structural interconnection between the oscillatory systems.","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114636597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sleep disorders in neurology.","authors":"R. Radtke","doi":"10.1097/00004691-200103000-00001","DOIUrl":"https://doi.org/10.1097/00004691-200103000-00001","url":null,"abstract":"","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121315857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Neurophysiology and functional neuroimaging of the somatosensory system.","authors":"A. Schnitzler","doi":"10.1097/00004691-200011000-00001","DOIUrl":"https://doi.org/10.1097/00004691-200011000-00001","url":null,"abstract":"","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122271130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quantitative topographic electroencephalographic mapping during drowsiness and sleep onset.","authors":"R. Broughton, J. Hasan","doi":"10.1097/00004691-199507000-00007","DOIUrl":"https://doi.org/10.1097/00004691-199507000-00007","url":null,"abstract":"The topographic EEG features of drowsiness and sleep onset are much less well documented than are their temporal aspects. A commercial topographical mapping system was used to assess the main EEG features employing all 19 international 10/20 system electrode sites referenced to linked ears during wakefulness, stages 1A and 1B drowsiness, stage 2 sleep, and sleep onset REM periods in 19 patients. All patients had been referred for a diagnostic EEG or a Multiple Sleep Latency Test and had essentially normal EEGs. Anterior alpha of drowsiness seldom represented frontal spread of the occipital alpha rhythm but usually was a distinct activity of apparent separate origin. Theta activities of drowsiness were maximum at CZ and FZ. Vertex sharp waves and sawtooth waves of rapid eye movement (REM) sleep had similar fields maximum at the midline with a steep decrease laterally. Isolated anterior mainly negative waves were identified. Sleep spindles were usually maximal in fronto central, occasionally centro parietal, or even parietal areas.","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129365586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hiroshi Otsubo, Paul A. Hwang, A. Hunjan, Derek Armstrong, S. Holowka, James M. Drake, Harold J. Hoffman
{"title":"Use of frameless stereotaxy with location of electroencephalographic electrodes on three-dimensional computed tomographic images in epilepsy surgery.","authors":"Hiroshi Otsubo, Paul A. Hwang, A. Hunjan, Derek Armstrong, S. Holowka, James M. Drake, Harold J. Hoffman","doi":"10.1097/00004691-199507000-00006","DOIUrl":"https://doi.org/10.1097/00004691-199507000-00006","url":null,"abstract":"Epileptiform activity corresponding to structural lesions was identified by three-dimensional (3D) imaging using computed tomographic (CT) scan data concurrently with scalp EEG electrodes. The electrodes, placed according to the international 10-20 system, were used to record interictal and ictal epileptogenic foci in eight patients. Electrodes placed where marked or moderate epileptiform activity was detected were replaced with markers detectable on CT. Scans with these markers on the skin were obtained and the data transferred to a 3D imaging system, and correlated with underlying cerebral structures. The reformatted images were used to assess the relation among intracranial lesions, brain surface structures, and epileptogenic zones depicted by the markers. The images help the surgeon plan a craniotomy with enough space for both lesionectomy and resection of the epileptogenic zone. In the central regions where crucial motor functions are located, the markers indicate the central fissure or postcentral gyrus. An intraoperative 3D frameless stereotactic pointing device helps in directing further examination of the epileptogenic zone. This system improves on the precision available through intraoperative electrocorticographic recording in the extratemporal lobes, thus avoiding only approximate excision of lesion and epileptogenic zone and enabling the neurosurgeon to perform epilepsy surgery with greater confidence.","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"185 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121048241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Ahern, D. Labiner, D. Talwar, A. Herring, M. Weinand
{"title":"Quantitative analysis of the electroencephalogram in the intracarotid amobarbital procedure: II. Coherence analysis.","authors":"G. Ahern, D. Labiner, D. Talwar, A. Herring, M. Weinand","doi":"10.1097/00004691-199505010-00006","DOIUrl":"https://doi.org/10.1097/00004691-199505010-00006","url":null,"abstract":"Thirty-seven subjects underwent bilateral internal carotid artery injections of amobarbital before surgery for intractable epilepsy. The electroencephalograms (EEG) of these patients were continuously monitored during these 74 procedures and were later subjected to quantitative analysis. Analysis of interhemispheric coherence in the delta, theta, alpha, and beta 1 bands was performed. Prominent changes occurred in interhemispheric coherence, which showed a precipitous drop in the first 2 min after amobarbital injection, followed by a gradual return to near baseline levels. These results suggest that interhemispheric relationships are significantly disrupted by intracarotid amobarbital injection.","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"47 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117333791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Middle-latency somatosensory evoked potentials after stimulation of the radial and median nerves: component structure and scalp topography.","authors":"R. Treede, V. Kunde","doi":"10.1097/00004691-199505010-00007","DOIUrl":"https://doi.org/10.1097/00004691-199505010-00007","url":null,"abstract":"Somatosensory evoked potentials (SEPs) after radial nerve stimulation are studied less frequently than those after median nerve stimulation. Therefore, little is known about their component structure and scalp topography. We investigated radial nerve SEPs after electrical stimulation at the left wrist. For comparison, the median nerve was also stimulated at the wrist. SEPs were recorded with 15 scalp electrodes (bandpass 0.5-200 Hz) in 27 healthy subjects. The waveform of the radial nerve SEP at a contralateral parietal lead was comparable to that of the median nerve SEP, consisting of P14, N20, P30, and N60. In spite of comparable stimulus intensities, SEP amplitudes were smaller after radial than after median nerve stimulation. Significant latency differences were found only for N20 (earlier for median nerve) and P30 (earlier for radial nerve). The duration of the primary complex N20-P30 thus was significantly shorter for the radial nerve. Whereas N20 and P30 were present with either earlobe or frontal reference, N60 had a prerolandic maximum and was best recorded with a bipolar transverse derivation. In addition, another middle-latency negativity (N110) was found near the secondary somatosensory cortex, which had previously been described only for radial nerve stimulation. In standard SEP derivations, the N110 is riding on the ascending limb of the vertex negativity. It could best be recorded in low temporal leads versus a midline reference. The scalp topographies of P30, N60, and N110 were similar for radial and median nerve stimulation.","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114623795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}