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57. A case of serotonin syndrome assessed by repeated EEG recordings
In the interictal interval in all of our patients, either in resting EEG or during HV, NONFOCAL EEG ABNORMALITIES were recorded. During migraine attack in the majority of patients EEG ABNORMALITIES only moderately increased in the intensity. Immediately before the EEG recording 8 (eight) of patients received SUMATRIPTAN per os and the other 4 (four) patients DHE i.m or per os: Paracetamol + Caffein, Ergotamin or Trodon. All patients treated with Sumatriptan were almost completely pain free after cca 30 minutes but abnormalities in the repeated EEG at that time didn't change. In spite of small patent's group, this finding speaks against hypothesis of cortical and in favor of possible subcortical mechanism of pain release efficacy of Sumatriptan.
Serial quantitative electroencephalography Electroencephalography and Clinical Neurophysiology |
Serial quantitative electroencephalography Electroencephalography and Clinical Neurophysiology, Volume 47, Issue 5, November 1979, Pages 614-622 Milos Matousek, Anders Arvidsson, Sven Friberg Abstract Repeated EEG examinations are often used in diagnostically difficult cases to assess whether an EEG abnormality is progressive, regressive, or stationary. The conventional visual method is, however, poorly adapted to consider the variability when consecutive EEG recordings are compared. Using computer analysis of EEGs, the feature of the recordings as well as their variances can be measured, and the differences between the recordings can be tested statistically. The aim of the present study was to develop a practicable method for quantitative serial EEG examinations. Twenty EEGs from 5 volunteers were recorded to obtain reference data. The data acquisition was automated to obtain data without visual bias. The previously developed method using age ratios was employed for the primary analysis. The changes of the EEG activity during the observation period were evaluated statistically. Differences between consecutive EEGs could be observed even in normal subjects but the number of ‘false positive’ findings was reduced by the automatic data selection, by the choice of proper measures, and by adequate statistical treatment. The diagnostic value of the method was tested in 59 EEGs from 13 patients with well-defined brain disorders. Most EEG changes which could be attributed to the development of the disease were discovered and labelled as statistically significant. RésuméIl est fréquent de procéder á plusieurs examens EEG successifs dans des cas de diagnostic difficile, ceci pour préciser le caractére progressif, régressif ou stationnaire des anomalies. La méthode conventionnelle d'examen visuel ne permet cependant que trés mal d'évaluer la variabilité lorsque plusieurs EEG successifs sont comparés. En traitant l'EEG par ordinateur, les caractéristiques du tracé, ainsi que leurs variations peuvent être quantifiées et les différences entre enregistrements, ainsi testées statistiquement.Le but de la présente étude était de développer une méthode pratique d'examen quantitatif de tracés EEG successifs. Vingt EEG furent pris sur 5 volontaires, pour servir de référence, l'acquisition des données s'effectuant automatiquement pour éliminer le biais visuel. Une méthode (dévéloppée antérieurement), basée sur les rapports d'âges, a été appliquée dans l'analyse primaire. Les modifications de l'activité EEG pendant la période d'observation ont ainsi étéévaluées statistiquement. Des différences entre EEG consécutifs purent être observées même chez des sujets normaux, mais le nombre de cas ‘faussement positifs’ a pu être réduit par la sélection automatique des données, par le choix de mesures appropriées, et par un traitement statistique adapté. La valeur diagnostique de la méthode a été testée pour 59 EEGs de 13 patients souffrant d'affections cérébrales bien identifiées. La plupart des modifications EEG attribuables au dévéloppement de l'affection, purent être identifiées et désignées comme statistiquement significatives. Purchase PDF (645 K) |
Stability of EEG inter Electroencephalography and Clinical Neurophysiology |
Stability of EEG inter Electroencephalography and Clinical Neurophysiology, Volume 102, Issue 3, March 1997, Pages 248-255 M. Corsi-Cabrera, S. Solís-Ortiz, M. A. Guevara Abstract EEG correlation and coherence analyses have been used to study functional relationships between cortical regions, and found to vary as a function of physiological conditions, sex hormones and cognitive processes. However, the utility of serial EEG studies is dependent upon the within-subject reliability of repeated EEG recordings. The present study was undertaken to assess the within-subject and within-group stability of EEG correlations in a group of young women (n = 9). EEG was recorded during relaxed wakefulness at F3, F4, C3, C4, P3, P4, O1 and O2 for 11 sessions, during 1 month. Ten artifact-free 2-s epochs of EEG from each session were digitally filtered by means of a fast Fourier transform into 6 broad bands, and correlation coefficients between the EEG activity of every pair of derivations and bands were calculated in the time domain. All EEG features were submitted to principal component analysis and the first 5 components did not show significant differences between sessions (ANOVAs) for any band or pair of derivations. Alpha and beta showed higher variability whereas slow bands showed very little variability. The within-subject stability was assessed calculating multiple correlation coefficients between all EEG features of the eleven sessions of each subject: R-values ranged from 0.85 to 0.97. Present results indicate that the pattern of functional relationships between cortical regions during resting wakefulness is a stable characteristic for each woman at least over a 1 month period and that there are no significant group differences over sessions when menstrual phases are randomly distributed between women. Purchase PDF (671 K) |
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57. A case of serotonin syndrome assessed by repeated EEG recordings