Frontopolar ictal epileptiform discharges on scalp electroencephalogram in temporal lobe epilepsy

OBJECTIVE: To determine the prevalence of the smoking habit among Mexican physicians as well as some of their attitudes and information on specific issues concerning smoking. MATERIAL AND METHODS: In 1993, a survey was carried out among 3,568 physicians of the three major official health care institutions in Mexico City. A questionnaire designed for The Mexican National Survey of Addictions (ENA 1993) was used. Prevalence of cigarette smoking, age of onset, number of cigarettes per day; also information and attitudes concerning smoking were assessed. RESULTS: The mean age was 37, 66% were males. Of the 3,488 (98%) surveyed, 26.9% were smokers (62% daily), 20.6% were ex-smokers and 52.5% non-smokers. There were differences related to age and sex (p < 0.05). Of daily smokers, 36% smoked between 1 and 5 cigarettes. There was a significant trend among ex-smokers that linked the time they had ceased smoking with the fear to start smoking again. Physicians were well informed of the relationship between cigarette smoking and lung cancer. Over 80% considered tobacco an addictive drug but only 65% were in favor of banning smoking from their workplaces and over 10% were not aware that it is forbidden to smoke inside health care facilities. CONCLUSIONS: These results differ from other studies that find the prevalence of smoking among physicians lower than in the general population. Our study revealed a greater prevalence of the smoking habit among female physicians and the number of cigarettes smoked per day was greater than in the general population regardless of sex.     

The effect of cutaneous and deep pain on the electroencephalogram during sleep--an experimental study

The interaction between sleep and pain has been insufficiently studied, and no experiments have investigated whether pathologic sleep patterns as seen in pain patients can be replicated experimentally by well-defined pain stimuli. An experimental model would therefore be valuable for further studies on the interaction between pain and sleep. In this study, three well-defined experimental stimuli (muscle, joint, and cutaneous pain) were applied during sleep, and the electroencephalogram (EEG) pattern was quantified. The pain stimuli were applied during slow-wave sleep in 10 healthy subjects. Using nine surface recordings, the EEG was sampled before and during pain stimuli. Frequency analysis was performed, resulting in 10 EEG features describing the responses to pain. During the muscle-pain stimulus an arousal effect was observed and a decrease in delta (0.5-3.5 Hz) and sigma (12-14 Hz) as well as increases in alpha 1 (8-10 Hz) and beta (14.5-25 Hz) activities were seen. During joint pain, however, more universal EEG changes were seen with a decrease in the lowest frequency bands [delta, theta (3.5-8 Hz) and alpha 1] and an increase in the higher frequencies [alpha 2 (10-12 Hz), sigma and beta bands]. No background EEG changes were observed during the cutaneous stimulus. There were several differences in the responses from the nine EEG channels, but no derivation seemed especially sensitive to detect the evoked changes. The study highlights the complexity of pain on the sleep EEG. The experimental model has shown that pain from different body structures, as well as signals from various EEG derivations, may give different responses in sleep microstructure.     

Antiemetic effect of propofol

Propofol is known to possess direct antiemetic effects. Its use for induction and maintenance of anaesthesia has been shown to be associated with a lower incidence of postoperative nausea and vomiting (PONV) when compared to any other anaesthetic drug or technique. However, its mechanism of action in this context is still not well understood. In this article, the best ways to take advantage of propofol's antiemetic properties are emphasized. The possible effects of propofol on the cerebral cortex, its interactions with the dopaminergic and the serotoninergic systems are evaluated by the known clinical and basic science results. Finally, the advantages and disadvantages of using propofol to decrease the incidence of PONV in clinical practice are discussed.     

The effect of propofol on midazolam metabolism in human liver microsome suspension

We have studied the inhibitory effects of propofol on the metabolism of midazolam using human liver microsomes. In addition, we also investigated whether the lipid in which propofol is solubilised inhibits the metabolism of midazolam. Only high concentrations of propofol (> 100 mmol), greater than those found in clinical practice, inhibited the metabolism of midazolam. The lipid had no effect on the metabolism of midazolam. This study differs from other laboratory studies looking at the inhibitory effects of propofol. These showed inhibition at concentrations similar to those seen in patients. The reasons for the differences may be explained by the use of different substrates or methodology. Propofol may be an enzyme inhibitor, but this remains to be shown to be important in patients.     

Cyclic alternating pattern of sleep electroencephalogram in patients with panic disorder

Alport's syndrome (hereditary nephritis with deafness), is an uncommon disease and is seen very infrequently in India. We report a fatal case in a young girl with characteristic ultrastructural changes in the kidney thus emphasising the exception noted in the observation that females have a better prognosis compared to males.     

The effect of rate of administration on brain concentrations of propofol in sheep

Lipopolysaccharide (LPS) and interleukin (IL)-1beta have been reported to induce airway hyperresponsiveness in several animal models. This study investigated the effect of LPS or IL-1beta on bradykinin-induced human isolated bronchi contraction. LPS (100 ng x mL(-1) for 3-6 h) and IL-1beta (3x10(-10) and 3x10(-9) M for 20 min to 3 h) time-dependently potentiated bradykinin-induced contraction. This contraction was abolished, as in control experiments, by indomethacin (10(-6) M) or by the thromboxane (Tx) receptor antagonist GR 32191 but not by the cyclo-oxygenase-2 inhibitor, CGP28238. In contrast, the Tx mimetic U46619-induced contraction of human bronchi was not enhanced IL-1beta pretreatment. In the presence of GR 32191 (10(-6) M), bradykinin induced a prostanoid dependent relaxation that was not significantly modified by IL-1beta pretreatment. Determination of prostanoids in the organ bath fluid showed that bradykinin induced TxB2, the stable metabolite of TxA2, and 6-keto prostaglandin F1alpha, the stable metabolite of PGI2, release. Only TxA2 release was potentiated by IL-1beta. Taken together our results suggest that interleukin-1beta (1-3 h)-induced potentiation of the effect of bradykinin is linked to an increased activity of thromboxane synthase and, in turn, to increased thromboxane synthesis.     

The effect of midazolam and propofol on interleukin-8 from human polymorphonuclear leukocytes

Anesthetics and sedatives contribute to postoperative immunosuppression. Interleukin-8 (IL-8) is a chemotactic and activating factor that mediates neutrophil adhesion and margination and is essential for host defense. We investigated the effect of anesthetics on isolated human polymorphonuclear leukocyte production of IL-8. Healthy human polymorphonuclear leukocytes were isolated using a single-step density gradient and stimulated with lipopolysaccharide in the presence of varying concentrations of propofol or midazolam for up to 20 h. IL-8 was measured in both culture supernatants and cell lysates using enzyme immunoassay, and IL-8 mRNA in cells was measured using Northern blotting and phosphorimaging. Data were analyzed using Kruskal-Wallis analysis of variance or the Mann-Whitney U-test as appropriate. Lipopolysaccharide increased extracellular accumulation of interleukin-8, which was suppressed by both propofol (P = 0.025) and midazolam (P = 0.028). However, intracellular IL-8 increased with exposure to lipopolysaccharide (P = 0.028) and remained increased with both anesthetics. Northern blot analysis also revealed increased IL-8 mRNA levels in the presence of both midazolam and propofol, which was confirmed by molecular imaging. These data strongly suggest that the anesthetics modulate transport or secretion of IL-8 protein from the cell. Suppression of IL-8 by anesthetics and sedatives may predispose postoperative and intensive care patients to infection. Implications: Anesthesia causes immune suppression and alters neutrophil function. We investigated the effect of propofol and midazolam on interleukin-8, a neutrophil chemotactic agent in human neutrophils. Both anesthetics decreased extracellular interleukin-8 accumulation, but intracellular levels and mRNA remained high. This suggests that propofol and midazolam alter interleukin-8 secretion from cells.     

The effect of phenobarbital on patients with Dubin-Johnson syndrome

11 patients with jaundice of Dubin-Johnson type were treated for 2 weeks with phenobarbital. Serum bilirubin diminished and hepatic clearance of sulfobromophthalein was variably enhanced; other measures of hepatic function were not significantly changed during therapy.     

The postictal state. A clinically oriented observation of patients with epilepsy

Epileptic seizures are followed by dynamic alterations in neurologic function in the postictal period which have received little attention by clinicians over a long period of time. We therefore retrospectively studied videotapes of 160 patients with focal epilepsy who underwent presurgical evaluation, for the occurrence of postictal symptoms to determine whether these phenomena have any localizing or lateralizing value in defining the seizure onset zone. Results: (1) We found postictal paresis in 22 of 160 patients (18.8%) in each case contralateral to the hemisphere of seizure onset. (2) 'Perservative' automatisms which start during the ictus and continue in the postictal period occurred in 25.2% of 135 patients with temporal lobe epilepsy but not in patients with frontal lobe epilepsy. (3) Sexual automatisms defined as manipulations of the genitals were found exclusively in patients with temporal lobe epilepsy (in 5.9% of 135 patients). (4) Postictal 'Nose-wiping' was evident in 51.3% of 76 temporal lobe epilepsy patients but only in 12.0% of 25 extratemporal lobe epilepsy patients and was performed with the hand ipsilateral to the hemisphere of seizure onset in 86.5% of all temporal lobe seizures. (5) Postictal language disturbances were observed only in patients with temporal lobe epilepsy (34% of 97 patients) and pointed to a seizure onset in the dominant hemisphere in 80.8%. We conclude that postictal phenomena can provide reliable information for the localization of the seizure onset zone in patients with complex partial seizures. Thus, more attention should be given to the postictal state during presurgical epilepsy monitoring.     

The kindling effect as a model of epilepsy.

The kindling effect is described as involving a gradual change in behavior in response to periodic invariant electrical stimulation of specific brain sites, culminating in convulsions. Two premises are evaluated relative to kindling: (a) The kindling effect provides an excellent model of human epileptic conditions. (b) The amino acid taurine will act to suppress convulsions developed during kindling. Consideration of behavioral, electrophysiological, neurological, and chemical aspects of kindling suggest that behavioral aspects may model those of epilepsy, but it is probable that neurological mechanisms in some types of epilepsy are different from those underlying the kindling event. Although taurine appears to have an important role (e.g., as an inhibitory neurotransmitter) and has been successful in suppressing convulsions in humans and in some experimentally induced seizures, it has been found to have no effect on convulsions developed via kindling. (65 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Technology fuels hope for patients with epilepsy

Technological advances are making surgery a viable option for people with medically intractable epilepsy. More temporal lobectomies are being performed on young adults, fueled by recognition that many consequences of growing up with epilepsy can be avoided with early surgery.     

The electroencephalogram in the middle-aged and the elderly

A survey was made of the electroencephalographic (EEG) changes during the human lifespan. It was found that the EEG changes during childhood and adolescent maturation continue even between the ages of 30 and 60 years. There is a decrease in the abundance of alpha activity, with a reduction in the fast part and a relative increase in the slow part of the alpha band. In the span of life between 60 and 90, there is an increase of slow waves with a progressive slowing during the aging process and a shift in the dominant frequency from 9 cps to 7 cps. Computerization of results in the beta band (above 13 cps) enables differentiation of the waves of the lower part (13-25 cps) from those of the upper part (above 25-30 cps). The lower part of the beta band decreases parallel to the alpha activity but the upper part of the beta band increases in amount during the aging process. The meaning of the divergent behavior of these sub-groups of beta activity in the aged is discussed. The EEG seems to be an important factor in the study of aged persons.     

The clinical picture and electroencephalographic changes in patients with multifocal epilepsy depending on the location of the epileptic foci

As many 116 patients were examined for the clinical course and electroencephalographic changes as well as for the x-ray, CT and NMR-tomography data, on the basis of which different forms of multifocal epilepsy were distinguished: with unilateral epileptic foci (cortical and cortico-subcortical form), bitemporal and with multiple bilateral epileptic foci. The data provided make it possible to differentiate between multifocal epilepsy and generalized epilepsy and to perform surgical treatment using the optimal surgical intervention.     

Population analysis of the pharmacokinetics of tiagabine in patients with epilepsy

PURPOSE: In two open-label long-term safety studies, we determined tiagabine (TGB) pharmacokinetics in patients with epilepsy. METHODS: In all, 2,147 plasma samples from 511 patients who participated in the studies were available. The total daily dose ranged from 2 mg administered once daily to 80 mg administered in four doses. A one-compartment model with first-order absorption and elimination was used to fit the TGB plasma concentration-time data, with a population pharmacokinetic approach. RESULTS: The patients' average (+/-SD) weight and age were 73.8+/-20.7 kg and 32.1+/-12.3 years. The most significantly factor affecting TGB pharmacokinetics was concomitant administration of other antiepileptic drugs (AEDs). The central clearance value in patients receiving AEDs known to induce hepatic drug metabolism was 21.4 L/h, a value 67% higher than the central clearance estimate obtained for the patients receiving AEDs not known to affect hepatic drug metabolism (12.8 L/h). There was no evidence of any dose or time effect, indicating that TGB pharmacokinetics are linear. TGB pharmacokinetics were not different in white, black, or Hispanic patients, although our ability to explore racial effects was limited since 90% of the patients were white. No other demographic variables (including age and smoking) or any clinical chemistry measurements (including bilirubin, SGOT, and SGPT) were important in explaining the variability in the clearance estimates. CONCLUSIONS: TGB pharmacokinetics are linear, influenced by enzyme-inducing AEDs, and largely unaffected by other demographic variables.     

Increasing the yield from volumetric MRI in patients with epilepsy

Volumetric magnetic resonance imaging has become a routine investigation in the management of patients with chronic partial epilepsy. However, even with the use of reformatted images, an underlying cause for epilepsy cannot be found in many of these patients. We show that further processing of the data, including three-dimensional reconstruction and quantitative analysis of the volume and complexity of the images in three dimensions, reveals additional positive information in up to 75% of patients. This may be useful for surgical planning, prognostication, and understanding of the structure and development of the human brain.     

艺术家创作过程的脑电原理分析

用常用的短音信号和特殊的图形信号为靶,测量普通人和艺术家饮酒前后脑部事件相关电位波形的变化,从脑电的角度探索艺术家适量饮酒后能创作出高水平作品的原因.结果 发现普通人饮酒后脑电波峰出现时间延迟,波幅降低;艺术家饮酒后在常用信号刺激下脑电波峰出现时间延迟,波幅降低,但饮用适量酒后在他们感兴趣的图形信号刺激下脑电波峰时间延迟,波幅升高,波形面积增大.     

The high-frequency electroencephalogram: the results and outlook

At present, the significance of high-frequency (HF) components in brain electrical activity (EA) is widely discussed in literature. In particular, the gamma range of human EEG is considered as one of the indices of cognitive activity. In the paper a review is presented of the author's own data concerning the functional estimation of low-voltage HF components of the neocortical EA recorded in the broad band (1-100, 1-256 Hz) in the course of instrumental conditioning in dogs. Three different techniques of EA analysis were used in the study: 1) fast Fourier transformation (FFT) of EA in a broad band, 2) developed by us alternative method of non-harmonic expansion of the EEG curves taking into account their shape, 3) factor analysis of the EA spectral densities. Combination of these techniques allowed us to obtain some novel evidence indicative of high informativity of the HF fluctuations. Spatial cortical localization of the HF components of the EA is much more expressed in comparison with the traditional 1-30 Hz range. Results of factor analysis suggest functional heterogeneity of the HF band. Obtained data open new ways for researches concerning the phenomena of the functional mosaics in the neocortex as one of fundamental mechanisms in brain activity organization.