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At least 343 records · Page 19Linked to original sources

PubMed1994

The role of diet cholesterol changes on EEG.

Thirty three male albino rats, weight between 200 and 220 g were used in this experiment. Control animals consisting of 11 rats were fed with a normal lab diet for a period of 14 weeks and the others (22) were fed with a diet containing 1% cholesterol for the same period. At the end of the experimental period, plasma cholesterol level (Mean +/- SD) was 141.29 +/- 34.5 mg/dl in the cholesterol group and 70.66 +/- 10 mg/dl in the control group. Eleven of the rats from the cholesterol group were transferred to the normal diet for 14 weeks (normocholesterolemic group). Spectral analysis of EEG records from parietal lobes of animals showed that there was an obvious depression in the brain waves of hypercholesterolemic rats whereas no depression in normocholesterolemic rats.

Algorithms↗

PubMed1983

Influence of music on memory and education, and the application of its underlying principles to acupuncture.

The interrelations among learning, brain waves, music and the relief of pain by acupuncture are discussed from the standpoint of an educator, who has some practical experience in suggestive-accelerative learning and teaching (S.A.L.T.). Through the diverse fields of science, e.g. educational psychology, physiology, electronics and acoustics, the principal law governing the l/f fluctuations (where f is frequency), or the inverse frequency distribution of the power spectrum, seems to play an important role in their phenomenological mechanism. The author totally explained in this paper such relations and he arranged the related phenomena into physical, physiological, psychological and pedagogical fields. Finally, he referred to an interesting example of the application of l/f fluctuations to the relief of pain by acupuncture.

Acupuncture Therapy↗

PubMed2001

Multiple bottlenecks in information processing? An electrophysiological examination.

When two stimuli are to be processed in rapid succession, reaction time (RT) to the second stimulus is delayed. The slowing of RT has been attributed to a single processing bottleneck at response selection (RS) or to a central bottleneck following the initiation of the first response. The hypothesis of a response initiation bottleneck is mainly based on reports of underadditive interactions between stimulus onset asynchrony (SOA) and the number of stimulus-response alternatives (simple vs. two-choice response). The present study tested the hypothesis of a response initiation bottleneck by recording the lateralized readiness potential (LRP), a brain wave, emerging during or immediately following RS. The LRP findings were consistent with a central bottleneck but did not support the late bottleneck hypothesis. Instead, the LRP provided direct evidence that the underadditive interaction of number of alternatives and SOA is due to an increase of response anticipations in the simple response condition.

Adult↗

PubMedDate not supplied

The use of propofol as an induction agent for halothane and isoflurane anesthesia in dogs.

Cardiovascular, pulmonary, and quantitative electroencephalographic parameters were assessed in 12 anesthetized dogs to determine the compatibility of the injectable anesthetic propofol with halothane and isoflurane. No cases of apnea were observed during induction of anesthesia. An adequate level of anesthesia was established in each protocol as judged by both the lack of response to mechanical noxious stimuli (i.e., tail clamping) and evidence of reduction in total amplitude of brain wave activity. The initial propofol-mediated decrease in arterial blood pressure continued during either halothane (52.4%) or isoflurane (38%) anesthesia without a simultaneous increase in heart rate. The results of this study suggest that propofol, in combination with inhalant agents, can be used effectively and safely for canine anesthesia in veterinary practice.

Analysis of Variance↗

PubMed2004

[A trial of titration in oral appliance therapy for obstructive sleep apnea syndrome].

This study evaluated the effect of titration in oral appliance therapy for obstructive sleep apnea syndrome (OSAS), and examined problems with this test. However, the method of predicting the appropriate mandible position has not yet been established. In this study, titration was attempted in order to predict appropriate mandible position prior to wearing an oral appliance. Twenty-three male patients diagnosed as OSAS by a physician participated in this study. The mandible was protruded by a titratable splint (TS) until apneic and hypopneic signs had disappeared. Moreover, polisomnography (PSG) was used to monitor brain wave patterns, eye movement, muscle tone, body movement and breathing. Sleep study was performed by a portable sleep monitoring device before and after examination wearing titrated oral appliance (OA), and the effect of therapy was evaluated. The results obtained were as follows. 1. In the Apnea Hypopnea Index (AHI), Apnea Hypopnea density (AH density), lowest SpO2, Oxygen Desaturation Index (ODI), there was a statistically significant improvement. The mean AHI reduced from 13.8 to 4.7 (p<0.001). The mean AH density reduced from 12.0 to 3.5 (p<0.001). The mean lowest SpO2 increased from 78.7 to 84.7 (p<0.0001). The mean ODI reduced from 15.7 to 6.1 (p<0.001). 2.. The average proportion of protrusive distance for movable distance was 71.7%. 3. Only one patient complained of discomfort in the maxillofacial region, however, this discomfort disappeared after adjustment of OA. Therefore, it is suggested that titration for OA is a very useful examination for OSAS therapy.

Adult↗

PubMed1976

A need for more psychophysiological research in australia.

Western communities are becoming increasingly more interested in altered states of consciousness such as hypnosis, meditation and other states associated with certain "brain wave" patterns. In the United States of America especially, psychophysiological research is beginning to lead to an understanding of some of the basic mechanisms underlying certain mental phenomena and their therapeutic uses. In Australia, on the other hand, experimental investigations in this area are negligible. It is important to begin intensive psychophysiological research now.

Alpha Rhythm↗

PubMed1991

Differentiation of convulsive syncope and epilepsy with head-up tilt testing.

OBJECTIVE: To evaluate the usefulness of head-upright tilt table testing in the differential diagnosis of convulsive syncope from epileptic seizures in patients with recurrent idiopathic seizure-like episodes. DESIGN: Prospective, nonrandomized study. SETTING: Electrophysiology laboratory of a university hospital. PATIENTS: Fifteen patients (8 men and 7 women patients; mean age, 29 +/- 20 years) with recurrent unexplained seizure-like episodes, unresponsive to antiseizure medication. MEASUREMENTS: Head-upright tilt table testing with or without isoproterenol infusion. Five patients who were initially tilt positive had a second tilt test with continuous electroencephalographic (EEG) recording. MAIN RESULTS: Syncope associated with tonic-clonic seizure-like activity occurred in six patients (40%) during the baseline tilt and in four patients (27%) during isoproterenol infusion (total positive tests, 67%). The EEG showed diffuse brain wave slowing (not typical of epileptic seizures) in five of five patients during the convulsive episode. All patients who had positive test results eventually become tilt table negative after therapy, and over a mean follow-up period of 21 +/- 2 months, no further seizure-like episodes have occurred. CONCLUSION: Upright tilt table testing combined with isoproterenol infusion may be useful to distinguish convulsive syncope from epileptic seizures.

Adolescent↗

PubMed2003

[Occipital spectral EEG parameters in newly diagnosed, untreated patients with epilepsy].

INTRODUCTION: Minor spectral EEG alterations hidden to the naked eye may be of interest in the field of epileptology, cognitive performances, and drug effects. In order to introduce new scientific results of brain wave research into the clinical field of epilepsy- and drug-related cognitive problems, a normative quantitative EEG database for epilepsy was constructed. PATIENTS AND METHODS: 171 newly referred, five to 50 years old patients with untreated "new" epilepsy (that is, clinical, EEG, MRI investigations had been done in 24 months after the first unprovoked seizure) were collected. EEG was recorded with closed eyes, in the waking-relaxed state. Effects that are known to influence EEG spectra (nearby seizures, drugs, etc.) were excluded as far as possible. A total of two minutes of waking-resting EEG activity was chosen for spectral analysis. Fast Fourier transformation of the selected samples were calculated resulting in absolute power, percent power and mean alpha frequency (AA, RA, and AMF respectively) for the right and left occipital derivations. For each patient (and also for 37 healthy controls), the deviation of the individual values from the age-adjusted normative mean was expressed in Z-score. Main diagnostic epilepsy categories were compared to the control group as well as to each other. In addition, effects of MRI-defined cerebral lesions and interictal spiking on spectral EEG parameters were investigated. RESULTS: All group averages were within the 95 per cent confidence interval. Overwhelming majority of the individual data fell within a 3Z range. Statistically significant differences were found for AA and RA, but seldom for AMF. Right and left alpha-parameters were surprisingly symmetrical in all groups. The main difference between epilepsy groups and controls was less AA and RA power in the epilepsy groups. MRI-defined lesions and interictal epileptiform activity did not significantly influence EEG spectral variables. CONCLUSION: These results might serve as reference data and might help planning of further quantitative EEG studies in the triangle of epilepsy, cognitive problems, and drug effects.

Adolescent↗

PubMed2005

Improving quality of life beyond seizure control.

More than 50 years ago, Lennox and Markham urged physicians who treated patients with epilepsy to "match modern drug and surgical therapy with practical sociopsychological therapy" and to be "concerned not only with turbulent brain waves but with disturbed emotions". Indeed, while seizure frequency and severity correlate with quality of life and psychosocial outcomes for patients with drug-resistant epilepsy, numerous other epilepsy-related factors may also be significant determinants. These factors include medical and psychiatric co-morbidities, side effects of therapy, stigma, parental anxiety, employment status, seizure worry, self-esteem and self-mastery. Importantly, these epilepsy-related factors may be amenable to educational or therapeutic interventions, which if successful may benefit patients even without a concomitant reduction in seizure frequency or severity. Therefore, while further research is needed, physicians and other health care providers should comprehensively attend to these factors and refer patients with treatment-resistant seizures, when appropriate, for further evaluation and treatment to improve their quality of life beyond seizure control.

Anxiety↗

PubMed1991

The octave approach to EEG analysis.

A "tonal" approach to EEG spectral analysis is presented which is compatible with the concept of physical octaves, thus providing a constant resolution of partial tones over the full frequency range inherent to human brain waves, rather than for equidistant frequency steps in the spectral domain. The specific advantages of the tonal approach, however, mainly pay off in the field of EEG sleep analysis where the interesting information is predominantly located in the lower octaves. In such cases the proposed method reveals a fine structure which displays regular maxima possessing typical properties of "overtones" within the three octaves 1-2 Hz, 2-4 Hz and 4-8 Hz. Accordingly, spectral patterns derived from tonal spectral analyses are particularly suited to measure the fine gradations of mutual differences between individual EEG sleep patterns and will therefore allow a more efficient investigation of the genetically determined proportion of sleep EEGs. On the other hand, we also tested the efficiency of tonal spectral analyses on the basis of our 5-year follow-up data of 30 healthy volunteers. It turned out that 28 persons (93.3%) could be uniquely recognized after five years by means of their EEG spectral patterns. Hence, tonal spectral analysis proved to be a powerful tool also in cases where the main EEG information is typically located in the medium octave 8-16 Hz.

Algorithms↗

PubMed1989

[Visual EEG analysis in controlling intravenous anesthesia using propofol].

Since the discovery of brain waves by Berger, repeated efforts have been made to use the electroencephalogram EEG for monitoring and controlling anesthesia. Owing to its susceptibility to failure and the high expenditure regarding technology and personnel, the technique has not yet been adopted in routine anesthesia, however. In the study now reported an attempt was made to apply the positive experience with the recording and interpretation of EEG in the development of new anesthetic agents in the experimental laboratory, during routine clinical operations. The anesthetic used in the study was Propofol, an induction hypnotic that has only recently been introduced, together with nitrous oxide and repeated doses of fentanyl. Propofol is distinguished by its fast onset of action and short inactivation time; it is therefore suitable for induction and maintenance of anesthesia. The aim of the study was to maintain predetermined stages of sleep during anesthesia with the aid of visual on-line analysis of the EEG and to establish the dose of Propofol required for this purpose. The operations-general and orthopedic surgery-lasted 70-190 min (average duration: 120 min). In accordance with the randomization plan, the maintenance dose of Propofol was controlled in such a way that in ten patients light sleep levels (C0 to D1) and in the other ten deep sleep levels were maintained. The EEG was recorded via five active scalp electrodes (FP2, F4, C4, P4, O2) with reference to a joint electrode (A2). The stages of sleep were classified according to Kugler.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

The 1994 Clinical Research Award. A prospective clinical study of the polysomnographic stages of sleep after burn injury.

Although subjective evidence suggests that patients with burns are deprived of sleep, previous clinical studies have been limited to observational data and have not to date included electroencephalographic or polysomnographic recordings. The purpose of this study was to characterize the sleep pattern of patients suffering from thermal injury. Biweekly 24-hour polysomnographic measurements (electromyography, electrooculography, and electroencephalography) were performed with 12 leads. This measuring permitted continuous recording of intrinsic electrical activity in skeletal muscles via chin electrodes, eye movement via outer canthal electrodes, and brain wave activity with the other bipolar electrodes. Determinations were obtained on 11 patients with thermal injuries for a total of 43 24-hour periods. The patients had a mean age of 8.31 +/- 1.5 years (range 1.4 to 16 years), a mean total body surface area burn of 55.1% +/- 16.5% (range 17.5% to 90.5%), and a mean full-thickness burn of 48.5% +/- 8.1% (range 10.5% to 90.5%). Although mean total sleep time was seemingly adequate (625.1 +/- 31.6 min/patient/24 hrs), large aberrations in sleep stage distribution were noted. Significant decreases in stage 3 + 4 and in rapid eye movement (deep sleep) and increases in stages 1 and 2 (light sleep) were noted, suggesting a cycling back to stages 1 or 2 after disruption of sleep. Overall, in 43 runs 40% of the subjects were completely lacking stage 3 + 4, and 19% were missing rapid eye movement during an entire 24-hour run.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

The neurophysiology of sexual desire, with particular reference to paedophilia.

Bancroft has proposed a central arousability system as an androgen-sensitive neurophysiological substrate of sexual desire. The present paper describes the author's explorations of a brain-wave measure, the contingent negative variation (CNV), as a putative index of sexual desire under conditions of sexually-relevant stimulation in paedophilic child sex offenders and in non-offender control men. As a group, the former showed undifferentiated CNV responses to adult and child stimuli, unlike non-paedophilic child sex offenders and controls, who showed larger CNVs to adult than to child stimuli. These results suggest that CNV may be usefully developed as an adjunct to penile plethysmographic (PPG) assessment of deviant sexual interests in offenders. Some possible directions for future research are indicated.

Contingent Negative Variation↗

PubMed1996

[Stress and fatigue in long distance 2-man cockpit crew].

Common rules on flight-duty times and rest requirements within the European Union are under intense discussion. In the deliberations, results from scientific investigations should be considered. As part of a research programme concerning legal aspects of two-pilot operations on long-haul routes, the purpose of the studies was to investigate two-crew extended range operations during transmeridian and transequatorial flight schedules. The studies were conducted with two German charter airlines on the transmeridian routes Düsseldorf (DUS)-Atlanta (ATL) and Hamburg (HAM)-Los Angeles (LAX), and on the north-south route Frankfurt (FRA)-Mahe (SEZ) including two consecutive night flights with a short layover. In total, 25 rotations (50 flights) have been investigated by pre-, in-, and post-flight data collection from the two pilots being the minimum required crew. Recordings included sleep, taskload, fatigue and stress by measurements of EEG, ECG, motor activity and subjective ratings. During the transmeridian schedules, pilots lost one night of sleep because of the return flights which were conducted at night. The resulting sleep deficit was 8.2 h. During the layover of the SEZ-rotation with a duration of 14 h on average, sleep was shortened by 2 h compared with baseline sleep. The two consecutive night flights resulted in a sleep loss of 9.3 h upon return to home base. Inflight ratings of taskload showed low levels during the atlantic flights, and moderate grades during the north-south transitions. Fatigue ratings exhibited an increasing level with progressing flight duration. Towards the end of long US-westcoast flights performed at day-time, and in all night flights, fatigue was enhanced compared to the "baseline" ratings collected during the DUS-ATL flights. Fatigue was scored at a critical level by several pilots, particularly during the return flight SEZ-FRA when fatigue was severely pronounced. The subjective fatigue ratings were confirmed by the objective measurements of motor activity, brain-wave activity (occurrences of micro-sleep) and heart rate which indicated drowsiness and a low state of vigilance and alertness during all night flights under study. From the findings it is concluded that duty schedules, as conducted on the route HAM-LAX (because of long duty hours), and particularly on the route FRA-SEZ, (because of consecutive night duties) are coming close to the limits of mental and physiological capacity. With respect to legal aspects, the results have significance and should promote further deliberations for advanced schemes of flight duty time limitations and rest requirements.

Adult↗

PubMed1996

Modern management of epilepsy: Vagus nerve stimulation.

Vagus nerve stimulation (VNS) was first tried as a treatment for seizure patients in 1988. The idea to stimulate the vagus nerve and disrupt or prevent seizures was proposed by Jacob Zabarra. He observed a consistent finding among several animal studies which indicated that stimulation of the vagus nerve could alter the brain wave patterns of the animals under study. His hypothesis formed the basis for the development of the vagus nerve stimulator, an implantable device similar to a pacemaker, which is implanted in the left chest and attached to the left vagus nerve via a stimulating lead. Once implanted, the stimulator is programmed by a physician to deliver regular stimulation 24 hours a day regardless of seizure activity. Patients can also activate extra 'on-demand' stimulation with a handheld magnet. Clinical studies have demonstrated VNS therapy to be a safe and effective mode of treatment when added to the existing regimen of severe, refractory patients with epilepsy. Efficacy ranges from seizure free to no response with the majority of patients (> 50%) reporting at least a 50% improvement in number of seizures after 1.5 years of treatment. The side-effect profile is unique and mostly includes stimulation-related sensations in the neck and throat. The mechanism of action for VNS is not clearly understood although two theories have emerged. First, the direct connection theory hypothesizes that the anticonvulsant action of VNS is caused by a threshold raising effect of the connections to the nucleus of the solitary tract and on to other structures. The second is the concept that chronic stimulation of the vagus nerve increases the amount of inhibitory neurotransmitters and decreases the amount of excitatory neurotransmitters. Additional research into the optimal use of VNS is ongoing. Animal and clinical research have produced some interesting new data suggesting there are numerous ways to improve the clinical performance of vagus nerve stimulation as a treatment for refractory patients.

Adult↗

PubMed1976

Drugs and PGO waves in the lateral geniculate body of the curarized cat. III. PGO wave activity and brain catecholamines.

The possible implication of central catecholamines in the phasic phenomenon of ponto-geniculo-occipital (PGO) waves was investigated using PGO waves induced by the benzoquinolizine derivative, Ro 4-1284 (=PGO(1284), and the inhibitor of tryptophan hydroxylase, p-chlorophenylalanine (=PGO(PCPA); they were continuously recorded and counted in the lateral geniculate bodies of unanaesthetized immobilized cats as described in a previous report. The effect on PGO(1284) and PGO(PCPA) of various drugs interacting with the different steps of catecholaminergic transmission was studie. Injections of noradrenaline (NA) and of dopamine (DA) into the lateral brain ventricle tended to decrease the density of PGO(1284). The stimulant of central alpha-adrenoceptors, clonidine, suppressed PGO(1284) and PGO(PCPA) in very small doses. Apomorphine in high doses had inconsistent depressant effects which were probably not related to its stimulant action on DA receptors. Release of brain NA by dexamphetamine and beta-tetrahydronaphthylamine decreased the density of PGO waves, alpha-Methyldopa diminished PGO(PCPA) but not PGO(1284. The MAO-inhibitor, nialamide, depressed PGO(PCPA) more than PCO(1284), whereas pheniprazine was inactive. The inhibitor of catechol-O-methyltransferase, tropolone, reduced the density of bially blocks the uptake of NA, was more potent on PGO(PCPA) than on PGO(1284). The alpha-adrenoceptor blocking agent, phenosybenzamine, markedly increased the density of PGO(PCPA). Similar effects were obtained with thioridazine and clozapine, which aare also known to be blockers of central alpha-adrenoceptors. Inhibition of tyrosine hydroxylase (by alpha-methyltyrosine) and of DA-beta-hydroxylase (by disulfiram or Ro 8-1981), in addition to the inhibition of tryptophan hydroxylase by PCPA, induced PGO waves comparable in density and temporal distribution to those occurring following the application of Ro 4-1284. The acute bilateral lesion of the dorsal and caudal parts of thel ocus coeruleus increased the density of PGO(PCPA). The results strongly suggest that, in addition to the 5-hydroxytryptaminergic system, noradrenergic neurones, probably originating in the locus coeruleus, depress the neurones in the pontine reticular formation involved in the generation of PGO waves.

Animals↗

PubMed1986

Auditory brain stem response wave IV-V abnormalities from the ear opposite large cerebellopontine lesions.

This report focuses on auditory brain stem response (ABR) from the ear contralateral to large cerebellopontine angle (CPA) tumors. Specifically, eleven of fifteen patients with large CPA tumors demonstrated contralateral ABRs for which wave IV and/or V were abnormal, while waves I and III were normal. In some cases, waves IV and/or V were absent, while in other cases one or both waves were delayed. The clinical interpretation for this type of ABR finding and the possible implications in relation to generator sites of the various ABR waves are discussed.

Adult↗

PubMedDate not supplied

Changes in minute waves of superslow brain activity after various methods for electrostimulating two neocortical zones.

Changes in the oscillations of the decasecond and minute waves of superslow activity in the 0 to 1 Hz range were compared using various techniques for electrostimulating neocortical zones in rabbits with gold electrodes chronically implanted in structures of the brain. Successive stimulation of the frontal and motor zones of the cortex with a 2.5-3.0 microA current strength was accompanied by changes of negligible duration and amplitude in the decasecond and minute waves, which were of a more local character primarily in the stimulation zones. Simultaneous synchronous stimulation of two neocortical zones with the same strength evoked considerable shifts in amplitude for a long period in various structural formations of the brain including the dorsal hippocampus. Ethimizole at a dose of 1.5 mg/kg fixed the given changes in the amplitude of the decasecond and minute waves for an extended time. For two weeks the overall level of metabolism of the neocortical zones was altered after the method of artificial stable functional connections (ASFC); for one week, after a shortened reflex. It was shown that the application of a shortened reflex and the application of artificial stable functional connections are of a differing functional organization of intracentral relationships.

Animals↗