Sudden unexpected death in epileptics following sudden, intense, increases in geomagnetic activity: prevalence of effect and potential mechanisms

The Subjective and Objective Improvement of Non-Invasive Treatment of Schumann Resonance in Insomnia-A Randomized and Double-Blinded Study

Purpose

Accumulated studies revealed that electromagnetic field can affect human brain and sleep, and the extremely low-frequency electromagnetic field, Schumann resonance, may have the potential to reduce insomnia symptoms. The purpose of this study was to investigate the responses of patients with insomnia to a non-invasive treatment, Schumann resonance (SR), and to evaluate its effectiveness by subjective and objective sleep assessments.

Patients and Methods

We adopted a double-blinded and randomized design and 40 participants (70% female; 50.00 ± 13.38 year) with insomnia completed the entire study. These participants were divided into the SR-sleep-device group and the placebo-device group and were followed up for four weeks. The study used polysomnography (PSG) to measure objective sleep and used sleep diaries, Pittsburgh Sleep Quality Inventory (PSQI), Epworth Sleepiness Scale (ESS), and visual analogy of sleep satisfaction to measure subjective sleep. The 36-Item Short-Form Health Survey (SF-36) was used to evaluate quality of life. Chi-square test, Mann-Whitney U-test, and Wilcoxon test were used to analyze the data.

Results

About 70% of the subjects were women, with an average age of 50±13.38 years and an average history of insomnia of 9.68±8.86 years. We found that in the SR-sleep-device group, objective sleep measurements (sleep-onset-latency, SOL, and total-sleep-time, TST) and subjective sleep questionnaires (SOL, TST, sleep-efficiency, sleep-quality, daytime-sleepiness, and sleep-satisfaction) were significantly improved after using the SR-sleep-device; in the placebo-device group, only such subjective sleep improvements as PSQI and sleep-satisfaction were observed.

Conclusion

This study demonstrates that the SR-sleep-device can reduce the insomnia symptoms through both objective and subjective tests, with minimal adverse effects. Future studies can explore the possible mechanism of SR and health effects and, with a longer tracking time, verify the effectiveness and side effects.

Effectiveness of Natural Frequency Technology® on cognition, sleep, and mood of adults with high perceived stress: A randomized, double-blind, placebo-controlled crossover study

INTRODUCTION

NexQuest Natural Frequency Technology^® (NFT^® ), intended to enhance biological function using naturally occurring frequencies, may be a nonpharmacological intervention to improve stress and health. The study purpose was to determine the effectiveness of NFT^® for improving stress, sleep quality, mood, and cognition in adults.

METHODS

Using a double-blind placebo-controlled crossover design, participants with high perceived stress (N = 42, M age = 43.8) were assessed at baseline (BL) and assigned to either the Placebo Watch (PW) or Wellness Watch (WW) condition for 2 weeks, and then 2 weeks in the alternate condition. Participants completed the following self-report surveys of Perceived Stress Scale, Pittsburgh Sleep Quality Index, Insomnia Severity Index, Food Craving Questionnaire, and Profile of Mood States, as well as the CNS Vital Signs neurocognitive test at BL and following each condition.

RESULTS

The WW condition had significant improvements in sleep duration and Complex Attention compared to the PW group. Compared to BL, both conditions had significant improvements for perceived stress, food cravings, mood, sleep quality, and several cognitive tests, p's < .05.

CONCLUSION

Despite the placebo effect, NFT^® may be a natural alterative for improving stress and health. Research is needed examining the efficacy of NFT^® in a variety of populations and environments.

Electromagnetic activity: a possible player in epilepsy

Epilepsy is a common disease with frequent occurrences. Many precipitating factors contribute to epileptic seizures, such as hyperventilation and alcohol consumption. An increasing number of studies have also found that electromagnetic activity in the environment can also affect epileptic seizures. However, many neuromodulatory devices that produce electromagnetic fields have been applied in the diagnosis and treatment of epilepsy. In this paper, we performed literature search in the PubMed, Medline and EMBASE databases and reviewed retrospective, prospective, or cross-sectional studies and case reports on the effects of electromagnetic activity on epilepsy. The application of electromagnetic activity in the diagnosis and treatment of epilepsy is also reviewed.

[Sudden unexpected death in epilepsy (SUDEP) : Epidemiology, cardiac and other risk factors]

Sudden unexpected death in epilepsy (SUDEP) is one of the most frequent epilepsy-related causes of death. The incidence of SUDEP is estimated to be approximately 1.2/1000 person-years (PY); however, it varies considerably depending on disease-specific and demographic factors. The estimated incidence of SUDEP in children seems to be significantly lower (0.22/1000 PY) than in adults but recent studies in children (>12 years) indicated a similar incidence to that of adults. Based on these estimations, approximately 700 SUDEP cases would be expected in Germany annually but no reliable data or epidemiological studies on SUDEP are available. Various risk factors and predictors for SUDEP have been investigated, e.g. age, seizure frequency, number of antiepileptic drugs, non-compliance and comorbidities, with sometimes contradictory results. This is understandable given that the exact mechanisms of SUDEP are unclear; however, it is very likely that the frequency of (nocturnal) generalized tonic-clonic seizures is the most important risk factor. Nocturnal monitoring of seizures (using devices) or the presence of another person at night may represent important factors to reduce the risk of SUDEP. Thus, seizure control and seizure monitoring are, according to current knowledge, the most important factors to avoid SUDEP. Some recent studies have contributed to a better understanding of possible pathomechanisms of SUDEP; however, further research is needed to identify predictive clinical factors and biomarkers and in particular to prevent SUDEP.

Long-Term Study of Heart Rate Variability Responses to Changes in the Solar and Geomagnetic Environment

This long-term study examined relationships between solar and magnetic factors and the time course and lags of autonomic nervous system (ANS) responses to changes in solar and geomagnetic activity. Heart rate variability (HRV) was recorded for 72 consecutive hours each week over a five-month period in 16 participants in order to examine ANS responses during normal background environmental periods. HRV measures were correlated with solar and geomagnetic variables using multivariate linear regression analysis with Bonferroni corrections for multiple comparisons after removing circadian influences from both datasets. Overall, the study confirms that daily ANS activity responds to changes in geomagnetic and solar activity during periods of normal undisturbed activity and it is initiated at different times after the changes in the various environmental factors and persist over varying time periods. Increase in solar wind intensity was correlated with increases in heart rate, which we interpret as a biological stress response. Increase in cosmic rays, solar radio flux, and Schumann resonance power was all associated with increased HRV and parasympathetic activity. The findings support the hypothesis that energetic environmental phenomena affect psychophysical processes that can affect people in different ways depending on their sensitivity, health status and capacity for self-regulation.

Synchronization of Human Autonomic Nervous System Rhythms with Geomagnetic Activity in Human Subjects

A coupling between geomagnetic activity and the human nervous system’s function was identified by virtue of continuous monitoring of heart rate variability (HRV) and the time-varying geomagnetic field over a 31-day period in a group of 10 individuals who went about their normal day-to-day lives. A time series correlation analysis identified a response of the group’s autonomic nervous systems to various dynamic changes in the solar, cosmic ray, and ambient magnetic field. Correlation coefficients and p values were calculated between the HRV variables and environmental measures during three distinct time periods of environmental activity. There were significant correlations between the group’s HRV and solar wind speed, Kp, Ap, solar radio flux, cosmic ray counts, Schumann resonance power, and the total variations in the magnetic field. In addition, the time series data were time synchronized and normalized, after which all circadian rhythms were removed. It was found that the participants’ HRV rhythms synchronized across the 31-day period at a period of approximately 2.5 days, even though all participants were in separate locations. Overall, this suggests that daily autonomic nervous system activity not only responds to changes in solar and geomagnetic activity, but is synchronized with the time-varying magnetic fields associated with geomagnetic field-line resonances and Schumann resonances.

Group planarian sudden mortality: Is the threshold around global geomagnetic activity ≥K6?

Sudden deaths in groups of animals have been observed by field and laboratory biologists. We have measured mortalities in large group-housed planarian during the infrequent periods of very intense geomagnetic activity. In 13 separate episodes over the last 5 y we have observed the sudden death in our laboratory of hundreds of planarian if their density was about 1 worm per cc and the global geomagnetic activity was K≥6 the day before or the day of the observation of the mortality. Such mortality never occurred in other conditions or days. Both estimates of the "magnetic moment" of a planarian in magnetic fields above this threshold of sustained magnetic flux density as well as the magnetic energy within the planarian volume predict values that could affect phenomenon associated with the total numbers of pH-dependent charges within each worm. These conditions could affect the Levin-Burr bioelectrical signals and networks that affect patterning information and sustainability in whole living systems. The establishment of a central reservoir for the report of these transient events might allow Life Scientists to more fully appreciate the impact of these pervasive global stimuli upon dense groups of animals.

Are stress responses to geomagnetic storms mediated by the cryptochrome compass system?

A controversial body of literature demonstrates associations of geomagnetic storms (GMS) with numerous cardiovascular, psychiatric and behavioural outcomes. Various melatonin hypotheses of GMS have suggested that temporal variation in the geomagnetic field (GMF) may be acting as an additional zeitgeber (a temporal synchronizer) for circadian rhythms, with GMS somehow interfering with the hypothesized system. The cryptochrome genes are known primarily as key components of the circadian pacemaker, ultimately involved in controlling the expression of the hormone melatonin. Cryptochrome is identified as a clear candidate for mediating the effect of GMS on humans, demonstrating the prior existence of several crucial pieces of evidence. A distinct scientific literature demonstrates the widespread use of geomagnetic information for navigation across a range of taxa. One mechanism of magnetoreception is thought to involve a light-dependent retinal molecular system mediated by cryptochrome, acting in a distinct functionality to its established role as a circadian oscillator. There is evidence suggesting that such a magnetosense--or at least the vestiges of it--may exist in humans. This paper argues that cryptochrome is not acting as secondary geomagnetic zeitgeber to influence melatonin synthesis. Instead, it is hypothesized that the cryptochrome compass system is mediating stress responses more broadly across the hypothalamic-pituitary-adrenal (HPA) axis (including alterations to circadian behaviour) in response to changes in the GMF. Two conceptual models are outlined for the existence of such responses--the first as a generalized migrational/dispersal strategy, the second as a stress response to unexpected signals to the magnetosense. It is therefore proposed that GMS lead to disorientation of hormonal systems in animals and humans, thus explaining the effects of GMS on human health and behaviour.

The global coherence initiative: creating a coherent planetary standing wave

The much anticipated year of 2012 is now here. Amidst the predictions and cosmic alignments that many are aware of, one thing is for sure: it will be an interesting and exciting year as the speed of change continues to increase, bringing both chaos and great opportunity. One benchmark of these times is a shift in many people from a paradigm of competition to one of greater cooperation. All across the planet, increasing numbers of people are practicing heart-based living, and more groups are forming activities that support positive change and creative solutions for manifesting a better world. The Global Coherence Initiative (GCI) is a science-based, co-creative project to unite people in heart-focused care and intention. GCI is working in concert with other initiatives to realize the increased power of collective intention and consciousness. The convergence of several independent lines of evidence provides strong support for the existence of a global information field that connects all living systems and consciousness. Every cell in our bodies is bathed in an external and internal environment of fluctuating invisible magnetic forces that can affect virtually every cell and circuit in biological systems. Therefore, it should not be surprising that numerous physiological rhythms in humans and global collective behaviors are not only synchronized with solar and geomagnetic activity, but disruptions in these fields can create adverse effects on human health and behavior. The most likely mechanism for explaining how solar and geomagnetic influences affect human health and behavior are a coupling between the human nervous system and resonating geomagnetic frequencies, called Schumann resonances, which occur in the earth-ionosphere resonant cavity and Alfvén waves. It is well established that these resonant frequencies directly overlap with those of the human brain and cardiovascular system. If all living systems are indeed interconnected and communicate with each other via biological, electromagnetic, and nonlocal fields, it stands to reason that humans can work together in a co-creative relationship to consciously increase the coherence in the global field environment, which in turn distributes this information to all living systems within the field. GCI was established to help facilitate the shift in global consciousness from instability and discord to balance, cooperation, and enduring peace. A primary goal of GCI is to test the hypothesis that large numbers of people when in a heart-coherent state and holding a shared intention can encode information on the earth's energetic and geomagnetic fields, which act as carrier waves of this physiologically patterned and relevant information. In order to conduct this research, a global network of 12 to 14 ultrasensitive magnetic field detectors specifically designed to measure the earth's magnetic resonances is being installed strategically around the planet. More important is GCI's primary goal to motivate as many people as possible to work together in a more coherent and collaborative manner to increase the collective human consciousness. If we are persuaded that not only external fields of solar and cosmic origins but also human attention and emotion can directly affect the physical world and the mental and emotional states of others (consciousness), it broadens our view of what interconnectedness means and how it can be intentionally utilized to shape the future of the world we live in. It implies that our attitudes, emotions, and intentions matter and that coherent, cooperative intent can have positive effects. GCI hypothesizes that when enough individuals and social groups increase their coherence baseline and utilize that increased coherence to intentionally create a more coherent standing reference wave in the global field, it will help increase global consciousness. This can be achieved when an increasing number of people move towards more balanced and self-regulated emotions and responses. This in turn can help facilitate cooperation and collaboration in innovative problem solving and intuitive discernment for addressing society's significant social, environmental, and economic problems. In time, as more individuals stabilize the global field and families, workplaces, and communities move to increased social coherence, it will lead to increased global coherence. This will be indicated by countries adopting a more coherent planetary view so that social and economic oppression, warfare, cultural intolerance, crime, and disregard for the environment can be addressed meaningfully and successfully.

A review of sudden unexpected death in epilepsy: prediction of patients at risk

This review attempts to provide up-to-date quantitative data from published reports on sudden unexpected death in epilepsy (SUDEP) appearing on Medline and, especially, to provide a means to predict the probability of SUDEP in a given patient. The mean incidence of SUDEP was 1.8/1000, similar to the median of 1.5. The mean standardized mortality ratio was 6.8, and the mean percentage of SUDEP cases among deaths from epilepsy was 16.6. Seventeen risk factors were identified, each given a value according to the number of studies in the literature that specified that condition as a significant risk. The addition of these 17 values then indicated the risk for a given patient. The author calculated these for a group of 91 patients who died of SUDEP and also for 91 live patients. Many of their values for the different risks were significantly different. The sensitivity of these SUDEP values was 71.3%, the specificity 81.8%, and the positive predictive value 84.6%. A discussion includes the question of whether the death in SUDEP is primarily cardiac or pulmonary and the suggestion that it may be either or both in a given patient. The most important risk factor in this study was noncompliance with antiepileptic medication, and the main message of this study to caregivers is that therapeutic drug levels are crucial to avoid SUDEP.

Moonstruck? The effect of the lunar cycle on seizures

Recent reports on the effects of the lunar cycle on seizure occurrence have yielded mixed results. If the moon phase is influential, we hypothesized that this would be due to the moon's contribution to nocturnal illumination, rather than its waxing or waning state, and that significant correlations would not be apparent if local cloud cover were controlled for. We found a significant negative correlation between the mean number of seizures and the fraction of the moon illuminated by the sun (rho=-0.09, P<0.05) in 1571 seizures recorded in a dedicated epilepsy inpatient unit over 341 days. This correlation disappeared when we controlled for the local clarity of the night sky, suggesting that it is the brightness of the night and the contribution the moon phase makes to nocturnal luminance, rather than the moon phase per se, that may influence the occurrence of epileptic seizures.

Effect of long-term geomagnetic field deprivation on the concentration of some elements in the hair of laboratory rats

The aim of the study was to determine the effect of long-term geomagnetic field (GMF) deprivation on the concentration of selected elements in the hair of laboratory rats. A total of 32 Wistar laboratory rats were divided into four equal groups (males and females) kept under hypomagnetic conditions (GMF vertical component below 20nT) and two control groups (males and females) kept free of field disturbances (GMF vertical component approx. 38000nT). At the beginning and at 7 months of the experiment, hair was taken from the dorsal part of all rats and analysed using atomic emission spectrometry for the concentration of selected magnetic elements (Fe, Ni, Co, Cr, Mn and Cu). Long-term GMF deprivation was found to affect the concentration of Fe, Mn, Cu and Cr, but had no significant effect on the concentration of Co or Ni in the hair of the analysed rats.

Geomagnetic activity and human melatonin metabolite excretion

Elevated geomagnetic activity has been linked with human psychological, neurological and cardiovascular outcomes, and altered melatonin production has been implicated as an underlying mechanism to explain these effects. The relationship between geomagnetic activity and overnight excretion of the melatonin metabolite, 6-hydroxymelatonin sulfate (6-OHMS), was evaluated in a population of 153 male electric utility workers. The effect of geomagnetic activity combined with either 60Hz magnetic field or ambient light exposures was also evaluated. Elevated equivalent amplitudes (USGS, Boulder, CO) were associated with lower adjusted mean nocturnal 6-OHMS/cr concentrations and reduced total overnight 6-OHMS excretion, consistent with a previous study. Time intervals in which geomagnetic activity predicted the largest differences in mean 6-OHMS excretion generally occurred between 15- and 33-h prior to urine sample collection. These times coincide with key periods of melatonin regulation and production, respectively, suggesting that geomagnetic activity may play a role in the entrainment of human melatonin rhythms.

Lagged association between geomagnetic activity and diminished nocturnal pain thresholds in mice

A wide variety of behaviors in several species has been statistically associated with the natural variations in geomagnetism. To examine whether changes in geomagnetic activity are associated with pain thresholds, adult mice were exposed to a hotplate paradigm once weekly for 52 weeks during the dark cycle. Planetary A index values from the previous 6 days of a given hotplate session were correlated with the mean response latency for subjects to the thermal stimulus. We found that hotplate latency was significantly (P < 0.05) and inversely correlated (rho = -0.25) with the daily geomagnetic intensity 3 days prior to testing. Therefore, if the geomagnetic activity was greater 3 days before a given hotplate trial, subjects tended to exhibit shorter response latencies, suggesting lower pain thresholds or less analgesia. These results are supported by related experimental findings and suggest that natural variations in geomagnetic intensity may influence nociceptive behaviors in mice.

Correlations of life-span variation parameters in 128 successive generations of Drosophila melanogaster with changes in atmospheric pressure and geomagnetic activity

Correlations between the parameters of life-span (LS) distribution of Drosophila melanogaster, including mean LS (MLS) and the time of 10 and 90% population mortality, and some geophysical parameters that are usually beyond the control of researchers dealing with laboratory cultures, including atmospheric pressure, solar activity indices (Wolf's sunspot numbers and 2,800-MHz radio flux), and geomagnetic activity (planetary index, K(p)), were studied. Geophysical data were obtained from free-access official web sites of the National Oceanic & Atmospheric Administration of the US Department of Commerce and the Institute of Terrestrial Magnetism and Radiowave Propagation of the Russian Academy of Sciences. The geophysical parameters were calculated only for the period corresponding to 10 days of preimaginal development of the flies from egg to imago. Canonical correlation analysis, calculation of the non-parametric Spearman rank-order correlation coefficients, and graphical data analysis were used. Highly significant correlations between parameters of LS distribution in males and females and environmental factors, such as the atmospheric pressure on the 4th and 5th day of development and geomagnetic activity indices (K(p)) on the 6th and 10th day of development were found, with correlation coefficients varying from 0.31 to 0.37 (P<0.02). Assuming a causal relationship between geophysical factors and LS, it may be hypothesized that energetically weak environmental factors determine the formation of LS oscillatory dynamics in laboratory populations. The possible mechanisms underlying the contribution of these environmental factors to the LS variation in successive generations are discussed.

Sudden death in epileptic rats exposed to nocturnal magnetic fields that simulate the shape and the intensity of sudden changes in geomagnetic activity: an experiment in response to Schnabel, Beblo and May

To test the hypothesis that sudden unexplained death (SUD) in some epileptic patients is related to geomagnetic activity we exposed rats in which limbic epilepsy had been induced to experimentally produced magnetic fields designed to simulate sudden storm commencements (SSCs). Prior studies with rats had shown that sudden death in groups of rats in which epilepsy had been induced months earlier was associated with the occurrence of SSCs and increased geomagnetic activity during the previous night. Schnabel et al. [(2000) Neurology 54:903-908] found no relationship between SUD in human patients and geomagnetic activity. A total of 96 rats were exposed to either 500, 50, 10-40 nT or sham (less than 10 nT) magnetic fields for 6 min every hour between midnight and 0800 hours (local time) for three successive nights. The shape of the complex, amplitude-modulated magnetic fields simulated the shape and structure of an average SSC. The rats were then seized with lithium and pilocarpine and the mortality was monitored. Whereas 10% of the rats that had been exposed to the sham field died within 24 h, 60% of the rats that had been exposed to the experimental magnetic fields simulating natural geomagnetic activity died (P<.001) during this period. These results suggest that correlational analyses between SUD in epileptic patients and increased geomagnetic activity can be simulated experimentally in epileptic rats and that potential mechanisms might be testable directly.

Is sudden unexplained death in adult epileptic patients associated with geomagnetic disturbances at the day of death or the 4 days before?

Geomagnetic disturbances are controversially discussed as risk factor for sudden unexplained death in epilepsy (SUDEP). An autopsy-based cohort of 39 adult patients with definite SUDEP were compared to 102 epileptic patients with known cause of death (KCD), who died between 1981 and 1992. Most of them had suffered from therapy-resistant epilepsies, predominantly characterized by generalized tonic-clonic seizures (about 70%). We analyzed an international geomagnetic index, the mean planetary daily amplitude (Ap), and the appearance of storm sudden commencement (SSC) at the individual day of decease and the 4 days before (and after). The SUDEP and KCD patients did not substantially differ with respect to the Ap values (Mann-Whitney test; P>0.2) and frequency of SSC (Fisher test; P>0.2) at death or the 4 premortem days. In addition, Ap values above 50 nanoTesla, postulated as critical threshold by other authors, showed no significant difference between SUDEP and KCD group for the day of death (5.1 versus 3.9%) or the 4 days before (5.1 versus 11.8%) (Fisher test; P>0.2). Consequently, the current data did not support the hypothesis that geomagnetic activities may act as a relevant risk factor for SUDEP.

Geomagnetic activity influences the melatonin secretion at latitude 70 degrees N

Factors other than light may affect variations in melatonin, including disturbances in the geomagnetic field. Such a possibility was tested in Alta, Norway, located at latitude 70 degrees N, where the aurora borealis is a result of large changes in the horizontal component (H) of the geomagnetic field. Geomagnetic disturbances are felt more strongly closer to the pole than at lower latitudes. Also noteworthy in Alta is the fact that the sun does not rise above the horizon for several weeks during the winter. To examine whether changes in geomagnetic activity influence the secretion of melatonin, saliva was collected from 25 healthy subjects in Alta several times during the day-night and at different times of the year. Single cosinor analyses yielded individual estimates of.the circadian amplitude and MESOR of melatonin. A 3-hour mean value for the local geomagnetic activity index, K, was used for approximately the same 24-hour span. A circadian rhythm was found to characterize both melatonin and K, the peak in K (23:24) preceding that of melatonin (06:08). During the span of investigation, a circannual variation also characterized both variables. Correlation analyses suggest that changes in geomagnetic activity had to be of a certain magnitude to affect the circadian amplitude of melatonin. If large enough (> 80 nT/3 h), changes in geomagnetic activity also significantly decreased salivary melatonin concentration.

Synergistic induction of severe hypothermia (poikilothermia) by limbic seizures, acepromazine and physical restraint: role of noradrenergic alpha-1 receptors

The maintained production of extreme reductions in core temperature (20-22 degrees C) or poikilothermia can be reliably produced by the synergistic interaction of limbic seizures (induced by lithium and pilocarpine), postseizure administration of a single injection of acepromazine, and physical restraint. Administration of the specific and nonspecific dopamine antagonists haloperidol, chlorpromazine, SCH23390, or clozapine did not simulate the effect at clinically effective dosages. Single injections of phentolamine and prazosin but not of propranolol instead of acepromazine following the seizures produced the poikilothermia. This effect was also reproduced by reducing the amount of the rats' adipose weight before the induction of the seizures and physical restraint. Rats that had been restrained or not restrained and displayed either euthermia or hypothermia exhibited significantly different patterns in brain damage within limbic and thalamic structures.

Brief successive temporal observational sampling as a possible indicator of daily overt seizure activity in epileptic rats

Chronic, limbic epilepsy was induced in male rats by a single systemic injection of lithium and pilocarpine. In two separate experiments, each 6 mo. in duration, the proportion of the population that displayed an overt motor seizure (head nodding, rearing, and forelimb clonus) within 10 min. each day after delivery of food pellets (despite food provided ad libitum) was recorded. Cumulative records for the numbers of rats in each population that displayed overt seizure for the first time during the observation period were plotted as a function of time. The occurrence of the saturated (approaching 100%) asymptote at about five months was interpreted to indicate that brief (10 min.) sampling over the 144 successive days that would compose a single 24-hr. period could serve as an estimate of the average probability of an overt seizure during an average 24-hr. period. If this assumption is correct, then these rats would have displayed about one overt seizure per day.

Sudden unexpected deaths in epileptics--a literature review

In summary, SUDEP accounts for death in approximately 8% of the young epileptic population. It is commoner in young male epileptics with a long history of generalised seizures, who have a history of head trauma and alcohol excess, and who are taking more than one antiepileptic drug. Most deaths are unwitnessed and occur at home, usually in bed and presumably overnight. Subtherapeutic AED levels do not necessarily imply non compliance, and may simply reflect drug degradation in the plasma after death. Many victims have pulmonary oedema on postmortem examination, and some show ischaemic damage of the heart despite normal coronary arteries. This possibly arises as a result of repeated episodes of vasoconstriction from seizure related catecholamine bursts. Animal studies have demonstrated the occurrence of central apnoea and also support the theory of acute fatal cardiac failure. Possible association with the daily level of geomagnetic activity is reported. The precise reason for a particular seizure being fatal in an otherwise healthy individual is as yet undetermined.

Geomagnetic disturbances are associated with reduced nocturnal excretion of a melatonin metabolite in humans

The effects of geomagnetic disturbances on urinary excretion of the melatonin metabolite, 6-hydroxymelatonin sulfate (6-OHMS), were studied in conjunction with 60 Hz magnetic field (MF) and ambient light exposure in 132 electric utility workers. Geomagnetic activity was assessed using a local (equivalent amplitude or A(K), Boulder, CO) and global (average antipodal or aa) index. Personal exposures to 60 Hz MFs and light were obtained using data-logging meters. The relationship between geomagnetic activity and 6-OHMS was assessed with adjustment for age, light exposure, and month of participation. Mean overnight 6-OHMS excretion was lower on days when the 36-h A(K) or aa values exceeded 30 nT. A greater reduction in 6-OHMS excretion was observed when increased geomagnetic activity was combined with elevated 60 Hz MF or reduced ambient light exposures.

Geophysical variables and behavior: LXXXV. Sudden infant death, bands of geomagnetic activity, and pc1 (0.2 to 5 HZ) geomagnetic micropulsations

Pc1s (continuous pulsations) within the geomagnetic field, whose durations are about 30 minutes but which can reoccur several times nightly, are observed during periods when global geomagnetic activity is very low (less than 10 nT). The hypothesis that these 0.2 to 5 Hz synchronized micropulsations or hydromagnetic emissions might stimulate physical chemical cascades within the brain that precipitate the sudden death in infants was tested by correlational analysis for a two-year period (1960-1961) for Ontario. Results were consistent with the hypothesis that the monthly incidences of these unexpected deaths, pcl micropulsations and geomagnetic activity less than 10 nT displayed a shared source of variance. Implications are discussed.

Influence of melatonin upon the protective action of conventional anti-epileptic drugs against maximal electroshock in mice

Melatonin (50 mg/kg; 60 min before the test) significantly raised the electroconvulsive threshold in mice. The protective action of melatonin (50 mg/kg) in the electroconvulsive threshold test was reversed by aminophylline, picrotoxin and bicuculline. Melatonin at the subconvulsive dose of 25 mg/kg potentiated the anticonvulsive activity of carbamazepine and phenobarbital (ED50 values were significantly decreased from 12.1 to 8.3 and from 18.9 to 11.8 mg/kg, respectively). No potentiation was observed in the case of valproate and diphenylhydantoin (their ED50s were changed from 253 to 249 and from 10.3 to 9.7 mg/kg, respectively). Melatonin did not influence the plasma or brain levels of anti-epileptics studied, so a pharmacokinetic interaction is not probable. Melatonin (25 mg/kg) alone and its combinations with carbamazepine or phenobarbital, providing a 50% protection against maximal electroshock, were devoid of significant motor adverse effects, but caused strong long-term memory deficit. Consequently, it does not seem to be a good candidate for the treatment of epilepsy.

Geophysical variables and behavior: LXXXII. A strong association between sudden infant death syndrome and increments of global geomagnetic activity--possible support for the melatonin hypothesis

A significant subpopulation of young infants who die suddenly (SIDS) often exhibit anomalies consistent with disruptions within the pineal-limbic system. We have hypothesized that sudden decreases in nocturnal melatonin by a specific range of geomagnetic activity would precipitate sudden infant death. A correlation of .90 was found between the numbers of cases of Sudden Infant Death Syndrome per month during the years 1960 and 1961 in Ontario and an increase (primarily) in numbers of days per month with average geomagnetic activity between 11 and 20 nT and 31 through 40 nT but a decrease in the numbers of days with values between 21 and 30 nT. This nonlinear sensitivity, presumably associated with specific ripple frequencies within the geomagnetic field, may explain the failure by other researchers to detect linear associations between the numbers of these types of deaths and gross, scalar indicators of geomagnetic activity.

Experimental simulation of the effects of increased geomagnetic activity upon nocturnal seizures in epileptic rats

This experiment was designed to simulate experimentally the specific parameters of geomagnetic activity that evoke epileptic seizures. The numbers of overt limbic seizures (rearing, paroxysmal forelimb clonus and falling) in a population of epileptic rats were recorded nightly for 65 successive days between 0200 and 0400 h during red light conditions. On some nights an experimental 7 Hz magnetic field whose magnitudes shifted in successive steps from zero to approximately 50 nT every 3 min was presented. The partial regression coefficients from the analysis indicated that either the presence of the 'synthetic' geomagnetic activity or increased magnitudes of the daily, natural geomagnetic activity (regional range approximately 10-70 nT) during the observational period significantly (P < 0.05) increased the proportion of nightly seizures. The effect sizes (6-8%) for both magnetic sources were comparable and additive. Concerted efforts to experimentally simulate the temporal profiles of geomagnetic activity may help reveal the neuromechanisms by which biobehavioral changes during geomagnetic perturbations occur within susceptible populations.

Increases in geomagnetic activity are associated with increases in thyroxine levels in a single patient: implications for melatonin levels

Blood levels of free T4 (thyroxine), cortisol and prolactin over 19 successive days from a single limbic epileptic patient were correlated with daily geomagnetic activity (aa values) for the northern hemisphere. Only thyroxine levels were correlated (r = 0.66) significantly with the daily geomagnetic activity; the strongest association (rho = 0.76) occurred between thyroxine levels and the geomagnetic activity (Kp values) during the previous night (2:00 A.M. to 5:00 A.M. local time). These results support the hypothesis that suppression of (nocturnal) melatonin levels by increased geomagnetic activity attenuates the tonic inhibition by this pineal compound upon thyroidal metabolism.

Enhanced hypnotic suggestibility following application of burst-firing magnetic fields over the right temporoparietal lobes: a replication

The suggestibility of normal, young men and women as assessed by Spiegel's Hypnosis Induction Profile (HIP) before and after weak (1 micro Tesla), burst-firing magnetic fields were applied for 20 min over the left or over the right temporoparietal lobe or both hemispheres; a fourth group received sham treatment. Only the group that received the stimulation over the right hemisphere exhibited a marked increase in suggestibility (eta = 0.58) following the treatment. These results replicate components of several different previous experiments and suggest that attribution of symptomatic changes following exposures to weak, extremely low frequency magnetic fields, to placebo effects may not be correct. Instead, fields whose signatures contain biorelevant information may directly affect the neurocognitive processes that are associated with hypnotizability.

Enhancement of limbic seizures by nocturnal application of experimental magnetic fields that simulate the magnitude and morphology of increases in geomagnetic activity

Over a 200 day period, chronic (limbic) epileptic rats were exposed intermittently, for either one or three nights (00 to 08 hr), once very approximately 10 days to experimental magnetic fields whose morphology (incremental changes in intensity over time) simulated geomagnetic activity. One of two intensities and two ripple frequencies (7 Hz, 45 Hz) was employed. The display of over seizures following synchronized food presentation significantly increased by a factor 3.1 relative to controls when the fields had been activated for one or two but not three successive nights. The combined effects of the experimental field and ambient geomagnetic activity (> 40 nT) explained approximately 12 to 15% of the variance in the daily incidence of seizures. Implications for the transient disinhibition of electrical lability within the limbic system following suppression of nocturnal melatonin are discussed.

Attempts to simulate the association between geomagnetic activity and spontaneous seizures in rats using experimentally generated magnetic fields

In three separate experiments, chronic epileptic male rats (ns = 24, 24, and 4) were exposed to experimental magnetic fields whose intensities were either constant or varied. The ripple frequency was always 7 Hz. Only exposure to a field with a constant intensity (700 nT) appeared to inhibit occurrence of the seizures. Although exposure to a field configuration whose strength increased and decreased by fixed increments during the hour before feeding did not affect the incidence of seizures, exposure to these fields for 5 min, only once per hour (increments of 15 to 20 nT for 30 sec. to a maximum of 70 nT) during the previous night between midnight and 0800 hr. increased the proportion of seizures following the presentation of food. An explanation is given for the persistent antithetical effects of experimental magnetic fields and geomagnetic activity upon seizure phenomena.

Geophysical variables and behavior: LXXIX. Overt limbic seizures are associated with concurrent and premidscotophase geomagnetic activity: synchronization by prenocturnal feeding

Approximately 35% of the variance (multiple r = 0.59) in the proportion of overt seizures (forelimb clonus) within a group of 35 chronically epileptic male rats during 65, daily 10-min. observation periods was significantly accommodated by the variations in the magnitude of the increased geomagnetic activity at the same time as the seizures and with activity during the previous midscotophase. The results supported the hypothesis that increased geomagnetic activity during specific subintervals of the circadian period suppresses the activity of the endogenous anticonvulsant melatonin and lowers the threshold for paroxysmal electrical seizures. The possibility of employing large populations of (limbic) epileptic patients as a network or a very large array of biomonitors for geomagnetic activity is considered.