12-month, double-blind clinical test of magnetic mattress pads
- Out of 375 patients sleeping on the magnetic mattress pads, 80.27% reported positive results.
- Over 70% of the experimental patients realized the effects within 5 days.
- Benefits included significant reductions in back pain, neck & shoulder pain, leg pain, insomnia and fatigue.
- No reported side effects.
16-week randomized, double-blind study of magnetic mattress pad use for Fibromyalgia
- Sleeping on a magnetic mattress pad provides statistically
significant and clinically relevant pain relief, sleep improvement, and
improved physical functioning in subjects with fibromyalgia.
- Subjects sleeping on the sham mattress pad experienced no significant changes.
- No adverse reactions were noted in the experimental group.
6-month randomized, controlled trial of magnetic sleep pads for Fibromyalgia
- Subjects sleeping on magnetic sleep pads reported statistically
significant reductions in pain intensity compared to the two sham
- A greater reduction in the number of tender points, tender point
intensity, and improvements in functional status were also reported in
the magnet group, however these improvements were not statistically
Full List of Study Abstracts:
Summary of a 12-month double-blind, clinical test of magnetic mattress pads.
Carried out by Sanikukal Hospital, Tokyo Communications Hospital and Kouseikai Suzuki Hospital, by Dr. Kazuo Shimodaira. 1990.
The mattress pads used in this study were typical full-size pads
containing 124 permanent ferrite magnets with magnetic field strengths
of 750-950 gauss each. The pads themselves were made of two sheets of
felt with the magnets sandwiched between them. The felt sheets were then
wrapped in a cloth cover. The total number of subjects of this
double-blind clinical experiment was 431 (216 male, 215 female). 375
subjects were given the magnetic pads, 56 were given non-magnetic pads.
None of the 431 subjects knew which pad they were sleeping on. Subjects
selected for the experiment were those with chief complaints related to:
- Neck and Shoulder pain
- Back and Lower Back Pain
- Back Pain (general)
- Lower Limb Pain
To determine the presence of any side effects, blood pressure,
hemoglobin, number of erythrocytes, and number of leukocytes were
examined before and after the use of the mattress pads. Besides blood
sedimentation, and TP, COL, ALP, GOT, GPT, Na, and K were also examined,
as were functions of the kidneys, liver, pancreas, and the entire
||# of Positive
||% of Total
||# of No Results
||% of Total
|Neck & Shoulder Pain
|Lower Back Pain
|General Back Pain
|Lower Limb Pain
Out of 375 total subjects with symptoms:
- 301 (80.27%) reported positive results.
- 74 cases (19.73%) reported no results
Time of Response:
The percentage of subjects who realized the effect of the magnetic mattress pad within 3 days:
|Neck & Shoulder Pain
|Back & Lower Back Pain
|Back Pain (general)
|Lower Limb Pain
Out of 375 total subjects who slept on the magnetic mattress pads:
- 200 (53.3%) realized the effects within 3 days.
- Over 70% realized the effects within 5 days.
Testing for side effects was conducted at the conclusion of the
experiment. Symptoms such as tinnitus, headache, hearing problems,
visual disturbances, vertigo, palpitation, perceptive abnormality,
motorial disturbance, fever, digestive disturbance, coetaneous symptoms,
and other clinical symptoms to suggest any side effects were found to
be totally absent. Extensive testing was also done before and after the
experiment to check functions of kidneys liver, pancreas, blood
pressure, and the circulatory system. No clinical symptoms were found to indicate any side effects whatsoever.
Dr. Shimodaira's conclusion of this year-long study conducted in 3 of Japan's foremost hospitals:
"The magnetized health mattress pad is proved to be effective on neck
and shoulder pain, back and lower back pain, back pain, lower limb pain,
insomnia, and fatigue, and to have no side effects."
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Magnetic Mattress Pad Use in Patients with Fibromyalgia: a Randomized Double-blind Pilot Study.
Agatha P. Colbert, M.D.
Clinical Assistant Professor of Physical Medicine and Rehabilitation
Tufts University School of Medicine, Boston, MA 02111
Marko S Markov, Ph.D.
Department of Orthopedics
Mount Sinai School of Medicine, New York
Mandira Baneiji, M.A.
Research Assistant, Litterst & Associates, Newton, MA
Arthur A Pilla, Ph.D.
Department of Orthopedics, Mount Sinai School of Medicine, New York
Department of Biomedical Engineering, Columbia University, New York
OBJECTIVE: To determine if the chronic pain and sleep disturbances
experienced by patients with fibromyalgia can be improved by sleeping on
a magnetic mattress pad.
PATIENTS: Thirty-five female subjects diagnosed with fibromyalgia
syndrome were recruited. Thirty met inclusion/exclusion criteria and
entered the study. Twenty-five completed it. One was lost to follow-up.
Three were withdrawn for protocol violations and one because of an
INTERVENTION: Sleeping on an experimental (magnetized at a magnet
surface field strength of 1100 +/- 50 Gauss and delivering 200-600 Gauss
to the skin surface or a sham (non-magnetized) mattress pad over a 16
MAIN OUTCOME MEASURES: Visual Analog Scales (VAS) for global
well-being, pain, sleep, fatigue and tiredness on awakening; Total
Myalgic Score; Pain Distribution Drawings; and a modified Fibromyalgia
RESULTS: Subjects sleeping on the experimental mattress pad
experienced a significant decrease in pain ~ <.05), fatigue
~<.006), total myalgic score ~ <.03), and pain distribution
drawing (1) <.02). Additionally, these subjects showed significant
improvement in reported sleep (p <.01) and physical functioning as
evidenced from the modified Fibromyalgia Impact Questionnaire ~
<.04). Subjects sleeping on the sham mattress pad experienced no
significant change in these same outcome measures. Subjects in both the
control and experimental groups showed improvement in tiredness on
wakening, demonstrating a placebo effect in this parameter. Neither
group showed any effect on global wellbeing.
CONCLUSIONS: Sleeping on a magnetic mattress pad, with a magnet
surface field strength of 1100 +/- 50 Gauss, delivering 200-600 Gauss at
the skin surface provides statistically significant and clinically
relevant pain relief and sleep improvement in subjects with
fibromyalgia. No adverse reactions were noted during the 16-week trial
Journal of Back and Musculoskeletal Rehabilitation 13(1999) 19-31
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Static magnetic fields for treatment of fibromyalgia: a randomized controlled trial.
Alfano AP, Taylor AG, Foresman PA, Dunkl PR, McConnell GG, Conaway MR, Gillies GT.
Department of Physical Medicine and Rehabilitation, University of
Virginia Health System, Charlottesville, USA. email@example.com
OBJECTIVE: To test effectiveness of static magnetic fields of two
different configurations, produced by magnetic sleep pads, as adjunctive
therapies in decreasing patient pain perception and improving
functional status in individuals with fibromyalgia.
DESIGN: Randomized, placebo-controlled, 6-month trial conducted from November 1997 through December 1998.
SETTING AND SUBJECTS: Adults who met the 1990 American College of
Rheumatology criteria for fibromyalgia were recruited through clinical
referral and media announcements and evaluated at a university-based
INTERVENTIONS: Subjects in Functional Pad A group used a pad for 6
months that provided whole-body exposure to a low, uniform static
magnetic field of negative polarity. Subjects in the Functional Pad B
group used a pad for 6 months that exposed them to a low static magnetic
field that varied spatially and in polarity. Subjects in two Sham
groups used pads that were identical in appearance and texture to the
functional pads but contained inactive magnets; these groups were
combined for analysis. Subjects in the Usual Care group continued with
their established treatment regimens.
OUTCOME MEASURES: Primary outcomes were the change scores at 6 months
in the following measures: functional status (Fibromyalgia Impact
Questionnaire), pain intensity ratings, tender point count, and a tender
point pain intensity score.
RESULTS: There was a significant difference among groups in pain
intensity ratings (p = 0.03), with Functional Pad A group showing the
greatest reduction from baseline at 6 months. All four groups showed a
decline in number of tender points, but differences among the groups
were not significant (p = 0.72). The functional pad groups showed the
largest decline in total tender point pain intensity, but overall
differences were not significant (p = 0.25). Improvement in functional
status was greatest in the functional pad groups, but differences among
groups were not significant (p = 0.23).
CONCLUSIONS: Although the functional pad groups showed improvements
in functional status, pain intensity level, tender point count, and
tender point intensity after 6 months of treatment, with the exception
of pain intensity level these improvements did not differ significantly
from changes in the Sham group or in the Usual Care group.
J Altern Complement Med 2001 Feb;7(1):53-64
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Sleep inducing effect of low energy emission therapy.
Reite M, Higgs L, Lebet JP, Barbault A, Rossel C, Kuster N, Dafni U, Amato D, Pasche B.
Department of Psychiatry, University of Colorado Health Sciences Center, Denver.
The sleep inducing effect of a 15 min treatment with either an active
or an inactive Low Energy Emission Therapy (LEET) device emitting
amplitude-modulated electromagnetic (EM) fields was investigated in a
double-blind cross-over study performed on 52 healthy subjects. All
subjects were exposed to both active and inactive LEET treatment
sessions, with an interval of at least 1 week between the two sessions.
LEET consists of 27.12 MHz amplitude-modulated (sine wave) EM fields
emitted intrabuccally by means of an electrically conducting mouthpiece
in direct contact with the oral mucosa. The estimated local peak SAR is
less than 10 W/kg in the oral mucosa and 0.1 to 100 mW/kg in brain
tissue. No appreciable sensation is experienced during treatment, and
subjects are therefore unable to tell whether they are receiving an
active or an inactive treatment. In this study the active treatment
consisted of EM fields intermittently amplitude-modulated (sine wave) at
42.7 Hz for 3 s followed by a pause of 1 s during which no EM fields
were emitted. During the inactive treatment no EM fields were emitted.
Baseline EEGs were obtained and 15 min post-treatment EEGs were recorded
and analyzed according to the Loomis classification. A significant
decrease (paired t test) in sleep latency to stage B2 (-1.78 +/- 5.57
min, P = 0.013), and an increase in the total duration of stage B2 (1.15
+/- 2.47 min, P = 0.0008) were observed on active treatment as compared
with inactive treatment.
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Static Magnetotherapy for the Treatment of Insomnia.
Shieh YY, Tsai FY.
Department of Radiological Sciences, School of Medicine, UC Irvine Medical Center, Orange, CA 92868, USA.
Magnets have been used for centuries to treat a number of physical
disorders. The vast majority of research, however, on static magnet
therapy for insomnia has been confined to the auricular type of therapy,
with publications limited to Chinese journals. Most of these studies
have depended on the subjective self-assessment of participants rather
than objective scientific measurements. In this study, the authors
report the positive preliminary results of insomnia treatment using
pillows with embedded magnets, magnetic insoles and TriPhase bracelets.
The analysis is based on objective actigraphic and polysomnographic
data. A theory of accelerated transition from wakefulness to sleep is
proposed to explain the process of insomnia relief through low-strength
static magnetic fields. Analysis by functional Magnetic Resonance
Imaging (fMRI) is used to further investigate the theory.
Int J Electron Healthc. 2008;4(3-4):339-49.
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Effects of low energy emission therapy in chronic psychophysiological insomnia.
Pasche B, Erman M, Hayduk R, Mitler MM, Reite M, Higgs L, Kuster N, Rossel C, Dafni U, Amato D, Barbault A, Lebet JP.
Symtonic USA, Inc., New York, New York 10162, USA.
The treatment of chronic psychophysiological insomnia presents a
challenge that has not been met using currently available
pharmacotherapy. Low energy emission therapy (LEET) has been developed
as a potential alternative therapy for this disorder. LEET consists of
amplitude-modulated electromagnetic fields delivered intrabuccally by
means of an electrically conducting mouthpiece in direct contact with
the oral mucosa. The effect of LEET on chronic psychophysiological
insomnia was assessed with polysomnography (PSG) and sleep rating forms
on a total of 106 patients at two different centers. Active or inactive
LEET was administered for 20 minutes in late afternoon three times a
week for a total of 12 treatments. Primary efficacy endpoints evaluating
the results were changes from baseline in PSG-assessed total sleep time
(TST) and sleep latency (SL). Secondary endpoints were changes in sleep
efficiency (SE), sleep stages, and reports by the subjects of SL and
TST. There was a significant increase in TST as assessed by PSG between
baseline and post-treatment values for the active treatment group (76.0
+/- 11.1 minutes, p = 0.0001). The increase for the inactive treatment
group was not statistically significant. The TST improvement was
significantly greater for the active group when compared to the inactive
group (adjusted for baseline TST; p = 0.020. R1 = 0.20). There was a
significant decrease in SL as assessed by PSG between baseline and
post-treatment values for the active treatment group (-21.6 +/- 5.9
minutes, p = 0.0006), whereas the decrease noted for the inactive
treatment group was not statistically significant. The difference in SL
decrease between the two treatment groups was marginally significant
(adjusted for baseline SL and center, p = 0.068, R2 = 0.60). The number
of sleep cycles per night increased by 30% after active treatment (p =
0.0001) but was unchanged following inactive treatment. Subjects did not
experience rebound insomnia, and there were no significant side
effects. The data presented in this report indicate that LEET
administered for 20 minutes three times a week increased TST and reduced
SL in chronic psychophysiological insomnia. LEET is safe and well
tolerated and it effectively improved the sleep of chronic insomniacs
given 12 treatments over a 4-week period by increasing the number of
sleep cycles without altering the percentage of the various sleep stages
during the night. The therapeutic action of LEET differs from that of
currently available drug therapies in that the sleep pattern noted in
insomniacs following LEET treatment more closely resembles nocturnal
physiological sleep. This novel treatment may offer an attractive
alternative therapy for chronic insomnia.
Sleep. 1996 May;19(4):327-36.
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Pulsed high-frequency electromagnetic field affects human sleep and sleep electroencephalogram.
Borbely AA, Huber R, Graf T, Fuchs B, Gallmann E, Achermann P.
Institute of Pharmacology and Toxicology, University of Zurich, Switzerland. firstname.lastname@example.org
To investigate whether the electromagnetic field (EMF) emitted by
digital radiotelephone handsets affects the brain, healthy, young
subjects were exposed during an entire night-time sleep episode to an
intermittent radiation schedule (900 MHz; maximum specific absorption
rate 1 W/kg) consisting of alternating 15-min on-15-min off intervals.
Compared with a control night with sham exposure, the amount of waking
after sleep onset was reduced from 18 to 12 min. Spectral power of the
electroencephalogram in non-rapid eye movement sleep was increased. The
maximum rise occurred in the 10-11 Hz and 13.5-14 Hz bands during the
initial part of sleep and then subsided. The results demonstrate that
pulsed high-frequency EMF in the range of radiotelephones may promote
sleep and modify the sleep EEG.
Neurosci Lett. 1999 Nov 19;275(3):207-10.
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The effects of natural and man-made electromagnetic fields on mood and behavior: the role of sleep disturbances.
Natural and man-made electromagnetic fields influence the mood and
behavior of healthy and sick people. Considerable evidence suggests that
electromagnetic fields affect sleep. The author suggests that
electromagnetic field-induced changes in sleep may mediate the effects
of electromagnetic fields on mood, behavior, and cognitive abilities.
The author further suggests that the development of sleep abnormalities
in persons exposed to artificial electromagnetic fields may predict the
onset of a psychiatric disorder at a later time and that early
intervention may prevent the onset of a psychiatric disease. Copyright
2000 Harcourt Publishers Ltd.
Med Hypotheses. 2000 Apr;54(4):630-3.
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Space environment, electromagnetic fields, and circadian rhythm.
Izumi R, Ishioka N, Mizuno K, Goka T.
Human space activity began in 1961. About 400 persons have gone to
space since then, and about 70 of them have stayed more than 1 month.
Circadian rhythm and sleep in space have been investigated several
times, though the effect of longer stays in space has not been
adequately clarified. Electromagnetic fields are different in the space
environment, especially in deeper space missions, such as the Moon or
Mars, but their effects on human health have rarely been studied. In
this article, we summarize the current status of the International Space
Station project, study circadian rhythm and sleep in space, investigate
electromagnetic fields, and state the necessity for investigating this
Biomed Pharmacother. 2001;55 Suppl 1:25s-31s.
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Modulation by ultralow intensity electromagnetic fields on pharmacologic effects of psychotropic drugs.
Shtemberg AS, Bazian AS, Shikhov SN, Cherniakov GM, Uzbekov MG.
National Research Center Institute of Medical and Biological
Problems, Institute of Higher Nervous Activity and Neurophysiology,
Russian Academy of Sciences, Research Institute of Psychiatry, Russian
Ministry of Public Health, Moscow.
The ultralow-intensity electromagnetic fields (EMF, frequency of
4200, modulated by a quasistochastic signal in the range of 20-20,000
Hz, power density of 15 microW/cm2, specific body absorption rate up to
4.5 mJ/kg) potentiated the hypnogenic effect of hexenal. The exposure to
the EMF shortened the time of falling asleep induced by this drug and
increased sleep duration in rats. The exposure to the EMF also
potentiated haloperidol catalepsy: it decreased the drug threshold dose
and increased the catalepsy duration. The EMF influence on the
haloperidol effects was of a prolonged character: it was manifest in a
selected suppression of the emotional excitation in the open-field test
within 24 hours after the exposure.
Zh Vyssh Nerv Deiat Im I P Pavlova. 2001 May-Jun;51(3):373-7.
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Impulse magnetic-field therapy for insomnia: a double-blind, placebo-controlled study.
Pelka RB, Jaenicke C, Gruenwald J.
Universitat der Bundeswehr Munchen Neubiberg/Munich, Germany.
This 4-week double-blind, placebo-controlled study assessed the
efficacy of impulse magnetic-field therapy for insomnia. One hundred one
patients were randomly assigned to either active treatment (n = 50) or
placebo (n = 51) and allocated to one of three diagnostic groups: (1)
sleep latency; (2) interrupted sleep; or (3) nightmares. Efficacy
endpoints were intensity of sleep latency, frequency of interruptions,
sleepiness after rising, daytime sleepiness, difficulty with
concentration, and daytime headaches. In the active-treatment group, the
values of all criteria were significantly lower at study end (P <
.00001). The placebo group also showed significant symptomatic
improvement (P < .05), but the differences between groups were highly
significant (P < .00001). 70% (n = 34) of the patients given active
treatment experienced substantial or even complete relief of their
complaints; 24% (n = 12) reported clear improvement; 6% (n = 3) noted a
slight improvement. Only one placebo patient (2%) had very clear relief;
49% (n = 23) reported slight or clear improvement; and 49% (n = 23) saw
no change in their symptoms. No adverse effects of treatment were
Adv Ther. 2001 Jul-Aug;18(4):174-80.
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The influences of extremely low frequency magnetic fields on clonidine-induced sleep in 2-day-old chicks.
Min YS, Jeong JH, Choi YM, Lee BC, Huh IH, Lee SY, Sohn UD.
Department of Pharmacology, College of Pharmacy, Chung Ang University, Seoul 156-756, Republic of Korea.
1. It has been shown that magnetic fields (MFs) affect a variety of
biological effects in animal brains. There have been few experiments on
the effects of MFs on sleep. Therefore, we investigated whether
extremely low frequency (ELF) MFs affect the sleep induced by clonidine,
a central alpha(2)-adrenoceptor agonist. Clonidine produced
dose-related increase of the sleeping time and dose-related decrease of
the onset time in 2-day-old chicks. 2. Exposure of chicks to MFs (5, 10,
20 G; for 3, 6, 9, 12 h) significantly increased the clonidine-induced
sleep time as a direct function of intensity and duration of MF
application. Clonidine reduced noradrenaline or tyrosine in the brain,
an effect which was not further changed in animals exposed to MF. 3. To
determine whether the gamma amino butyric acid A
(GABA(A))/benzodiazepine (BZD) receptor system is involved in the
decrease in clonidine-induced sleep caused by activation of central
alpha(2)-adrenergic systems, we examined exposure of chicks to the
effects of the BZD receptor antagonist flumazenil (0.5 mg kg(-1), i.p.)
and GABA(A) antagonist bicuculline (0.1 mg kg-1, i.p.) on
clonidine-induced sleep. Bicuculline and flumazenil inhibited the
increase of clonidine-induced sleep time by MFs. Clonidine or MFs did
not change GABA levels in the brain. 4. These results suggest that MFs
can increase clonidine-induced sleep via a change of GABA(A) and BZD
receptor system irrespective of the concentration of GABA or
noradrenaline in the brain of 2-day-old chicks.
J Auton Pharmacol. 2001 Aug;21(4):197-203.
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Electromagnetic fields, such as those from mobile phones, alter regional cerebral blood flow and sleep and waking EEG.
Huber R, Treyer V, Borbely AA, Schuderer J, Gottselig JM, Landolt HP, Werth E, Berthold T, Kuster N, Buck A, Achermann P.
Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
Usage of mobile phones is rapidly increasing, but there is limited
data on the possible effects of electromagnetic field (EMF) exposure on
brain physiology. We investigated the effect of EMF vs. sham control
exposure on waking regional cerebral blood flow (rCBF) and on waking and
sleep electroencephalogram (EEG) in humans. In Experiment 1, positron
emission tomography (PET) scans were taken after unilateral head
exposure to 30-min pulse-modulated 900 MHz electromagnetic field
(pm-EMF). In Experiment 2, night-time sleep was polysomnographically
recorded after EMF exposure. Pulse-modulated EMF exposure increased
relative rCBF in the dorsolateral prefrontal cortex ipsilateral to
exposure. Also, pm-EMF exposure enhanced EEG power in the alpha
frequency range prior to sleep onset and in the spindle frequency range
during stage 2 sleep. Exposure to EMF without pulse modulation did not
enhance power in the waking or sleep EEG. We previously observed EMF
effects on the sleep EEG (A. A. Borbely, R. Huber, T. Graf, B. Fuchs, E.
Gallmann and P. Achermann. Neurosci. Lett., 1999, 275: 207-210; R.
Huber, T. Graf, K. A. Cote, L. Wittmann, E. Gallmann, D. Matter, J.
Schuderer, N. Kuster, A. A. Borbely, and P. Achermann. Neuroreport,
2000, 11: 3321-3325), but the basis for these effects was unknown. The
present results show for the first time that (1) pm-EMF alters waking
rCBF and (2) pulse modulation of EMF is necessary to induce waking and
sleep EEG changes. Pulse-modulated EMF exposure may provide a new,
non-invasive method for modifying brain function for experimental,
diagnostic and therapeutic purposes.
J Sleep Res. 2002 Dec;11(4):289-95.
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Influence of pulsating magnetic field used in magnet therapy and magnet stimulation on cortisol secretion in human.
Woldanska-Okonska M, Czernicki J.
Oddzialu Rehabilitacji, Samodzielnego Publicznego Zakladu Opieki Zdrowotnej w Sieradzu.
The aim of our study was to test the influence of magnetic fields
during magnetotherapy and magnetostimulation over a longer period of
time (like in physiotherapy) on cortisol secretion in humans. The study
population was divided into two groups: magnetotherapy group (16 men)
and magnetostimulation group (10 men). Magnetotherapy in the form of
magnetic field induction (2.9 microT; frequency--40 Hz; square wave;
bipolar; Magnetronic MF--10 apparatus) was applied for 20 min to the
lumbar area in patients with chronic low back pain. Magnetostimulation
(Viofor JPS system; M2P2 program; induction--25-80 microT;
frequency--200 Hz, complex saw-like shape with a plateau halfway the
height of the wave; bipolar) was applied every day for 12 min in
patients with the same health problem. In both groups, the procedures
were repeated 15 times (about 10:00 a.m.) with weekend breaks. Serum
samples were collected at 6:00, 12:00, 16:00 and 24:00 and estimated by
the micromethod of chemiluminescence (DPC Poland; Cat. No. LKC01). The
circadian profile of cortisol was determined prior to the application, a
day and a month after application. The data were analyzed
statistically, using paired and unpaired Student's test. Magnetotherapy
affects the cortisol secretion in the circadian profile by decreasing
its level at 16:00 a day after 15 applications, whereas
magnetostimulation by increasing its level at 12:00 a month after 15
applications, which may suggest its long-term effect on
hypothalamic-pituitary axis. The comparison of the results indicated
that a day after magnetotherapy and magnetostimulation, the circadian
curves of cortisol secretion differed significantly by about 100%. All
hormone oscillations did not exceed the physiological norms of the
circadian cortisol level, not reaching the level so high as in an
intense stress. This suggests rather their controlling effect on the
cortisol level than their significant stressogenic nature.
Med Pr. 2003;54(1):29-32.
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Effects of an acute D2-dopaminergic blockade on the somatosensory
cortical responses in healthy humans: evidence from evoked magnetic
Huttunen J, Kahkonen S, Kaakkola S, Ahveninen J, Pekkonen E.
BioMag Laboratory, Medical Engineering Centre Department of Clinical
Neurophysiology, Helsinki University Central Hospital, P.O. Box 340,
SUMMARY: We tested the possible role of dopaminergic activity in the
processing of somatosensory afferent information in healthy humans.
Somatosensory evoked magnetic fields (SEFs) were recorded in seven
subjects in response to left median nerve stimulation. SEFs were
obtained in all subjects after oral administration of 2 mg haloperidol,
an antagonist to dopaminergic D2 receptors, and placebo, which were
given in a randomized, double-blind cross-over design. SEFs were
analyzed using a multiple equivalent current dipole (ECD) model, with
one dipole at the right primary somatosensory cortex (SI) and at both
left and right secondary somatosensory cortices (SII). The earliest
responses from SI, peaking at about 20 ms (N20m) and 35 ms (P35m), were
not affected by haloperidol. A later deflection peaking at about 75 ms
(P60m), however, was slightly reduced (p < 0.05). Responses arising
from SII were not significantly changed. The results suggest that
dopaminergic activity may be involved in modulating somatosensory
processing after the initial stages of cortical activation.
Neuroreport. 2003 Aug 26;14(12):1609-12.
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Effects of magnetic field exposure on open field behaviour and nociceptive responses in mice.
Del Seppia C, Mezzasalma L, Choleris E, Luschi P, Ghione S.
Institute of Clinical Physiology, CNR, via Moruzzi 1, 56124 Pisa, Italy. email@example.com
Results of previous studies have shown that nociceptive sensitivity
in male C57 mice is enhanced by exposure to a regular 37 Hz or an
irregularly varying (<1 Hz) electromagnetic field. In order to test
whether these fields affect more generally mouse behaviour, we placed
Swiss CD-1 mice in a novel environment (open field test) and exposed
them for 2 h to these two different magnetic field conditions. Hence, we
analysed how duration and time course of various behavioural patterns
(i.e. exploration, rear, edge chew, self-groom, sit, walk and sleep) and
nociceptive sensitivity had been affected by such exposure. Nociceptive
sensitivity was significantly greater in magnetically treated mice than
in controls. The overall time spent in exploratory activities was
significantly shorter in both magnetically treated groups (< 1 Hz,
33% and 37 Hz, 29% of total time), than in controls (42%). Conversely,
the time spent in sleeping was markedly longer in the treated groups
(both 27% of total time) than in controls (11%). These results suggest
that exposure to altered magnetic fields induce a more rapid habituation
to a novel environment.
Behav Brain Res. 2003 Sep 15;144(1-2):1-9.
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