“DEPRESSION TREATMENT WITH ELF MAGNETIC FIELDS OF pT INTENSITY”
DOCTORAL THESIS
Juan Pedro Ramírez García.
Director: Dr. José Luis Bardasano Rubio
Universidad
de Alcalá de Henares -Madrid. Faculty
of Medicine. Department of Medical Specalities
Alcalá de Henares 2006
INTRODUCTION
The
incidence of depressive disorder is one of the highest among the population and
increases yearly. The distimic disorder is a form of chronic depression the
prevalence of which ranges from 3 – 4 %.
Transcranial
magnetic stimulation (TMS) is a non invasive technique to stimulate nerve cells
in determined parts of the brain. This is a complementary or coadjuvant therapy
to pharmacologic treatment in severe depression and is used as an alternative to
electroconvulsive therapy (ECT) in patients with resistant depression.
In
commercial TMS equipment coils, which generate very strong magnetic fields, are
used to induce potential differentials great enough to produce motor-evoked
potentials. Nevertheless, this treatment is costly, may carry side effects and
requires specialised professionals for its implementation.
The
intensity of Tesla used in rTMS may be much higher than required for achieving
therapeutic effects.
The
hypothesis of this study was that extremely low frequency magnetic fields (pT)
may be effective in the treatment of drug-resistant
distimic disorder (stages 1 and 2 according to
the Thase and Rush classification).
MATERIAL
AND METHODS
A
prototype producing low intensity (pT) and extremely high frequency (8
Hz) magnetic fields was used as a transcranial magnetic stimulator applied
with a helmet-shaped electrode containing 32 stimulating coils.
A
Stage II multicenter, double-blind, randomized, parallel, placebo-controlled
clinical trial was carried out in four outpatient clinics: CLIAM
Clinic in Madrid (6 patients), CENAC in Barcelona (5 patients),
Health Center in La Pueblanueva,
Toledo (14 patients) and Manuel Fajardo
Polyclinic in Havana City, Cuba (32 patients). The total sample size was 57
patients, 30 in the treatment group and 27 in the placebo group. The inclusion
criteria were: to be diagnosed with a drug-resistant
distimic disorder (stages 1 and 2 according to the Thase and Rush
classification),
to have a final score on
the CET-DE scale>
32
points, patient consent, and
age > 18 years.
Exclusion
criteria were: a
final CET-DE
score
< 32,
patient refusal to participate,
puerperium or breastfeeding, age < 18, presence of psychotic or maniac
disorders, depression associated with a chronic disease, epilepsy, previous CVA,
presence of medical devices (cardiac pacemakers, drug infusion pumps,
intracardiac electrodes) and a history of severe migraine.
Results
were evaluated using two measurement instruments: the CET-DE questionnaire and a
self-administered Inventory (Beck’s Inventory), both of which have been
validated for the diagnosis and follow up of depression. These questionnaires
were given on three occasions: immediately before treatment, on completion of
treatment, and one month after treatment conclusion, the latter being performed
to evaluate the persistence of the therapeutic effects.
None of the patients dropped out from the study.
RESULTS
AND DISCUSSION
The
comparison of CET-DE before and after the treatment showed a clinical and statistically
significant
result favouring treatment (P<0.05).
On comparing verum treatment versus
placebo with Beck’s Inventory after treatment no statistical significance was
observed (P = 0.57). Neither was significance achieved with the criteria
considered clinically significant.
The
CET-DE and Beck’s Inventory evaluate different aspects of the depressive
spectrum which may explain this lack of congruence. The Beck Inventory gives
mores importance to cognitive components rather than to the somatic and
behavioural components of depression.
Another
possible explanation to justify the differences observed may be that the
treatment initially modifies the cognitive aspects less. Cognitive components
react more slowly than those which are somatic and behavioural components which
may be observed on analysing the results achieved with the Beck’s Inventory
after one month, with a trend to statistically significant differences being
observed (P<0.05).
CONCLUSIONS
The
picotesla ELF magnetic fields (8 Hz) applied as TMS are an effective tool with
no relevant side effects for the treatment drug-resistant distimic disorder. It
has many beneficial effects on the symptoms of depression which persist one
month after treatment conclusion.
The
evaluation of the design and construction of the stimulator prototype used here
was found to be technically ideal for clinical application.