Study type: Medical/biological study (experimental study)

Nocebo as headache trigger: evidence from a sham-controlled provocation study with RF fields. med./bio.

Published in: Acta Neurol Scand Suppl 2008; 188: 67-71

Aim of study (acc. to author)

To investigate clinical features and diagnosis of headache experienced by participants in a provocation study (exposure to mobile phone signals) and to discuss the results in relation to the nocebo phenomenon.

Background/further details

17 subjects (12 men) who exhibited a close temporal relation between symptoms in the head and use of mobile phones in a provocation test were selected for the study. Participants performed four sessions (two days break between the sessions) that each consisted of an exposure and a sham exposure condition in randomized order. 15 participants completed all four trials.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 902.4 MHz
Modulation type: pulsed
Exposure duration: continuous for 30 min
  • SAR: 1 W/kg peak value (1 g)

Exposure 1

Main characteristics
Frequency 902.4 MHz
Type
Exposure duration continuous for 30 min
Modulation
Modulation type pulsed
Duty cycle 12.5 %
Repetition frequency 217 Hz
Exposure setup
Exposure source
Setup test person's head positioned between two dipole antennae of which only one was activated during each exposure
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1 W/kg peak value - 1 g -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

In most subjects, the reported headache was compatible with tension-type headache. No significant differences were observed between exposure and sham exposure in headache type, laterality or location. No detectable effect on pulse rate or blood pressure was observed, indicating that the exposures were not stress-provoking (possible mediator of headache).
The results indicate that headache occuring in connection with mobile phone signals was not related to radio frequency electromagnetic fields, but most likely caused by negative expectations (nocebo).

Study character:

Study funded by

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