Authors

Vecchio F, Babiloni C, Ferreri F, Buffo P, Cibelli G, Curcio G, Dijkman SV, Melgari JM, Giambattistelli F, Rossini PM. Mobile phone emission modulates inter-hemispheric functional coupling of EEG alpha rhythms in elderly compared to young subjects. Clin Neurophysiol. Dec 11, 2009 Ahead of print.

Background
The use of mobile phone exposes the head to electromagnetic fields (EMFs), leading to concerns over potential effects on brain functioning. Small temperature increases in the head subsequent to GSM-EMF exposure have been noted, but the non-thermal biological effects, and effects on cognitive function, are poorly understood. Among young subjects, GSM-EMFs of a mobile phone modulate eyes-closed resting electroencephalographic (EEG) rhythms, a measure of brain function. There is concern about whether the effects of GSM-EMFs exposure vary as people age, since the nervous system is particularly susceptible to insult later in life.

Objective
The authors tested the hypothesis that the effects of GSM-EMFs from a mobile phone affect eyes-closed resting EEG measures differently depending on age.

Methods
Study participants were 16 healthy elderly volunteers, ranging from 47 to 84 years of age, none of whom had ever suffered from neurological or psychiatric disorders. The reference group of young people were 15 healthy male volunteers, ranging in age from 20-37 years, including 10 subjects from a previous reference study by the same authors. A standard and commercially available mobile phone was mounted on a helmet and was positioned 1.5 cm from the ear with the microphone oriented towards the corner of the mouth. To mimic normal conditions of mobile phone use, subjects were allowed to move around the room during the exposure session and to chat with the experimenters. Each subject participated in two 45-minute sessions separated by one week. One session consisted of real GSM-EMF exposure and the other consisted of sham exposure, with the order decided randomly and subjects and experimenters blind to the test condition. EEG recordings in an eyes-closed, resting position lasted 5 minutes before and after exposure.

Results
Following GSM but not sham-exposure, a change in EEG recordings in elderly relative to young subjects was observed.

Interpretation and Limitations
This study found that 45 minutes of exposure to GSM-EMFs modified the EEG rhythms indicative of synchronization between hemispheres of the brain in both healthy young adults and elderly persons. However the GSM-EMFs induced higher synchronization in the elderly compared to young subjects and it was found that the higher the subjects’ age, the higher the measure of synchronization. The authors believe that conclusive interpretation of these results is premature, but they may reflect hyper-excitability possibly provoked by an age-related physiological reduction in the cholinergic tone. This study is limited by the small number of subjects.

Conclusion
This study found that GSM-EMFs of a mobile phone affect inter-hemispheric synchronization of EEG rhythms as a function of aging.



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