The pilot study’s preliminary results contrast findings shown in trials involving rat models of epilepsy and mobile phones.
BALTIMORE—Using mobile phones does not result in increased or altered ongoing epileptiform activity, according to a pilot study of 10 patients with epilepsy that was reported at the 65th Annual Meeting of the American Epilepsy Society.
Eleftherios S. Papathanasiou, PhD, Clinical Neurophysiologist, and Savvas S. Papacostas, MD, Senior Neurologist, both of the Cyprus Institute of Neurology and Genetics in Nicosia, Cyprus, investigated whether the electromagnetic fields generated by mobile phones affect epileptic activity in humans. Although rat models of epilepsy have shown seizure induction and changes in gene expression in the brain in response to mobile phones, no prior literature has demonstrated the impact of mobile phone use on human epileptic activity.
Recruiting and Monitoring Patients
Drs. Papathanasiou and Papacostas prospectively recruited 11 patients with a mean age of 36.8 (range, 15 to 62) for the study, but one of the 11 patients did not use a mobile phone. As a result, 10 patients (six females) were analyzed—one had idiopathic generalized epilepsy, six had focal-onset epilepsy with or without secondary generalization, two had recurrent syncopal episodes that were under investigation to exclude epilepsy, and one had unclassifiable seizure disorder.
“The sample size of 10 patients is a relatively small one,” Dr. Papathanasiou told Neurology Reviews. “We plan to study more patients, at least 50, before publishing the results formally.”
Patients’ brain activity was observed in a long-term video EEG monitoring unit, and patients were instructed to independently decide how to use their mobile phones. To determine when each patient used his or her phone, the researchers manually scanned the monitoring video and then analyzed EEG results 15 minutes before and after mobile phone use, as well as during mobile phone use.
Results showed that patients used their phones a mean of 4.2 times (range 1 to 7) for a mean duration of 118.7 seconds (range 15 to 436). “One good aspect of our study is that we incorporated the normal use of mobile phones,” said Dr. Papathanasiou. “The extremes of cell phone exposure noted in our study … can be seen in everyday life.”
No New Epileptiform Activity
The researchers recorded no new appearance of epileptiform activity in any of the 10 patients during their mobile phone use. Furthermore, nine of the 10 patients showed no abnormal brain activity immediately prior to or following phone use, though one patient exhibited focal irregular delta wave activity that did not change during mobile phone use. Five of the 10 patients displayed EEG abnormalities at points in the recording when they were not using their mobile phones. These abnormalities included focal spikes, polyspikes or sharp waves, and focal slow waves or bifrontal fast activity.
“Our results contrast with what has been found in animals, specifically in rats. In the latter, studies have shown seizure induction, which we have not found so far in humans,” said Dr. Papathanasiou. “Animal studies have shown changes in levels of amino acid neurotransmitters—both increases and decreases—but these findings followed exposure of one hour per day for several months.”
Harmful changes in brain activity may depend on the duration of mobile phone use, he explained, as well as on the differences between animals and humans. “Future research may need to focus on human results, as we have done, rather than on animal studies,” concluded Dr. Papathanasiou.
—Lauren LeBano