Introduction: We report a unique EEG phenomenon in patients with paroxysmal neurological events undergoing video EEG monitoring.
Methods: Two epilepsy centers analyzed the interictal scalp EEG in patients using personal electronic devices during epilepsy monitoring. The texting rhythm (TR) was defined as a reproducible, stimulus-evoked, generalized frontocentral monomorphic burst of 5-6 Hz theta consistently induced by active text messaging. An independent prospective and retrospective cohort was analyzed and compared from two sites in Florida and Illinois. We assessed age, gender, diagnosis, epilepsy classification, MRI, and EEG to compare patients with a TR. Analysis was performed with statistical significance set at P < 0.05.
Results: We identified 24 of 98 evaluable patients with a TR in a prospective arm at one center and 7 of 31 patients in a retrospective arm at another totaling 31/129 (24.0%). The waveform prevalence was similar at both centers independent of location. TR was highly specific to active texting. A similar waveform during independent cognitive, speech or language, motor activation and audio cellular telephone use was absent (P < 0.0001). It appeared to be increased in patients with epilepsy in one cohort (P = 0.03) and generalized seizures in the other (P = 0.025). Age, gender, epilepsy type, MRI results, and EEG lateralization in patients with focal epileptic seizures did not bear a relationship to the presence of a TR in either arm of the study (P = NS).
Conclusions: The TR is a novel waveform time-locked to text messaging and associated with active use of smartphones. Electroencephalographers should be aware of the TR to separate it from an abnormality in patients undergoing video EEG monitoring. Larger sample sizes and additional research may help define the significance of this unique cognitive-visual-cognitive-motor network that is technology-related and task-specific with implications in communication research and transportation safety.