Abstracts

Rationale: Many patients admitted for video-EEG monitoring will text during their evaluation in the epilepsy monitoring unit. Recently we have identified a "texting rhythm" during active use of cellular phones on the epilepsy monitoring unit (EMU). We therefore, sought to characterize the clinical neurophysiological features associated with this finding. Methods: Patients with paroxysmal events were admitted to the EMU for diagnostic video-EEG monitoring. Studies ranging from 2-4 days were recorded on XLTEK video-EEG monitoring system (Natus Medical Inc., Oakville, CA) with 24 channels of EEG placed in accordance with the 10-20 International system of electrode placement. The texting rhythm (TR) was defined as a generalized burst of 5-6 Hz theta maximal in the fronto-central head regions during active texting with a cellular phone. Inclusion criteria included baseline mental activation, mathematic computation, scanning eye movements, and speech/cognitive testing of orientation. Text conversations and audio telephone conversations were captured in all patients and compared. Fisher's exact 2-tailed, chi squared and logistic regression were used to calculate the significance (p = < 0.05). Results: 41 patients (29 F; mean age 35.5 years) had video-EEG with 35/41 receiving a definitive diagnosis of epileptic seizures (ES) or non-epileptic seizures (NES). Focal epilepsy (n=22), Non-epileptic seizures (n= 13), Generalized epilepsy (n=5), and 1 patient with unavailable records were monitored for 2-4 days. A TR was present in 48.7% of patients lasting for 2 seconds to continuous runs during the activity. The presence of a TR was highly specific to texting without the appearance of a similar waveform during baseline activation or audio cellular phone use in any patient (p<0.0001). It was present in 59.3% of patients with ES and only 23.1% of patients with NES (p=0.05). Similarly, in ES patients no distinction was present between generalized (59.3% with TR) and focal seizures (59.1% with RT) (p=1.00). The baseline alpha rhythm was 9.3 Hz (range 8.0-11.0 Hz). There was an association between baseline frequency and the presence of a TR. The average baseline frequency of the alpha rhythm with a TR was 8.95 Hz and without a TR was 9.68Hz (p= 0.03). Conclusions: A TR is a new and specific waveform linked to the use of new technology associated with text messaging. It likely reflects a unique visual-cognitive network activation to produce a measurable neurophysiological metric in the absence of similar occurrence during mental concentration or audio cell phone use. The presence appears independent of ES and may carry implications during activities requiring full attention where distraction should be avoided such as operating a motor vehicle.