Seizures captured on a smartphone found diagnostic for epilepsy

WASHINGTON – Smartphone videos brought to the clinic by patients are valid tools for the diagnosis of epilepsy, according to a prospective blinded and multicenter study of 41 consecutive videos presented at the American Epilepsy Society annual meeting.

“These findings have global implications, because they suggest that smartphone videos are a cost effective tool that can accelerate the time to diagnosis even in places where video-EEG monitoring is not readily available,” reported William Tatum, DO , professor of neurology, Mayo Clinic, Jacksonville, Fla.

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Dr. William Tatum

In addition to submitting a smartphone video, all patients in this study underwent a history and physical (H&P) and were evaluated with video-EEG monitoring. The smartphone videos underwent review by 10 epilepsy experts and 8 general neurology residents blinded to the video EEG findings. The latter group was selected to test the value of smartphone video in clinicians with general knowledge but no special expertise.

The final diagnosis was made on the basis of all the clinical information, including the video-EEG, which Dr. Tatum characterized as the gold standard for the diagnosis of epilepsy. Based on the video-EEG, 11 of the 41 patients (26.8%) had seizures, 26 (63.4%) had psychogenic nonepileptic seizures (PNES), 3 (7.4%) had physiologic nonepileptic events (PhysNEE), and 1 (2.4%) had both PhysNEE and PNES.

On the basis of the blinded smartphone video alone, the median correct diagnosis was 71.4% for experts and 66.7% for residents. Although this difference was not significant, Dr. Tatum reported that there was substantially less inter-rater variability among experts.

“Overall, smartphone video review correctly differentiated epilepsy from PNES in 68% of the videos evaluated by experts and 58% assessed by residents,” Dr. Tatum reported.

For experts, the smartphone video assessment yielded a specificity of 43% and sensitivity of 83% for epilepsy. For PNES, these figures were 80% and 54%, respectively. Among residents, the sensitivities and specificities for epilepsy (32% and 83%) and PNES (82% and 53%) were similar. Dr. Tatum noted that H&P predicted the definitive diagnosis in 75.6% of cases.

The rate of correct diagnoses with blinded smartphone video analysis in this study was respectable, but Dr. Tatum suggested that smartphone video should be an adjunctive tool that is reviewed in the context of H&P, which would be expected to further boost accuracy. Although he acknowledged that smartphone videos plus H&P will not completely supplant the need for video-EEG monitoring to reach a definitive diagnosis in all cases, he believes that it is accurate in many, and it accelerates the time to diagnosis.

“The median duration of the smartphone review was about a minute and a half. The median duration of H&P was 60 minutes, but the median time to a result with video-EEG was 2.54 days,” said Dr. Tatum, noting that this difference was highly significant (P lees than .001). If a diagnosis can be reached without video-EEG, it would also be expected to greatly reduce costs.