Validation of the Smartphone Brain Scanner for the Detection of Epileptiform Discharges a among Epilepsy Outpatients in Bhutan

Objective: To assess the Smartphone Brain Scanner-2 (SBS2)’s ability to detect abnormal and epileptiform cortical discharges compared to standard electroencephalogram (EEG) among people with epilepsy (PWE) in Bhutan. Background: The SBS2 is a software application, utilizing a 14-lead headset connected wirelessly to an Android device.

Portable, easily operated, and low-cost (<500USD per device), the SBS2 may aid in the diagnosis of epilepsy in resource-limited settings. Methods: PWE or suspected seizures in Bhutan underwent a SBS2 and a standard EEG (each ≥20 minutes duration). The SBS2 used circumference-matched EasyCaps with ring electrodes positioned at F3, C3, P3, O1, F4, C4, P4, O2, Fz, Cz, Pz, Fpz, A1, A2.

The standard EEG (Xltek, Natus) used 10-20 system electrode placement and peripheral leads. Neurologists, blinded to clinical data, categorized recordings as normal or abnormal, and abnormalities as epileptiform or background. Each SBS2 recording was read once. Each standard EEG was independently assessed by ≥2 neurologists.

A third neurologist or a group of neurologists resolved discrepancies. Results: 215 participants (53[percnt] female, mean age 25 years) completed both SBS2 and standard EEG with no safety or tolerability concerns. Epileptiform discharges were present on 25[percnt] and 15[percnt] of standard and SBS2 EEGs.

For the detection of all abnormalities, the SBS2 had a sensitivity of 0.51, specificity of 0.84, and positive and negative predictive values of 0.65 and 0.74 versus standard EEG. For the detection of epileptiform discharges, the SBS2 had a sensitivity of 0.36, specificity of 0.94, and positive and negative predictive values of 0.68 and 0.84 versus standard EEG.

Conclusions: The SBS2 EEG is specific but not sensitive for the detection of epileptiform discharges, and may have clinical relevance to help confirm a suspected epilepsy diagnosis in resource-limited settings. Sensitivity may be improved with hardware modifications including the addition of electrodes along the temporal chain.