Forty patients with epilepsy were recruited during their clinic encounter. Participants were first asked whether they reported experiences suggesting GCS. Those reporting GCS underwent a standard online consistency and congruency battery test (). Epilepsy features, electroencephalogram (EEG) findings, and magnetic resonance imaging (MRI) findings were collected and analyzed.

Of the 40 study participants (mean age was 49.9 years old; 52.5% females), 21 reported GCS experiences and 3 (7.5%) resulted synesthetes from the battery test. Analysis of the test results showed that participants with focal seizures had lower consistency scores (median score 1.2) and higher congruency scores (median score 76.4) compared to patients with generalized-onset seizures (median scores 2.9 and 51.4 respectively; p=0.006, p=0.001). Participants with non-motor seizures had lower consistency scores (median score 1.1) and higher congruency scores (median score 79.2) compared to patients with motor seizures (median scores 2.8 and 52.8, respectively; p=0.011, p=0.036).