Abstracts

Rationale: Rationale: Loss of consciousness in epileptic seizures can cause substantial issues such as social stigma, physical injuries, and car accidents. However, the underlying mechanisms involved in the loss of consciousness are poorly understood because directly evaluating consciousness during randomly occurring and brief epileptic seizures is technically difficult. Previous studies have been limited by the lack of standardized behavioral testing batteries to assess consciousness during seizures. To evaluate consciousness during seizures efficiently, both active patient-initiated behavioral techniques and passive patient responses to tests initiated by the examiner should be included. Therefore, we investigated two methods, one active (video game performance) and one passive (response to examination) to assess patients consciousness during seizures. Methods: For patient-initiated testing, three video games were studied: rFactor: a customized racing video game, SNIP: an open-source Tetris clone, and Frets on Fire: an open-source Guitar Hero clone. These computer-based games were played on a modified bed-side table with appropriate game controllers. Passive evaluation was assessed using the Responsiveness in Epilepsy Scale (RES) which included memory, motor, sensory and language function measurements. While monitored by 24 hour continuous video/EEG, patients with confirmed epilepsy were encouraged to play the video games as often as possible. A trained researcher at the patient s bedside detected seizure onset and repeatedly administered the RES procedures until all functions returned to the baseline level. Results: Of the total 139 patients recruited, 44 were studied using only RES, 109 were observed utilizing only video games and 18 were tested by employing both. There were 64 male, 75 female, 117 right-handed, and 22 left-handed . Mean age was 35.6 years. Furthermore, 8 Intracranial EEG, 120 Scalp EEG, and 11 ictal SPECT patients were studied. Altogether, 30 seizures were captured from 14 patients during video games: 2 secondarily generalized, 14 partial, 5 absence, 6 auras, and 3 subclinical seizures. During RES evaluation, 34 seizures were captured from 16 patients: 4 secondarily generalized, and 30 partial seizures. The average seizure duration was 121 seconds. During subclinical seizures and auras, patients continued to play the video games. Patients stopped playing during secondarily generalized seizures. Impairment varied more in partial and absence seizures. According to the RES evaluations, the patients responsiveness over time showed more severe impairment in secondarily generalized seizures compared with partial seizures. However, some functions were spared even during generalized seizures. Conclusions: Our results demonstrate the feasibility of using standardized prospective behavioral techniques for assessing consciousness during various types of seizures. These approaches may ultimately help elucidate the anatomical structures of the consciousness network and delineate fundamental mechanisms of impaired consciousness in epilepsy.