Method
Participants
Participants were recruited at St. Joseph's Hospital and Medical Center (SJHMC) in Phoenix, Arizona between 2005 and 2011. A total of 434 participants were recruited, and 228 were diagnosed with epilepsy and 206 with psychogenic non-epileptic seizures. Differentiation of ES from PNES was determined based on an inpatient epilepsy monitoring unit evaluation with video electroencephalogram. The seizure diagnosis was determined by the attending epileptologist and epilepsy fellow. Demographic variables are available in Table 1.
Measures
Rey Auditory Verbal Learning Task
The Rey Auditory Verbal Learning Task (RAVLT) is a commonly used neuropsychological test designed to examine working memory, learning rate, delayed recall, recognition, and interference. The RAVLT was administered to all participants according to standard protocol. Administration of the RAVLT begins by reading a list of 15 words to participants five separate times, with the participant repeating as many words as he or she can remember after each trial. An interference list of 15 different words is then presented to the participant. The participant is then asked to recall the initial list without additional repetition by the examiner. Finally, the participant is presented with a list of words and is asked to identify which ones were on the initial list.
Reported reliability of the RAVLT has been varied, but Cronbach's α has been reported to be .70. Test-retest reliability at one-year follow-up was reported at .55. Additionally, the RAVLT has shown discriminant validity to discriminate between neurologically impaired individuals (e.g., individuals with Alzheimer's Disease from typically aging populations from individuals with mild cognitive impairment).
Procedure
Each patient underwent a neuropsychological examination in addition to a neurological examination and video electroencephalogram. The neuropsychological exam was completed on the same day as admission to the epilepsy monitoring unit. Thus, the evaluation was completed before the patient's first seizure, before changes were made to seizure medications, and before the establishment of a seizure diagnosis.