Abstracts

Rationale: Video EEG recording (vEEG) is accepted as the best way of identifying patients with epileptic events (EE) and non epileptic seizure like events (NESLE). Unfortunately, many patients who undergo vEEG have no events (NoE) during vEEG. Numerous studies have examined the differences between patients with EE and NESLE, but little attention has been focused on the NoE patients who do not receive definitive diagnosis after vEEG. This study compared the results of the Minnesota Multiphasic Personality Inventory (MMPI) of patients with NoE, EE, and NESLE during vEEG to see if the NoE patients were unique with regards to the results of personality testing or were more similar to either patients with EE and NEE.Methods: Records of patients who were admitted for video EEG monitoring and had at least 24 hours of video EEG monitoring were reviewed. Patients were included if vEEG results suggested clear EE, NESLE and no evidence of even subtle abnormality on video EEG, or NoE and no EEG abnormality. In addition all patients were seen for clinical interviews by the first author and completed the Minnesota Multiphasic Personality Inventory as part of standard clinical care.Results: Of the 153 reports of monitoring available for review, 57 recorded EE, 51 recorded NESLE and 30 had NoE. In the other cases patients had events that were not clearly classifiable or showed some evidence of EEG abnormality. ANOVAs comparing age, years of education, and reported time since first seizure or event found significant differences in time since first event (p<.001), with post hoc analyses finding that the average for the EE group (X = 20 years) was significantly greater than the NESLE (X = 8.6 years) and NoE (X = 6.0 years) groups. The percentages of patients showing elevations (i.e., t scores > 65) on MMPI validity and clinical scales are listed in Table 1. NoE and NESLE patients were significantly more likely to show elevations on scales sensitive to over reporting symptoms, somatic concern and preoccupation, low mood, developing physical symptoms in response to psychological distress, anxiety, mistrust, and confused thinking relative to patient with EE. NoE patients were not significantly different from NESLE in their likelihood of elevations on any MMPI scales.Conclusions: Prior studies have found differences in the MMPI results between patients with EE and NESLE. We found, comparing these groups with NoE patients, that NoE patients have similar rates of scale elevations suggesting questionable validity and psychopathology, as measured by formal personality testing, to NESLE patients. These rates of elevation for NoE and NESLE patients are significantly higher compared to EE patients. The similar rates of scale elevations, between the NESLE and the NoE patients, who are suspected of having NESLE prior to monitoring, provide additional evidence that the events that the NoE patients are reporting are likely to be psychogenic rather than EE, in spite of vEEG results that do not provide a conclusive diagnosis.