Abstracts

Rationale: Early diagnosis of non-epileptic seizures (NES) is important in order to avoid unnecessary use of AED and to guide toward proper treatment. Unfortunately, delay in diagnosis of NES is quite common, partially due to their resemblance to epileptic seizures (ES) and lack of awareness among general medical community. Video-EEG study (vEEG) is considered the gold standard in distinguishing NES from ES. We examined the inpatient vEEG data to determine if there is a significant delay in the diagnosis of NES in comparison to ES. Methods: We retrospectively reviewed 2,708 consecutive adult vEEG patients at the Barrow Neurological Institute from 2006 to 2013. Data collection included age of onset, age at vEEG admission, and the diagnosis. We excluded patients if the vEEG diagnosis was unclear or contained both NES and ES. In addition, patients with phase II monitoring with intracranial electrodes were also excluded from the analysis. The timing of diagnosis was calculated by subtracting the age at the onset of typical events from the age when vEEG was performed. Mean duration of years to diagnosis were compared, and statistical significance was analyzed via Mann-Whitney U test. Mann-Whitney U test had to be used because we were unable to rectify variance heterogeneity. Results: A total of 1,656 patients met the study parameters out of 2,708 records. 762 (46%) were diagnosed with NES (71.6% female). There was not a statistically significant difference between women and men in terms of duration to diagnosis in NES. The mean age of onset for NES patients was 29.76 years (SD=18.60), and the mean age at vEEG diagnosis of NES was 37.68 years (SD=17.07). The mean years before the vEEG diagnosis of NES was 7.91 years (SD=11.210). In comparison, ES patients had their vEEG evaluation and diagnosis at the mean duration of 16.21 years (SD=14.223). The difference between the duration to diagnose of the two groups was statistically significant (U=193312.5, z = -15.212, p < 0.001). Conclusions: Our study supports the notion that NES diagnosis is quite delayed and often many years after the onset. However, when compared to the ES population, NES patients were much more readily referred to vEEG.