Abstracts

Rationale: Seizures are the main symptoms of epilepsy and the focus of treatment. Thus, accurate knowledge of seizure frequency is important for evaluating therapeutic efficacy. Information about seizure frequency is usually gathered from patients although evidence from previous studies show that this could be unreliable. The goal of this study was to assess patients' reporting of their seizures. We also looked at predictors that could influence reporting of seizures. Further, we examined the impact that deficits in memory and consciousness could have on patients' seizure reporting. Methods: We recruited patients undergoing continuous VEEG evaluation at the Yale Comprehensive Epilepsy Center over a 2-year period. We compared their subjective response to daily questionnaires with a more objective measure by analyzing the video recordings of their seizures. We determined statistical significance using Chi-squared or Fisher's exact tests where appropriate to evaluate relationships between patients' characteristics and seizure reporting. To determine which factors impacted seizure reporting, a multivariate binary logistic regression was performed. Results: 115 patients were recruited, of which 65 met all criteria for analysis (confirmed epilepsy, completed questionnaires, seizures captured during VEEG monitoring). For these 65 patients, 51% were female and 49% were male. The mean age was 34 years at time of admission, with 59 adults (≥18 years) and 6 pediatric patients. Overall, we captured a total of 295 partial and 42 sGTC seizures. 30% of all seizures were not reported while 70% were reported. On the patient level, 80% had partial seizures (SPS and GTC) only while 20% had only sGTC. Also, 54% of patients always reported their seizures while 46% did not always report their seizures. We found that SPS were more often reported than both CPS and sGTC in pair-wise comparisons, with p-values of 0.008 and <0.001 respectively (Chi-square). This was consistent with our finding on patient level, where patients with only SPS more often reported their seizures. We also found that loss of consciousness (OR 0.25 95% CI 0.07-0.92 p=0.037) and temporal lobe onset (OR 0.17 95% CI 0.08-0.37 p<0.001) had a negative influence on seizure reporting. Although patients who were awake at seizure onset reported more of their seizures (Chi-square 17.34 p<0.0001), sleep state was not a significant independent predictor of seizure reporting. We didn't observe an effect of seizure lateralization on seizure reporting. Conclusions: This study demonstrates that seizures with impaired consciousness were more likely to go unreported suggesting that consciousness may be a factor influencing the ability of patients to recognize and accurately report their seizures. Temporal lobe onset significantly influenced seizure reporting. The impact of altered memory function and language impairment on seizure reporting needs to be further assessed. Relying exclusively on patients' seizure reporting may lead to inadequate treatment of seizures. Additional measures should be used clinically to determine accurate seizure frequency.