Abstracts

Rationale: Although the majority of patients with idiopathic generalized epilepsy have well controlled seizures, a significant percentage remains refractory to antiepileptic drugs (AEDs). These patients are poorly characterized in the literature, and their neuropsychological and psychosocial profiles have rarely been described. Such data would aid in patient counseling and clinical management. Methods: A retrospective chart review of patients admitted to the Brigham and Women's epilepsy monitoring unit (EMU), between 2003 to 2011, was performed. During the admission, patients had neuropsychological assessment. Patients with a diagnosis of an idiopathic generalized epilepsy (IGE) were selected if they failed at least 2 medications, had a full scale IQ >70, a nonlesional MRI, and completed neuropsychological testing. A control sample consisted of unilateral temporal lobe epilepsy (TLE) patients who underwent similar testing and did not have a history of encephalitis, traumatic brain injury, prior epilepsy surgery, or brain tumor. Epilepsy characteristics, level of education, and employment status were also obtained. Results: A total of 17 IGE and 18 TLE patients fulfilled study criteria with a mean (±SD) age of epilepsy onset of 13.5 (±3.7) and 14.6 (±8.8) years respectively, and a mean epilepsy duration of 36.5 (±15.7) vs. 36.1 (±9.9) years. There was an average monthly seizure-days of 10.3 (±13.3) vs. 5.9 (±9.0) years, and average yearly generalized tonic clonic seizures (GTCs) of 9.5 (± 14.7) vs. 1.7 (±2.0) (p =0.001). Of the IGE patients, 53% had a college education and 41% were on disability or unemployed as compared to 44% and 28% for the TLE patients. There was a trend for IGE patients to have lower scores on the beck depression inventory (BDI-II) 8.7 v.s. 15.8 ( p=0.08), while the quality of life in epilepsy (QOLIE-31) scores were not significantly different (54.3 vs. 49.3). Patients with IGE performed worse on the trails making A and B tests, 51.8(±29.0) and 144.2(±86.2) compared to 29.7(±6.9) and 74.7(±35.7) seconds respectively (p = 0.0028, p= 0.0033). IGE patients also had lower scores on the Performance IQ 91.7 (±15.4) v.s. 101.3 (±12.5), (p=0.05). There were no differences in full scale IQ, verbal IQ, the controlled oral word association test, or Ray auditory verbal learning test. Conclusions: Patients with poorly controlled IGE performed worse on tests of executive functioning than patients with poorly controlled TLE. Interestingly, despite a higher burden of convulsions for the IGE patients, they had a trend of lower depression scores than patients with TLE, which suggests factors other than seizure burden in the pathophysiology of depression in TLE. Further research on patients with uncontrolled IGE may provide insights into mechanisms of cognitive dysfunction, which may in turn guide patient counseling, and treatment planning.