Comparisons of impulsivity among patients with different subtypes of epilepsy

Purpose: This study assessed whether patients with epilepsy have a higher level of impulsivity than healthy controls, and compared impulsivity among patients with different subtypes of epilepsy. Methods: The multicenter study included 108 subjects with epilepsy and 56 healthy volunteers. Subjects were evaluated by the Barratt Impulsiveness Scale-11 (BIS-11) and Patient Health Questionnaire-9, with BIS-11 scores analyzed as both dichotomized and continuous variables. High impulsivity was defined as a total BIS-11 score >= 67. Results: Of the 108 subjects with epilepsy, 36 had idiopathic generalized epilepsy (IGE), 47 had temporal lobe epilepsy (TLE), and 25 had frontal lobe epilepsy (FLE). A significantly higher percentage of subjects with epilepsy (22.2%) than controls (1.8%) had BIS-11 scores >= 67 (p = 0.001), although mean BIS-11 scores were similar in subjects with epilepsy (59.5 +/- 10.0) and controls (58.8 +/- 4.6). Higher percentages of subjects with IGE and FLE had BIS-11 scores >= 67 than subjects with TLE and controls. Mean total BIS-11 scores did not differ between controls and subjects with IGE and FLE, but were lower in subjects with TLE than in controls. Differences in impulsivity among controls and subjects with epilepsy subtypes varied depending on BIS-11 subscale. Conclusions: Patients with epilepsy, particularly IGE and FLE, were more likely to have high impulsivity scores, defined by a certain cutoff on the BIS-11, than controls and subjects with TLE. However, mean impulsivity scores did not differ among controls and subjects with IGE and FLE. Dichotomizing BIS-11 scores may be necessary to avoid false negative results in subjects with epilepsy.