The relationship between seizure subtype and interictal personality. Results from the Vietnam Head Injury Study

A wide variety of interictal personality traits has been associated with complex partial (CP) epilepsy. However, the specificity of these behavioural changes to CP epilepsy has been questioned in several controlled studies. To address this issue, we examined personality and behavioural characteristics in 467 Vietnam veterans 15 years post penetrating head injury. Of this sample, 238 (51%) had developed seizure disorders which were classified as follows: 39 simple partial (SP), 59 CP, 76 partial with secondary generalization (PG), and 64 generalized (G). Seizure patients were compared with two demographically matched control groups: 229 penetrating head-injured Veterans without seizures (PHI-C) and 84 uninjured veterans (UC). Dependent measures included self-report and examiner rating scales, and history of psychiatric treatment. Pre-injury intelligence, brain volume loss (CT scan), seizure frequency and duration of epilepsy served as covariates. We found statistically significant increases in interictal psychopathology in the CP, PG and G groups when compared with the two control groups (PHI-C and UC). No group differences were observed across seizure subtypes. These results suggest that interictal personality and behavioural abnormalities are not specific to individuals with CP seizures. Furthermore, the increased psychopathology in seizure groups when compared with the PHI-C group suggests that personality changes cannot be accounted for by structural brain damage alone.