The evaluation of behavioral disturbances in epilepsy.

The evaluation of behavioral disturbances in epilepsy is an area fraught with complexity. On the one hand, there are no instruments that have been developed specifically for the assessment of behavioral disturbances in epilepsy. On the other hand, the phenomenology and pathophysiology of behavioral disturbances in epilepsy are unique and defy conventional descriptions in the psychiatric literature. The vast majority of studies have used instruments that have not been validated for this purpose. Studies with a psychiatric orientation generally tend to employ unvalidated semistructured or structured tools except for the Structured Clinical Interview for DSM, which has been validated for epilepsy. Studies with a neurological orientation generally use screening questionnaires and interpret the results of these as diagnostic. Neither approach is valid and both generally fail to measure potential confounders, such as seizure frequency, seizure severity, temporality of seizure occurrence in relation to time of assessment, life events, disablement, quality of life, and other socioeconomic indicators. Furthermore, instruments are generally employed using cutoff scores that may not be valid for epilepsy populations; the emphasis is often on symptom severity rather than symptom multiplicity (or load), which may also have an impact on the patient's outcome. In addition, instruments that have a basis in psychiatric criteria as opposed to symptomatology have inherent pitfalls at the interface between epilepsy and behavior. These and other issues in evaluating behavioral disturbances in people with epilepsy are reviewed and some solutions for the future are proposed.