Pseudoresistance in patients with epilepsy--characteristics and determining factors.

Introduction: In pseudorefractory epilepsy (20% of the cases diagnosed with refractory epilepsy) the factors responsible for triggering the seizures are extraneous to epilepsy and the seizures can be controlled after diagnostic and therapeutic re-evaluation.

Aim: To determine the factors causing development of pseudoresistance in patients with epilepsy.

Patients And Methods: Detailed case histories of 191 patients with a diagnosis of drug-resistant epilepsy were collected; the medical records were analyzed retrospectively. Thirty-nine patient (20.42%) were found to be with pseudorefractory epilepsy. The patients were classified by demographic criteria and specific clinical signs, and by laboratory findings.

Results: The patients (age range 18 to 72 years, mean duration of disease 27 years) presented with partial (56.41%), generalized (43.59%) and polymorphic seizures (17.95%) with a higher relative percentage of the patients with symptomatic (41.03%) and cryptogenic (35.9%) epilepsy. The main groups of factors that determined pseudoresistance were diagnostic (46.15%) and therapeutic errors (69.23%), poor compliance (33.33%), external factors (5.12%), as well as a combination of these (53.84%). We found that compliance correlated weakly with age and education, but showed high and moderate correlation with duration of epilepsy less than 20 years and male gender. Therapy adjustment had a beneficial effect in 16 of 24 patients (66.67%) in our study.

Conclusion: The detailed analysis of the causes for pseudoresistance focuses on some pitfalls of the diagnostic and therapeutic process, compliance of the patient and influence of external factors aiming at reduction of the number of cases with pseudorefractory epilepsy and achieving more favourable clinical effect of treatment.