Measuring outcome in psychogenic nonepileptic seizures: how relevant is seizure remission?

To examine whether seizure remission is a comprehensive marker of outcome in psychogenic nonepileptic seizures (PNESs).

A postal questionnaire was returned by 147 patients with PNESs a mean of 4.2 years after diagnosis (mean age at follow-up, 38.1 years). The proportion of patients who were "unproductive" (receiving health-related state benefits) at follow-up was determined, with a comparison of markers of ongoing psychopathology (Global Severity Index, anxiety and depression scores of the Symptom Checklist 90, Somatization Index DSM of the SOMS-2) in three outcome groups: group 1, continuing seizures; group 2, seizures stopped but patients "unproductive;" and group 3, seizures stopped, patients "productive."

Of the patients, 71.4% continued to have seizures, and 28.6% had achieved seizure remission; 60.0% of patients with continuing seizures and 42.7% of patients in remission were "unproductive" (difference, NS). Ongoing psychopathology was related to the factor "group membership" with higher values in groups 2 and 3 than in group 1 (GSI, p < 0.001; anxiety, p = 0.01; depression, p = 0.02; Somatization Index DSM, p < 0.001). Across all patients and in the subgroup with PNESs and additional epilepsy, differences were significant only between groups 2 and 3, not between groups 1 and 2. In patients with PNESs alone, differences were significant only between groups 1 and 2.

Seizure remission is not a comprehensive measure of good medical or psychosocial outcome in PNESs. Nearly half the patients who become seizure free remain unproductive. Many of these patients continue to report symptoms of psychopathology. Seizure control should not be the only focus of treatment in clinical practice or outcome observation in research studies.