What is the significance of subjective events recorded during long-term EEG video monitoring?

PURPOSE

Purely subjective events, identified as "seizures" by patients but not accompanied by any clinical or EEG changes, commonly occur during evaluation of patients for intractable epilepsy. We wished to determine the significance of such events.

METHODS

We analyzed the frequency of subjective episodes in 379 adults who underwent EEG video monitoring as part of their evaluation for intractable epilepsy and the relationship of these experiences to epileptic and psychogenic nonepileptic (NES) seizures. We examined the results of tests of mental ability and of emotional, psychosocial, and quality of life (QOL) adjustment to determine if individuals with subjective events alone could be distinguished from those with epileptic seizures only, NES only, or no events, by these measures.

RESULTS

We noted subjective events in 39% (147 of 379) of the patients. Of patients with subjective episodes, 52% also had epileptic seizures, 7% had NES, 1% had both epileptic seizures and NES, and 40% had subjective events alone. As a group, patients with subjective events alone were slightly more intelligent and less impaired neuropsychologically than people in the other groups, but they performed more poorly on several important measures of adjustment.

CONCLUSIONS

The identification of persons with purely subjective episodes apart from all other episodes is important both phenomenologically and from a practical viewpoint.