Postictal psychiatric events during prolonged video-electroencephalographic monitoring studies
A. M. Kanner, S. Stagno, P. Kotagal and H. H. Morris
Section of Epilepsy and Clinical Neurophysiology, Cleveland (Ohio) Clinic, USA.
BACKGROUND: Postictal psychiatric events presenting as postictal psychotic
events and postictal nonpsychotic events are known to occur following
seizure clusters. Accordingly, patients undergoing prolonged
video-electroencephalographic (EEG) monitoring studies may be at increased
risk of experiencing postictal psychiatric event, as they often have
flurries of seizures during these studies. OBJECTIVES: To determine the
annual incidence and clinical characteristics of postictal psychotic events
and postictal nonpsychotic events in video-EEG monitoring studies in
patients with partial seizure disorders and to identify potential
pathogenic factors. RESULTS: Thirteen patients met the criteria for a
postictal psychiatric event during the 18-month study period, 10 presenting
as postictal psychotic events and three as postictal nonpsychotic events.
The annual incidence of postictal psychiatric events at our monitoring unit
for 1988 was 7.8%, 6.4% presenting as postictal psychotic events and 1.4%
as postictal nonpsychotic events. Seven patients had their first-ever
postictal psychiatric event during the monitoring study. In 12 of the 13
patients, the postictal psychiatric events mimicked well-defined
psychiatric entities of shorter duration (mean, 66.5 hours); they appeared
12 to 72 hours after the last seizure and remitted spontaneously or with
the use of low-dose psychotropic medication. No significant differences in
EEG, neuroradiologic, psychiatric, medical, or psychosocial data were found
between the patients with postictal psychiatric events and a group of 13
age-matched control patients. Follow-up data of comparable duration were
available in nine patients with postictal psychiatric events and nine
controls. Psychiatric events were reported more frequently by patients with
postictal psychiatric events than by control patients (P=.03). In three
patients, postictal psychiatric events converted to interictal events.
CONCLUSION: These findings suggest that monitoring studies increase the
risk for postictal psychiatric events, which neurologists need to be
familiar with, as they represent important morbidity associated with these
studies.
