Postictal Psychiatric Symptoms in Epilepsy

Prevalence and Clinical Characteristics of Postictal Psychiatric Symptoms in Partial Epilepsy

Kanner AM, Soto A, Gross-Kanner H

Neurology 2004;62(5):708–713

OBJECTIVES: To identify the prevalence and clinical characteristics of postictal psychiatric (PPSs) and cognitive (PCSs) symptoms in patients with refractory partial epilepsy and to investigate whether interictal psychiatric and cognitive symptoms worsened in severity during the postictal period.

METHODS: With a 42-item questionnaire, the authors determined the prevalence and clinical characteristics of PPSs and PCSs that occurred after >50% of seizures in 100 of 114 consecutive patients with refractory partial epilepsy during a 3-month period. The postictal period was defined as the 72 hours that followed a seizure. The prevalence of all interictal psychiatric and cognitive symptoms was identified, and the frequency with which they worsened postictally determined.

RESULTS: A mean of 2.8 ± 1.8 PCSs (median, 3) and 5.9 ± 5.3 PPSs (median, 5) was identified, which included postictal symptoms of depression (PSDs) in 43 patients, anxiety (PSAs) in 45, postictal psychotic symptoms (PIPs) in 7, hypomanic symptoms in 22, neurovegetative symptoms in 52, and fatigue in 37. Most patients experienced more than one type of PPSs. Independent of the occurrence of PPSs, 38 patients reported a worsening of interictal psychiatric and cognitive symptoms postictally. A history of depression and anxiety significantly increased the number of PSDs, PSAs, and PIPs.

CONCLUSIONS: Postictal psychiatric symptoms are common among patients with refractory partial epilepsy, and the severity of interictal psychiatric and cognitive symptoms commonly worsens during the postictal period.

Commentary

Dysfunction of neural networks in regions of the brain, such as the temporal lobes, may manifest as seizures, cognitive impairments, or psychiatric disorders. Additional cognitive and psychiatric problems also may occur from the increase in brain dysfunction that immediately follows a seizure. Consistent with these concepts, patients with refractory epilepsy have a high incidence of interictal psychiatric comorbidities and cognitive impairments (1). Further, postictal psychiatric and cognitive symptoms are known to occur, but their prevalence and clinical characteristics are uncertain. Kanner et al. performed a systematic analysis of postictal psychiatric and cognitive symptoms in 100 patients with refractory epilepsy by using a standardized questionnaire. They found that most (88%) of the patients experienced postictal psychiatric or cognitive difficulties after more than 50% of their seizures over a 3-month period. The duration of postictal symptoms was minutes to days. The most common postictal psychiatric symptoms were neurovegetative (62%), anxiety (45%), and depression (43%). Postictal psychotic symptoms were seen in 7% of patients. The majority of the patients experienced a cluster of multiple symptoms. Although 82% of the patients experienced postictal cognitive difficulties, only 14% had postictal cognitive deficits without postictal psychiatric symptoms. The association of cognitive and psychiatric symptoms also was evidenced by the fact that the postictal cognitive disturbances were worse in those with postictal depression. Further, patients with interictal psychiatric and cognitive difficulties were at higher risk for postictal exacerbations.

The Kanner et al. study is important because it highlights the high prevalence of postictal neuropsychiatric symptoms and helps characterize these symptoms. The patients in this study had refractory epilepsy, so that the results may not generalize to all patients with epilepsy. Nevertheless, postictal symptoms appear to be very common in refractory epilepsy and may impair a patient's quality of life beyond the effects of the seizure during the ictus. Treatments that result in seizure freedom are the ideal prevention, but other factors that might modulate postictal symptoms remain uncertain and are largely unexamined. For example, none of the patients in this study were taking psychoactive agents other than antiepileptic drugs (AEDs). Is it possible that antidepressants, anxiolytics, or antipsychotics reduce or increase the risk of postictal psychiatric postictal symptoms? Given that AEDs have both positive and negative psychotropic effects, could certain AEDs be associated with an increased or decreased risk?

Patients with epilepsy who have psychiatric problems are frequently undiagnosed and untreated (2). Adding to this problem, relatively few systematic studies of psychiatric disorders have been done in patients with epilepsy, given the scope of the problem. The first step, as taken by Kanner et al., is to define the clinical characteristics so that future studies can examine the underlying mechanisms and systematically evaluate treatments.