Yasunori Oana

Psychoses and epilepsy: are interictal and postictal psychoses distinct clinical entities?

Summary:  Purpose: To evaluate further the relevance of designating psychotic episodes as either postictal or interictal, we compared several biologic variables between epilepsy patients with and without psychosis.

A Multicenter Study on the Prevalence of Psychiatric Disorders among New Referrals for Epilepsy in Japan

Summary:  Purpose: To investigate the prevalence rate and risk factors of psychiatric disorders among new referrals for epilepsy, a multicenter study was conducted by using the International League Against Epilepsy (ILAE) criteria for epilepsy and the ICD‐10 criteria for psychiatric disorders.

Predictive variables of interictal psychosis in epilepsy

Objective: To evaluate which variables predict interictal psychosis in epilepsy. Methods: The authors reviewed the biological backgrounds, clinical characteristics, and EEG findings in 246 patients with epilepsy and interictal psychosis and in 658 control patients with epilepsy and no psychotic history. With a logistic regression approach, the significance of each variable for the development of interictal psychosis was evaluated. Results: There are significant differences in family history of psychosis, age at onset of epilepsy, type of epilepsy, lateralization of epileptiform discharges, and level of intelligence between patients with interictal psychosis and those without it. Subsequent logistic regression analysis with all variables demonstrated that family history of psychosis, age at onset of epilepsy, type of seizures, and level of intelligence significantly correlated with psychosis. Conclusions: A family history of psychosis, earlier age at onset of epilepsy, complex partial seizures or generalized tonic clonic seizures, and borderline intellectual functioning were the most important predictors for development of interictal psychosis.

A polydiagnostic and dimensional comparison of epileptic psychoses and schizophrenia spectrum disorders.

After establishing the validity of the Japanese version of the Operational Criteria Checklist for Psychotic Illness (OPCRIT), we applied it to 58 consecutive patients with epileptic psychoses (index group) and to age- and sex-matched controls with schizophrenia spectrum disorders (control group). Compared with the control group, the index group had a low family history of schizophrenia, high premorbid personality disorder and unemployment, abrupt or acute onset of psychosis, good recovery with single or multiple episodes, and low deterioration from a premorbid level of function. From 9% to 52% of the index group and 38% to 84% of the control group were diagnosed with schizophrenia according to the operational criteria used. The percentages of patients diagnosed with schizophrenia based on various diagnostic criteria in the two groups were similar. In the index group, a diagnosis of schizophrenia was more commonly made among patients with inter-ictal psychosis than among those with post-ictal psychosis. An exploratory factor analysis identified five factor solutions of manic, negative, depressive, vegetative, and positive symptoms. Although positive and negative factor values were lower in the index group than in the control group, the two groups shared a similar factor profile. These results indicate that the difference in symptomatology between the two groups was quantitative rather than qualitative.

Epileptic, organic and genetic vulnerabilities for timing of the development of interictal psychosis

BACKGROUND Age at the first psychotic episode and an interval between the onset of epilepsy and that of psychosis reflect developmental processes of interictal psychosis. However, factors relating to these indices remain unknown. AIMS To identify clinical variables that are associated with the timing of the development of interictal psychosis. METHOD In 285 adults with epilepsy with interictal psychosis, effects of epileptic (epilepsy type), organic (intellectual functioning) and genetic (family history of psychosis) variables on timing of the development of psychosis were examined. RESULTS The mean interval between the onset of epilepsy and that of psychosis was 14.4 years. Some psychosis occurred within a few years of the first seizure. Generalised epilepsy, normal intellectual function and a positive family history of psychosis were associated with early onset of psychosis. CONCLUSIONS Early development of interictal psychosis in people with epilepsy may reflect other individual vulnerabilities to psychosis rather than epilepsy-related damage.

Difference in age of onset of psychosis between epilepsy and schizophrenia

To clarify the nature of psychosis development in epilepsy patients, we studied differences in age of onset of psychosis between epilepsy patients with psychosis (epilepsy-psychosis) and schizophrenia patients. Subjects were 282 patients with epilepsy-psychosis (36 postictal, 224 interictal, and 22 bimodal psychoses) and 612 schizophrenia patients. Age of onset was compared between the schizophrenia group and the whole epilepsy-psychosis group as well as its subgroups. Effects of sex and family history of psychosis on age of onset were also evaluated. Epilepsy patients developed psychosis later (mean age 30.1) than schizophrenia patients (mean age 26.6). Among epilepsy-psychosis subgroups, postictal psychosis and interictal psychosis showed a later onset than schizophrenia. In interictal psychosis, while chronic schizophrenia-like psychosis occurred at similar age compared to schizophrenia, brief episodic psychosis occurred at later age. Epilepsy-psychosis patients showed no sex difference in age of onset, whereas female schizophrenia patients showed a later onset than male schizophrenia patients. Both the epilepsy and schizophrenia patients with family history of psychosis tended to develop psychosis at an earlier age, although this did not reach statistically significant level. The findings of the study suggest that the nature of epilepsy-psychosis is not fully equivalent to that of schizophrenia.

Frequency and age-related variables in interictal psychoses in localization-related epilepsies

PURPOSE Several studies have described that patients with temporal lobe epilepsy (TLE) develop psychoses more frequently than patients with extra-temporal localization-related epilepsy (LRE). However, few controlled studies have demonstrated an increased susceptibility to psychosis in TLE patients. As one of a series of multi-center studies on psychosis in epilepsy, we investigated whether the frequency of interictal psychosis differs between types of LRE. METHODS We reviewed some biological characteristics of 197 PE patients with interictal psychosis and of 456 LRE patients with no history of psychosis. Type of PE was determined as TLE, frontal lobe epilepsy, parietal lobe epilepsy, occipital lobe epilepsy, and multi-lobar epilepsy/undifferentiated lobar epilepsy by clinical symptoms, EEG findings, and neuroimaging. The frequency of psychosis for each type of LRE was compared. Ages at onset of epilepsy and psychosis and the time interval between onset of each were also analyzed. RESULTS There was no significant correlation between psychosis and epilepsy type (P=0.211). Age-related variables also failed to show any significant differences between LRE types (age at onset of epilepsy, P=0.369; age at onset of psychosis, P=0.852; the time interval, P=0.893). CONCLUSIONS Patients with LREs as well as with TLE are susceptible to interictal psychosis. The mean ages at onset of symptoms and the interval between onset of epilepsy and onset of psychosis that we observed suggest that patients with LREs, regardless of focus, may share similar processes in the development of psychiatric symptoms.

Intellectual Disability and Psychotic Disorders of Adult Epilepsy

Summary:  Purpose: To investigate the prevalence, psychopathology, and cognitive functions associated with psychotic disorders among adult epilepsy patients with intellectual disability (ID) based on a multicenter study in Japan.

Proposal for a New Five-Axis Classification Scheme for Psychoses of Epilepsy

Based on an overview of the literature and a multicenter study in Japan, we propose a new five-axis classification scheme for psychoses of epilepsy: (1) epilepsy variables, (2) psychopathology variables, (3) ictus/EEG variables, (4) precipitating factors of psychoses, (5) organic background. A total of 128 patients, 63 males and 65 females, with epilepsy and psychoses were recruited from five treatment centers. A wide heterogeneity of psychoses of epilepsy was demonstrated and categorization by a single axis was shown to be inadequate. Cluster analysis revealed four subgroups characterized by their psychopathology, temporal relationship to seizure occurrence, and EEG changes during psychoses. By comparing with the control epileptic group without psychoses, higher rates of mild intelligence disturbance and abnormal findings by brain imaging were proven among the psychotic group. The scheme involves a dimensional representation of individual patients to capture the complexity of their clinical background and to relay clinical information accurately and systematically. It is believed to hold direct therapeutic implications and to contribute to promoting research by enabling accumulation of a large number of patients on a multicenter basis.

Analogy between psychosis antedating epilepsy and epilepsy antedating psychosis

Purpose:  Patients with recurrent epileptic seizures after the development of psychosis (Psychosis‐Epilepsy) have been regarded as belonging to a different clinical entity from those with epilepsy antedating the development of psychosis (Epilepsy‐Psychosis). However, clinical characteristics of patients with Psychosis‐Epilepsy have not been well described, except for early German studies. We aimed to estimate the reliability of distinction between Psychosis‐Epilepsy and Epilepsy‐Psychosis by comparing their clinical characteristics.