Interictal Psychoses in Comparison with Schizophrenia—A Prospective Study

Abstract

Schizophrenia and epileptic psychosis showed different symptom profiles. On average, epilepsy patients with interictal psychoses achieved higher remission rates with lower doses of antipsychotic drugs as compared to patients with schizophrenia in the present 1-year follow-up study.

Schizophrenia-like psychoses of epilepsy

“…All the patients in that study had either complex partial seizures or temporal epileptogenic foci in electroencephalographic findings. In our previous study, we reported that patients with schizophrenia had a significantly earlier age of onset of psychosis compared to epilepsy patients, with mean ages of 21.6 and 35.7 years, respectively (p = 0.003) [17]. In an investigation of the difference in age of onset of psychosis between epilepsy and schizophrenia, Adachi et al [43] found that patients with epileptic psychoses experienced their first psychotic episode significantly later in life than schizophrenic patients (p = 0.000).…”

“…Our previous study also revealed differences in symptom profiles between schizophrenia and psychoses in epilepsy [17]. We employed the Positive and Negative Syndrome Scale (PANSS) to assess psychotic symptoms and found that negative symptoms such as blunted affect were less apparent in epilepsy patients with psychoses.…”

“…McGrath et al [16] reported a median incidence of schizophrenia of 15.2 per 100,000 individuals, whereas the reported incidence of psychosis in epilepsy patients was a digit greater. In a prospective study of interictal psychoses of epilepsy, we previously reported an average annual incidence of 0.42% among adult epilepsy outpatients during a 56-month study period [17]. Onuma et al [18] conducted a retrospective study of psychosis in patients with epilepsy who visited their adult epilepsy clinic between 1980 and 1994, and found that the annual incidence of newly developed psychosis varied from a minimum of 0% to a maximum of 0.77%, with an average of 0.3%.…”

A 15-Year-Old Boy with Aggression and Paranoia

“…1 When compared with primary psychosis, patients with interictal psychosis usually exhibit fewer negative symptoms, express greater insight, and do not demonstrate a deterioration of personality throughout the course of the illness. 5,6 Proposed etiologies of schizophrenia and epilepsy describe shared frontal-limbic neurocircuitry defects. However, cognitive deficits and disorganization (found primarily in schizophrenia) are thought to be secondary to frontal lobe dysfunction, whereas the positive symptoms of delusions and hallucinations (found in both schizophrenia and potentially temporal lobe epilepsy) are thought to originate from the dysfunction of temporal lobe structures.…”

The Neurology of Psychosis

“…There are reports of clinical phenomena that are more typical of epilepsy occurring in schizophrenia, and there is substantial evidence of abnormal electroencephalograph recordings in schizophrenia, but the consensus is that these abnormalities are not typical of epilepsy. Nonetheless, interest in the interrelationships between epilepsy and schizophrenia continues unabated and both empirical and theoretical works on this subject continue [24,[45][46][47][48][49] , including the role of kindling [33,[50][51][52] .…”