A Prospective Study of Postictal Psychoses with Emphasis on the Periictal Type

Hiding in Plain Sight: A case of post ictal psychosis with suicidal behavior

Postictal psychosis (PIP) is a serious, often unrecognized complication of epilepsy. Early diagnosis and intervention can prevent life-threatening outcomes. We report the case of a 26-year-old woman with childhood-onset frontal lobe epilepsy who attempted suicide, during a postictal psychotic episode, several days after undergoing inpatient video-EEG monitoring. This case presents a real-world scenario with clear guidelines for the on-call neurologist who will need to accurately diagnose and confidently manage PIP with psychotropic medications. Moreover, this case may stimulate discussion about the complex relationship between epilepsy and psychosis.

Psychosis and schizophrenia among patients with epilepsy: A systematic review and meta-analysis

BACKGROUND

Prior research has indicated an association between epilepsy and psychosis. This review aimed to estimate the global prevalence rate of psychosis and schizophrenia in epilepsy and assess the odds of psychosis and schizophrenia among patients with epilepsy (PWE).

METHOD

A comprehensive literature search was carried out utilizing relevant keywords in PubMed/MEDLINE and Scopus, covering from January 1, 1990, to November 18, 2023. The meta-analysis was performed using R software employing a random-effect model to establish the overall prevalence and odds ratio (OR), with 95 % confidence intervals (95 % CI), of psychosis and schizophrenia in epilepsy.

RESULT

Eighty-one studies encompassing 970,497 PWE met the inclusion criteria. The meta-analysis revealed that the overall prevalence of psychosis and schizophrenia among PWE was 7.8 % (95 % CI: 6.3-9.2 %, I2 = 100 %) and 3 % (95 % CI: 1.7-4.3 %, I2 = 95 %), respectively. Moreover, epilepsy was associated with a threefold rise in the odds of psychosis (OR = 3.41, 95 % CI: 2.3-5.08, p-value < 0.01, I2 = 99 %, p-heterogeneity < 0.01). Furthermore, epilepsy was found to be significantly correlated with a fivefold increased odds of schizophrenia (OR = 5.22, 95 % CI: 2.99-9.11, p-value < 0.01, I2 = 94 %, p-heterogeneity < 0.01) CONCLUSION: Epilepsy can increase the risk of developing psychosis and schizophrenia. Additional longitudinal research is warranted to elucidate the influence of epilepsy and its treatments on the risk of psychosis and schizophrenia, and also a comprehensive suite of confounding adjustments will be requisite.

Prevalence and factors associated with psychosis among adults with epilepsy at a tertiary hospital in Uganda, cross-sectional study

BACKGROUND

Psychotic disorders are prevalent among people with epilepsy compared to the general population. However, there is limited information regarding psychosis among people with epilepsy in Uganda. This study therefore determined the prevalence and associated factors of psychosis among adults with epilepsy attending Butabika National Referral Mental Hospital in Uganda.

METHODS

This was a cross-sectional study involving adults with epilepsy. The diagnosis of psychosis was assessed using the Mini-International Neuropsychiatric Interview, module for Psychotic disorders. Logistic regression analysis identified factors associated with psychosis.

RESULTS

Out of 250 participants, 6.8% had psychosis and 13.6% had depression. Psychosis was significantly associated with older age, greater perceived stigma and substance use.

CONCLUSION

Psychosis affects nearly 7% of adults with epilepsy in Uganda especially among those who are older, with perceived stigma and substance use. Routine screening and early intervention to management of psychosis in PWE is highly recommended.

Psychiatric comorbidities among people with epilepsy: A population-based assessment in disadvantaged communities

Psychiatric disorders are frequent among people with epilepsy but often under-recognized. The diagnosis and treatment of these disorders in low- and low-middle-income countries (LMICs) are challenging.

METHODS

This cross-sectional survey included people recruited during a community epilepsy screening program involving 59,509 individuals from poor communities in Ludhiana in Northwest India. Adults (age ≥18 years) with confirmed epilepsy on antiseizure medications were screened for depression and anxiety using the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) and Generalized Anxiety Disorder-7 (GAD-7) twice over two years of follow-up. They were later interviewed for symptoms using the Brief Psychiatric Rating Scale, which was then confirmed by assessments by an experienced psychiatrist.

RESULTS

Of the 240 people with confirmed epilepsy, 167 (70%) were adults, of whom, 116 (70%) eventually participated in the study. The NDDI-E with a cut-off of 15 identified depression in 14 (12%) of 116 people after one year of follow-up and 17 (15%) at two years. The GAD-7 using a cut-off of 6 identified 22 (19%) at one year and 32 (28%) with anxiety at two years. The area under the curves for NDDI-E was estimated as 0.62 (_95%CI, 0.51-0.73; SE: 0.06; p = 0.04) and for GAD-7 as 0.62 (_95%CI, 0.46-0.78; SE: 0.08; p = 0.12). Brief Psychiatric Rating Scale identified 63 (54%) people with psychiatric symptoms, for whom, a psychiatric diagnosis was confirmed in 60 (52%). A psychiatric diagnosis was associated with education below high school [Odds Ratio (OR): 2.59, _95%CI, 1.12-5.1; p = 0.03], later age of seizure onset (OR, 1.05, _95%CI: 1.0-1.10; p = 0.04), seizure frequency of at least one/year at enrolment (OR, 2.36, _95%CI: 1.0-5.58; p = 0.05) and the use of clobazam (OR, 5.09, _95%CI, 1.40-18.42; p = 0.01).

CONCLUSION

Depression and anxiety are common in people with epilepsy. Our findings underscore the low yields of screening instruments, NDDI-E and GAD-7, and comparatively better professionally-administered diagnostic assessments in resource-limited settings in LMICs. Moreover, previously established cut-offs do not apply to the community studied.

Bidirectionality of antiseizure and antipsychotic treatment: A population-based study

PURPOSE

To study the prevalence and directionality of comorbid epilepsy and psychosis in Norway.

METHODS

The Norwegian Prescription Database (NorPD) provided individual-based information on all antiseizure medications (ASMs) and antipsychotic drugs (APDs) dispensed during 2004-2017. Subjects were ≥18 years of age at the end of the study period. Diagnosis-specific reimbursement codes from the 10th revision of the International Classification of Diseases/2nd edition of the International Classification of Primary Care (ICD-10/ICPC-2) combined with ATC codes were used as indicators of diagnosis. Subjects had collected ASMs for epilepsy or APDs for psychosis at least four times, at least once issued with an ICD-10 code from the specialist healthcare service. Directionality was analyzed in subjects receiving both treatments. To reduce prevalent comorbidity bias, we employed a four-year comorbidity-free period (2004-2007). The use of specific ASMs and APDs was analyzed.

RESULTS

A total of 31,289 subjects had collected an ASM for epilepsy at least four times, 28,889 an APD for psychosis. Both the prevalence of treatment for epilepsy and of treatment for psychosis was 0.8%. Further, 891 subjects had been treated for both conditions; 2.8% with epilepsy had been treated for psychosis, and 3.1% with psychosis had been treated for epilepsy. Among 558 subjects included in the analyses of directionality, 56% had collected the first APD before an ASM, whereas 41% had collected an ASM first. During the last year prior to comorbidity onset, levetiracetam, topiramate, or zonisamide had been used for epilepsy by approximately 40%, whereas olanzapine and quetiapine were most used in patients with psychosis, and clozapine in 13%.

CONCLUSION

The proportion of patients with prior antipsychotic treatment at onset of epilepsy is higher than previously acknowledged, as demonstrated in this nation-wide study. Apart from a shared neurobiological susceptibility, the bidirectionality of epilepsy and psychosis may be influenced by various environmental factors, including the interaction of pharmacodynamic effects. APDs may facilitate seizures; ASMs may induce psychiatric symptoms. In patients with combined treatment, these potential drug effects should receive ample attention, along with the psychosocial consequences of the disorders. A prudent multi-professional approach is required.

Treatment of psychoses in patients with epilepsy: an update

Psychotic disorders represent a relatively rare but serious comorbidity in epilepsy. Current epidemiological studies are showing a point prevalence of 5.6% in unselected samples of people with epilepsy going up to 7% in patients with temporal lobe epilepsy, with a pooled odds ratio of 7.8 as compared with the general population. This is a narrative review of the most recent updates in the management of psychotic disorders in epilepsy, taking into account the clinical scenarios where psychotic symptoms occur in epilepsy, interactions with antiepileptic drugs (AEDs) and the risk of seizures with antipsychotics. Psychotic symptoms in epilepsy can arise in a number of different clinical scenarios from peri-ictal symptoms, to chronic interictal psychoses, comorbid schizophrenia and related disorders to the so-called forced normalization phenomenon. Data on the treatment of psychotic disorders in epilepsy are still limited and the management of these problems is still based on individual clinical experience. For this reason, guidelines of treatment outside epilepsy should be adopted taking into account epilepsy-related issues including interactions with AEDs and seizure risk. Second-generation antipsychotics, especially risperidone, can represent a reasonable first-line option because of the low propensity for drug-drug interactions and the low risk of seizures. Quetiapine is burdened by a clinically significant pharmacokinetic interaction with enzyme-inducing drugs leading to undetectable levels of the antipsychotic, even for dosages up to 700 mg per day.

Perspectives on seizure clusters: Gaps in lexicon, awareness, and treatment

Seizure clusters in epilepsy can result in serious outcomes such as missed work or school, postictal psychosis, emergency room visits, or hospitalizations, and yet they are often not included in discussions between health-care professionals (HCPs) and their patients. The purpose of this paper was to describe and compare consumer (patient and caregivers) and professional understanding of seizure clusters and to describe how consumers and HCPs communicate regarding seizure clusters. We reviewed social media discussion sites to explore consumers' understanding of seizure clusters. We analyzed professional (medical) literature to explore the HCPs' understanding of seizure clusters. Major themes were revealed in one or both groups, including: communication about diagnosis; frequency, duration, and time frame; seizure type and pattern; severity; and self-management. When comparing discussions of professionals and consumers, both consumers and clinicians discussed the definition of seizure clusters. Discussions of HCPs were understandably clinically focused, and consumer discussions reflected the experience of seizure clusters; however, both groups struggled with a common lexicon. Seizure cluster events remain a problem associated with serious outcomes. Herein, we outline the lack of a common understanding and recommend the development of a common lexicon to improve communication regarding seizure clusters.

A change in electrographic activity and blood flow during interictal and postictal psychotic states in a patient with epilepsy

We report a patient with epilepsy who experienced interictal and postictal psychoses. Her psychiatric symptoms consisted of grandiose and fantastic delusions during both psychotic states. During remission, electroencephalography showed bitemporal epileptiform discharges that were predominant in the right temporal region. Epileptiform discharges present during the psychotic states were predominant in the left temporal region. Single-photon emission computed tomography showed hyperperfusion in the left basal ganglia during the interictal psychotic state and hyperperfusion in the right temporal lobe and left basal ganglia during the postictal psychotic state. We suggest that the occurrence of postictal and interictal psychotic states in this patient were associated with a common change in electrographic activity and blood flow.

Basic treatment principles for psychotic disorders in patients with epilepsy

In patients with epilepsy, coexisting psychoses, either interictal (IIP) or postictal (PIP), are associated with serious disturbance in psychosocial function and well-being, and often require the care of a specialist. Unfortunately, evidence-based treatment systems for psychosis in patients with epilepsy have not yet been established. This article aims to propose concise and practical treatment procedures for IIP and PIP based on currently available data and international consensus statements, and primarily targeting nonpsychiatrist epileptologists who are often the first to be involved in the management of these complex patients. Accurate and early diagnosis of IIP and PIP and their staging in terms of acuity and severity form the essential first step in management. It is important to suspect the presence of psychosis whenever patients manifest unusual behavior. Knowledge of psychopathology and both individual and epilepsy-related vulnerabilities relevant to IIP and PIP facilitate early diagnosis. Treatment for IIP involves (1) obtaining consent to psychiatric treatment from the patient, whenever possible, (2) optimization of antiepileptic drugs, and (3) initiation of antipsychotic pharmacotherapy in line with symptom severity and severity of behavioral and functional disturbance. Basic psychosocial interventions will help reinforce adherence to treatment and should be made available. Due consideration must be given to patients' ability to provide informed consent to treatment in the short term, with the issue being revisited regularly over time. Given the often prolonged and recurrent nature of IIP, treatment frequently needs to be long-term. Treatment of PIP consists of two aspects, that is, acute protective measures and preventive procedures in repetitive episodes. Protective measures prioritize the management of risk in the early stages, and may involve sedation with or without the use of antipsychotic drugs, and the judicious application of local mental health legislation if appropriate. As for preventative procedures, optimizing seizure control by adjusting antiepileptic drugs or by surgical treatment is necessary.

Psychotic illness in patients with epilepsy

Apart from the rather rare ictal psychotic events, such as non-convulsive status epilepticus, modern epileptic psychoses have been categorized into three main types; chronic and acute interictal psychoses (IIPs) and postictal psychosis (PIP). Together, they comprise 95% of psychoses in patients with epilepsy (PWE). Four major questions, that is, "Is psychosis in PWE a direct consequence of epilepsy or schizophrenia induced by epilepsy?", "Is psychosis in PWE homogeneous or heterogeneous?", "Does psychosis in PWE have symptomatological differences from schizophrenia and related disorders?", "Is psychosis in PWE uniquely associated with temporal lobe epilepsy (TLE)?" are tried to be answered in this review with relevant case presentations. In the final section, we propose a tentative classification of psychotic illness in PWE, with special attention to those who have undergone epilepsy surgery. Psychotic disorders in PWE are often overlooked, mistreated, and consequently lingering on needlessly. While early diagnosis is unanimously supported as a first step to avoid this delay, necessity of switching from antiepileptic drugs with supposedly adverse psychotopic effects. to others is more controversial. To elucidate the riddle of alternative psychosis, we need badly further reliable data.

Postictal psychosis and its electrophysiological correlates in invasive EEG: a case report study and literature review

We identified two patients with medically refractory temporal lobe epilepsy, from whom intracranial EEG recordings were obtained at the time of postictal psychosis. Both patients had mesial temporal epilepsy associated with hippocampal sclerosis. In both patients, the postictal psychosis was associated with a continual "epileptiform" EEG pattern that differed from their interictal and ictal EEG findings (rhythmical slow wave and "abortive" spike-slow wave complex activity in the right hippocampus and lateral temporal cortex in case 1 and a periodic pattern of triphasic waves in the contacts recording activity from the left anterior cingulate gyrus). Some cases of postictal psychosis might be caused by the transient impairment of several limbic system structures due to the "continual epileptiform discharge" in some brain regions. Case 2 is the first report of a patient with TLE in whom psychotic symptoms were associated with the epileptiform impairment of the anterior cingulate gyrus.

Psychiatric comorbidity in patients with two prototypes of focal versus generalized epilepsy syndromes

The frequency of psychiatric disorders (PD) in a homogeneous series of patients with temporal lobe epilepsy with mesial temporal sclerosis (TLE-MTS) compared to patients with juvenile myoclonic epilepsy (JME) was evaluated, aiming to determine the frequency of PD and possible differences in psychiatric diagnoses between these two epileptic syndromes. Data from 248 patients with refractory TLE-MTS and from 124 JME patients were reviewed and compared. There was a high prevalence of PD in both groups of epilepsy patients, present in 100 TLE-MTS (41%) and in 58 JME patients (46.7%). Mood (23.7%), anxiety (13.7%) and psychotic (11.6%) disorders were the most frequent diagnoses in TLE-MTS group, while mood and anxiety disorders (25% and 21%, respectively) were the most common PD among JME. Psychoses were significantly associated with TLE-MTS (p=0.01). These observations are concordant with our previous study, reforcing the existence of a possible anatomic correlation of PD and brain structures involved in both epilepsy syndromes.

Nonconvulsive status epilepticus and the postictal state

Postictal symptoms, because of activation of inhibitory systems, have to be distinguished from ongoing ictal activity. The categorical concept of pure ictal and pure postictal symptoms cannot be supported by clinical observation alone. Differentiation between postictal and ictal behavioral phenomena can be difficult even with the use of electroencephalography, as clear-cut definitions of ictal and postictal changes are not available. Five different aspects can be considered: (1) hallucinatory symptoms recorded during and after a seizure, (2) prolonged postictal confusional states, (3) prolonged postictal psychotic states, (4) epileptic and other encephalopathies, and (5) coma with or without clinical signs of nonconvulsive status epilepticus. Presenting symptoms and conceptual considerations are presented in this review.

Neuropsychiatric evaluations of postictal behavioral changes

Postictal behavioral changes (PBCs), including psychosis, aggression, and mood change, are commonly observed in patients with epilepsy. Recognition and description of the clinical manifestations of PBCs would help in understanding and treating patients. Additionally, various quantified objective scales that are widely available in clinical psychiatry could be used to assess the clinical symptoms of PBCs. There are few reports in which objective rating scales have been used to assess neuropsychiatric symptoms in patients with epilepsy. However, there have been a small number of studies on interictal psychosis and depression in which either the Brief Psychiatric Rating Scale or the Hamilton Depression Scale was used. These inventories are likely to be useful for the assessment of PBCs. Other rating scales used for schizophrenia, depression, mania, and aggressive behavior are reviewed here. The author suggests that cross-sectional and longitudinal neuropsychiatric measurement combined with other modalities, including functional neuroimaging, could provide clues to the pathophysiology of PBCs.

The effect of surgery on the postictal state

The effect of surgery on the postictal state has not been studied in a systematic fashion. There is limited literature looking at the effect on postictal psychosis. The effect of surgery on this phenomenon has been varied with post ictal psychosis occurring post surgery when it has not occurred prior to surgery as well as resolution after surgery. Case reports of post ictal Kluver Bucy Syndrome and Capgas Syndrome have been reported after resective epilepsy surgery as well.

Postictal psychosis: common, dangerous, and treatable

Postical psychosis often complicates chronic epilepsy, especially in patients with seizure clusters that include tonic-clonic seizures, bilateral cerebral dysfunction (e.g., bilateral epileptiform activity or history of encephalitis), and a family history of psychiatric illness. Psychosis includes delusions, auditory and visual hallucinations, mood changes, and aggressive behavior. It typically emerges after a lucid interval of hours or days after the last seizure. This treatable disorder is associated with serious morbidity and mortality.

Norman Geschwind's contribution to the understanding of behavioral changes in temporal lobe epilepsy: the February 1974 lecture

Norman Geschwind catalyzed academic interest in the study of interictal behavioral changes in temporal lobe epilepsy. His contributions to this area comprise a series of 11 articles, chapters, editorials, and commentaries published between 1973 and 1984. This article summarizes, both chronologically and by behavioral topic, Geschwind's contributions and opinions on behavioral changes in temporal lobe epilepsy. A previously unpublished lecture (see article in this issue), "Personality Change in Temporal Lobe Epilepsy," from his course at Harvard Medical School on The Neurology of Behavior (1974), is also quoted to further illustrate his views on specific features of this syndrome. Notably, many of Geschwind's observations and formulations regarding this topic were highly developed in 1974, reflecting his long-standing interest in behavioral changes in epilepsy. Geschwind and his collaborators viewed temporal lobe epilepsy as an important model of behavioral change resulting from a stimulating lesion in the limbic system. This neurobiology accounted for the overarching increased interictal emotionality that underlay the increased religious interests, hypergraphia, increased aggression, increased moral and philosophical concerns, viscosity, and seriousness (lack of humor). Hyposexuality was the exception, although it was consistent with a discharging lesion altering this emotion-driven behavior. Geschwind provided a series of arguments to support the existence of this limbic syndrome and explain why alternative views (e.g., destructive lesion, psychological factors) and arguments against the syndrome's existence are inconsistent with the data.

Delusions, illusions and hallucinations in epilepsy: 2. Complex phenomena and psychosis

In this second paper the clinical features and electrophysiological underpinnings of more complex psychotic states associated with epilepsy are reviewed. (a) Complex partial status epilepticus, in particular of temporal lobe origin, may result in mental states remarkably similar to those seen in the primary psychoses. This non-convulsive state is associated with prolonged epileptic discharges on intracranial stereoelectroencephalography (SEEG) in hippocampal and other mesial temporal structures, sometimes without abnormalities on the scalp EEG. Where hallucinatory or psychotic symptomatology does occurs, it can be considered an examples of an ictal psychosis. The phenomenology and electrophysiological features of this condition are reviewed. (b) Postictal psychosis is noted for its similarity to schizophrenia-like/paranoid and affective psychoses and there is convincing SEEG evidence that, for some cases at least, the psychosis is not in fact postictal but rather an ictal psychosis due to ongoing limbic seizure activity and a form of non-convulsive status epilepticus. It has been suggested that postictal psychosis should be divided into two sub-groups: the classical 'nuclear' postictal type and an atypical periictal type. (c) Interictal hallucinosis in epilepsy has been poorly studied, but is probably commoner than appreciated. To what extent it represents subclinical epileptic discharges (i.e. auras) is not known. It may interestingly also be associated with abnormal affective states in epilepsy. (d) The interictal psychosis of epilepsy is often indistinguishable from primary schizophrenia. It occurs more commonly in temporal lobe (limbic) epilepsy, in those with frequent seizures and only in patients with a long history of epilepsy (usually over 10 years). There is convincing SEEG evidence of frequent, semi-continuous and sometimes continuous epileptic activity in limbic structures at the time of psychotic and hallucinatory ideation and behaviour, suggesting that in some cases at least, the epileptic activity is the cause of the symptoms. Whether the psychosis is directly 'driven' by subclinical electrographic activity or is indirectly a consequence of function change induced by such activity is not clear. An intriguing question also arises as to whether similar electrophysiological changes could underpin psychosis in patients without epilepsy but evidence on this point is sparse. The effects of temporal lobe surgery on the psychoses of epilepsy are described and these might throw light on the mechanisms of epileptic psychosis. The principles of pharmacological therapy of epileptic hallucinosis and psychosis are outlined.

Psychiatric comorbidity in epilepsy: a study comparing patients with mesial temporal sclerosis and juvenile myoclonic epilepsy

We evaluated the frequency of psychiatric disorders (PDs) in a homogenous series of patients with temporal lobe epilepsy with mesial temporal sclerosis (TLE-MTS), as compared with patients with juvenile myoclonic epilepsy (JME), aiming to determine possible differences in psychiatric diagnoses between these two epileptic syndromes. Data from 170 patients with refractory TLE-MTS and from 100 patients with JME were reviewed and compared. The prevalence of PDs was high in both groups of patients with epilepsy: PDs were present in 85 patients with TLE-MTS (50%) and 49 patients with JME (49%). Among the TLE-MTS group, mood (25.8%), psychotic (15.8%), and anxiety (14.1%) disorders were the most frequent diagnoses, whereas anxiety and mood disorders (23 and 19%, respectively) were the most common among patients with JME. Psychoses were significantly associated with MTS (P<0.01) and anxiety disorders with JME (P<0.05). These findings suggest the existence of an anatomic correlation between PDs and brain structures involved in both epilepsy syndromes.

Spirituality and religion in epilepsy

Revered in some cultures but persecuted by most others, epilepsy patients have, throughout history, been linked with the divine, demonic, and supernatural. Clinical observations during the past 150 years support an association between religious experiences during (ictal), after (postictal), and in between (interictal) seizures. In addition, epileptic seizures may increase, alter, or decrease religious experience especially in a small group of patients with temporal lobe epilepsy (TLE). Literature surveys have revealed that between .4% and 3.1% of partial epilepsy patients had ictal religious experiences; higher frequencies are found in systematic questionnaires versus spontaneous patient reports. Religious premonitory symptoms or auras were reported by 3.9% of epilepsy patients. Among patients with ictal religious experiences, there is a predominance of patients with right TLE. Postictal and interictal religious experiences occur most often in TLE patients with bilateral seizure foci. Postictal religious experiences occurred in 1.3% of all epilepsy patients and 2.2% of TLE patients. Many of the epilepsy-related religious conversion experiences occurred postictally. Interictal religiosity is more controversial with less consensus among studies. Patients with postictal psychosis may also experience interictal hyper-religiosity, supporting a "pathological" increase in interictal religiosity in some patients. Although psychologic and social factors such as stigma may contribute to religious experiences with epilepsy, a neurologic mechanism most likely plays a large role. The limbic system is also often suggested as the critical site of religious experience due to the association with temporal lobe epilepsy and the emotional nature of the experiences. Neocortical areas also may be involved, suggested by the presence of visual and auditory hallucinations, complex ideation during many religious experiences, and the large expanse of temporal neocortex. In contrast to the role of the temporal lobe in evoking religious experiences, alterations in frontal functions may contribute to increased religious interests as a personality trait. The two main forms of religious experience, the ongoing belief pattern and set of convictions (the religion of the everyday man) versus the ecstatic religious experience, may be predominantly localized to the frontal and temporal regions, respectively, of the right hemisphere.

Interictal psychoses in comparison with schizophrenia--a prospective study

PURPOSE

To prospectively investigate the incidence of interictal psychoses of epilepsy patients, and make a comparison between those with interictal psychoses and patients with schizophrenia in respect to their responses to antipsychotic drugs, as well as psychotic states.

METHODS

We undertook a two-part prospective investigation. In Part I, the psychotic episodes of 619 epilepsy patients were investigated, while 182 patients with psychotic syndromes were followed in Part II, of whom 59 were diagnosed with schizophrenia and 13 with epilepsy with interictal psychoses. The Positive and Negative Syndrome Scale was used for efficacy assessment.

RESULTS

The average annual incidence of interictal psychosis was 0.42% during the 56-month study period. A significant difference was found between patients with schizophrenia and epilepsy patients with interictal psychoses in respect to results on the negative subscale of the PANSS at the initial examination (mean scores of 18.1 and 13.2, respectively, p = 0.004). The response rates one year later for these groups were 27.1% and 53.8%, respectively, which showed a trend of better response to the antipsychotic medication by the epilepsy group (p = 0.098). Initial and maximum doses of antipsychotic drugs used for epilepsy patients with interictal psychoses were significantly lower than those used for patients with schizophrenia (p = 0.008 and p = 0.006, respectively).

CONCLUSIONS

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.