Predictive variables of interictal psychosis in epilepsy

Epilepsy and psychosis

Psychotic disorders are eight times more frequent in epilepsy than in the general population. The various clinical syndromes are classified according to their chronology of onset in relation to epileptic seizures: ictal psychoses (during epileptic discharge), post-ictal psychoses (PIP, after a seizure), interictal psychoses (IIP, with no chronological link) and those related to complete seizure control. Antiepileptic drugs can cause psychotic disorders in all these situations. Post-ictal psychoses (PIP) are affective psychoses that occur after a lucid interval lasting 12 to 120hours following a cluster of seizures. They last an average of 10days, with an abrupt beginning and end. PIP are directly linked to epileptic seizures, and disappear when the epilepsy is controlled. Interictal psychoses are schizophrenias. The management of psychotic disorders in epilepsy is neuropsychiatric, and requires close collaboration between epileptologists and psychiatrists. Antipsychotics can be prescribed in persons with epilepsy. Even today, psychotic disorders in epilepsy are poorly understood, under-diagnosed and under-treated.

Psychotic Disorders in Epilepsy: Do They Differ from Primary Psychosis?

Any attempt to compare the definitions of symptoms listed for "primary psychoses" with those adopted in studies of psychoses in patients with epilepsy (PWE) will encounter problems of heterogeneity within both conditions. In this manuscript, five psychotic illnesses listed in Diagnostic and Statistical Manual of Mental Disorders-5th Edition (DSM-5), that is, brief psychotic illness, schizophreniform disorder, schizophrenia, delusional disorder, and schizoaffective disorder are compared with postictal (or periictal) and interictal psychotic disorders in PWE. After examining definitions of primary psychoses, definitions of psychoses adopted in the papers dealing with postictal and interictal psychoses are summarized. Further, diagnostic criteria of five types of psychotic disorders in PWE proposed in 2007 by Krishnamoorthy et al. are also discussed, which include postictal psychosis, comorbid schizophrenia, iatrogenic psychosis caused by antiepileptic drugs (AEDs) (AED-induced psychotic disorder: AIPD), and forced normalization. Evidently, a comparison between postictal psychosis and schizophrenia is pointless. Likewise, schizophrenia may not be an appropriate counterpart of forced normalization and AIPD, given their acute or subacute course.Based on these preliminary examinations, three questions are selected to compare primary psychoses and psychoses in PWE: Is postictal psychosis different from a brief psychotic disorder? Does epilepsy facilitate or prevent the development of psychosis or vice versa? Is interictal psychosis of epilepsy different from process schizophrenia? In conclusion, antagonism between psychosis and epileptic seizures in a later stage of active epilepsy seems not to be realized without reorganization of the nervous system promoted during an earlier stage. Both genetic predisposition and the summated effects of epileptic activity must be taken into consideration as part of a trial to explain interictal psychosis. Interictal psychosis is an aggregate of miscellaneous disorders, that is, co-morbid schizophrenia, AED-induced psychotic disorders, forced normalization, and "epileptic" interictal psychosis. Data are lacking to conclude whether differences exist between process schizophrenia and "epileptic" interictal psychosis in terms of negative symptoms, specific personal traits, and the "bizarre-ness" of delusory-hallucinatory contents. These discussions may shed light on the essence of process schizophrenia, thus allowing it stand out and receive increased focus.

Psychosis rarely occurs in patients with late-onset focal epilepsy

AIMS

We examined psychosis occurrence in patients with late-onset focal epilepsy.

SUBJECTS AND METHODS

Case records of consecutive patients with focal epilepsy without central nervous system (CNS) disease (n = 873) were retrospectively examined, with gender, age at epilepsy onset, duration of epilepsy, epilepsy type (temporal or extratemporal), and age at the initial examination used as clinical and demographic variables. Patients with onset ≤49 years old (control) were compared with those with late-onset.

RESULTS

In the control group (n = 775), 38 had a history of psychosis, while none in the late-onset group (n = 98) reported that (p = 0.016). Psychosis was only interictal in 32 and predominantly postictal in 6, while 2 patients showed both interictal and postictal psychosis. Duration of illness (p = 0.000001) and temporal lobe epilepsy (p = 0.000343) were significant determinants associated with psychosis. Gender (p = 0.210) and age at examination (p = 0.084) were found to be not contributory to psychosis.

DISCUSSION

The prevalence for a history of psychosis in the present cohort (2.5%) agrees well with that noted in previous studies, and duration of illness proved to be the most powerful determining factor leading to that. A keen awareness of unrecognized underlying CNS or metabolic disease is important when psychosis appears in patients with nonlesional late-onset epilepsy, which should lead to an in-depth investigation of possible underlying and still uncovered CNS disease.

[Interictal psychosis of epilepsy]

Interictal psychosis (IIP) refers to psychosis that occurs in clear consciousness in persons with epilepsy (PWE) with temporal onset not during or immediately following a seizure. The pooled prevalence estimate of psychosis in PWE is 5.6%. PWE and schizophrenia have very high mortality, and more than one in four persons with both disorders die between the age of 25 and 50years. IIP can manifest in brief or chronic forms. The chronic forms of IIP may closely resemble schizophrenia. However, some authors have described the typical presence of persecutory and religious delusions, sudden mood swings and the preservation of affect, as well as rarity of negative symptoms and catatonic states, but these differences remain controversial. Typically, IIP starts after many years of active temporal lobe epilepsy. Several epilepsy-related variables are considered pathogenically relevant in IIP including epilepsy type and seizure characteristics. Risk factors for developing IIP are family history of psychosis, learning disability, early age of onset of epilepsy, unilateral or bilateral hippocampal sclerosis, history of status epilepticus, history of febrile seizures, and poorly controlled temporal lobe epilepsy. In patients with epilepsy and psychosis, structural imaging studies have shown several relevant changes leading to conflicting findings. Altered neuronal plasticity and excitability have been described in epilepsy and psychotic disorders. Neuropathological data suggest that IIP are not the result of classic epileptic pathology of the temporal lobe. Forced normalization (FN) and alternating psychosis refer to patients with poorly controlled epilepsy (focal or generalized) who have had psychotic episodes associated with remission of their seizures and disappearance of epileptiform activity on their EEGs. FN mainly occurs in temporal lobe epilepsy when patients have frequent seizures that are abruptly terminated triggered by an antiepileptic drug, vagus nerve stimulation or epilepsy surgery. Treatment is based on withdrawal of the responsible drug, and by transient use of antipsychotics for acute symptomatic control on a case-by-case basis. FN is an entity whose pathophysiology remains uncertain. Antiepileptic drugs (AEDs) may sometimes induce psychotic symptoms and psychosis could be a direct effect of the AEDs. IIP has been reported more frequently following the initiation of zonisamide, topiramate, and levetiracetam when compared with other antiepileptic drugs. However, AEDs do not appear to be the only determinant of IIP. The management of IIP requires a multidisciplinary approach with early involvement of a liaison psychiatrist associated with a neurologist. IIP are underdiagnosed and mistreated. Existing recommendations are extrapolated from those established for the treatment of schizophrenia with some additional guidance from expert opinions. A two-step procedure, not necessarily consecutive, is suggested. The first step requires reevaluation of the antiepileptic treatment. The second step requires initiation of atypical neuroleptics. Antipsychotic drugs should be selected with consideration of the balance between pharmacological profiles, efficacy, and adverse effects. Regarding pharmacokinetic interactions, AEDs with inducing properties reduce the blood levels of all antipsychotics. It is important to consider implications of combining neuroleptics and AEDs with a similar spectrum of side effects. Regarding the duration of treatment, IIP episodes are more likely to be recurrent than in primary schizophrenia. In practice, atypical neuroleptics with few motor side effects such as risperidone can be used as first choice, given the low propensity for drug-drug interactions and the low seizure risk, with the added suggestion to start low and go slow. Clozapine could be prescribed in selected cases.

Common psychiatric comorbidities in epilepsy: How big of a problem is it?

Psychiatric illness and epilepsy commonly co-occur in adults and in children and adolescents. Theories of comorbidity are complex, but recurring associations between the conditions suggest overlap that is more than simple co-occurrence. Common underlying pathophysiology may imply that epilepsy itself may constituently include psychiatric symptoms. Conditions such as depression or cognitive difficulties commonly occur and in some cases, are considered to be associated with specific epilepsy characteristics such as localization or seizure type. Regardless of etiologic attributions to psychiatric comorbidity, it is clear today that treatment for epilepsy needs to target psychiatric illness. In many cases, quality-of-life improvements depend more upon addressing psychiatric symptoms than seizures themselves. This article is part of the Special Issue "Obstacles of Treatment of Psychiatric Comorbidities in Epilepsy".

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.

Seizure activity and individual vulnerability on first-episode interictal psychosis in epilepsy

OBJECTIVE

Despite a theoretical consensus that interictal psychosis (IIP) is related to various epilepsy-related factors, the impact of seizure activity on development of IIP remains inconclusive. This is the first controlled study using quantitative seizure-activity measures at the onset of IIP.

METHODS

One hundred and eighty-one patients with epilepsy who exhibited first-episode IIP (IIP group) and 427 patients with epilepsy without psychotic episodes (control group) were enrolled. The control group was matched for age, epilepsy type, and duration of epilepsy. The two seizure-activity indices (seizure frequency at the time of onset of first-episode IIP and the number of seizures before the onset of IIP) were evaluated and compared between the IIP and control groups. Logistic regression analysis was used for extracting risk variables to develop first-episode IIP.

RESULTS

The sum of previous seizures was greater in the IIP than in control groups. This was particularly the case in the patients with partial epilepsies (PE). Higher seizure frequency in the patients with PE was associated with the development of first-episode IIP while no association was found in the whole cohort or in the patients with generalized epilepsies (GE). Subsequent multivariate analysis revealed the sum of previous seizures and family history of psychosis as risk variables to first-episode IIP.

CONCLUSIONS

The accumulation of seizure-related damages and family history of psychosis is associated with the onset of IIP episodes, particularly in the patients with PE. Seizure activity and individual vulnerability to psychosis are likely to be interacted for as the development of IIP in patients with epilepsy.

Psychoses in epilepsy: A comparison of postictal and interictal psychoses

We retrospectively analyzed data of patients with epilepsy (n=1434) evaluated with prolonged EEG monitoring in order to estimate the prevalence of postictal psychosis (PP) and interictal psychosis (IP), to investigate a potential association of psychosis subtype with epilepsy type, and to assess differences between PP and IP. The overall prevalence of psychosis was 5.9% (N=85); prevalence of PP (N=53) and IP (N=32) was 3.7% and 2.2%, respectively. Of patients with psychosis, 97.6% had localization-related epilepsy (LRE). Prevalence of psychosis was highest (9.3%) in patients with temporal lobe epilepsy (TLE). When comparing PP with IP groups on demographic, clinical, and psychopathological variables, patients with IP were younger at occurrence of first psychosis (P=0.048), had a shorter interval between epilepsy onset and first psychosis (P=0.002), and more frequently exhibited schizophreniform traits (conceptual disorganization: P=0.008; negative symptoms: P=0.017) than those with PP. Postictal psychosis was significantly associated with a temporal seizure onset on ictal EEG (P=0.000) and a higher incidence of violent behavior during psychosis (P=0.047). To conclude, our results support the presumption of a preponderance of LRE in patients with psychosis and that of a specific association of TLE with psychosis, in particular with PP. Given the significant differences between groups, PP and IP may represent distinct clinical entities potentially with a different neurobiological background.

Periodic epileptiform discharges in mesial temporal lobe epilepsy with hippocampal sclerosis

PURPOSE

Periodic epileptiform discharges (PEDs) are an uncommon, abnormal EEG pattern seen usually in patients with acute diseases and less frequently in chronic conditions, such as mesial temporal lobe epilepsy (mTLE). Evaluate the clinical histories, neuroimaging findings, and serial electrophysiological studies prior to the appearance of PEDs in patients with mTLE secondary to hippocampal sclerosis (HS).

METHODS

We searched 19, 375 EEGs (2006-2012) for the presence of PEDs secondary to mTLE due to HS.

RESULTS

12 patients were included. The patients with PEDs had a high prevalence of psychiatric comorbilities, including major depression (50%), interictal psychosis (16%) and dementia (8%). All of the patients had intractable epilepsy with similar clinical findings. We observed a sequential neurophysiological worsening of the EEG patterns prior to the appearance of PEDs. Five patients with PEDs underwent epilepsy surgery and four were seizure free at follow-up 15 (±9) months.

CONCLUSIONS

PEDs are rare in patients with mTLE and HS and their presence in these cases could reflect clinical severity and neurophysiologic worsening, clinically manifested by intractable epilepsy and severe psychiatric comorbidities. The presence of PEDs in EEGs of patients with mTLE, however, was not associated with poor postsurgical seizure-freedom.

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.

Uncovering the neurobehavioural comorbidities of epilepsy over the lifespan

Epilepsy is a common neurological disorder that is complicated by psychiatric, cognitive, and social comorbidities that have become a major target of concern and investigation in view of their adverse effect on the course and quality of life. In this report we define the specific psychiatric, cognitive, and social comorbidities of paediatric and adult epilepsy, their epidemiology, and real life effects; examine the relation between epilepsy syndromes and the risk of neurobehavioural comorbidities; address the lifespan effect of epilepsy on brain neurodevelopment and brain ageing and the risk of neurobehavioural comorbidities; consider the overarching effect of broader brain disorders on both epilepsy and neurobehavioural comorbidities; examine directions of causality and the contribution of selected epilepsy-related characteristics; and outline clinic-friendly screening approaches for these problems and recommended pharmacological, behavioural, and educational interventions.

Impact of antiepileptic drugs on genesis of psychosis

Opinions regarding the impact of antiepileptic drugs (AEDs) on the genesis of psychotic symptoms are varied. To re-examine this issue, the records of adult patients with partial epilepsy and newly added AEDs were retrospectively surveyed. The types of newly added AEDs and clinical characteristics were compared between 38 patients with active psychosis and 212 without psychotic history during a follow-up period of 3 to 6 months after initiation of AED administration. Using multivariate logistic regression analysis, the significance of possible predictive variables for development of psychosis was evaluated, which demonstrated that use of zonisamide (ZNS) and phenytoin (PHT), presence of complex partial seizures (CPS), and low intelligence level were significantly correlated with psychosis. We concluded that ZNS and PHT are possible risk factors for development of psychosis along with clinical variables, including the presence of CPS and low intelligence level.

Epilepsy, mental health disorder, or both?

Temporal lobe epilepsy (TLE), a subset of the seizure disorder family, represents a complex neuropsychiatric illness, where the neurological presentation may be complemented by varying severity of affective, behavioral, psychotic, or personality abnormalities, which, in turn, may not only lead to misdiagnosis, but also affect the management. This paper outlines a spectrum of mental health presentations, including psychosis, mood, anxiety, panic, and dissociative states, associated with epilepsy that make the correct diagnosis a challenge.

Bidirectional relation between schizophrenia and epilepsy: a population-based retrospective cohort study

PURPOSE

Schizophrenia and epilepsy may share a mutual susceptibility. This study examined the bidirectional relation between the two disorders.

METHODS

We used claims data obtained from the Taiwan National Health Insurance database to conduct retrospective cohort analyses. Analysis 1 compared 5,195 patients with incident schizophrenia diagnosed in 1999-2008 with 20,776 controls without the disease randomly selected during the same period, frequency matched with sex and age. Analysis 2 comprised a similar method to compare 11,527 patients with newly diagnosed epilepsy with 46,032 randomly selected sex- and age-matched controls. At the end of 2008, analysis 1 measured the incidence and risk of developing epilepsy and analysis 2 measured the incidence and risk of developing schizophrenia.

KEY FINDINGS

In analysis 1, the incidence of epilepsy was higher in the schizophrenia cohort than in the nonschizophrenia cohort (6.99 vs. 1.19 per 1,000 person-years) with an adjusted hazard ratio (aHR) of 5.88 [95% confidence interval (CI) 4.71-7.36] for schizophrenia patients. In analysis 2, the incidence of schizophrenia was higher in the epilepsy cohort than in the nonepilepsy comparison cohort (3.53 vs. 0.46 per 1,000 person-years) with an aHR of 7.65 (95% CI 6.04-9.69) for epilepsy patients. The effect of schizophrenia on subsequent epilepsy was greater for women, but the association between epilepsy and elevated incidence of schizophrenia was more pronounced in men.

SIGNIFICANCE

We found a strong bidirectional relation between schizophrenia and epilepsy. These two conditions may share common causes. Further studies on the mechanism are required.

Misdiagnosis of epileptic seizures as manifestations of psychiatric illnesses

BACKGROUND

Epileptic seizures may be misdiagnosed if they manifest as psychiatric symptoms or seizures occur in patients with known psychiatric illness.

METHODS

We present clinical profiles of six patients with epilepsy (three male, mean age 39 ± 12 years) that presented with prominent psychiatric symptoms.

RESULTS

Two patients had pre-existing psychiatric illnesses. Three patients were initially diagnosed with panic attacks, two with psychosis, and one with schizophrenia. Five patients had temporal lobe epilepsy (TLE) while the sixth patient was subsequently found to have absence status epilepticus (SE). Cranial computed tomogram (CT) including contrast study was unremarkable in five patients and showed post-traumatic changes in one patient. Cranial magnetic resonance imaging (MRI) revealed dysembryoplastic neuroepithelial tumour (DNET) in one patient, cavernous hemangioma in one, and post-traumatic changes plus bilateral mesial temporal sclerosis in another patient but it was normal in two TLE patients. Routine electroencephalography (EEG) revealed absence SE in one patient but it was non-diagnostic in the TLE patients. Video-EEG telemetry in the epilepsy monitoring unit (EMU) was necessary to establish the diagnosis in four TLE patients. None of the patients responded to medications aimed at treating psychiatric symptoms alone. Two patients required surgery while the other four required treatment with anti-epileptic drugs. All the patients had favorable response to the treatment of their epilepsy.

CONCLUSIONS

This case series illustrates that epileptic patients may experience non-convulsive seizures that might be mistaken as primary psychiatric illnesses. In this subset of patients, evaluation by an epileptologist, MRI of the brain, and/or video-EEG telemetry in an EMU was necessary to confirm the diagnosis of epilepsy if routine EEGs and cranial CT are normal.

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.

Working memory abnormalities in chronic interictal epileptic psychosis and schizophrenia revealed by magnetoencephalography

Working memory (WM) deficits are considered a core cognitive dysfunction in schizophrenia. To determine cognitive abnormalities in chronic interictal psychosis (CIP), and to assess whether these abnormalities are distinguishable from those seen in schizophrenia in terms of WM deficits, we used magnetoencephalography during a WM task performed by patients with CIP, nonpsychotic epilepsy, and schizophrenia and by healthy subjects. Multiple Source Beamformer and Brain-Voyager were used for analysis. In both patients with CIP and those with schizophrenia, we found dorsolateral prefrontal hyperactivation and left inferior temporal hypoactivation, as indicated by alpha event-related desynchronization and synchronization, respectively. Patients with schizophrenia also showed alpha2 event-related desynchronization in the mid-prefrontal cortex relative to healthy controls. Direct comparison of patients with CIP and schizophrenia rendered no difference in source-power changes. Our findings indicate similar functional cognitive abnormalities in CIP and schizophrenia in the prefrontal and left temporal cortex, which supports the possibility that these disorders share common underlying pathophysiological mechanisms.

Predicting epileptic seizures with a mental simulation task: a prospective study

The unpredictability of seizures is one of the most disabling aspects of epilepsy. We assessed the possibility of forecasting seizure onset by means of a behavioral task using mental simulation of biological and nonbiological movements. Four patients with epilepsy were included in a longitudinal study. In two patients with right temporal lobe epilepsy (RTLE), performance of the task changed depending on the epileptic cycle. In the preictal phase, timing precision decreased during simulation of biological movements and increased during simulation of nonbiological movements. In two other patients, the timing precision during simulation of biological movements was chronically decreased. The observed phase dependency of performance in patients with RTLE may indicate changes in brain states hours in advance of seizure onset. We suggest that our paradigm might be a simple and accurate method for the prediction of epileptic seizures. The validity of the approach for different types of epilepsy should be assessed in future studies.

Long-term significance of postictal psychotic episodes II. Are they predictive of interictal psychotic episodes?

OBJECTIVE

The aim of this study was to determine whether postictal psychotic episodes (PIPE) are predictive of the development of interictal psychotic episodes (IPE).

METHODS

This was a retrospective study of 18 consecutive adults with a partial seizure disorder and PIPE (study group) and 36 patients with a partial seizure disorder but without PIPE (control group). These two groups were compared with respect to the likelihood of developing IPE over an 8-year follow-up period and the variables operant in the development of IPE. Statistical analyses consisted of logistic regression models to identify the variables predictive of the development of IPE. Predictors included: number and location of ictal foci, seizure type, etiology, age at seizure onset, duration of seizure disorder, MRI abnormalities, and psychiatric history prior to the index video/EEG monitoring (other than PIPE).

RESULTS

Seven patients with PIPE and one control patient went on to develop an IPE. Predictors of IPE in univariate logistic regression analyses included a history of PIPE (P=0.006), male gender (P=0.028), and having bilateral ictal foci (P=0.048). Significance disappeared for all of these variables when they were entered into a multivariate analysis.

CONCLUSIONS

A history of PIPE may be a risk factor for the development of IPE. Yet, the disappearance of significance on multivariate analysis indicates that it is not an independent predictor.

Development of psychogenic non-epileptic seizures in response to auditory hallucinations

Psychogenic non-epileptic seizures can co-exist with epileptic seizures. Differentiating between the two is central to appropriate management. We report the case of a patient with established focal epilepsy who developed psychogenic non-epileptic seizures in direct response to second-person auditory hallucinations. To our knowledge, this is the first description of such an occurrence. These non-epileptic seizures improved with treatment of the underlying psychosis. The relationship between epilepsy and psychosis is outlined, and the possible causes and nosology of these psychogenic non-epileptic seizures are discussed.

Interactions between seizure frequency, psychopathology, and severity of intellectual disability in a population with epilepsy and a learning disability

Despite observations associating lower IQ and psychopathology in epilepsy, the possible differential effects of varying severity of learning (intellectual) disability (LD) on the manifestation of psychopathology in people with LD and epilepsy have not been clarified. In this study of retrospectively collected data describing the epilepsy, learning disability, and psychopathology of 175 patients with epilepsy and LD over a 3-month period, we observed that 65 patients had no recent seizures, whereas 110 had experienced at least one seizure in the preceding 3 months. We found that depression and psychoses were more common in those with no seizures in the preceding 3 months, but that which of these psychiatric states was manifest was related to the severity of LD. Psychosis rates were higher in those with mild LD, whereas depression rates were higher in those with severe LD.

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.

Corpora amylacea in mesial temporal lobe epilepsy: Clinico-pathological correlations

PURPOSE

To investigate the electro-clinical significance of premature accumulation of corpora amylacea (CoA) in the resected hippocampus of patients with medically refractory mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS).

METHODS

We compared the clinical and EEG characteristics, and post-operative seizure outcome of 373 (mean age 29.4 years, range 7-55 years) surgically treated MTLE-HS patients with (MTLE-HS-CoA(+), n=129 [34.5%]) and without (MTLE-HS-CoA(-), n=244 [65.5%]) CoA.

RESULTS

Age at surgery was significantly higher and duration of epilepsy before surgery was significantly longer for MTLE-HS-CoA(+) patients compared to MTLE-HS-CoA(-) patients. Although the distribution of interictal epileptiform EEG abnormalities did not differ, type 1 ictal EEG pattern was more frequent in MTLE-HS-CoA(+) patients. Among the 21 patients with major interictal psychosis detected prior to epilepsy surgery, 19 (90.5%) belonged to MTLE-HS-CoA(+) group. Schizophrenia-like psychosis was most prevalent. The post-operative seizure-free outcome was comparable, but significantly more MTLE-HS-CoA(-) patients were free of antiepileptic drugs.

CONCLUSIONS

Overall, our observations support the hypothesis that the pathological process in MTLE-HS is progressive. MTLE-HS-CoA(+) patients are predisposed to increased psychiatric morbidity. In vivo detection of hippocampal CoA accumulation in the future will help us to understand the neurobiological significance of this phenomenon.

A magnetization transfer imaging study in patients with temporal lobe epilepsy and interictal psychosis

BACKGROUND

Findings from previous neuropathological and neuroimaging studies in patients with epilepsy and interictal psychosis have been inconclusive, and both focal and widespread brain abnormalities have been reported. Thus, further investigation with advanced in vivo magnetic resonance imaging (MRI) techniques, such as magnetization transfer imaging, capable of detecting more subtle brain abnormalities, is warranted.

METHODS

Twenty patients with temporal lobe epilepsy and interictal psychosis were compared with 20 nonpsychotic patients. Patients were matched with respect to conventional MRI findings. Each group comprised of 10 patients with hippocampal sclerosis (6 left, 4 right) and 10 patients without focal lesions on MRI. A voxel-based analysis was used for the group comparisons.

RESULTS

Voxel-based analysis revealed significant reductions of magnetization transfer ratio (an index of signal loss derived from magnetization transfer imaging) in the left superior and middle temporal gyri in the psychotic patients for the subgroup of patients with no focal lesions on MRI. There were no significant volumetric differences between the psychotic and nonpsychotic patients.

CONCLUSIONS

Focal cortical magnetization transfer ratio abnormalities in the left temporal lobe unrelated to volume changes can be demonstrated in some temporal lobe epilepsy patients with interictal psychosis. Our findings might reflect subtle neuropathological abnormalities that are undetected by conventional MRI.

Risk for schizophrenia and schizophrenia-like psychosis among patients with epilepsy: population based cohort study

OBJECTIVES

To investigate whether age at onset of epilepsy, type of epilepsy, family history of psychosis, or family history of epilepsy affect the risk of schizophrenia or schizophrenia-like psychosis among patients with epilepsy.

DESIGN

Comparison of population based data.

SETTING

Danish longitudinal registers.

SUBJECTS

The cohort comprised 2.27 million people.

MAIN OUTCOME MEASURES

Epilepsy, psychosis, personal birth data.

RESULTS

We found an increased risk of schizophrenia (relative risk 2.48, 95% confidence interval 2.20 to 2.80) and schizophrenia-like psychosis (2.93, 2.69 to 3.20) in people with a history of epilepsy. The effect of epilepsy was the same in men and in women and increased with age. Family history of psychosis and a family history of epilepsy were significant risk factors for schizophrenia and schizophrenia-like psychosis, and the effect of epilepsy, both in cases and families, was greater among people with no family history of psychosis. In addition, the increased risk for schizophrenia or schizophrenia-like psychosis did not differ by type of epilepsy but increased with increasing number of admissions to hospital and, particularly, was significantly greater for people first admitted for epilepsy at later ages.

CONCLUSIONS

There is a strong association between epilepsy and schizophrenia or schizophrenia-like psychosis. The two conditions may share common genetic or environmental causes.

Intellectual Disability and Psychotic Disorders of Adult Epilepsy

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.

METHODS

The study was divided into three phases: a prevalence study of psychotic disorders among new referrals of epilepsy, a polydiagnostic comparative study of patients with psychotic epilepsy and those with schizophrenia, and a neuropsychological study of patients with psychotic epilepsy and education level-matched controls.

RESULTS

Among 336 new referrals of epilepsy, a higher prevalence of psychotic disorders was found among patients with ID (24%) than among those with normal intelligence (6%). The psychotic symptoms and operational diagnoses of psychotic epilepsy patients with ID were similar to those of patients with normal intelligence. A wide range (7-86%) of psychotic epilepsy patients was diagnosed as having schizophrenia, depending on the operational criteria used. Patients with psychotic epilepsy had more disturbances in verbal memory and attention functions than controls.

CONCLUSIONS

Epilepsy patients with ID show a predisposition to develop psychotic disorders. Distinguishing their psychotic symptoms from those of schizophrenia is difficult. Subtle cognitive disturbances predispose to psychotic disorders in epilepsy.

The psychiatric comorbidity of epilepsy

Several studies have assessed the prevalence of psychiatric disorders in epilepsy. They are characterized by considerable heterogeneity, because of differences in the population setting and type of study. A non-systematic review of the literature allows us to draw some useful, although not definite, conclusions. Six per cent of people with epilepsy in the general population appear to suffer from a psychiatric disorder, while this rises to 10-20% in populations with temporal lobe and/or refractory epilepsy. Mood disorders are the most common culprit (24-74%), particularly depression (30%), followed by anxiety disorders (10-25%), psychoses (2-7%) and personality disorders (1-2%). This comorbidity appears to be related to endogenous and exogenous (including iatrogenic) factors and to the severity and chronicity of epilepsy. Conditions such as schizophrenia-like psychosis of epilepsy and interictal dysphoric disorder are represented only in epilepsy. Adequate recognition and treatment of psychiatric conditions in epilepsy is essential for patient management because of their considerable burden in morbidity and quality of life.

Diagnosis and management of depression and psychosis in children and adolescents with epilepsy

The neurologic dysfunction underlying epilepsy can predispose patients to psychiatric disorders, and the incidence of both depression and psychosis is increased in people with epilepsy. Depressive disorders are the most frequently recognized psychiatric comorbidities in people with epilepsy, but depression in children can be particularly difficult to recognize. Clinicians need to inquire about not only classic symptoms of depression such as anhedonia but also less obvious symptoms such as unprovoked irritability, unsubstantiated complaints of lack of love from family members, somatic complaints, and problems with concentration and poor school performance. The diagnosis of depressive disorders in children with epilepsy and mental retardation is even more difficult. Physicians need to be alert for the presence of iatrogenic depression, which may result from antiepileptic drugs or epilepsy surgery. People with epilepsy are also at increased risk for psychosis, which can be interictal, postictal, or (rarely) an expression of ictal activity. This psychosis can be related to seizure remission (ie, alternative psychosis) or iatrogenic (eg, related to antiepileptic drugs or following temporal lobectomy). Although both antidepressants and antipsychotic drugs have the potential to lower the seizure threshold and increase seizures, careful drug selection, dosing, and slow titration can minimize this risk, allowing treatment to proceed.

Enhancement of central dopaminergic activity in the kainate model of temporal lobe epilepsy: implication for the mechanism of epileptic psychosis

There is an increased incidence of schizophrenia-like psychosis in temporal lobe epilepsy (TLE), and several risk factors have been implicated, including the duration of epilepsy and temporal lobe neuropathology. To investigate the biological mechanism of epileptic psychosis, we examined alterations of central dopaminergic systems in the kainate model of TLE. In adult rats, kainate was microinjected into the left amygdala to induce status epilepticus. An indirect dopamine agonist methamphetamine (MAP, 2 mg/kg, i.p.) was administered before and 1 month after the kainate treatment. MAP-induced locomotor activity was significantly enhanced in the kainate group compared with the baseline (pre-kainate) level, which was antagonized by pretreatment with haloperidol. The enhancement of locomotor activity in the kainate group was significantly correlated with the density of hippocampal CA1 neurons. Although the basal extracellular dopamine concentration was significantly lower in the striatum in the kainate group than in the control group (5.5 vs 39.2 fmol/20-min sample), the maximal concentration following MAP administration did not differ between the two groups. These results clearly demonstrate that hypersensitivity of the dopamine systems develops in the chronic phase of the kainate-induced TLE model, which may be responsible for the mechanism of epileptic psychosis.

Medical comorbidities in the treatment of epilepsy

The treatment of epilepsy extends far beyond seizure control. Many comorbidities have a significant impact on the medical management and quality of life of patients with epilepsy. In this review, we examine interactions between epilepsy and some common medical conditions. Psychiatric disorders with a high prevalence in epilepsy include mood disorders, anxiety disorders, and psychosis. Depression is common, psychosis occurs both in direct relation to seizures and interictally, and suicide rates are increased. Changes in sexual function and reduced fertility and marriage rates are described, including a discussion of polycystic ovary syndrome, which is increased in women with epilepsy. The effects of other chronic medical comorbid conditions are reviewed, including the effects of antiepileptic medications on bone health and the impact of renal insufficiency on pharmacological therapy of epilepsy.

Recurrent postictal psychosis after remission of interictal psychosis: further evidence of bimodal psychosis

PURPOSE

To ascertain whether bimodal psychosis (i.e., independent postictal and interictal psychosis) in patients with epilepsy can be characterized by postictal psychosis that develops after interictal psychosis remits.

METHODS

We reviewed the records of 14 patients with bimodal psychosis treated at a national center hospital. Clinical and psychopathological characteristics of the patients were examined.

RESULTS

Among the 14 patients with bimodal psychosis, four initially had interictal psychosis, and 10 initially had postictal psychosis. That is, interictal-antecedent bimodal psychosis characterized four cases, and postictal-antecedent bimodal psychosis characterized 10 cases. Patients with interictal-antecedent bimodal psychosis composed 2.2% of the total patients with epilepsy and psychosis (n = 180) and 28.5% of total patients with bimodal psychosis. All four patients with interictal-antecedent bimodal psychosis had partial epilepsy with complex partial seizures, bilateral EEG abnormalities, and borderline (or decreased) intellectual functioning. Most of these clinical features are common to both types of bimodal psychosis. Among patients with interictal-antecedent bimodal psychosis, the mean age at the onset of the initial symptoms was 10.8 years (SD, 4.3 years) for epilepsy, 24.4 (6.1) years for interictal psychosis, and 33.8 (4.5) years for postictal psychosis.

CONCLUSIONS

In a few patients, postictal psychosis develops after the remission of interictal psychosis. Interictal-antecedent bimodal psychosis is not likely a discrete entity because of several characteristics common to both types of bimodal psychosis. Patients may have greater vulnerability to psychosis and develop psychotic episodes easily, regardless of the presence of preceding seizures.

A multicenter study on the prevalence of psychiatric disorders among new referrals for epilepsy in Japan

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.

METHODS

From April 2000 to March 2001, 398 patients with epilepsy, who were referred to nine neuropsychiatric outpatient clinics specialized for epilepsy in the Tokyo metropolitan area, were evaluated by using a newly developed five-axis classification scheme.

RESULTS

Forty-two percent of the subjects showed a psychiatric disorder. Twenty-four percent of the total showed psychiatric disorders, including neurotic disorders in 8%, psychotic disorders in 7%, and affective disorders in 1%. In addition, 23% of the total showed mental retardation, and 18% showed personality disorders. A logistic regression analysis revealed that the three risk factors for a psychiatric disorder were mental retardation, temporal lobe epilepsy (as opposed to other subtypes), and a high seizure frequency.

CONCLUSIONS

The presence of mental retardation was the primary risk factor for developing a psychiatric disorder, especially a schizophrenia-spectrum disorder. The type of epilepsy alone is not a strong predictor of psychiatric illness, and intractable temporal lobe epilepsy with a high seizure frequency is accountable for the link between the epilepsy and the psychiatric illness.

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

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.

METHODS

The study subjects comprised 282 patients with psychosis (36 with postictal psychosis, 224 with interictal psychosis, and 22 with both postictal and interictal psychoses, i.e., bimodal psychosis), and 658 epilepsy patients without psychosis. The clinical characteristics of these patients were reviewed retrospectively by experienced neuropsychiatrists. Factors predicting the development of each type of psychosis were determined by serial multivariate logistic regression analyses.

RESULTS

Factors that were comparable between postictal and interictal psychoses were intellectual function, family history of psychosis, epilepsy type, and the presence of complex partial seizures. In contrast, age at the onset of epilepsy and at the onset of psychosis and the presence of generalized tonic-clonic seizures differed for the three types of psychosis. Patients with bimodal psychosis showed characteristics associated with both postictal and interictal psychoses.

CONCLUSIONS

This study documented conditions, including both general factors and epilepsy-related factors, common to epilepsy patients with psychosis, regardless of chronologic distinctions. Certain epileptic processes appear to have equal influence on postictal and interictal psychoses. However, some differences between postictal and interictal psychoses suggest that these chronologic descriptors are valid. Our findings confirmed that psychosis associated with epilepsy should not be defined as a single, simple condition but rather as a complex condition with several possible subcategories.

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.