Neuropsychiatric morbidity in focal epilepsy

Antidepressants for people with epilepsy and depression

BACKGROUND

Depressive disorders are the most common psychiatric comorbidity in people with epilepsy, affecting around one-third, with a significant negative impact on quality of life. There is concern that people may not be receiving appropriate treatment for their depression because of uncertainty regarding which antidepressant or class works best, and the perceived risk of exacerbating seizures. This review aimed to address these issues, and inform clinical practice and future research. This is an updated version of the original Cochrane Review published in Issue 12, 2014.

OBJECTIVES

To evaluate the efficacy and safety of antidepressants in treating depressive symptoms and the effect on seizure recurrence, in people with epilepsy and depression.

SEARCH METHODS

For this update, we searched CRS Web, MEDLINE, SCOPUS, PsycINFO, and ClinicalTrials.gov (February 2021). We searched the World Health Organization Clinical Trials Registry in October 2019, but were unable to update it because it was inaccessible. There were no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and prospective non-randomised studies of interventions (NRSIs), investigating children or adults with epilepsy, who were treated with an antidepressant and compared to placebo, comparative antidepressant, psychotherapy, or no treatment for depressive symptoms.  DATA COLLECTION AND ANALYSIS: The primary outcomes were changes in depression scores (proportion with a greater than 50% improvement, mean difference, and proportion who achieved complete remission) and change in seizure frequency (mean difference, proportion with a seizure recurrence, or episode of status epilepticus). Secondary outcomes included the number of participants who withdrew from the study and reasons for withdrawal, quality of life, cognitive functioning, and adverse events. Two review authors independently extracted data for each included study. We then cross-checked the data extraction. We assessed risk of bias using the Cochrane tool for RCTs, and the ROBINS-I for NRSIs. We presented binary outcomes as risk ratios (RRs) with 95% confidence intervals (CIs) or 99% CIs for specific adverse events. We presented continuous outcomes as standardised mean differences (SMDs) with 95% CIs, and mean differences (MDs) with 95% CIs.  MAIN RESULTS: We included 10 studies in the review (four RCTs and six NRSIs), with 626 participants with epilepsy and depression, examining the effects of antidepressants. One RCT was a multi-centre study comparing an antidepressant with cognitive behavioural therapy (CBT). The other three RCTs were single-centre studies comparing an antidepressant with an active control, placebo, or no treatment. The NRSIs reported on outcomes mainly in participants with focal epilepsy before and after treatment for depression with a selective serotonin reuptake inhibitor (SSRI); one NRSI compared SSRIs to CBT.  We rated one RCT at low risk of bias, three RCTs at unclear risk of bias, and all six NRSIs at serious risk of bias. We were unable to conduct any meta-analysis of RCT data due to heterogeneity of treatment comparisons. We judged the certainty of evidence to be moderate to very low across comparisons, because single studies contributed limited outcome data, and because of risk of bias, particularly for NRSIs, which did not adjust for confounding variables. More than 50% improvement in depressive symptoms ranged from 43% to 82% in RCTs, and from 24% to 97% in NRSIs, depending on the antidepressant given. Venlafaxine improved depressive symptoms by more than 50% compared to no treatment (mean difference (MD) -7.59 (95% confidence interval (CI) -11.52 to -3.66; 1 study, 64 participants; low-certainty evidence); the results between other comparisons were inconclusive. Two studies comparing SSRIs to CBT reported inconclusive results for the proportion of participants who achieved complete remission of depressive symptoms.  Seizure frequency data did not suggest an increased risk of seizures with antidepressants compared to control treatments or baseline. Two studies measured quality of life; antidepressants did not appear to improve quality of life over control. No studies reported on cognitive functioning. Two RCTs and one NRSI reported comparative data on adverse events; antidepressants did not appear to increase the severity or number of adverse events compared to controls. The NSRIs reported higher rates of withdrawals due to adverse events than lack of efficacy. Reported adverse events for antidepressants included nausea, dizziness, sedation, headache, gastrointestinal disturbance, insomnia, and sexual dysfunction.  AUTHORS' CONCLUSIONS: Existing evidence on the effectiveness of antidepressants in treating depressive symptoms associated with epilepsy is still very limited. Rates of response to antidepressants were highly variable. There is low certainty evidence from one small RCT (64 participants) that venlafaxine may improve depressive symptoms more than no treatment; this evidence is limited to treatment between 8 and 16 weeks, and does not inform longer-term effects. Moderate to low evidence suggests neither an increase nor exacerbation of seizures with SSRIs.  There are no available comparative data to inform the choice of antidepressant drug or classes of drug for efficacy or safety for treating people with epilepsy and depression. RCTs of antidepressants utilising interventions from other treatment classes besides SSRIs, in large samples of patients with epilepsy and depression, are needed to better inform treatment policy. Future studies should assess interventions across a longer treatment duration to account for delayed onset of action, sustainability of treatment responses, and to provide a better understanding of the impact on seizure control.

Psychiatric symptoms are the strongest predictors of quality of life in patients with drug-resistant epilepsy or psychogenic nonepileptic seizures

OBJECTIVE

This cross-sectional study aimed to determine the effect of psychiatric comorbidity and neurocognitive deficits on the quality of life in a cohort of patients admitted for Video-EEG Monitoring (VEM) for investigation into a presumed seizure disorder.

METHODS

Patients were recruited from an inpatient VEM unit between January 2009 and December 2016. All patients had formal neuropsychiatric assessment. All patients completed questionnaires assessing psychiatric symptomatology (SCL-90-R), Anxiety and Depression (HADS), quality of life (QOLIE-89), and cognition (NUCOG).

RESULTS

A total of 451 patients were enrolled. Upon discharge, 204 patients were diagnosed to have epilepsy, 118 psychogenic nonepileptic seizures (PNES), and 29 both epilepsy and PNES, while the diagnosis was uncertain diagnosis in 100. Diagnosis (p = .002), HADS Depression score (p < .001), SCL-90-R positive symptoms total (p < .001), and NUCOG total score (p < .001) were found to be significant predictors of QOLIE-89 total scores, together explaining 65.4% of variance in quality of life. Seizure frequency was not a significant predictor of quality of life (p = .082). Patients with PNES had significantly worse quality of life, and scored higher on measures of psychiatricsymptomatology, compared to patients with epilepsy alone. The prevalence of psychiatric comorbidity was significantly higher in patients with PNES (70.3%) or both PNES and epilepsy (62.1%) compared to patients with epilepsy alone (41.2%) (p < .001).

SIGNIFICANCE

Psychiatric symptomatology, depression, and cognition were stronger determinants of quality of life than seizure frequency in this study population of patients with drug-resistant epilepsy and PNES. Patients with PNES with or without comorbid epilepsy had similar neuropsychiatric profiles.

A systematic review of neuroimaging studies of depression in adults with epilepsy

OBJECTIVE

Depression is a relatively common comorbidity in people with epilepsy with a lifetime history identified in 1 in 4 individuals. In this paper, we aimed to provide a systematic review of structural and functional brain region-specific group differences of adults with epilepsy and depression and to discuss existing evidence as compared to that in people with depression.

METHODS

We undertook a systematic review of neuroimaging studies of depression in adults with epilepsy through MEDLINE/PubMed, Embase and PsycInfo searches until June 2020.

RESULTS

A total of 44 studies were included in the qualitative synthesis: 21 on structural neuroimaging, 9 on functional, and 14 on pharmaco/metabolic neuroimaging. Almost all studies focused on temporal lobe epilepsy (TLE). Patterns of changes in the hippocampi and subcortical structures seem to be different from those reported in depression outside epilepsy. Cortical changes are grossly similar as well as the lack of any laterality effect. Serotonin dysfunction seems to be due to different mechanisms with reduced synaptic availability for depression in epilepsy as compared to reduced 5HT1 receptor density outside epilepsy. Depressive symptoms seem to correlate with a dysfunction in temporolimbic structures contralateral to the epileptogenic zone especially in patients with de novo postsurgical depression.

CONCLUSIONS

Depression, at least in TLE, seems to be associated with a different pattern of brain changes as compared to major depression, potentially supporting the notion of phenomenological peculiarities of depression in epilepsy.

Predicting mood decline following temporal lobe epilepsy surgery in adults

OBJECTIVE

To develop a model to predict the probability of mood decline in adults following temporal lobe resection for the treatment of pharmacoresistant epilepsy.

METHODS

Variable selection was performed on 492 patients from the Cleveland Clinic using best subsets regression. After completing variable selection, a subset of variables was requested from four epilepsy surgery centers across North America (n = 100). All data were combined to develop a final model to predict postoperative mood decline (N = 592). Internal validation with bootstrap resampling was performed. A clinically significant increase in depressive symptoms was defined as a 15% increase in Beck Depression Inventory-Second Edition score and a postoperative raw score > 11.

RESULTS

Fourteen percent of patients in the Cleveland Clinic cohort and 22% of patients in the external cohort experienced clinically significant increases in depressive symptoms following surgery. The final prediction model included six predictor variables: psychiatric history, resection side, relationship status, verbal fluency score, age at preoperative testing, and presence/absence of malformation of cortical development on magnetic resonance imaging. The model had an optimism-adjusted c-statistic of .70 and good calibration, with slight probability overestimation in higher risk patients.

SIGNIFICANCE

Clinicians can utilize our nomogram via a paper tool or online calculator to estimate the risk of postoperative mood decline for individual patients prior to temporal lobe epilepsy surgery.

Mortality in patients with psychogenic nonepileptic seizures

Objective

To investigate the hypothesis that patients diagnosed with psychogenic nonepileptic seizures (PNES) on video-EEG monitoring (VEM) have increased mortality by comparison to the general population.

Methods

This retrospective cohort study included patients evaluated in VEM units of 3 tertiary hospitals in Melbourne, Australia, between January 1, 1995, and December 31, 2015. Diagnosis was based on consensus opinion of experienced epileptologists and neuropsychiatrists at each hospital. Mortality was determined in patients diagnosed with PNES, epilepsy, or both conditions by linkage to the Australian National Death Index. Lifetime history of psychiatric disorders in PNES was determined from formal neuropsychiatric reports.

Results

A total of 5,508 patients underwent VEM. A total of 674 (12.2%) were diagnosed with PNES, 3064 (55.6%) with epilepsy, 175 (3.2%) with both conditions, and 1,595 (29.0%) received other diagnoses or had no diagnosis made. The standardized mortality ratio (SMR) of patients diagnosed with PNES was 2.5 (95% confidence interval [CI] 2.0–3.3). Those younger than 30 had an 8-fold higher risk of death (95% CI 3.4–19.8). Direct comparison revealed no significant difference in mortality rate between diagnostic groups. Among deaths in patients diagnosed with PNES (n = 55), external causes contributed 18%, with 20% of deaths in those younger than 50 years attributed to suicide, and “epilepsy” was recorded as the cause of death in 24%.

Conclusions

Patients diagnosed with PNES have a SMR 2.5 times above the general population, dying at a rate comparable to those with drug-resistant epilepsy. This emphasizes the importance of prompt diagnosis, identification of risk factors, and implementation of appropriate strategies to prevent potential avoidable deaths.

The P2X7 receptor in activated microglia promotes depression- and anxiety-like behaviors in lithium -pilocarpine induced epileptic rats

Depressive and anxious behaviors are the most common psychiatric symptoms of epilepsy, and may aggravate the epileptic condition and affect the patient's quality of life. Accumulating data obtained from both experimental animal models and patients have convincingly shown a critical role of P2X7 receptor (P2X7R) during depression and anxiety. Our study showed for the first time that the P2X7R is involved in promoting depression- and anxiety-like behaviors in lithium pilocarpine-induced epileptic rats. More importantly, direct anti-depressive and anti-anxiety effects were produced by the P2X7R antagonist Brilliant Blue G (BBG) is in this study, and the effect was similar to that of the classic anti-depressant and anti-anxiety drug fluoxetine. We also found that BBG did not affect the development of spontaneous recurrent seizures (SRS) and had a neuroprotective effect via inhibition of microglial activation after status epilepticus (SE). Thus, our data provide evidence that the P2X7R in activated microglia promotes depression- and anxiety-like behaviors in lithium-pilocarpine induced epileptic rats. Since previous studies have indicated that some anti-depression and anti-anxiety drugs may exacerbate seizures, our data support that the P2X7R is a promising therapeutic target for epilepsy associated with depression and anxiety.

Common mental disorders and its determinants among epileptic patients at an outpatient epileptic clinic in Felegehiwot Referral Hospital, Bahirdar, Ethiopia: cross-sectional study

Background

Epilepsy is a chronic neurological condition that is highly predisposed to a variety of mental health problems due to its huge biological, social and psychological burdens. Despite this, there is a paucity of research in this area. Therefore, assessing common mental disorders and its determinants among epileptic patients would be of great importance.

Objective

This study was aimed to asses prevalence and associated factors of common mental disorders among people with epilepsy attending Felegehiwot Referral Hospital, Bahirdar, Ethiopia, 2019.

Methods

Institutional based analytic cross-sectional study design was utilized from January to February 2019 at Felegehiwot Referral Hospital among 422 epileptic patients who were diagnosed clinically and on follow up treatment. Systematic random sampling was applied to recruit participants. Interviewer based and pretested Self Reporting Questionnaire‐20 was used to screen common mental illness with a cut-off point 7 and above as having a common mental disorder. Bivariate and multivariable logistic regression analysis with 95% CI were computed and variables with p < 0.05 in the final model were considered as associated factors for common mental disorders.

Result

Four hundred twenty-two patients with epilepsy were included in our study with a response rate of 100% and 64.5% were males. The mean age of participants was 59 ± 13.37 years. Common mental disorder among epileptic patients was found to be 35.8%. There was a statistically significant association between marital status, comorbid medical illness, nicotine dependence, alcohol misuse, and medication non-adherence with common mental disorders at p < 0.05.

Conclusion

The prevalence of common mental distress was high (35.8%) suggesting that it is a public health issue. Marital status, comorbid medical illness, nicotine dependence, alcohol misuse, and medication non-adherence were the factors having an association with a common mental disorder. Therefore, early screening and recognition of mental distress symptoms should be a routine activity while managing epileptic patients.

The psychopharmacology of epilepsy

Epilepsy affects 1% of the world's population and is defined as two or more unprovoked seizures. Psychiatric conditions (depression, psychosis, anxiety, and attention deficit hyperactivity disorder (ADHD)) may coexist and are linked to negative seizure outcomes and poorer quality of life. There is an increasing body of evidence to suggest a bidirectional relationship between epilepsy and psychiatric disorders, which may imply shared pathophysiologic mechanisms. Extensive research has examined neurobiologic and neuroanatomic substrates for this association revealing some interesting similarities. Psychiatric disorders in people with epilepsy often go underdiagnosed and undertreated, due to fears of exacerbating psychiatric symptoms or provoking seizures, which may cause delays in optimal management. This chapter covers psychiatric conditions in epilepsy largely focusing on depressive disorders and psychotic disorders. Anxiety and ADHD in association with epilepsy are also discussed. Epidemiology, pathophysiologic mechanisms, and pharmacotherapies used to treat epilepsy and psychiatric disorders are also covered.

Psychiatric complications after epilepsy surgery… but where are the psychiatrists?

In patients with refractory epilepsy, there is a significant risk of postoperative psychiatric complications after epilepsy surgery. The main risk factors for this phenomenon include a lifetime or family history of psychiatric illness; these risk factors can be easily identified through a preoperative evaluation performed by a psychiatrist. Despite this, very few comprehensive epilepsy centers include a psychiatrist on the treatment team. Preoperative evaluations often fail to identify patients at risk of postoperative psychiatric complications, thus missing the opportunity to counsel and prophylactically treat patients at risk. In this article, we review the risk factors for the development of postoperative psychiatric complications and discuss the reasons why epilepsy centers continue to perform presurgical evaluations without psychiatrists. Additionally, we provide practical solutions for neurologists in the identification and management of postoperative psychiatric disorders. This article is part of the Special Issue "Obstacles of Treatment of Psychiatric Comorbidities in Epilepsy".

Bilateral volume reduction in posterior hippocampus in psychosis of epilepsy

OBJECTIVE

Psychosis of epilepsy (POE) occurs more frequently in temporal lobe epilepsy, raising the question as to whether abnormalities of the hippocampus are aetiologically important. Despite decades of investigation, it is unclear whether hippocampal volume is reduced in POE, perhaps due to small sample sizes and methodological limitations of past research.

METHODS

In this study, we examined the volume of the total hippocampus, and the hippocampal head, body and tail, in a large cohort of patients with POE and patients with epilepsy without psychosis (EC). One hundred adults participated: 50 with POE and 50 EC. Total and subregional hippocampal volumes were manually traced and compared between (1) POE and EC; (2) POE with temporal lobe epilepsy, extratemporal lobe epilepsy and generalised epilepsy; and (3) patients with POE with postictal psychosis (PIP) and interictal psychosis (IP).

RESULTS

Compared with EC the POE group had smaller total left hippocampus volume (13.5% decrease, p<0.001), and smaller left hippocampal body (13.3% decrease, p=0.002), and left (41.5% decrease, p<0.001) and right (36.4% decrease, p<0.001) hippocampal tail volumes. Hippocampal head volumes did not differ between groups.

CONCLUSION

Posterior hippocampal volumes are bilaterally reduced in POE. Volume loss was observed on a posteroanterior gradient, with severe decreases in the tail and moderate volume decreases in the body, with no difference in the hippocampal head. Posterior hippocampal atrophy is evident to a similar degree in PIP and IP. Our findings converge with those reported for the paradigmatic psychotic disorder, schizophrenia, and suggest that posterior hippocampal atrophy may serve as a biomarker of the risk for psychosis, including in patients with epilepsy.

Emotional asymmetries in refractory medial temporal and frontal lobe epilepsy: Their impact on predicting lateralization and localization of seizures

BACKGROUND

Emotional disturbances have been reported in patients with epilepsy. Although conflicting results emanate from relevant studies, depressive symptoms are seen more often in temporal lobe epilepsy (TLE) whereas, hypomanic/manic symptoms usually accompany frontal lobe epilepsy (FLE); the above psychiatric symptoms are especially seen in refractory epilepsy. However, neocortical TLE and medial TLE are considered as distinct epileptic syndromes, and there is limited literature on comparison of affective traits in medial TLE (MTLE) and FLE.

AIM

In the present study, we sought to investigate affective traits among epilepsy surgery candidates suffering refractory left medial TLE (LMTLE), right medial TLE (RMTLE), left FLE (LFLE), and right FLE (RFLE).

RESULTS

Our results revealed that patients with MTLE scored significantly higher than the ones with FLE in depression, anxiety, asthenia, and melancholia as measured by the Symptoms Rating Scale for Depression and Anxiety (SRSDA), while patients with FLE scored significantly higher in mania than those with MTLE. Moreover, patients with MTLE scored significantly higher than their FLE counterparts on the anxiety scale of the State Trait Personality Inventory (STPI)-trait version. When laterality of the seizure focus was taken into account, no differences were found among both patients with MTLE and patients with FLE, with exception for the Trail Making Test part B (TMT-B) in which patients with RMTLE performed significantly worse than patients with LMTLE. Seizure frequency was higher for FLE.

CONCLUSIONS

We provide evidence for an anterior-frontal versus a posterior-medial temporal cerebral functional asymmetry with regard to the manifestation of manic and depressive emotional traits in FLE and MTLE, respectively. Our results are mainly discussed within the frame of their contribution in localizing and to a lesser extent in lateralizing seizures foci in epilepsy surgery candidates. We suggest that this is of great importance in the context of preoperative monitoring of epilepsy surgery, especially when neuropsychologists are called upon to provide anatomical information in defining the functional deficit zone.

[Prognosis for surgical treatment of pharmacoresistant epilepsy: the role of mental and cognitive disorders]

This review focuses on the role of mental and cognitive disorders in the prognosis for surgical treatment of pharmacoresistant epilepsy. The authors analyze historical aspects of the surgical treatment of epilepsy and present current data on the prognosis of operative intervention with respect to seizure control, cognitive functioning, and psychiatric disorders. The psychiatrist's role in the structure of preoperative and postoperative management of patients is considered.

Are mental distress and cognitive impairment related in temporal lobe epilepsy?

OBJECTIVE

Cognitive impairment and depression often co-exist among patients with epilepsy. However, there is still debate whether depression and cognition are related in patients with temporal lobe epilepsy (TLE). Even if they were related, it is still unclear whether symptoms of depression specifically, or rather symptoms of mental distress in general, have a negative impact on cognition in patients with TLE. In the present study, we examined whether self-rated symptoms of mental distress and of depression are related to different cognitive functions in unilateral TLE.

METHODS

We retrospectively studied 162 patients undergoing preoperative evaluation for epilepsy surgery (95 patients with left TLE (LTLE) and 67 patients with right TLE (RTLE)). Severity of mental distress and symptoms of depression were measured with the Symptom Checklist-90-Revised (SCL-90-R) and the Beck Depression Inventory (BDI), respectively. Bivariate correlations were calculated between these two measures and neuropsychological measures of verbal recall, figural learning, psychomotor speed, and phonemic word fluency. Due to multiple testing, a corrected level of p < 0.0063 was regarded as significant, only.

RESULTS

Seventeen and 19% of patients reported meaningful mental distress and meaningful symptoms of depression, respectively. Mental distress highly correlated with symptoms of depression (r_s = 0.80). We found no significant correlations of either mental distress or symptoms of depression with measures of cognitive function.

CONCLUSIONS

In contrast to some former studies with smaller sample sizes, the present study could not detect a relationship of depression with cognitive impairment in patients with unilateral TLE. Likewise, mental distress and cognition were unrelated in our sample of patients. Our results may argue against theoretical models claiming a causal link between depression and cognitive impairment or a common pathogenic mechanism for these conditions in patients with TLE.

Systematic review of structural and functional brain alterations in psychosis of epilepsy

This systematic review critically assesses structural and functional neuroimaging studies of psychosis of epilepsy (POE). We integrate findings from 18 studies of adults with POE to examine the prevailing view that there is a specific relationship between temporal lobe epilepsy (TLE) and POE, and that mesial temporal lobe pathology is a biomarker for POE. Our results show: (1) conflicting evidence of volumetric change in the hippocampus and amygdala; (2) distributed structural pathology beyond the mesial temporal lobe; and (3) changes in frontotemporal functional network activation. These results provide strong evidence for a revised conceptualisation of POE as disorder of brain networks, and highlight that abnormalities in mesial temporal structures alone are unlikely to account for its neuropathogenesis. Understanding POE as a disease of brain networks has important implications for neuroimaging research and clinical practice. Specifically, we suggest that future neuroimaging studies of POE target structural and functional networks, and that practitioners are vigilant for psychotic symptoms in all epilepsies, not just TLE.

Factors Associated With Pre- and Postoperative Seizures in 1033 Patients Undergoing Supratentorial Meningioma Resection

BACKGROUND

Risk factors for pre- and postoperative seizures in supratentorial meningiomas are understudied compared to other brain tumors.

OBJECTIVE

To report seizure frequency and identify factors associated with pre- and postoperative seizures in a large single-center population study of patients undergoing resection of supratentorial meningioma.

METHODS

Retrospective chart review of 1033 subjects undergoing resection of supratentorial meningioma at the author's institution (1991-2014). Multivariate regression was used to identify variables significantly associated with pre- and postoperative seizures.

RESULTS

Preoperative seizures occurred in 234 (22.7%) subjects. At 5 years postoperative, probability of seizure freedom was 89.9% among subjects without preoperative seizures and 62.2% with preoperative seizures. Multivariate analysis identified the following predictors of preoperative seizures: presence of  ≥1 cm peritumoral edema (odds ratio [OR]: 4.45, 2.55-8.50), nonskull base tumor location (OR: 2.13, 1.26-3.67), greater age (OR per unit increase: 1.03, 1.01-1.05), while presenting symptom of headache (OR: 0.50, 0.29-0.84) or cranial nerve deficit (OR: 0.36, 0.17-0.71) decreased odds of preoperative seizures. Postoperative seizures after discharge were associated with preoperative seizures (OR: 5.70, 2.57-13.13), in-hospital seizure (OR: 4.31, 1.28-13.67), and among patients without preoperative seizure, occurrence of medical or surgical complications (OR 3.39, 1.09-9.48). Perioperative anti-epileptic drug use was not associated with decreased incidence of postoperative seizures.

CONCLUSIONS

Nonskull base supratentorial meningiomas with surrounding edema have the highest risk for preoperative seizure. Long-term follow-up showing persistent seizures in meningioma patients with preoperative seizures raises the possibility that these patients may benefit from electrocorticographic mapping of adjacent cortex and resection of noneloquent, epileptically active cortex.

An objective score to identify psychogenic seizures based on age of onset and history

OBJECTIVE

Psychogenic nonepileptic seizure (PNES) is a common diagnosis after evaluation of medication resistant or atypical seizures with video-electroencephalographic monitoring (VEM), but usually follows a long delay after the development of seizures, during which patients are treated for epilepsy. Therefore, more readily available diagnostic tools are needed for earlier identification of patients at risk for PNES. A tool based on patient-reported psychosocial history would be especially beneficial because it could be implemented in the outpatient clinic.

METHODS

Based on the data from 1375 patients with VEM-confirmed diagnoses, we used logistic regression to compare the frequency of specific patient-reported historical events, demographic information, age of onset, and delay from first seizure until VEM in five mutually exclusive groups of patients: epileptic seizures (ES), PNES, physiologic nonepileptic seizure-like events (PSLE), mixed PNES plus ES, and inconclusive monitoring. To determine the diagnostic utility of this information to differentiate PNES only from ES only, we used multivariate piecewise-linear logistic regression trained using retrospective data from chart review and validated based on data from 246 prospective standardized interviews.

RESULTS

The prospective area under the curve of our weighted multivariate piecewise-linear by-sex score was 73%, with the threshold that maximized overall retrospective accuracy resulting in a prospective sensitivity of 74% (95% CI: 70-79%) and prospective specificity of 71% (95% CI: 64-82%). The linear model and piecewise linear without an interaction term for sex had very similar performance statistics. In the multivariate piecewise-linear sex-split predictive model, the significant factors positively associated with ES were history of febrile seizures, current employment or active student status, history of traumatic brain injury (TBI), and longer delay from first seizure until VEM. The significant factors associated with PNES were female sex, older age of onset, mild TBI, and significant stressful events with sexual abuse, in particular, increasing the likelihood of PNES. Delays longer than 20years, age of onset after 31years for men, and age of onset after 40years for women had no additional effect on the likelihood of PNES.

DISCUSSION

Our promising results suggest that an objective score has the potential to serve as an early outpatient screening tool to identify patients with greater likelihood of PNES when considered in combination with other factors. In addition, our analysis suggests that sexual abuse, more than other psychological stressors including physical abuse, is more associated with PNES. There was a trend of increasing frequency of PNES for women during childbearing years and plateauing outside those years that was not observed in men.

Depressive disorders in patients with pharmaco-resistant mesial temporal lobe epilepsy

Objectives To assess depressive disorders in patients with mesial temporal lobe epilepsy (MTLE) refractory to medical treatment. Methods Adult patients with refractory MTLE completed two questionnaires (Mini International Neuropsychiatric Interview (MINI) and the Beck Depression Inventory (BDI) had a semi-structured psychiatric interview and a high resolution MRI scan. For complete neuropsychiatric diagnosis, as per International Classification of Diseases (ICD-10), the results were combined with clinical history and additional information from the patients' family. Results Of the 40 patients identified for this case series study which took place from 2008-2012, 31 (77.5%) had a depressive disorder: 14 had dysthymia, 11 had recurrent depressive disorder and 6 had bipolar disorder. Of the nine patients without a firm diagnosis of mood disorder, seven had isolated symptoms of depression or anxiety and two presented with mixed depression/anxiety symptoms. Only 8/31 (25.8%) patients were receiving antidepressant treatment. There was no association between BDI scores and seizure frequency. No significant difference was found between patients with and without depression and the presence or laterality of HA. Conclusions Depressive disorders are common, underdiagnosed and undertreated in patients with refractory MTLE.

Postepileptic seizure PTSD: A very rare psychiatric condition in patients with epilepsy

PURPOSE

It has been shown that relatives of patients with epilepsy could experience a seizure as a traumatic event followed by a posttraumatic stress disorder (PTSD). In one questionnaire study, 51% of the patients with epilepsy were reported to have a PTSD caused by a traumatic seizure, termed postepileptic seizure PTSD by the authors. However, it remained unclear whether these patients had further psychiatric comorbidities and if certain seizure features may foster the development of the proposed epilepsy-specific PTSD.

METHODS

We conducted a structured clinical interview assessing psychiatric disorders in 120 patients with difficult-to-treat epilepsies. We also used a modified version of the Posttraumatic Stress Diagnostic Scale conducted as an interview to assess the number of patients who fulfilled the criteria for a PTSD caused by an epileptic seizure. We additionally compared certain features of traumatic versus nontraumatic seizures.

RESULTS

Fifty of the 120 patients identified a seizure that fulfilled the criteria for a traumatic event, whereas 28 patients identified a worst seizure not meeting the trauma definition. Six patients fulfilled all PTSD criteria caused by a traumatic seizure. However, three of these patients also had a regular PTSD, and in two further patients, the results of the clinical interview suggested that the PTSD-like symptoms could be better explained by an adjustment disorder. We could not identify seizure characteristics differentiating traumatic from nontraumatic seizures.

CONCLUSION

Our results showed that it is recommendable to conceptualize an epileptic seizure as being potentially traumatic in nature when assessing PTSD in patients with epilepsy, although we could not identify specific characteristics that could differentiate between traumatic and nontraumatic seizures. However, while using interview-based psychiatric assessment, we found a very low rate of a postepileptic seizure PTSD. It is worth conducting a comprehensive psychiatric diagnostic interview to differentiate PTSD-like symptoms from other comorbidities, such as epilepsy-related adjustment disorder.

Current psychiatric disorders in patients with epilepsy are predicted by maltreatment experiences during childhood

PURPOSE

Childhood maltreatment has been shown to be a risk factor for the development of psychiatric disorders. Although the prevalence of psychiatric disorders is high in epilepsy patients, it is unknown if childhood maltreatment experiences are elevated compared to the normal population and if early maltreatment is a risk factor for current psychiatric comorbidities in epilepsy patients. This is the main purpose of this study.

METHODS

Structured interviews were used to assess current Axis I diagnoses in 120 epilepsy patients from a tertiary Epilepsy Center (34 TLE patients, 86 non-TLE patients). Childhood maltreatment in the family and peer victimization were assessed with validated questionnaires. Patients' maltreatment scores were compared with those of a representative matched control group. Logistic regression analysis was conducted to assess the potential impact of childhood maltreatment on current psychiatric comorbidity in epilepsy patients.

RESULTS

Compared to a matched control group, epilepsy patients had higher emotional and sexual maltreatment scores. Patients with a current psychiatric diagnosis reported more family and peer maltreatment than patients without a psychiatric disorder. Family maltreatment scores predicted the likelihood of a current psychiatric disorder. TLE patients did not differ from non-TLE patients according to maltreatment experiences and rates of current psychiatric disorders.

CONCLUSION

Our findings suggest that in epilepsy patients emotional and sexual childhood maltreatment is experienced more often than in the normal population and that early maltreatment is a general risk factor for psychiatric comorbidities in this group.

Psychopathology in adolescents with TLE and FLE

BACKGROUND

To describe the rates and types of psychiatric disorders among adolescents with chronic symptomatic epilepsies and to evaluate syndrome-specific differences between temporal lobe (TLE) and frontal lobe (FLE) epilepsies.

METHODS

A cross-sectional single-center study design applying the Youth Self Report (YSR) to investigate psychopathological symptoms and the Weinberger Adjustment Inventory (WAI) to investigate personality dimensions was used. Consecutive adolescents between 14 and 18 years of age with drug-resistant symptomatic TLE and FLE were investigated during pre-surgical evaluation prior to epilepsy surgery. Data from twenty-eight patients (19 with TLE and 9 with FLE) were analyzed for this report.

RESULTS

Compared with the test norm, higher prevalence rates and a wider range of psychopathological symptoms were seen in patients with TLE. This result was not seen in patients with FLE. Concerning personality dimensions, significantly higher values of repressive defensiveness and significantly lower values of positive emotion and confidence were found in patients with TLE. In contrast, significantly lower levels of distress and significantly higher levels of repressive defensiveness and denial of distress were seen in patients with FLE. Comparing TLE with FLE, a significantly higher mean score for distress, and a significantly lower mean score for positive emotion and denial of distress were found in patients with TLE.

CONCLUSION

In summary, psychiatric comorbidity was frequently found in this sample of youths with chronic drug-resistant localization-related epilepsies. Although results have to be interpreted with caution because of the small sample size, psychiatric symptomatology was significantly different between TLE and FLE. Our results show that continuous and syndrome-specific psychiatric monitoring is essential in young patients with epilepsy.

Early childhood trauma and hippocampal volumes in patients with epileptic and psychogenic seizures

OBJECTIVE

Exposure to early life childhood trauma has been implicated as resulting in a vulnerability to epileptic and psychogenic nonepileptic seizures (PNES), hippocampal atrophy, and psychiatric disorders. This study aimed to explore the relationships between childhood trauma, epilepsy, PNES, and hippocampal volume in patients admitted to a video-electroencephalogram monitoring (VEM) unit.

METHODS

One hundred thirty-one patients were recruited from the Royal Melbourne Hospital VEM unit. The diagnostic breakdown of this group was: temporal lobe epilepsy (TLE) (32), other epilepsy syndromes (35), PNES (47), other nonepileptic syndromes (5), both epilepsy and PNES (6), and uncertain diagnosis (6). All patients completed a questionnaire assessing exposure to childhood trauma, the Childhood Trauma Questionnaire (CTQ), as well as questionnaires assessing psychiatric symptomatology (SCL-90-R), Anxiety and Depression (HADS), quality of life (QOLIE-98) and cognition (NUCOG). Volumetric coronal T1 MRI scans were available for 84 patients. Hippocampal volumes were manually traced by a blinded operator.

RESULTS

The prevalence of childhood trauma in patients with PNES was higher than in patients with other diagnoses (p=0.005), and the group with PNES overall scored significantly higher on the CTQ (p=0.002). No association was found between CTQ scores and hippocampal volumes; however, patients with a history of sexual abuse were found to have smaller left hippocampal volumes than patients who had not (p=0.043). Patients reporting having experienced childhood trauma scored lower on measures of quality of life and higher on measures of psychiatric symptomatology.

SIGNIFICANCE

Patients with PNES report having experienced significantly more childhood trauma than those with epileptic seizures, and in both groups there was a relationship between a history of having experienced sexual abuse and reduced left hippocampal volume. Patients with PNES and those with epilepsy who have a history of childhood trauma have overall worse quality of life and more psychiatric symptomatology.

The Diathesis-Epilepsy Model: How Past Events Impact the Development of Epilepsy and Comorbidities

In epilepsy, seizures and comorbidities (e.g., cognitive deficits and depression) occur when specific thresholds are crossed. These thresholds depend on the diathesis (or vulnerability) of a given individual. The diathesis is controlled by multiple genetic and environmental factors. Diathesis changes over multiple timescales: on a daily basis, and as part of the development/aging processes, etc. The diathesis-epilepsy model introduced here provides a conceptual framework to understand how past events (e.g., a very stressful event) can directly influence the occurrence of epilepsy and comorbidities later in life. Experimental evidence supports this model, and the existence of biomarkers predictive of a vulnerability state have led to the development of preventive therapeutic strategies. Epigenetic modifications could be a key determinant of diathesis. Their role is discussed.

Is psychiatric assessment essential for better epilepsy surgery outcomes?

Epilepsy surgery is one of the most accepted and beneficial treatment for resistant epilepsies. However there is some variability in the comprehensive epilepsy care programs offered globally. Many centers do not do a psychiatric assessment unless required. It is now evident from a large body of research that epilepsy is associated with psychiatric morbidity which is also seen in patients considered for epilepsy surgery. There is also evidence to state that the risk for worsening or de novo psychiatric disorders is often seen post surgery. This calls for a comprehensive psychiatric assessment of all patients enrolled for the epilepsy surgery program to be evaluated pre and post surgically to minimize the risk of post surgical psychological disturbances and/or poor quality of life. Efficacious treatment of psychiatric disorders in those having psychiatric morbidity contributes to improved patient wellbeing, seizure freedom and better quality of life. Hence there is a need for most centers globally to include regular psychiatric assessment of epilepsy surgery patients as a protocol.

Predicting and treating stress-induced vulnerability to epilepsy and depression

Accumulation of stressful events can render individuals susceptible to develop epilepsy and comorbidities. Whether such vulnerability can be predicted and reversed is not known. Here we show that social defeat, although not producing depression by itself, produced in 50% of rats reduced threshold for status epilepticus (SE), accelerated epileptogenesis, and once epilepsy was induced, depression-like profile and cognitive deficits. Low serum brain-derived neurotrophic factor (BDNF) levels measured before SE identified this vulnerable population. Treatment with a BDNF analog before SE prevented the occurrence of comorbidities. Thus, vulnerability to comorbidities after epilepsy onset due to unresolved past stressful events may be predicted and reversed.

Antidepressants for people with epilepsy and depression

BACKGROUND

Depressive disorders are the most common psychiatric comorbidity in patients with epilepsy, affecting around one-third, with a significant negative impact on quality of life. There is concern that patients may not be receiving appropriate treatment for their depression because of uncertainty regarding which antidepressant or class works best and the perceived risk of exacerbating seizures. This review aims to address these issues and inform clinical practice and future research.

OBJECTIVES

We aimed to review and synthesise evidence from randomised controlled trials of antidepressants and prospective non-randomised studies of antidepressants used for treating depression in patients with epilepsy. The primary objectives were to evaluate the efficacy and safety of antidepressants in treating depressive symptoms and the effect on seizure recurrence.

SEARCH METHODS

We conducted a search of the following databases: the Cochrane Epilepsy Group Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 5), MEDLINE (Ovid), SCOPUS, PsycINFO, www.clinicaltrials.gov and conference proceedings, including studies published up to 31 May 2014. There were no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and prospective non-randomised cohort controlled and uncontrolled studies investigating children or adults with epilepsy treated with an antidepressant for depressive symptoms. The intervention group consisted of patients receiving an antidepressant drug in addition to an existing antiepileptic drug regimen. The control group(s) consisted of patients receiving a placebo, comparative antidepressant, psychotherapy or no treatment in addition to an existing antiepileptic drug regimen.

DATA COLLECTION AND ANALYSIS

We extracted data on trial design factors, patient demographics and outcomes for each study. The primary outcomes were changes in depression scores (proportion with a greater than 50% improvement or mean difference) and change in seizure frequency (mean difference or proportion with a seizure recurrence or episode of status epilepticus, or both). Secondary outcomes included the number of patients withdrawing from the study and reasons for withdrawal, as well as any adverse events. Two authors undertook data extraction separately for each included study. We then cross-checked the data extraction. We assessed risk of bias using a version of the extended Cochrane Collaboration tool for assessing risk of bias in both randomised and non-randomised studies. We presented binary outcomes as risk ratios (RRs) with 95% confidence intervals (CIs). We presented continuous outcomes as standardised mean differences (SMDs) with 95% CIs, and mean differences (MDs) with 95% CIs. If possible we intended to use meta-regression techniques to investigate possible sources of heterogeneity however this was not possible due to lack of data.

MAIN RESULTS

We included in the review eight studies (three RCTs and five prospective cohort studies) including 471 patients with epilepsy treated with an antidepressant. The RCTs were all single-centre studies comparing an antidepressant versus active control, placebo or no treatment. The five non-randomised prospective cohort studies reported on outcomes mainly in patients with partial epilepsy treated for depression with a selective serotonin reuptake inhibitor (SSRI). We rated all the RCTs and one prospective cohort study as having unclear risk of bias. We rated the four other prospective cohort studies as having high risk of bias. We were unable to perform any meta-analysis for the proportion with a greater than 50% improvement in depression scores because the studies reported on different treatment comparisons. The results are presented descriptively and show a varied responder rate of between 24% and 97%, depending on the antidepressant given. For the mean difference in depression score we were able to perform a limited meta-analysis of two prospective cohort studies of citalopram, including a total of 88 patients. This gave low quality evidence for the effect estimate of 1.17 (95% CI 0.96 to 1.38) in depression scores. Seizure frequency data were not reported in any RCTs and we were unable to perform any meta-analysis for prospective cohort studies due to the different treatment comparisons. The results are presented descriptively and show that treatment in three studies with a selective serotonin reuptake inhibitor did not significantly increase seizure frequency. Patients given an antidepressant were more likely to withdraw due to adverse events than inefficacy. Reported adverse events for SSRIs included nausea, dizziness, sedation, gastrointestinal disturbance and sexual dysfunction. Across three comparisons we rated the evidence as moderate quality due to the small sizes of the contributing studies and only one study each contributing to the comparisons. We rated the evidence for the final comparison as low quality as there was concern over the study methods in the two contributing studies.

AUTHORS' CONCLUSIONS

Existing evidence on the effectiveness of antidepressants in treating depressive symptoms associated with epilepsy is very limited. Only one small RCT demonstrated a statistically significant effect of venlafaxine on depressive symptoms. We have no high quality evidence to inform the choice of antidepressant drug or class of drug in treating depression in people with epilepsy. This review provides low quality evidence of safety in terms of seizure exacerbation with SSRIs, but there are no available comparative data on antidepressant classes and safety in relation to seizures. There are currently no comparative data on antidepressants and psychotherapy in treating depression in epilepsy, although psychotherapy could be considered in patients unwilling to take antidepressants or where there are unacceptable side effects. Further comparative clinical trials of antidepressants and psychotherapy in large cohorts of patients with epilepsy and depression are required to better inform treatment policy in the future.

Risk factors for psychological distress in community-treated epilepsy

The study aimed to determine risk factors for psychological distress in a community-treated sample of patients with epilepsy. This study investigated the Tasmanian Epilepsy Register participants. Participants included were as follows: aged 13 years and over, able to complete the individual computer-assisted participant interview, and diagnosed with epilepsy following an epilepsy specialist review of the diagnostic epilepsy interview, which was interpreted using standardized diagnostic guidelines. Psychological distress was assessed with the Kessler-10 questionnaire. Risk factors were grouped into four domains: sociodemographic factors, disease-related factors, psychological factors, and treatment-related factors. High or very high levels of psychological distress were reported by 22% of the participants, with 7.8% having very high distress. The regression model showed that psychological distress was significantly associated with female gender (F=18.1, p<0.001), diabetes mellitus (F=8.7, p=0.003), intellectual disability (F=7.1, p=0.06), and not receiving phenytoin (F=5.1, p=0.02). While the model was significant (F=5.78, p<0.001), only 11% of the variance of the K-10 score was explained by these factors (adjusted R-squared=0.11). This study identifies female gender and comorbid medical conditions as risk factors for psychological distress and the use of phenytoin as a protective factor. The few factors identified and the limited variance explained suggest that a focus on epilepsy-related variables is unlikely to explain key influences underlying psychiatric comorbidity in patients with epilepsy.

Nonepileptic seizures under levetiracetam therapy: a case report of forced normalization process

Nonepileptic seizures (NES) apparently look like epileptic seizures, but are not associated with ictal electrical discharges in the brain. NES constitute one of the most important differential diagnoses of epilepsy. They have been recognized as a distinctive clinical phenomenon for centuries, and video/electroencephalogram monitoring has allowed clinicians to make near-certain diagnoses. NES are supposedly unrelated to organic brain lesions, and despite the preponderance of a psychiatric/psychological context, they may have an iatrogenic origin. We report a patient with NES precipitated by levetiracetam therapy; in this case, NES was observed during the disappearance of epileptiform discharges from the routine video/electroencephalogram. We discuss the possible mechanisms underlying NES with regard to alternative psychoses associated with the phenomenon of the forced normalization process.

Screening for depression in people with epilepsy: comparative study among neurological disorders depression inventory for epilepsy (NDDI-E), hospital anxiety and depression scale depression subscale (HADS-D), and Beck depression inventory (BDI)

PURPOSE

We aimed to assess and compare the psychometric properties of the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E), Hospital Anxiety and Depression Scale Depression Subscale (HADS-D), and Beck Depression Inventory (BDI) as screening instruments for depression and suicidality in people with epilepsy.

METHODS

One hundred twenty-six people (54% women) diagnosed with epilepsy were recruited and evaluated on their sociodemographic and clinical features. Depression and suicide risk were assessed with a structured psychiatric interview, the Mini International Neuropsychiatric Interview (MINI-Plus), and the performance of NDDI-E, HADS-D, and BDI was evaluated.

RESULTS

The sensitivity and specificity of BDI for the diagnosis of depression was around 90%; HADS-D and NDDI-E have sensitivity higher than 80%, and specificity was greater than 75%. For identifying suicide risk, the NDDI-E sensitivity was 92.9%, and HADS-D sensitivity was 85.7%, and a reasonable specificity (68%) was observed for both instruments. All instruments showed a negative predictive value of over 90%. Comparisons of the areas under the ROC curve for these instruments were not significantly different regarding depression or moderate/severe risk of suicide.

CONCLUSION

All three instruments evaluated have clinical utility in the screening of depression in people with epilepsy. Both NDDI-E and HADS-D are brief efficient screening instruments to identify depression in people with epilepsy. The BDI is a more robust instrument, but it takes longer to apply, which hampers its use by busy clinicians and by people with cognitive impairment.

Specific alterations in the performance of learning and memory tasks in models of chemoconvulsant-induced status epilepticus

Cognitive impairment is a common comorbidity in patients with Temporal Lobe Epilepsy (TLE). These impairments, particularly deficits in learning and memory, can be recapitulated in chemoconvulsant models of TLE. Here, we used two relatively low-stress behavioral paradigms, the novel object recognition task (NOR) and a spatial variation, the novel placement recognition task (NPR) to reveal deficits in short and long term memory, in both kainic acid (KA) and pilocarpine (Pilo) treated animals. We found that both KA- and Pilo-induced significant deficits in long term recognition memory but not short term recognition memory. Additionally, KA impaired spatial memory as detected by both NPR and Morris water maze. These deficits were present 1 week after SE. The characterization of memory performance of two chemoconvulsant-models, one of which is considered a surrogate organophosphate, provides an avenue for which targeted cognitive therapeutics can be tested.

Biomarkers of epileptogenesis: psychiatric comorbidities (?)

The last decade has witnessed a significant shift on our understanding of the relationship between psychiatric disorders and epilepsy. While traditionally psychiatric disorders were considered as a complication of the underlying seizure disorder, new epidemiologic data, supported by clinical and experimental research, have suggested the existence of a bidirectional relation between the two types of conditions: not only are patients with epilepsy at greater risk of experiencing a psychiatric disorder, but patients with primary psychiatric disorders are at greater risk of developing epilepsy. Do these data suggest that some of the pathogenic mechanisms operant in psychiatric comorbidities play a role in epileptogenesis? The aim of this article is to review the epidemiologic data that demonstrate that primary psychiatric disorders are more frequent in people who develop epilepsy, before the onset of the seizure disorder than among controls. The next question looks at the available data of pathogenic mechanisms of primary mood disorders and their potential for facilitating the development and/or exacerbation in the severity of epileptic seizures. Finally, we review data derived from experimental studies in animal models of depression and epilepsy that support a potential role of pathogenic mechanisms of mood disorders in the development of epileptic seizures and epileptogenesis. The data presented in this article do not yet establish conclusive evidence of a pathogenic role of psychiatric comorbidities in epileptogenesis, but raise important research questions that need to be investigated in experimental, clinical, and population-based epidemiologic research studies.

Impaired cognitive ability and anxiety-like behavior following acute seizures in the Theiler's virus model of temporal lobe epilepsy

Viral infection of the CNS can result in encephalitis and acute seizures, increasing the risk for later-life epilepsy. We have previously characterized a novel animal model of temporal lobe epilepsy that recapitulates key sequela in the development of epilepsy following viral infection. C57BL/6J mice inoculated with the Daniel's strain of Theiler's Murine Encephalomyelitis Virus (TMEV; 3×10(5) PFU, i.c.) display acute limbic seizures that secondarily generalize. A majority of acutely seized animals develop spontaneous seizures weeks to months later. As part of our investigation, we sought to assess behavioral comorbidity following TMEV inoculation. Anxiety, depression, cognitive impairment, and certain psychoses are diagnosed in persons with epilepsy at rates far more frequent than in the general population. We used a battery of behavioral tests to assess anxiety, depression, cognitive impairment, and general health in acutely seized animals inoculated with TMEV and compared behavioral outcomes against age-matched controls receiving a sham injection. We determined that TMEV-seized animals are less likely to move through the exposed center of an open field and are less likely to enter into the lighted half of a light/dark box; both behaviors may be indicative of anxiety-like behavior. TMEV-seized animals also display early and persistent reductions in novel object exploration during novel object place tasks and do not improve in their ability to find a hidden escape platform in Morris water maze testing, indicative of impairment in episodic and spatial memory, respectively. Cresyl violet staining at 35 and 250 days after injection reveals bilateral reductions in hippocampal area, with extensive sclerosis of CA1 evident bilaterally along the rostral-caudal axis. Early and persistent behavioral changes in the TMEV model provide surrogate markers for assessing disease progression as well as endpoints in screening for the efficacy of novel compounds to manage both seizure burden and comorbid conditions.

Neural correlates of de novo depression following left temporal lobe epilepsy surgery: a voxel based morphometry study of pre-surgical structural MRI

PURPOSE

To investigate cerebral grey matter (GM) volumetric abnormalities in temporal lobe epilepsy (TLE) patients who develop de novo depression following TLE surgery using voxel-based morphometry (VBM).

METHODS

We retrospectively examined pre-surgical grey matter (GM) volumes in 30 patients with TLE due to unilateral left-sided hippocampal sclerosis using 1.5-T MRI scan, which were segmented with optimised VBM parameters and normalised to a sample template using DARTEL, with SPM8 software. Voxel-wise GM differences between patients that developed de novo post-surgical depression (n=5) were compared with patients with no pre- or postoperative psychiatric diagnoses (n=25), using independent samples t-tests with age, gender and secondary generalised tonic-clonic seizures (SGTCS) as covariates (p<.001, unc).

KEY FINDINGS

Reduced preoperative bilateral GM in orbitofrontal cortices (OFC) and ipsilateral cingulate gyrus and thalamus were significantly associated with the development of de novo depression within 4 years postoperatively. Further analyses revealed no differences in seizure freedom (ILAE 1 vs 2-6) or postoperative memory decline between the groups.

SIGNIFICANCE

Although the development of postoperative de novo depression following TLE surgery is likely to be multi-factorial, our results suggest that bilateral OFC and ipsilateral cingulate gyrus and thalamic atrophy in left-sided TLE patients may play a modulatory role. Abnormalities in these areas have also been implicated in primary mood disorders. Prospective neuroimaging studies with larger cohorts are warranted to replicate these results, and further elucidate the neural correlates of de novo depression.

Neurobehavior inventory: correlation with clinical aspects and quality of life in patients with epilepsy

Fifty-five adult patients with epilepsy were evaluated, and the Neurobehavior Inventory (NBI) was administered. The relationship between the NBI data and clinical aspects and quality of life (QoL) was studied. The total NBI score was 58 ± 18.2. The domains with the highest scores were "religious conviction", "orderliness", and "sense of personal destiny". There was a significant difference in "hatred and revenge" and "religious conviction" according to the epileptic syndrome. The "physical well-being" score was higher for patients with mesial temporal lobe epilepsy with right hippocampal sclerosis than for left sclerosis (2.77 ± 1.6 × 1.57 ± 0.5, respectively, p = 0.002). The total NBI score was higher in patients with psychiatric comorbidities and with depression according to the Hamilton Depression Scale and was negatively correlated with the "emotional well-being" QOLIE score (-0.398, p = 0.005). The NBI findings showed that behavioral changes can be present in various epilepsies and that there is a complex bidirectional neurobiological relationship between epilepsy and psychiatric comorbidity, sustained by common physiopathological mechanisms.

Epilepsy and neuropsychological comorbidities

PURPOSE OF REVIEW

Epilepsy is a chronic disorder with several associated comorbidities requiring timely recognition and treatment. This article discusses aspects of cognitive impairment; psychiatric disorders including depression, anxiety, and psychosis; and health-related quality-of-life issues pertaining to patients with epilepsy.

RECENT FINDINGS

Cognitive problems in epilepsy may be present early in the disease course. Advances in imaging techniques are allowing correlation of structure and function as they relate to cognitive impairment in epilepsy. The relationship between epilepsy, depression, and anxiety is increasingly recognized, and these psychiatric comorbidities may affect suicide risk, patient-reported adverse antiepileptic drug effects, and quality of life. Psychiatric disorders are underrecognized and undertreated in patients with epilepsy.

SUMMARY

Physicians who treat patients with epilepsy should be aware of the major impact that cognitive impairment and psychiatric comorbidities have on these patients. Identifying and treating these comorbidities in epilepsy patients is just as important as seizure treatment.

Antidepressant therapy in epilepsy: can treating the comorbidities affect the underlying disorder?

There is a high incidence of psychiatric comorbidity in people with epilepsy (PWE), particularly depression. The manifold adverse consequences of comorbid depression have been more clearly mapped in recent years. Accordingly, considerable efforts have been made to improve detection and diagnosis, with the result that many PWE are treated with antidepressant drugs, medications with the potential to influence both epilepsy and depression. Exposure to older generations of antidepressants (notably tricyclic antidepressants and bupropion) can increase seizure frequency. However, a growing body of evidence suggests that newer ('second generation') antidepressants, such as selective serotonin reuptake inhibitors or serotonin-noradrenaline reuptake inhibitors, have markedly less effect on excitability and may lead to improvements in epilepsy severity. Although a great deal is known about how antidepressants affect excitability on short time scales in experimental models, little is known about the effects of chronic antidepressant exposure on the underlying processes subsumed under the term 'epileptogenesis': the progressive neurobiological processes by which the non-epileptic brain changes so that it generates spontaneous, recurrent seizures. This paper reviews the literature concerning the influences of antidepressants in PWE and in animal models. The second section describes neurobiological mechanisms implicated in both antidepressant actions and in epileptogenesis, highlighting potential substrates that may mediate any effects of antidepressants on the development and progression of epilepsy. Although much indirect evidence suggests the overall clinical effects of antidepressants on epilepsy itself are beneficial, there are reasons for caution and the need for further research, discussed in the concluding section.

Stress, epilepsy, and psychiatric comorbidity: how can animal models inform the clinic?

Psychiatric complaints afflict many patients with epilepsy, and these contribute significantly to the impaired quality of life experienced by sufferers of this common group of neurological conditions. Psychiatric disorders in epilepsy patients are under-diagnosed and under-treated. Moreover, evidence suggests that the psychiatric disorders may act as risk factors for some types of epilepsy and exacerbate disease progression in established cases, promoting the case for a bidirectional relationship between epilepsy and psychopathology. While cause and effect relationships can be difficult to establish in human studies, appropriate animal models provide valuable tools with which to study the interactions between epilepsy and stress-related disorders. Indeed, many epilepsy models exhibit behavioral phenotypes which are reflective of psychiatric disorders, and, conversely, stressful environments appear to promote a vulnerability to developing epilepsy. This review summarizes this research area, exploring the behavioral phenotypes in animal models of epilepsy and then examining the influence of stressful environments on susceptibility to seizures and epilepsy. The ultimate goal of this line of research is to be able to translate these findings to humans. Understanding the relationships between epilepsy and associated psychiatric disorders will facilitate effective treatment of mood disorders in epilepsy, inform about the pathophysiology of each individually, and potentially open up novel therapeutic disease-modifying strategies for patients with epilepsy.

Repeatedly stressed rats have enhanced vulnerability to amygdala kindling epileptogenesis

Psychiatric disorders associated with elevated stress levels, such as depression, are present in many epilepsy patients, including those with mesial Temporal Lobe Epilepsy (mTLE). Evidence suggests that these psychiatric disorders can predate the onset of epilepsy, suggesting a causal/contributory role. Prolonged exposure to elevated corticosterone, used as a model of chronic stress/depression, accelerates limbic epileptogenesis in the amygdala kindling model. The current study examined whether exposure to repeated stress could similarly accelerate experimental epileptogenesis. Female adult non-epileptic Wistar rats were implanted with a bipolar electrode into the left amygdala, and were randomly assigned into stressed (n=18) or non-stressed (n=19) groups. Rats underwent conventional amygdala kindling (two electrical stimulations per day) until 5 Class V seizures had been experienced ('the fully kindled state'). Stressed rats were exposed to 30min restraint immediately prior to each kindling stimulation, whereas non-stressed rats received control handling. Restraint stress increased circulating corticosterone levels (pre-stress: 122±17ng/ml; post-stress: 632±33ng/ml), with no habituation observed over the experiment. Stressed rats reached the 'fully kindled state' in significantly fewer stimulations than non-stressed rats (21±1 vs 33±3 stimulations; p=0.022; ANOVA), indicative of a vulnerability to epileptogenesis. Further, seizure durations were significantly longer in stressed rats (p<0.001; ANOVA). These data demonstrate that exposure to repeated experimental stress accelerates the development of limbic epileptogenesis, an effect which may be related to elevated corticosterone levels. This may have implications for understanding the effects of chronic stress and depression in disease onset and progression of mTLE in humans.

Psychiatric comorbidity in refractory focal epilepsy: a study of 490 patients

We studied the prevalence and associated factors of psychiatric comorbidities in 490 patients with refractory focal epilepsy. Of these, 198 (40.4%) patients had psychiatric comorbidity. An Axis I diagnosis was made in 154 patients (31.4%) and an Axis II diagnosis (personality disorder) in another 44 (8.97%) patients. After logistic regression, positive family history of psychiatric comorbidities (O.R.=1.98; 95% CI=1.10-3.58; p=0.023), the presence of Axis II psychiatric comorbidities (O.R.=3.25; 95% CI=1.70-6.22; p<0.0001), and the epileptogenic zone located in mesial temporal lobe structures (O.R.=1.94; 95% CI=1.25-3.03; p=0.003) remained associated with Axis I psychiatric comorbidities. We concluded that a combination of clinical variables and selected structural abnormalities of the central nervous system contributes to the development of psychiatric comorbidities in patients with focal epilepsy.

Psychiatric care in epilepsy surgery: who needs it?

At present there is considerable variability in the psychiatric evaluation and follow-up of patients in epilepsy surgery programs globally. There is a large body of research now demonstrating heightened risk for psychological disturbance in surgically remedial patients before and after surgery. This evidence provides a compelling case for the routine provision of psychiatric and psychological treatment to optimize the benefits of epilepsy surgery and patient outcomes. In a comprehensive model of care, presurgical psychiatric and psychosocial evaluation plays an integral role in shaping the team's understanding of surgical candidacy and the patient's capacity for informed consent. After surgery, efficacious treatment of psychiatric comorbidity increases the likelihood of seizure freedom as well as optimizes psychosocial functioning and quality of life. By contrast, failure to treat can allow psychiatric comorbidity to persist or psychological difficulties to develop as the patient adjusts to life after surgery.

Postoperative adverse outcomes in surgical patients with epilepsy: a population-based study

PURPOSE

People with epilepsy are more likely than healthy people to experience comorbidities and complications in various medical situations. However, the prevalence of postoperative complications, mortality, and use of medical resources in surgical patients with epilepsy has not been studied. The purpose of this study is to examine whether epilepsy is an independent risk factor for postoperative adverse outcomes of patients receiving major surgery.

METHODS

Retrospective cohort study using the National Health Insurance Research Database to identify patients with epilepsy who underwent major surgery in Taiwan between the years 2004 and 2007. For each case, four age- and sex-matched participants without epilepsy were included. Preoperative comorbidities in the 24 months before surgery were identified. Eight major postoperative complications, overall 30-day mortality, and in-hospital utilization of medical resources (including length of hospital stay, percentage of postoperative intensive care unit admissions, and in-hospital medical expenditures) served as the major outcome measurements. Comorbidities, status of receiving renal dialysis, teaching hospital status, types of surgery, and patients living in urban or rural areas were adjusted by multivariate logistic regression.

KEY FINDINGS

A total of 13,103 participants with epilepsy and 52,412 without were included. Patients with epilepsy have significantly more preoperative comorbidities and demonstrated more risks of any postoperative complications (odds ratio 2.02, 95% confidence interval 1.90-2.14). Consumption of in-hospital medical resources was also significantly higher in patients with epilepsy, but no significant differences in postoperative mortality rates between the two groups were noted.

SIGNIFICANCE

Stroke was identified as the most significant postoperative complication for surgical patients with epilepsy. Patients, especially those with previous hospitalization or emergency visits due to the disease, confronted significantly higher postoperative complication rates, and consumed more in-hospital medical resources without differences in overall mortality rates. Further revision of health care standards to provide early recognition of postoperative complications and better management for surgical patients with epilepsy is needed.

Is major depressive disorder specifically associated with mesial temporal sclerosis?

PURPOSE

Whether a specific lesion such as mesial temporal sclerosis (MTS) increases the risk for a mood disorder in epilepsy remains subject to debate. Despite evidence of limbic system involvement in the genesis of emotional symptoms, recent studies fail to support an association between depression and MTS. We aimed to clarify this controversial issue by overcoming prior methodologic limitations, hypothesizing that rates of major depressive disorder (MDD) would be higher in patients with MTS.

METHODS

Three hundred eight patients with focal epilepsy (International League Against Epilepsy [ILAE] criteria), were classified into three groups on the basis of neuroimaging findings: MTS, a lesion different from MTS, or absence of lesion. Patients were assessed using the Structured Interview for DSM-IV axis I psychiatric disorders (SCID-I), by a psychiatrist blinded to epilepsy subtype. The Spanish version of the Hospital Anxiety and Depression Scale (HADS) was also administered. A complete logistic regression analysis was performed to investigate the association between MTS and MDD.

KEY FINDINGS

MTS increased the likelihood of a lifetime MDD by nearly 2.5. No other current or "postseizure onset" lifetime Axis I DSM-IV psychiatric disorder was associated with MTS. Female gender, primary education, comorbid anxiety disorders, and antidepressant treatment were also associated with an increased risk of MDD. Marriage was found to be a protective factor for MDD.

SIGNIFICANCE

Our results support a specific association between MTS and lifetime "postseizure onset," MDD. The lack of association with current depression is in line with the hypothesis that the link between MTS and depression is more of a chronic than a state-dependent condition.

Depression in temporal lobe epilepsy: a review of prevalence, clinical features, and management considerations

Depression in temporal lobe epilepsy has been established as a frequent occurrence, and various possible mechanisms for this significant comorbidity have been posited. However, there is still little to guide a clinician in the recognition and management of depression in patients with temporal lobe epilepsy. This is in part due to the lack of consistent findings in earlier studies, which was likely partly due to variabilities in methodology, sampling, and diagnosis of both temporal lobe epilepsy and depression. However, in recent years, significant effort has been made to address these issues and provide a framework for diagnosis and management of depression in this population. The following is a review of the literature, with special emphasis on clinical phenomenology of depressive symptoms, described bidirectional risk between depression and temporal lobe epilepsy, and treatment strategies in the context of potential drug interactions with antiepileptic drugs.

Utility and validity of a brief cognitive assessment tool in patients with epileptic and nonepileptic seizures

OBJECTIVE

Cognitive impairment is not uncommon in patients with epilepsy, and may relate to the underlying pathophysiology of epilepsy, the effects of seizures, or epilepsy treatment. Formal neuropsychological testing is not available in many centers, and few cognitive screening tools have been validated in an epilepsy population. We aimed to ascertain the reliability and validity of a multidimensional cognitive screening instrument, the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG), in a mixed epilepsy population.

METHODS

One hundred sixty-one of 177 consecutive patients admitted to a video telemetry unit were assessed with the NUCOG and classified with respect to seizure semiology, and a subset (n=33) were formally neuropsychologically assessed.

RESULTS

Scores did not differ between patients with epileptiform, those with nonepileptiform, and those with mixed EEGs on the NUCOG, nor between patients with focal and those with generalized epilepsies. Patients with a temporal lobe focus performed more poorly in general, and in memory specifically, than patients with an extratemporal focus. Scores on the NUCOG subscales Memory, Attention, and Executive Functioning correlated significantly with neuropsychological testing of these same domains, although patients were not impaired on measures of language or spatial function.

CONCLUSION

The NUCOG appears to correlate strongly with neuropsychological functioning in a number of key cognitive areas affected in patients with epilepsy, and appears to robustly detect memory impairment in patients with temporal lobe epilepsy.