Victoria Vahle

Rapid detection of major depression in epilepsy: a multicentre study

BACKGROUND Depression is a common comorbid disorder in epilepsy but is not routinely assessed in neurology clinics. We aimed to create a rapid yet accurate screening instrument for major depression in people with epilepsy. METHODS We developed a set of 46 items to identify symptoms of depression that do not overlap with common comorbid cognitive deficits or adverse effects of antiepileptic drugs. This preliminary instrument and several reliable and valid instruments for diagnosis of depression on the basis of criteria from the Diagnostic and Statistical Manual IV, depression symptom severity, health status, and toxic effects of medication were applied to 205 adult outpatients with epilepsy. We used discriminant function analysis to identify the most efficient set of items for classification of major depression, which we termed the neurological disorders depression inventory for epilepsy (NDDI-E). Baseline data for 229 demographically similar patients enrolled in two other clinical studies were used for verification of the original observations. FINDINGS The discriminant function model for the NDDI-E included six items. Internal consistency reliability of the NDDI-E was 0.85 and test-retest reliability was 0.78. An NDDI-E score of more than 15 had a specificity of 90%, sensitivity of 81%, and positive predictive value of 0.62 for a diagnosis of major depression. Logistic regression showed that the model of association of major depression and the NDDI-E was not affected by adverse effects of antiepileptic medication, whereas models for depression and generic screening instruments were. The severity of depression symptoms and toxic effects of drugs independently correlated with subjective health status, explaining 72% of variance. Results from a separate verification sample also showed optimum sensitivity, specificity, and predictive power at a cut score of more than 15. INTERPRETATION Major depression in people with epilepsy can be identified by a brief set of symptoms that can be differentiated from common adverse effects of antiepileptic drugs. The NDDI-E could enable rapid detection and improve management of depression in epilepsy in accordance with internationally recognised guidelines.

Systematic screening allows reduction of adverse antiepileptic drug effects: A randomized trial

Objective: To determine the effectiveness of systematic screening with a brief 19-item self-report instrument, the Adverse Events Profile (AEP), to reduce adverse effects of antiepileptic drugs (AEDs) and improve subjective health status. Methods: The authors performed a prospective randomized trial comparing the use of the AEP with usual care without the AEP. Sixty-two patients with an AEP score of ≥45 were enrolled from a consecutive group of 200 consenting adults with epilepsy. Results: The mean percent improvement in AEP scores was greater in the patient group for which clinicians received the AEP compared with the usual care group (25% vs 5%; p < 0.01). Mean change in Quality of Life in Epilepsy Inventory (QOLIE)-89 total scores was not different between groups, but for the entire sample QOLIE-89 change was greater for patients having a 15-point improvement in AEP scores than for those with a 0- to 15-point improvement or a worsened score (24 vs 12 vs 3; analysis of variance, p < 0.008). More patients in the AEP group had a >15-point improvement in QOLIE-89 score (p < 0.03). Use of the AEP was associated with a 2.8-fold increase (95% CI, 1.7 to 4.8) in AED modifications. No difference in seizure rates was observed. Conclusions: Systematic screening for antiepileptic drug side effects may increase identification of toxicity and guide medication changes to reduce adverse effects and possibly improve subjective health status.

Depression in Epilepsy: Ignoring Clinical Expression of Neuronal Network Dysfunction?

Summary:  Epilepsy is a chronic disorder that adversely affects social, vocational, and psychological functioning. Despite the variety and complexity of the negative clinical associations with epilepsy, depression is remarkable in prevalence and related adverse effects on health status. An estimated 30–50% of persons with refractory epilepsy have major depression, and depression has a stronger correlation than seizure rate with quality of life. Suicide is one of the leading causes of death in epilepsy. Available data indicate that depression may result from underlying brain dysfunction rather than social and vocational disability. Most patients with depression are not screened systematically for the diagnosis, and are subsequently not treated. Although the density of serotonin receptors is greatest in limbic brain regions commonly involved in human epilepsy, such as the mesial temporal and prefrontal areas, no prior randomized controlled trials have evaluated the efficacy of serotonin reuptake inhibitors for depression in epilepsy.

Adverse antiepileptic drug effects: Toward a clinically and neurobiologically relevant taxonomy

Background: Adverse effects (AEs) of antiepileptic drugs (AEDs) are a major impediment to optimal dosing for seizure control. Better understanding of clinical properties of AEs is a prerequisite for systematic research of their neurobiological underpinnings. This study aimed to define specific patterns of AE occurrence and determine their clinical relevance based on their association with subjective health status. Methods: Two hundred subjects with epilepsy completed validated self-report health assessments, including the Adverse Event Profile (AEP) and Quality of Life in Epilepsy Inventory (QOLIE)-89. Factor analysis was performed on the 19 AEP items to identify distinct classes of AEs. Correlations between AE class scores and QOLIE-89 scores were evaluated. Multivariate analysis was used to assess contributions of AE class scores to QOLIE-89 scores after controlling for depression and seizure frequency. Relationships between changes in AE class scores and changes in QOLIE-89 scores were also investigated in a subgroup of 62 subjects enrolled in a randomized trial. Results: The mean number of AEs per subject was 6.5. AEs were segregated into five classes: Cognition/Coordination, Mood/Emotion, Sleep, Weight/Cephalgia, and Tegument/Mucosa. Higher scores in each AE class were associated with lower QOLIE-89 scores. Cognition/Coordination scores were the strongest predictor of QOLIE-89 scores. Improvements in Cognition/Coordination, Mood/Emotion, and Tegument/Mucosa scores were associated with improvements in QOLIE-89 scores. Improved Cognition/Coordination was the only predictor of improved QOLIE-89. Conclusion: Adverse effects (AEs) of antiepileptic drugs can be classified in five biologically plausible factors. When specific classes of AEs are identified and attempts are made to reduce them, quality of life is significantly improved. AE = adverse effect; AED = antiepileptic drug; AEP = Adverse Event Profile; BDI = Beck Depression Inventory; GABA = γ-aminobutyric acid; HRQOL = Health-Related Quality of Life; QOLIE = Quality of Life in Epilepsy Inventory.

Cognitive and behavioral effects of lamotrigine and topiramate in healthy volunteers

Background: The relative cognitive and behavioral effects of lamotrigine (LTG) and topiramate (TPM) are unclear. Methods: The authors directly compared the cognitive and behavioral effects of LTG and TPM in 47 healthy adults using a double-blind, randomized crossover design with two 12-week treatment periods. During each treatment condition, subjects were titrated to receive either LTG or TPM at a target dose of 300 mg/day for each. Neuropsychological evaluation included 17 measures yielding 41 variables of cognitive function and subjective behavioral effects. Subjects were tested at the end of each antiepileptic drug (AED) treatment period and during two drug-free conditions (pretreatment baseline and 1 month following final AED withdrawal). Results: Direct comparison of the two AEDs revealed significantly better performance on 33 (80%) variables for LTG, but none for TPM. Even after adjustment for blood levels, performance was better on 19 (46%) variables for LTG, but none for TPM. Differences spanned both objective cognitive and subjective behavioral measures. Comparison of TPM to the non-drug average revealed significantly better performance for non-drug average on 36 (88%) variables, but none for TPM. Comparison of LTG to non-drug average revealed better performance on 7 (17%) variables for non-drug average and 4 (10%) variables for LTG. Conclusions: Lamotrigine produces significantly fewer untoward cognitive and behavioral effects compared to topiramate (TPM) at the dosages, titrations, and timeframes employed in this study. The dosages employed may not have been equivalent in efficacy. Future studies are needed to delineate the cognitive and behavioral effects of TPM at lower dosages.

Relationship between depression and intractability of seizures

Patients with epilepsy have a higher prevalence of depressive disorders than the general population, but the relationship between seizure rates and depression has not been adequately studied. We used the Beck Depression Inventory to evaluate depressive symptoms in 143 consecutive epilepsy patients from outpatient clinics. Patients who were seizure free more than 6 months were considered not intractable. Thirty-six percent were neither intractable nor depressed, 43% had intractable epilepsy and were not depressed, 10% had intractable epilepsy and were depressed, and 11% did not have intractable epilepsy and were depressed. Patients with epilepsy have a higher prevalence of depression than the general population, but the intractability of the seizure disorder does not seem to be an independent risk factor for the occurrence of depression. There is no relationship between the severity of depression and monthly seizure rate.

Depression but not seizure factors or quality of life predicts suicidality in epilepsy

The objective of this study was to determine prevalence and predictive risk factors of suicidality in a large sample of epilepsy outpatients. We prospectively examined 193 consecutive adult epilepsy outpatients for depression, including suicidal ideation. Demographic and epilepsy factors, medication toxicity and health-related quality of life were also evaluated. The prevalence of suicidal ideation within the past two weeks was 11.9%. Although medication toxicity, health-related quality of life and BDI scores were each associated with suicidal ideation in the bivariate analyses, only the BDI remained significant in the logistic regression analysis. About one-fourth of the subjects with suicidal ideation had no significant symptoms of depression. Recent thoughts of suicide are a common occurrence in the outpatient epilepsy clinic setting, but these are not predicted by gender, age, seizure factors, medication toxicity or self-perceived quality of life. Although depression is associated with suicidal ideation, about one-fourth of the suicidal subjects were euthymic or only mildly depressed.

Correlation of Severity of FDG-PET Hypometabolism and Interictal Regional Delta Slowing in Temporal Lobe Epilepsy

Summary:  Purpose: We investigated the association of severity of hypometabolism detected by positron emission tomography (PET) with [18F]fluorodeoxyglucose (FDG) and persistence of interictal EEG focal slowing in patients with refractory temporal lobe epilepsy.

Self‐reported Seizure Frequency and Time to First Event in the Seizure Monitoring Unit

Summary:  Purpose: To compare seizure frequency reported in the clinic with time to first diagnostic event during video‐EEG monitoring. The effect of the artificial environment of the monitoring unit on self‐reported seizure frequency was explored.

Severe hippocampal atrophy is not associated with depression in temporal lobe epilepsy

Depression in temporal lobe epilepsy (TLE) is common, is a strong predictor of subjective disability, and may have unique pathophysiological characteristics. Previous studies showed that reduced hippocampal volume is associated with significant depressive symptoms in patients with TLE. We utilized regions of interest analysis of high-resolution brain MRI and a reliable and valid measure of depressive symptoms to evaluate 28 consecutive adult subjects with video-EEG-confirmed TLE. Regions of interest were based on prior human and animal studies of mood and behavioral dysfunction. Forty-three percent of the entire group had significant symptoms of depression, defined by a Beck Depression Inventory (BDI) score of greater than 15. Total hippocampal volumes were significantly smaller in the group with BDI<15, (p<0.007). None of the subjects in the quartile with the smallest left hippocampal volume had a BDI score greater than 15 compared with 57% of the subjects in the upper three quartiles (p<0.008). No other limbic brain structures (amygdala, subcallosal gyrus, subgenual gyrus, gyrus rectus), or total cerebral volume were associated with depressive symptoms. Adequate hippocampal integrity may be necessary to maintain depression symptoms in mesial temporal lobe epilepsy. This finding also supports the possibility of a unique mechanism for depression in mesial temporal lobe epilepsy, such as hyperexcitable neuronal influence on the limbic network.