Zoe Thayer

Examining factors related to accelerated long-term forgetting in epilepsy using ambulatory EEG monitoring

Some patients with epilepsy demonstrate normal memory when this is tested at relatively short intervals (e.g., 30 min), but substantial loss over longer delay periods (e.g., days or weeks) when compared to healthy control subjects. This pattern of “accelerated long‐term forgetting” (ALF) affects the everyday lives of patients, yet goes undetected by standard neuropsychological memory tests, and its pathophysiologic basis is poorly understood. By testing memory over a period of concurrent ambulatory electroencephalography (EEG), the current study aimed to investigate possible factors contributing to ALF.

Rates of DSM-IV mood, anxiety disorders, and suicidality in Australian adult epilepsy outpatients: A comparison of well-controlled versus refractory epilepsy

Despite recent research into the impact of seizure control on mood disorders in epilepsy, it is often assumed that rates of psychiatric disorders are higher in people with refractory rather than well-controlled epilepsy. We assessed the point prevalence of mood and anxiety disorders and suicide risk using the Mini International Neuropsychiatric Interview (MINI) in a consecutive sample of epilepsy outpatients from a tertiary referral center. One hundred and thirty patients, whose epilepsy was categorized as well-controlled versus drug-treatment-refractory epilepsy (69; 53% well-controlled epilepsy) were recruited. High rates of mood disorders (n = 34; 26%), anxiety disorders (n = 37; 29%) and suicide risk (n = 43; 33%) were found. However, there was no difference in rates of disorders or suicide risk for those with refractory versus well-controlled epilepsy. These results underscore the importance of assessment and management of psychopathology in all people with epilepsy, regardless of their seizure control.

Impairments in the perception of odor-induced tastes and their relationship to impairments in taste perception.

Certain odors have tastelike qualities when sniffed. To the extent that these qualities are akin to real taste experiences, impairment in perception of odor-induced tastes should be accompanied by taste impairment, and vice versa. Twelve patients were selected with possible odor-induced taste impairments or general taste impairments via a screening test, along with a further 6 patients with a probable taste impairment (insular lesion). These 18 patients, along with 19 normal controls, completed a battery of odor, taste, visual control, and neuropsychological tests to assess impairments in odor-induced taste perception and general taste perception. Four patients had an odor-induced taste impairment and were also impaired on taste perception. A further analysis, using regression on the whole sample, indicated that taste impairments were associated with odor-induced taste abnormalities independent of other predictors. This pattern also held for the patient group alone. The insular patients also exhibited both taste and odor-induced taste impairments. This study is the first to demonstrate a relationship between impaired taste perception and the perception of odor-induced tastes and suggests that both may rely on certain common neural substrates.

Focal retrograde amnesia: Extending the clinical syndrome of transient epileptic amnesia

A 44-year-old woman presented with focal retrograde amnesia and complaints of rapid forgetting in the absence of episodes of transient cognitive disturbance. Her MRI and 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) were normal. On standard neuropsychological tests she performed within the normal range although a test of autobiographical memory confirmed impoverished recall especially involving recent life events. The electroencephalograph (EEG) recordings were suggestive of temporal lobe epilepsy but no clear diagnosis was established. After 4 years the patients recurrent brief episodes of disorientation, suggestive of transient epileptic amnesia (TEA), were corroborated by her sister. This diagnosis was confirmed by an ambulatory EEG that revealed ictal activity. Several important points emerge from this study. Focal retrograde amnesia can be a prodromal symptom of TEA which can precede the full-blown syndrome by several years. Moreover, transient attacks might not be reported if patients live alone. The ictal EEG findings further substantiate the epileptic nature of the syndrome.

Accelerated long-term forgetting: A newly identified memory impairment in epilepsy

Recently, a pattern referred to as accelerated long-term forgetting (ALF) has been described in patients with epilepsy. In ALF, acquisition and retention over standard delayed recall intervals (up to 30 minutes) tend to be intact, but there is an abnormally rapid rate of forgetting over delays of days or weeks. ALF is associated with everyday memory complaints as well as impairments in autobiographical memory, but goes largely undetected by traditional neuropsychological measures. We consider here the characteristics of ALF and possible contributors to its underlying pathophysiology. Overall, a better understanding of this relatively newly recognised memory disorder should improve clinical treatment.

Assessing the efficacy of 2 screening measures for depression in people with epilepsy

Objectives: The aim of this study was to compare the efficacy of the Neurological Depressive Disorders Inventory for Epilepsy (NDDI-E) and the depression component of the Hospital Anxiety Depression Scale (HADS-D) for identifying depression and suicide risk in adults with epilepsy. Methods: A total of 147 (87 female [59% ]) outpatients attending a tertiary epilepsy center in Sydney Australia completed the NDDI-E and HADS-D. They then completed the depression and suicide sections of the Mini International Neuropsychiatric Inventory (MINI) with a clinician blind to symptom measure scores. Receiver operator characteristic analysis was performed for the clinical cutoff scores for depression on the NDDI-E ≥15 and HADS-D ≥8 to identify MINI-determined depression and suicidality. Results: The NDDI-E indicated strong sensitivity (84%) and acceptable specificity (78%), whereas the HADS-D had poor sensitivity (42%) but good specificity (97%) for identifying depression. For identifying suicide risk, the NDDI-E indicated strong sensitivity (81%) and reasonable specificity (66%), whereas the HADS-D had poor sensitivity (43%) but acceptable specificity (90%). Area under the curve comparisons for these measures were not significant. Conclusion: In clinical practice, it is essential that screening measures have the highest possible sensitivity values to limit the chances of false-negative results. In accordance with these guidelines, the NDDI-E was a superior screening measure compared with the HADS-D. Our results demonstrate the efficacy of the NDDI-E for identifying both major and minor depression and serious suicide risk. The poor sensitivity of the HADS-D suggests that it should not be used as a screen for depression or suicidality in adults with epilepsy.

Effective group-based memory training for patients with epilepsy

Patients with epilepsy experience memory problems, but there have been few attempts to provide and evaluate the effectiveness of memory training. We designed a 6-week, group-based, psychoeducation and strategy course that was evaluated using a waitlist crossover design, with three assessments conducted 12 weeks apart. Thirty-one patients with a history of seizures participated. Significant gains were found on tests of anterograde (Rey Auditory Verbal Learning Test) and appointment memory. In addition, patients reported using more strategies and experiencing fewer prospective memory difficulties in daily life. Memory was more likely to improve in participants who were younger, less educated, and less depressed. Moreover, lower baseline memory, but better attention corresponded to better outcome. Of the clinical variables related to epilepsy, only number of anticonvulsant medications was found to be associated with outcome. Our study provides evidence that a relatively short intervention can improve memory functioning in patients with epilepsy.

Anxiety in epilepsy: a neglected disorder.

OBJECTIVE Anxiety disorders and symptoms are highly prevalent and problematic comorbidities in people with epilepsy (PWE), yet they remain poorly understood and often go undetected. This research aimed to further our understanding about anxiety in PWE. METHODS Study 1 assessed the effectiveness of the commonly utilised yet unvalidated measure (Hospital Anxiety Depression Scale-Anxiety subscale; HADS-A) to identify DSM-IV anxiety disorders in 147 adult epilepsy outpatients. RESULTS This study found that although the HADS-A had reasonable specificity (75%), its poor sensitivity (61%) and inadequate area under the curve (.68) deemed it unreliable as a screener for anxiety disorders in this population. METHODS Study 2 aimed to further our understanding of the relationship between anxiety disorders, as defined by clinical interview, and psychosocial correlates in PWE. One hundred and twenty-two participants from Study 1 completed a battery of psychosocial measures. RESULTS Multivariate analysis revealed that the presence of an anxiety disorder was associated with unemployment, which was found to be the only independent predictor. That is, despite the fact that psychosocial factors together contributed to the variance in anxiety disorders none were revealed to be significant independent predictors. CONCLUSION These findings add to the literature indicating that the HADS may indicate distress, but does not adequately identify people with anxiety disorders and highlights the urgent need for the development of a reliable anxiety screening measure for PWE. Further, the results suggest that anxiety disorders in PWE are likely to be multiply determined with respect to psychosocial factors and require further investigation.

Accelerated long-term forgetting of verbal information in unilateral temporal lobe epilepsy: Is it related to structural hippocampal abnormalities and/or incomplete learning?

The factors contributing to accelerated long-term forgetting (ALF) are not yet clear. In this study, a 12-item word list was presented repeatedly to 23 patients with temporal lobe epilepsy (TLE) and 27 control participants (NC) until it was recalled completely on two consecutive trials or until 12 trials were undertaken. Compared to NCs, patients with hippocampal lesions and those who failed to learn the list showed ALF by one day post learning, but the alternative patient groups also showed ALF when tested after seven days. Overall, our findings suggest that in patients with TLE neither a preserved hippocampus nor intact learning protects against ALF.

Cognitive Behaviour Therapy to Improve Mood in People with Epilepsy: A Randomised Controlled Trial

This study compared a 9-week individualised Cognitive Behaviour Therapy (CBT) programme for people with epilepsy (PWE), with a wait-list control. Fifty-nine PWE were randomised and 45 (75%) completed post-treatment outcomes. People with lower quality of life (QoL), particularly for cognitive functioning, were more likely to drop out. Analyses based on treatment completers demonstrated significant improvements on the Neurological Depressive Disorders Inventory for Epilepsy (p = .045) and Hospital Anxiety Depression Scale-Depression subscale (p = .048). Importantly, CBT significantly reduced the likelihood of clinical depressive symptoms (p = .014) and suicidal ideation (p = .005). Improvements were not observed for anxiety, QoL or maintained overtime for depression. Results suggest that CBT was effective, however, and could be improved to increase patient retention and long-term outcomes.