Suncica Lah

Memory function in childhood epilepsy syndromes

Objective:  Children with epilepsy are at risk of specific cognitive deficits. We aimed to compare and characterize the memory function of children with childhood absence epilepsy (CAE), frontal lobe epilepsy (FLE) and temporal lobe epilepsy (TLE).

Intelligence in childhood epilepsy syndromes

UNLABELLED Intellectual deficits play a significant role in the psychosocial comorbidity of children with epilepsy. Early educational intervention is critical. OBJECTIVE This study aims to determine the intellectual ability of children with common childhood epilepsy syndromes-generalised idiopathic epilepsy (GIE), generalised symptomatic epilepsy (GSE), temporal lobe epilepsy (TLE), frontal lobe epilepsy (FLE), central epilepsy (CE) and non-localised partial epilepsy (PE). METHODS A prospective consecutive series of 169 children were recruited. Epilepsy syndrome was identified by clinical data, seizure semiology, interictal and ictal EEG in each child, using International League Against Epilepsy criteria. Each child had neuropsychology assessment using age-normed and validated instruments. After adjusting for important epilepsy variables, 95% confidence intervals were generated for mean full-scale intelligence quotient (FSIQ) using ANCOVA. RESULTS Significant differences between epilepsy syndrome groups were found for age of onset (P<0.001), duration of active epilepsy (P=0.027), seizure frequency (P=0.037) and polytherapy (P=0.024). Analysing FSIQ, children with GIE, CE and TLE performed best, and did not differ statistically. Children with GSE had a statistically lower FSIQ than other syndrome groups except PE. FLE functioned significantly better than GSE, but did not differ statistically from other groups. CONCLUSIONS In childhood epilepsy, delineation of the syndrome has important implications when considering intellectual potential. This information is invaluable in planning educational interventions and supporting the family.

Effects of Temporal Lobe Epilepsy on Retrograde Memory

Summary:  Purpose: In a previous investigation (Lah et al., 2004), we found deficits in retrograde memory in patients who had undergone temporal lobectomy (TL). In this study, we set out to determine whether such deficits are present before surgery in patients with temporal lobe epilepsy (TLE).

Memory for the past after temporal lobectomy: impact of epilepsy and cognitive variables

A few previous studies have revealed impairments in remote memory in patients with temporal lobe epilepsy, but many questions about the importance of lesion side, type of material, seizure history and deficits in other aspects of cognitive functions remain unanswered. In this study, patients who had undergone unilateral (15 right and 15 left) temporal lobectomy (TL) for the relief of epilepsy and 15 control subjects completed a range of public and autobiographical memory tests. Deficits in recall and recognition of details related to past famous world events were observed for both left and right TL groups. In addition, the left TL group showed impaired retrieval of famous names and TL patients as a group generated significantly fewer names of people from their own past. Current seizure- and medication-status influenced performance on a few measures, but duration of epilepsy and age of onset had no significant impact. Underlying cognitive deficits (especially naming ability) contributed to, but could not completely explain difficulties remembering the past. In particular, deficits in the ability to retrieve highly specific information learned in the past, such as names of famous people or details about famous events, remained evident in analyses that controlled for the impact of related cognitive skills.

One size does not fit all: Face emotion processing impairments in semantic dementia, behavioural-variant frontotemporal dementia and Alzheimer's disease are mediated by distinct cognitive deficits

Patients with frontotemporal dementia (both behavioural variant [bvFTD] and semantic dementia [SD]) as well as those with Alzheimers disease (AD) show deficits on tests of face emotion processing, yet the mechanisms underlying these deficits have rarely been explored. We compared groups of patients with bvFTD (n = 17), SD (n = 12) or AD (n = 20) to an age- and education-matched group of healthy control subjects (n = 36) on three face emotion processing tasks (Ekman 60, Emotion Matching and Emotion Selection) and found that all three patient groups were similarly impaired. Analyses of covariance employed to partial out the influences of language and perceptual impairments, which frequently co-occur in these patients, provided evidence of different underlying cognitive mechanisms. These analyses revealed that language impairments explained the original poor scores obtained by the SD patients on the Ekman 60 and Emotion Selection tasks, which involve verbal labels. Perceptual deficits contributed to Emotion Matching performance in the bvFTD and AD patients. Importantly, all groups remained impaired on one task or more following these analyses, denoting a primary emotion processing disturbance in these dementia syndromes. These findings highlight the multifactorial nature of emotion processing deficits in patients with dementia.

Tracking the progression of social cognition in neurodegenerative disorders

Background and purpose Behavioural-variant frontotemporal dementia (bvFTD) and Alzheimers disease (AD) patients experience behavioural and emotion recognition alterations, yet understanding of how socioemotional processing is affected with disease progression is minimal. Additionally, evidence suggests that bvFTD patients with limited brain atrophy on neuroimaging at presentation (bvFTD-la) have a more benign course than those with marked atrophy (bvFTD-ma). Longitudinal investigation of these patients, however, is lacking. Methods We investigated general cognition, emotion recognition and sarcasm detection in 20 bvFTD (8 with limited brain atrophy) and 17 AD patients longitudinally and used mixed models analyses to determine the level and rates of decline across groups over time. Results At baseline, all patient groups performed worse than controls on general cognition and emotion recognition measures. The bvFTD-ma group showed significant impairment on the sarcasm detection task compared with controls. Longitudinally, an overall effect of time was present for general cognition (p<0.001); however, the rate of decline did not differ across groups. Trends for interactions between time and diagnosis were observed for both emotion recognition tasks (p=0.055; p=0.062), with the bvFTD-ma group declining more rapidly than AD or bvFTD-la groups. On the sarcasm detection task, the bvFTD-ma and AD patients declined, whereas bvFTD-la patients remained stable over time (p=0.002). Conclusions Tasks of sarcasm detection represent a clinically useful tool to differentiate between bvFTD and AD at baseline. Furthermore, tasks of socioemotional functioning can track progression within bvFTD and identify bvFTD patients more likely to show a faster rate of decline.

Neuropsychological outcome following focal cortical removal for intractable epilepsy in children.

In children, surgery for epilepsy has been recognized as a viable treatment option since publication of S. Davidson and M.A. Falconers outcome study in 1975 [Lancet North Am Ed 5:1260-3], which demonstrated that medical outcome of children who underwent anterior temporal lobectomy paralleled that of adults. Pediatric surgical programs and the literature on medical outcome have grown considerably since that time, with surgery being offered to children with temporal but also extratemporal epilepsy foci. Comparatively little work has been conducted in the area of neuropsychological outcome. This article outlines differences in adult and pediatric outcome studies, reviews the literature on the intellectual and memory outcome in children, and discusses shortcomings of the pediatric outcome research conducted to date.

Facial emotion identification in early-onset and first-episode psychosis: a systematic review with meta-analysis.

OBJECTIVE Patients with chronic schizophrenia are characterized by deficits in identifying facial expressions of emotion, and these deficits relate to impaired social and occupational function. It is not yet known if these deficits are trait-like and present at the onset of psychosis, preceding a subsequent diagnosis of schizophrenia. Our objective was to systematically review and analyze the extant literature to assess if there is a consistent profile of emotion identification problems in early-onset and first-episode psychosis. METHODS We conducted a systematic review and meta-analysis of 12 peer-reviewed studies of facial emotion identification in early-onset and first-episode psychosis, published between 1980 and March 2013. We examined the average mean difference between patients and controls on measures of facial emotion identification. RESULTS Findings suggest that patients with early-onset and first-episode psychosis have impairment in identifying facial expressions of biologically salient emotion. Across the 12 studies, the onset of psychosis was distinguished by a generalized effect of significantly poorer accuracy for identifying facial expressions of emotion than healthy controls, and this difference had a substantial effect size (d=-0.88, N=378, 95% CI=-1.42 to -0.32). Within this general effect some emotions were also harder for patients to identify than others, with the magnitude of impairment found to be (i) large for disgust, fear and surprise, and (ii) medium for sadness, and happiness. No between groups mean differences were found for anger or neutral facial expressions. CONCLUSIONS Deficits in facial emotion identification are evident at first onset of a psychotic episode. The findings suggest that, over and above a generalized deficit in identifying facial emotion, patients may find some emotions harder to identifying than others. This reflects findings with chronic schizophrenia populations and suggests that emotion identification impairment represents a trait susceptibility marker, rather than a sequeale of illness. They signal the urgent need to treat emotion identification deficits at the onset of illness, which could improve functional outcomes.

Accelerated long-term forgetting in children with idiopathic generalized epilepsy

Purpose:  The rapid forgetting of information over long (but not short) delays (accelerated long‐term forgetting [ALF]) has been associated with temporal lobe epilepsy but not idiopathic generalized epilepsy (IGE). Long‐term memory formation (consolidation) is thought to demand an interaction between medial temporal and neocortical networks, which could be disrupted by epilepsy/seizures themselves. The present study investigates whether ALF is present in children with IGE and whether it relates to epilepsy severity.

One declarative memory system or two? The relationship between episodic and semantic memory in children with temporal lobe epilepsy.

OBJECTIVE This study explored verbal semantic and episodic memory in children with unilateral temporal lobe epilepsy to determine whether they had impairments in both or only 1 aspect of memory, and to examine relations between performance in the 2 domains. METHOD Sixty-six children and adolescents (37 with seizures of left temporal lobe onset, 29 with right-sided onset) were given 4 tasks assessing different aspects of semantic memory (picture naming, fluency, knowledge of facts, knowledge of word meanings) and 2 episodic memory tasks (story recall, word list recall). RESULTS High rates of impairments were observed across tasks, and no differences were found related to the laterality of the seizures. Individual patient analyses showed that there was a double dissociation between the 2 aspects of memory in that some children were impaired on episodic but not semantic memory, whereas others showed intact episodic but impaired semantic memory. CONCLUSIONS This double dissociation suggests that these 2 memory systems may develop independently in the context of temporal lobe pathology, perhaps related to differential effects of dysfunction in the lateral and mesial temporal lobe structures.