Prevalence and localization of nocturnal epileptiform discharges in mild cognitive impairment

Recent evidence shows that identifying and treating epileptiform abnormalities in patients with Alzheimer's disease could represent a potential avenue to improve clinical outcome. Specifically, animal and human studies have revealed that in the early phase of Alzheimer's disease, there is an increased risk of seizures. It has also been demonstrated that the administration of anti-seizure medications can slow the functional progression of the disease only in patients with EEG signs of cortical hyperexcitability. In addition, although it is not known at what disease stage hyperexcitability emerges, there remains no consensus regarding the imaging and diagnostic methods best able to detect interictal events to further distinguish different phenotypes of Alzheimer's disease. In this exploratory work, we studied 13 subjects with amnestic mild cognitive impairment and 20 healthy controls using overnight high-density EEG with 256 channels. All participants also underwent MRI and neuropsychological assessment. Electronic source reconstruction was also used to better select and localize spikes. We found spikes in six of 13 (46%) amnestic mild cognitive impairment compared with two of 20 (10%) healthy control participants (P = 0.035), representing a spike prevalence similar to that detected in previous studies of patients with early-stage Alzheimer's disease. The interictal events were low-amplitude temporal spikes more prevalent during non-rapid eye movement sleep. No statistically significant differences were found in cognitive performance between amnestic mild cognitive impairment patients with and without spikes, but a trend in immediate and delayed memory was observed. Moreover, no imaging findings of cortical and subcortical atrophy were found between amnestic mild cognitive impairment participants with and without epileptiform spikes. In summary, our exploratory study shows that patients with amnestic mild cognitive impairment reveal EEG signs of hyperexcitability early in the disease course, while no other significant differences in neuropsychological or imaging features were observed among the subgroups. If confirmed with longitudinal data, these exploratory findings could represent one of the first signatures of a preclinical epileptiform phenotype of amnestic mild cognitive impairment and its progression.

T1-/T2-weighted ratio reveals no alterations to gray matter myelination in temporal lobe epilepsy

Short-range functional connectivity in the limbic network is increased in patients with temporal lobe epilepsy (TLE), and recent studies have shown that cortical myelin content correlates with fMRI connectivity. We thus hypothesized that myelin may increase progressively in the epileptic network. We compared T1w/T2w gray matter myelin maps between TLE patients and age-matched controls and assessed relationships between myelin and aging. While both TLE patients and healthy controls exhibited increased T1w/T2w intensity with age, we found no evidence for significant group-level aberrations in overall myelin content or myelin changes through time in TLE.

Association of neighborhood deprivation with white matter connectome abnormalities in temporal lobe epilepsy

OBJECTIVE

Social determinants of health, including the effects of neighborhood disadvantage, impact epilepsy prevalence, treatment, and outcomes. This study characterized the association between aberrant white matter connectivity in temporal lobe epilepsy (TLE) and disadvantage using a US census-based neighborhood disadvantage metric, the Area Deprivation Index (ADI), derived from measures of income, education, employment, and housing quality.

METHODS

Participants including 74 TLE patients (47 male, mean age = 39.2 years) and 45 healthy controls (27 male, mean age = 31.9 years) from the Epilepsy Connectome Project were classified into ADI-defined low and high disadvantage groups. Graph theoretic metrics were applied to multishell connectome diffusion-weighted imaging (DWI) measurements to derive 162 × 162 structural connectivity matrices (SCMs). The SCMs were harmonized using neuroCombat to account for interscanner differences. Threshold-free network-based statistics were used for analysis, and findings were correlated with ADI quintile metrics. A decrease in cross-sectional area (CSA) indicates reduced white matter integrity.

RESULTS

Sex- and age-adjusted CSA in TLE groups was significantly reduced compared to controls regardless of disadvantage status, revealing discrete aberrant white matter tract connectivity abnormalities in addition to apparent differences in graph measures of connectivity and network-based statistics. When comparing broadly defined disadvantaged TLE groups, differences were at trend level. Sensitivity analyses of ADI quintile extremes revealed significantly lower CSA in the most compared to least disadvantaged TLE group.

SIGNIFICANCE

Our findings demonstrate (1) the general impact of TLE on DWI connectome status is larger than the association with neighborhood disadvantage; however, (2) neighborhood disadvantage, indexed by ADI, revealed modest relationships with white matter structure and integrity on sensitivity analysis in TLE. Further studies are needed to explore this relationship and determine whether the white matter relationship with ADI is driven by social drift or environmental influences on brain development. Understanding the etiology and course of the disadvantage-brain integrity relationship may serve to inform care, management, and policy for patients.

Application of data harmonization and tract-based spatial statistics reveals white matter structural abnormalities in pediatric patients with focal cortical dysplasia

Our study assessed diffusion tensor imaging (DTI) metrics of fractional anisotropy (FA), mean diffusivity (MD), and radial diffusivity (RD) in pediatric subjects with epilepsy secondary to Focal Cortical Dysplasia (FCD) to improve our understanding of structural network changes associated with FCD related epilepsy. We utilized a data harmonization (DH) approach to minimize confounding effects induced by MRI protocol differences. We also assessed correlations between DTI metrics and neurocognitive measures of the fluid reasoning index (FRI), verbal comprehension index (VCI), and visuospatial index (VSI). Data (n = 51) from 23 FCD patients and 28 typically developing controls (TD) scanned clinically on either 1.5T, 3T, or 3T-wide-bore MRI were retrospectively analyzed. Tract-based spatial statistics (TBSS) with threshold-free cluster enhancement and permutation testing with 100,000 permutations were used for statistical analysis. To account for imaging protocol differences, we employed non-parametric data harmonization prior to permutation testing. Our analysis demonstrates that DH effectively removed MRI protocol-based differences typical in clinical acquisitions while preserving group differences in DTI metrics between FCD and TD subjects. Furthermore, DH strengthened the association between DTI metrics and neurocognitive indices. Fractional anisotropy, MD, and RD metrics showed stronger correlation with FRI and VSI than VCI. Our results demonstrate that DH is an integral step to reduce the confounding effect of MRI protocol differences during the analysis of white matter tracts and highlights biological differences between FCD and healthy control subjects. Characterization of white matter changes associated with FCD-related epilepsy may better inform prognosis and treatment approaches.

The presence, nature and network characteristics of behavioural phenotypes in temporal lobe epilepsy

The relationship between temporal lobe epilepsy and psychopathology has had a long and contentious history with diverse views regarding the presence, nature and severity of emotional-behavioural problems in this patient population. To address these controversies, we take a new person-centred approach through the application of unsupervised machine learning techniques to identify underlying latent groups or behavioural phenotypes. Addressed are the distinct psychopathological profiles, their linked frequency, patterns and severity and the disruptions in morphological and network properties that underlie the identified latent groups. A total of 114 patients and 83 controls from the Epilepsy Connectome Project were administered the Achenbach System of Empirically Based Assessment inventory from which six Diagnostic and Statistical Manual of Mental Disorders-oriented scales were analysed by unsupervised machine learning analytics to identify latent patient groups. Identified clusters were contrasted to controls as well as to each other in order to characterize their association with sociodemographic, clinical epilepsy and morphological and functional imaging network features. The concurrent validity of the behavioural phenotypes was examined through other measures of behaviour and quality of life. Patients overall exhibited significantly higher (abnormal) scores compared with controls. However, cluster analysis identified three latent groups: (i) unaffected, with no scale elevations compared with controls (Cluster 1, 37%); (ii) mild symptomatology characterized by significant elevations across several Diagnostic and Statistical Manual of Mental Disorders-oriented scales compared with controls (Cluster 2, 42%); and (iii) severe symptomatology with significant elevations across all scales compared with controls and the other temporal lobe epilepsy behaviour phenotype groups (Cluster 3, 21%). Concurrent validity of the behavioural phenotype grouping was demonstrated through identical stepwise links to abnormalities on independent measures including the National Institutes of Health Toolbox Emotion Battery and quality of life metrics. There were significant associations between cluster membership and sociodemographic (handedness and education), cognition (processing speed), clinical epilepsy (presence and lifetime number of tonic-clonic seizures) and neuroimaging characteristics (cortical volume and thickness and global graph theory metrics of morphology and resting-state functional MRI). Increasingly dispersed volumetric abnormalities and widespread disruptions in underlying network properties were associated with the most abnormal behavioural phenotype. Psychopathology in these patients is characterized by a series of discrete latent groups that harbour accompanying sociodemographic, clinical and neuroimaging correlates. The underlying neurobiological patterns suggest that the degree of psychopathology is linked to increasingly dispersed abnormal brain networks. Similar to cognition, machine learning approaches support a novel developing taxonomy of the comorbidities of epilepsy.

Cerebral cortical thickness and cognitive decline in Parkinson's disease

In Parkinson's disease (PD), reduced cerebral cortical thickness may reflect network-based degeneration. This study performed cognitive assessment and brain MRI in 30 PD participants and 41 controls at baseline and 18 months later. We hypothesized that cerebral cortical thickness and volume, as well as change in these metrics, would differ between PD participants who remained cognitively stable and those who experienced cognitive decline. Dividing the participant sample into PD-stable, PD-decline, and control-stable groups, we compared mean cortical thickness and volume within segments that comprise the prefrontal cognitive-control, memory, dorsal spatial, and ventral object-based networks at baseline. We then compared the rate of change in cortical thickness and volume between the same groups using a vertex-wise approach. We found that the PD-decline group had lower cortical thickness within all 4 cognitive networks in comparison with controls, as well as lower cortical thickness within the prefrontal and medial temporal networks in comparison with the PD-stable group. The PD-decline group also experienced a greater rate of volume loss in the lateral temporal cortices in comparison with the control group. This study suggests that lower thickness and volume in prefrontal, medial, and lateral temporal regions may portend cognitive decline in PD.

Behavioral phenotypes of temporal lobe epilepsy

Objective

To identity phenotypes of self‐reported symptoms of psychopathology and their correlates in patients with temporal lobe epilepsy (TLE).

Method

96 patients with TLE and 82 controls were administered the Symptom Checklist 90‐Revised (SCL‐90‐R) to characterize emotional‐behavioral status. The nine symptom scales of the SCL‐90‐R were analyzed by unsupervised machine learning techniques to identify latent TLE groups. Identified clusters were contrasted to controls to characterize their association with sociodemographic, clinical epilepsy, neuropsychological, psychiatric, and neuroimaging factors.

Results

TLE patients as a group exhibited significantly higher (abnormal) scores across all SCL‐90‐R scales compared to controls. However, cluster analysis identified three latent groups: (1) unimpaired with no scale elevations compared to controls (Cluster 1, 42% of TLE patients), (2) mild‐to‐moderate symptomatology characterized by significant elevations across several SCL‐90‐R scales compared to controls (Cluster 2, 35% of TLE patients), and (3) marked symptomatology with significant elevations across all scales compared to controls and the other TLE phenotype groups (Cluster 3, 23% of TLE patients). There were significant associations between cluster membership and demographic (education), clinical epilepsy (perceived seizure severity, bitemporal lobe seizure onset), and neuropsychological status (intelligence, memory, executive function), but with minimal structural neuroimaging correlates. Concurrent validity of the behavioral phenotype grouping was demonstrated through association with psychiatric (current and lifetime‐to‐date DSM IV Axis 1 disorders and current treatment) and quality‐of‐life variables.

Significance

Symptoms of psychopathology in patients with TLE are characterized by a series of discrete phenotypes with accompanying sociodemographic, cognitive, and clinical correlates. Similar to cognition in TLE, machine learning approaches suggest a developing taxonomy of the comorbidities of epilepsy.

Network, clinical and sociodemographic features of cognitive phenotypes in temporal lobe epilepsy

This study explored the taxonomy of cognitive impairment within temporal lobe epilepsy and characterized the sociodemographic, clinical and neurobiological correlates of identified cognitive phenotypes. 111 temporal lobe epilepsy patients and 83 controls (mean ages 33 and 39, 57% and 61% female, respectively) from the Epilepsy Connectome Project underwent neuropsychological assessment, clinical interview, and high resolution 3T structural and resting-state functional MRI. A comprehensive neuropsychological test battery was reduced to core cognitive domains (language, memory, executive, visuospatial, motor speed) which were then subjected to cluster analysis. The resulting cognitive subgroups were compared in regard to sociodemographic and clinical epilepsy characteristics as well as variations in brain structure and functional connectivity. Three cognitive subgroups were identified (intact, language/memory/executive function impairment, generalized impairment) which differed significantly, in a systematic fashion, across multiple features. The generalized impairment group was characterized by an earlier age at medication initiation (P < 0.05), fewer patient (P < 0.001) and parental years of education (P < 0.05), greater racial diversity (P < 0.05), and greater number of lifetime generalized seizures (P < 0.001). The three groups also differed in an orderly manner across total intracranial (P < 0.001) and bilateral cerebellar cortex volumes (P < 0.01), and rate of bilateral hippocampal atrophy (P < 0.014), but minimally in regional measures of cortical volume or thickness. In contrast, large-scale patterns of cortical-subcortical covariance networks revealed significant differences across groups in global and local measures of community structure and distribution of hubs. Resting-state fMRI revealed stepwise anomalies as a function of cluster membership, with the most abnormal patterns of connectivity evident in the generalized impairment group and no significant differences from controls in the cognitively intact group. Overall, the distinct underlying cognitive phenotypes of temporal lobe epilepsy harbor systematic relationships with clinical, sociodemographic and neuroimaging correlates. Cognitive phenotype variations in patient and familial education and ethnicity, with linked variations in total intracranial volume, raise the question of an early and persisting socioeconomic-status related neurodevelopmental impact, with additional contributions of clinical epilepsy factors (e.g., lifetime generalized seizures). The neuroimaging features of cognitive phenotype membership are most notable for disrupted large scale cortical-subcortical networks and patterns of functional connectivity with bilateral hippocampal and cerebellar atrophy. The cognitive taxonomy of temporal lobe epilepsy appears influenced by features that reflect the combined influence of socioeconomic, neurodevelopmental and neurobiological risk factors.

Behavioral phenotypes of childhood idiopathic epilepsies

OBJECTIVE

To characterize the presence and nature of discrete behavioral phenotypes and their correlates in a cohort of youth with new and recent onset focal and generalized epilepsies.

METHODS

The parents of 290 youth (age = 8-18 years) with epilepsy (n = 183) and typically developing participants (n = 107) completed the Child Behavior Checklist for children aged 6-18 from the Achenbach System of Empirically Based Assessment. The eight behavior problem scales were subjected to hierarchical clustering analytics to identify behavioral subgroups. To characterize the external validity and co-occurring comorbidities of the identified subgroups, we examined demographic features (age, gender, handedness), cognition (language, perception, attention, executive function, speed), academic problems (present/absent), clinical epilepsy characteristics (epilepsy syndrome, medications), familial factors (parental intelligence quotient, education, employment), neuroimaging features (cortical thickness), parent-observed day-to-day executive function, and number of lifetime-to-date Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) diagnoses.

RESULTS

Hierarchical clustering identified three behavioral phenotypes, which included no behavioral complications (Cluster 1, 67% of epilepsy cohort [n = 122]), nonexternalizing problems (Cluster 2, 11% of cohort [n = 21]), and combined internalizing and externalizing problems (Cluster 3, 22% of cohort [n = 40]). These behavioral phenotypes were characterized by orderly differences in personal characteristics, neuropsychological status, history of academic problems, parental status, cortical thickness, daily executive function, and number of lifetime-to-date DSM-IV diagnoses. Cluster 1 was most similar to controls across most metrics, whereas Cluster 3 was the most abnormal compared to controls. Epilepsy syndrome was not a predictor of cluster membership.

SIGNIFICANCE

Youth with new and recent onset epilepsy fall into three distinct behavioral phenotypes associated with a variety of co-occurring features and comorbidities. This approach identifies important phenotypes of behavior problem presentations and their accompanying factors that serve to advance clinical and theoretical understanding of the behavioral complications of children with epilepsy and the complex conditions with which they co-occur.

Brain aging in temporal lobe epilepsy: Chronological, structural, and functional

The association of epilepsy with structural brain changes and cognitive abnormalities in midlife has raised concern regarding the possibility of future accelerated brain and cognitive aging and increased risk of later life neurocognitive disorders. To address this issue we examined age-related processes in both structural and functional neuroimaging among individuals with temporal lobe epilepsy (TLE, N = 104) who were participants in the Epilepsy Connectome Project (ECP). Support vector regression (SVR) models were trained from 151 healthy controls and used to predict TLE patients' brain ages. It was found that TLE patients on average have both older structural (+6.6 years) and functional (+8.3 years) brain ages compared to healthy controls. Accelerated functional brain age (functional - chronological age) was mildly correlated (corrected P = 0.07) with complex partial seizure frequency and the number of anti-epileptic drug intake. Functional brain age was a significant correlate of declining cognition (fluid abilities) and partially mediated chronological age-fluid cognition relationships. Chronological age was the only positive predictor of crystallized cognition. Accelerated aging is evident not only in the structural brains of patients with TLE, but also in their functional brains. Understanding the causes of accelerated brain aging in TLE will be clinically important in order to potentially prevent or mitigate their cognitive deficits.

Network analysis of prospective brain development in youth with benign epilepsy with centrotemporal spikes and its relationship to cognition

OBJECTIVE

Benign epilepsy with centrotemporal spikes (BECTS) is the most common childhood idiopathic localization-related epilepsy syndrome. BECTS presents normal routine magnetic resonance imaging (MRI); however, quantitative analytic techniques have captured subtle cortical and subcortical magnetic resonance anomalies. Network science, including graph theory (GT) analyses, facilitates understanding of brain covariance patterns, potentially informing in important ways how this common self-limiting epilepsy syndrome may impact normal patterns of brain and cognitive development.

METHODS

GT analyses examined the developmental covariance among cortical and subcortical regions in children with new/recent onset BECTS (n = 19) and typically developing healthy controls (n = 22) who underwent high-resolution MRI and cognitive assessment at baseline and 2 years later. Global (transitivity, global efficiency, and modularity index [Q]) and regional measures (local efficiency and hubs) were investigated to characterize network development in each group. Associations between baseline-based GT measures and cognition at both time points addressed the implications of GT analyses for cognition and prospective cognitive development. Furthermore, an individual contribution measure was investigated, reflecting how important for cognition it is for BECTS to resemble the correlation matrices of controls.

RESULTS

Groups exhibited similar Q and overall network configuration, with BECTS presenting significantly higher transitivity and both global and local efficiency. Furthermore, both groups presented a similar number of hubs, with BECTS showing a higher number in temporal lobe regions compared to controls. The investigated measures were negatively associated with 2-year cognitive outcomes in BECTS.

SIGNIFICANCE

Children with BECTS present a higher-than-normal global developmental configuration compared to controls, along with divergence from normality in terms of regional configuration. Baseline GT measures demonstrate potential as a cognitive biomarker to predict cognitive outcome in BECTS 2 years after diagnosis. Similarities and differences in developmental network configurations and their implications for cognition and behavior across common epilepsy syndromes are of theoretical interest and clinical relevance.

Cognitive slowing and its underlying neurobiology in temporal lobe epilepsy

Cognitive slowing is a known but comparatively under-investigated neuropsychological complication of the epilepsies in relation to other known cognitive comorbidities such as memory, executive function and language. Here we focus on a novel metric of processing speed, characterize its relative salience compared to other cognitive difficulties in epilepsy, and explore its underlying neurobiological correlates. Research participants included 55 patients with temporal lobe epilepsy (TLE) and 58 healthy controls from the Epilepsy Connectome Project (ECP) who were administered a battery of tests yielding 14 neuropsychological measures, including selected tests from the NIH Toolbox-Cognitive Battery, and underwent 3T MRI and resting state fMRI. TLE patients exhibited a pattern of generalized cognitive impairment with very few lateralized abnormalities. Using the neuropsychological measures, machine learning (Support Vector Machine binary classification model) classified the TLE and control groups with 74% accuracy with processing speed (NIH Toolbox Pattern Comparison Processing Speed Test) the best predictor. In TLE, slower processing speed was associated predominantly with decreased local gyrification in regions including the rostral and caudal middle frontal gyrus, inferior precentral cortex, insula, inferior parietal cortex (angular and supramarginal gyri), lateral occipital cortex, rostral anterior cingulate, and medial orbital frontal regions, as well as three small regions of the temporal lobe. Slower processing speed was also associated with decreased connectivity between the primary visual cortices in both hemispheres and the left supplementary motor area, as well as between the right parieto-occipital sulcus and right middle insular area. Overall, slowed processing speed is an important cognitive comorbidity of TLE associated with altered brain structure and connectivity.

Progressive dissociation of cortical and subcortical network development in children with new-onset juvenile myoclonic epilepsy

OBJECTIVE

Structural and functional magnetic resonance imaging (MRI) studies have consistently documented cortical and subcortical abnormalities in patients with juvenile myoclonic epilepsy (JME). However, little is known about how these structural abnormalities emerge from the time of epilepsy onset and how network interactions between and within cortical and subcortical regions may diverge in youth with JME compared to typically developing children.

METHODS

We examined prospective covariations of volumetric differences derived from high-resolution structural MRI during the first 2 years of epilepsy diagnosis in a group of youth with JME (n = 21) compared to healthy controls (n = 22). We indexed developmental brain changes using graph theory by computing network metrics based on the correlation of the cortical and subcortical structural covariance near the time of epilepsy and 2 years later.

RESULTS

Over 2 years, normally developing children showed modular cortical development and network integration between cortical and subcortical regions. In contrast, children with JME developed a highly correlated and less modular cortical network, which was atypically dissociated from subcortical structures. Furthermore, the JME group also presented higher clustering and lower modularity indices than controls, indicating weaker modules or communities. The local efficiency in JME was higher than controls across the majority of cortical nodes. Regarding network hubs, controls presented a higher number than youth with JME that were spread across the brain with ample representation from the different modules. In contrast, children with JME showed a lower number of hubs that were mainly from one module and comprised mostly subcortical structures.

SIGNIFICANCE

Youth with JME prospectively developed a network of highly correlated cortical regions dissociated from subcortical structures during the first 2 years after epilepsy onset. The cortical-subcortical network dissociation provides converging insights into the disparate literature of cortical and subcortical abnormalities found in previous studies.

Psychomotor slowing is associated with anomalies in baseline and prospective large scale neural networks in youth with epilepsy

Purpose

Psychomotor slowing is a common but understudied cognitive impairment in epilepsy. Here we test the hypothesis that psychomotor slowing is associated with alterations in brain status reflected through analysis of large scale structural networks. We test the hypothesis that children with epilepsy with cognitive slowing at diagnosis will exhibit a cross-sectional and prospective pattern of altered brain development.

Methods

A total of 78 children (age 8–18) with new/recent onset idiopathic epilepsies underwent 1.5 T MRI with network analysis of cortical, subcortical and cerebellar volumes. Children with epilepsy were divided into slow and fast psychomotor speed groups (adjusted for age, intelligence and epilepsy syndrome).

Results

At baseline, slow-speed performers (SSP) presented lower modularity, lower global efficiency, higher transitivity, and lower number of hubs than fast-speed performers (FSP). Community structure in SSP exhibited poor association between cortical regions and both subcortical structures and the cerebellum while FSP presented well-defined communities. Prospectively, SSP displayed lower modularity but higher global efficiency and transitivity compared to FSP. Modules in FSP showed higher integration between and within themselves compared to SSP. SSP showed hubs mainly from frontal and temporal regions while in FSP were spread among frontal, temporal, parietal, subcortical areas and the left cerebellum.

Implications

Results suggest the presence of widespread alterations in large scale networks between fast- and slow-speed children with recent onset epilepsies both at baseline and 2 years later. Slower processing speed appears to be a marker of abnormal brain development antecedent to epilepsy onset as well as brain development over the 2 years following diagnosis.

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Baseline: slow-speed performers (SSP) showed lower modularity and global efficiency

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They also showed higher transitivity but fewer hubs than fast-speed performers (FSP)

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Prospective: SSP showed lower modularity, harmonic mean and higher transitivity

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Regional volume changes seem to be occurring as one in SSP, but more modular in FSP

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SSP showed hubs mainly from frontal and temporal while FSP showed them widespread

Brain structure and organization five decades after childhood onset epilepsy

The purpose of this project was to characterize brain structure and organization in persons with active and remitted childhood onset epilepsy 50 years after diagnosis compared with healthy controls. Participants from a population-based investigation of uncomplicated childhood onset epilepsy were followed up 5 decades later. Forty-one participants had a history of childhood onset epilepsy (mean age of onset = 5.2 years, current chronological age = 56.0 years) and were compared with 48 population-based controls (mean age = 55.9 years). Of the epilepsy participants, 8 had persisting active epilepsy and in 33 the epilepsy had remitted. All participants underwent 3T MRI with subsequent vertex analysis of cortical volume, thickness, surface area and gyral complexity. In addition, cortical and subcortical volumes, including regions of the frontal, parietal, temporal, and occipital lobes, and subcortical structures including amygdala, thalamus, and hippocampus, were analyzed using graph theory techniques. There were modest group differences in traditional vertex-based analyses of cortical volume, thickness, surface area and gyral index, as well as across volumes of subcortical structures, after correction for multiple comparisons. Graph theory analyses revealed suboptimal topological structural organization with enhanced network segregation and reduced global integration in the epilepsy participants compared with controls, these patterns significantly more extreme in the active epilepsy group. Furthermore, both groups with epilepsy presented a greater number of higher Z-score regions in betweenness centrality (BC) than lower Z-score regions compared with controls. Also, contrary to the group with remitted epilepsy, patients with active epilepsy presented most of their high BC Z-score regions in subcortical areas including the amygdala, thalamus, hippocampus, pallidum, and accumbens. Overall, this population-based investigation of long term outcome (5 decades) of childhood onset epilepsy reveals persisting abnormalities, especially when examined by graph theoretical measurements, and provides new insights into the very long-term outcomes of active and remitted epilepsy. Hum Brain Mapp 38:3289-3299, 2017. © 2017 Wiley Periodicals, Inc.

Cognition and brain development in children with benign epilepsy with centrotemporal spikes

OBJECTIVE

Benign epilepsy with centrotemporal spikes (BECTS), the most common focal childhood epilepsy, is associated with subtle abnormalities in cognition and possible developmental alterations in brain structure when compared to healthy participants, as indicated by previous cross-sectional studies. To examine the natural history of BECTS, we investigated cognition, cortical thickness, and subcortical volumes in children with new/recent onset BECTS and healthy controls (HC).

METHODS

Participants were 8-15 years of age, including 24 children with new-onset BECTS and 41 age- and gender-matched HC. At baseline and 2 years later, all participants completed a cognitive assessment, and a subset (13 BECTS, 24 HC) underwent T1 volumetric magnetic resonance imaging (MRI) scans focusing on cortical thickness and subcortical volumes.

RESULTS

Baseline cognitive abnormalities associated with BECTS (object naming, verbal learning, arithmetic computation, and psychomotor speed/dexterity) persisted over 2 years, with the rate of cognitive development paralleling that of HC. Baseline neuroimaging revealed thinner cortex in BECTS compared to controls in frontal, temporal, and occipital regions. Longitudinally, HC showed widespread cortical thinning in both hemispheres, whereas BECTS participants showed sparse regions of both cortical thinning and thickening. Analyses of subcortical volumes showed larger left and right putamens persisting over 2 years in BECTS compared to HC.

SIGNIFICANCE

Cognitive and structural brain abnormalities associated with BECTS are present at onset and persist (cognition) and/or evolve (brain structure) over time. Atypical maturation of cortical thickness antecedent to BECTS onset results in early identified abnormalities that continue to develop abnormally over time. However, compared to anatomic development, cognition appears more resistant to further change over time.

Correlation of EEG with neuropsychological status in children with epilepsy

OBJECTIVE

To determine correlations of the EEG frequency spectrum with neuropsychological status in children with idiopathic epilepsy.

METHODS

Forty-six children ages 8-18 years old with idiopathic epilepsy were retrospectively identified and analyzed for correlations between EEG spectra and neuropsychological status using multivariate linear regression. In addition, the theta/beta ratio, which has been suggested as a clinically useful EEG marker of attention-deficit hyperactivity disorder (ADHD), and an EEG spike count were calculated for each subject.

RESULTS

Neuropsychological status was highly correlated with posterior alpha (8-15 Hz) EEG activity in a complex way, with both positive and negative correlations at lower and higher alpha frequency sub-bands for each cognitive task in a pattern that depends on the specific cognitive task. In addition, the theta/beta ratio was a specific but insensitive indicator of ADHD status in children with epilepsy; most children both with and without epilepsy have normal theta/beta ratios. The spike count showed no correlations with neuropsychological status.

CONCLUSIONS

(1) The alpha rhythm may have at least two sub-bands which serve different purposes. (2) The theta/beta ratio is not a sensitive indicator of ADHD status in children with epilepsy. (3) The EEG frequency spectrum correlates more robustly with neuropsychological status than spike count analysis in children with idiopathic epilepsy.

SIGNIFICANCE

(1) The role of posterior alpha rhythms in cognition is complex and can be overlooked if EEG spectral resolution is too coarse or if neuropsychological status is assessed too narrowly. (2) ADHD in children with idiopathic epilepsy may involve different mechanisms from those in children without epilepsy. (3) Reliable correlations with neuropsychological status require longer EEG samples when using spike count analysis than when using frequency spectra.

Survival in stage I-III breast cancer patients by surgical treatment in a publicly funded health care system

BACKGROUND

Recent investigations of breast cancer survival in the United States suggest that patients who receive mastectomy have poorer survival than those who receive breast-conserving surgery (BCS) plus radiotherapy, despite clinically established equivalence. This study investigates breast cancer survival in the publicly funded health care system present in Alberta, Canada.

PATIENTS AND METHODS

Surgically treated stage I-III breast cancer cases diagnosed in Alberta from 2002 to 2010 were included. Demographic, treatment and mortality information were collected from the Alberta Cancer Registry. Unadjusted overall and breast cancer-specific mortality was assessed using Kaplan-Meier and cumulative incidence curves, respectively. Cox proportional hazards models were used to calculate stage-specific mortality hazard estimates associated with surgical treatment received.

RESULTS

A total of 14 939 cases of breast cancer (14 633 patients) were included in this study. The unadjusted 5-year all-cause survival probabilities for patients treated with BCS plus radiotherapy, mastectomy, and BCS alone were 94% (95% CI 93% to 95%), 83% (95% CI 82% to 84%) and 74% (95% CI 70% to 78%), respectively. Stage II and III patients who received mastectomy had a higher all-cause (stage II HR = 1.36, 95% CI 1.13-1.48; stage III HR = 1.74, 95% CI 1.24-2.45) and breast cancer-specific (stage II HR = 1.39, 95% CI 1.09-1.76; stage III HR = 1.79, 95% CI 1.21-2.65) mortality hazard compared with those who received BCS plus radiotherapy, adjusting for patient and clinical characteristics. BCS alone was consistently associated with poor survival.

CONCLUSIONS

Stage II and III breast cancer patients diagnosed in Alberta, Canada, who received mastectomy had a significantly higher all-cause and breast cancer-specific mortality hazard compared with those who received BCS plus radiotherapy. We suggest greater efforts toward educating and encouraging patients to receive BCS plus radiotherapy rather than mastectomy when it is medically feasible and appropriate.

Children with epilepsy and anxiety: Subcortical and cortical differences

OBJECTIVE

Using a hypothesis-driven approach, subcortical and cortical regions implicated in anxiety disorders in the general population were examined in children with recent-onset epilepsy with versus without anxiety compared to controls. This study reports frequency of anxiety disorders while examining familial, clinical, and demographic variables associated with anxiety in children with epilepsy.

METHOD

Participants included 88 children with epilepsy aged 8-18 years: 25 with a current anxiety disorder and 63 children with epilepsy and no current anxiety disorder. Forty-nine controls without anxiety disorders were included. T1 volumetric magnetic resonance imaging (MRI) scans were collected; subcortical volumes and cortical thickness were computed using the FreeSurfer image analysis suite. Analyses focused on adjusted measures of subcortical volumes and cortical thickness.

RESULTS

Relative to controls, larger left amygdala volumes were found in the Epilepsy with Anxiety group compared to the Epilepsy without Anxiety group (p = 0.027). In the hippocampus, there were no significant differences between groups. Examination of cortical thickness demonstrated that the Epilepsy with Anxiety group showed thinning in left medial orbitofrontal (p = 0.001), right lateral orbitofrontal (p = 0.017), and right frontal pole (p = 0.009). There were no differences between groups in age, sex, IQ, age of onset, medications, or duration of epilepsy. There were more family members with a history of anxiety disorders in the Epilepsy with Anxiety group compared to the Epilepsy without Anxiety group (p = 0.005).

SIGNIFICANCE

Anxiety is a common psychiatric comorbidity in children with recent-onset epilepsy with volumetric enlargement of the amygdala and thinner cortex in orbital and other regions of prefrontal cortex, suggesting structural abnormalities in brain regions that are part of the dysfunctional networks reported in individuals with anxiety disorders in the general population. These findings are evident early in the course of epilepsy, are not related to chronicity of seizures, and may be linked to a family history of anxiety and depressive disorders.

Neurodevelopment in new-onset juvenile myoclonic epilepsy over the first 2 years

OBJECTIVE

Adults with juvenile myoclonic epilepsy (JME) have subtle brain structural abnormalities in the frontothalamocortical network, poorer cognitive function, and worse long-term social outcomes, even when their seizures are controlled and/or remitted. The natural history of JME and development of abnormalities in brain structure and cognition from epilepsy onset has not been studied.

METHODS

The maturational trajectories of cognitive and brain development were prospectively compared between 19 children with new-onset JME in the first 2 years after diagnosis and 57 healthy controls.

RESULTS

Cognitive abilities of children with JME were similar to or worse than healthy controls at baseline but failed to reach the competence level of healthy controls at follow-up across most of the tested cognitive abilities. Abnormal patterns of brain development, as assessed by magnetic resonance imaging studies, were evident in children with JME and included attenuation of age-related decline in cortical volume, thickness, and surface area compared to typically developing children. The altered brain developmental trajectory in the JME group was evident in higher-association frontoparietotemporal brain regions (p < 0.05, corrected for multiple comparisons).

INTERPRETATION

Children with JME have abnormal structural brain development and impaired cognitive development early in the course of their epilepsy.

Brain morphology in children with epilepsy and ADHD

Background

Attention deficit hyperactivity disorder (ADHD) is a common comorbidity of childhood epilepsy, but the neuroanatomical correlates of ADHD in epilepsy have yet to be comprehensively characterized.

Methods

Children with new and recent-onset epilepsy with (n = 18) and without (n = 36) ADHD, and healthy controls (n = 46) underwent high resolution MRI. Measures of cortical morphology (thickness, area, volume, curvature) and subcortical and cerebellar volumes were compared between the groups using the program FreeSurfer 5.1.

Results

Compared to the control group, children with epilepsy and ADHD exhibited diffuse bilateral thinning in the frontal, parietal and temporal lobes, with volume reductions in the brainstem and subcortical structures (bilateral caudate, left thalamus, right hippocampus). There were very few group differences across measures of cortical volume, area or curvature.

Conclusions

Children with epilepsy and comorbid ADHD exhibited a pattern of bilateral and widespread decreased cortical thickness as well as decreased volume of subcortical structures and brainstem. These anatomic abnormalities were evident early in the course of epilepsy suggesting the presence of antecedent neurodevelopmental changes, the course of which remains to be determined.

Neurodevelopmental alterations of large-scale structural networks in children with new-onset epilepsy

Recent neuroimaging and behavioral studies have revealed that children with new onset epilepsy already exhibit brain structural abnormalities and cognitive impairment. How the organization of large-scale brain structural networks is altered near the time of seizure onset and whether network changes are related to cognitive performances remain unclear. Recent studies also suggest that regional brain volume covariance reflects synchronized brain developmental changes. Here, we test the hypothesis that epilepsy during early-life is associated with abnormalities in brain network organization and cognition. We used graph theory to study structural brain networks based on regional volume covariance in 39 children with new-onset seizures and 28 healthy controls. Children with new-onset epilepsy showed a suboptimal topological structural organization with enhanced network segregation and reduced global integration compared with controls. At the regional level, structural reorganization was evident with redistributed nodes from the posterior to more anterior head regions. The epileptic brain network was more vulnerable to targeted but not random attacks. Finally, a subgroup of children with epilepsy, namely those with lower IQ and poorer executive function, had a reduced balance between network segregation and integration. Taken together, the findings suggest that the neurodevelopmental impact of new onset childhood epilepsies alters large-scale brain networks, resulting in greater vulnerability to network failure and cognitive impairment.

Patterns of cortical thickness and the Child Behavior Checklist in childhood epilepsy

The purpose of this investigation was to characterize the neuroanatomical correlates (cortical thickness) of variations in parent-reported Child Behavior Checklist (CBCL) scores. Ninety children with epilepsy (aged 8-18) underwent brain MRI, and their parents completed the CBCL. FreeSurfer-derived measures of cortical thickness were examined in relation to the CBCL broad and narrow band competence and behavioral problem scales, as well as the newer DSM-oriented scales. Parent reports of higher (better) social competence skills were associated with increased cortical thickness, especially in frontal regions. Parent reports of behavioral problems were associated with patterns of decreased cortical thickness that varied as a function of the specific behavioral issue under investigation. Congruence of patterns of cortical thinning between the DSM-oriented scales and conceptually related specific problem scales (e.g., ADHD Problems and Attention Problems) was generally weak. The parent-report version of the CBCL is associated with variations in cortical thickness among children with epilepsy. Anatomic abnormalities specific to selected competence and behavioral problem scales can be identified, with more reliable and robust patterns of thinning across scales assessing externalizing behaviors, with generally less prominent findings on scales assessing internalizing behaviors.

Cerebral white matter integrity in children with active versus remitted epilepsy 5 years after diagnosis

INTRODUCTION

Diffusion tensor imaging (DTI) studies have reported white matter abnormalities in childhood-onset epilepsy, but the mechanisms and timing underlying these abnormalities, and their resolution, are not well understood. This study examined white matter integrity in children with active versus remitted epilepsy.

METHODS

Tract-based spatial statistics (TBSS) was used to examine whole-brain DTI indices of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) in 20 children with epilepsy 5-6 years after diagnosis, compared to 29 healthy controls. To determine the status of white matter following cessation of seizures, participants with epilepsy were classified as active versus remitted and comparisons included: (1) controls versus all children with epilepsy, (2) controls versus children with remitted seizures, (3) controls versus children with active seizures, and (4) children with active versus remitted epilepsy.

RESULTS

In the active compared to remitted epilepsy group, significantly higher FA and lower MD, AD and RD values were dispersed in the internal capsule, cingulum, body of the corpus callosum, superior corona radiata and superior fronto-occipital fasciculus. Similar differences were found between the active epilepsy and the control group. There were no significant differences between the remitted epilepsy and control groups.

CONCLUSION

Children with active epilepsy differed in white matter integrity compared to children with remitted epilepsy and healthy controls. It remains to be determined whether these findings represent the outcomes of seizure remission versus an initial biomarker for those children who will ultimately have intractable epilepsy.

The neuropsychological and academic substrate of new/recent-onset epilepsies

OBJECTIVE

To characterize neuropsychological and academic status in children, ages 8-18 years, with new-/recent-onset idiopathic generalized epilepsy (IGE) and idiopathic localization-related epilepsy (ILRE) compared with healthy controls.

STUDY DESIGN

Participants underwent neuropsychological assessment, and parents were interviewed regarding their child's academic history. Cognitive scores for children with epilepsy were age- and sex-adjusted and compared with controls across both broad-band (IGE n = 41 and ILRE n = 53) and narrow-band (childhood/juvenile absence, juvenile myoclonic, benign epilepsy with centro-temporal spikes, and focal [temporal/frontal/not otherwise specified]) syndromes. Academic histories were examined, including problems antecedent to epilepsy onset and diagnosis.

RESULTS

Children with new/recent-onset epilepsies exhibit considerable cognitive abnormality at baseline, including patterns of shared abnormalities across syndromes (eg, psychomotor slowing) as well as unique syndrome-specific cognitive effects (eg, executive function in IGE and language/verbal memory in ILRE) that are observed and sometimes exacerbated in specific IGE and ILRE syndromes. Academic difficulties are evident in approximately 50% of the children with epilepsy, affecting all syndrome groups to an equal degree.

DISCUSSION

Patterns of shared and syndrome-specific cognitive abnormalities and academic problems are present early in the course of virtually all epilepsy syndromes examined here, including syndromes classically viewed as benign. This is the base upon which the effects of recurrent seizures, treatment, and psychosocial effects will be added over time.

Is lower IQ in children with epilepsy due to lower parental IQ? A controlled comparison study

AIM

The aim of this study was to determine the relationship between parent and child Full-scale IQ (FSIQ) in children with epilepsy and in typically developing comparison children and to examine parent-child IQ differences by epilepsy characteristics.

METHOD

The study participants were 97 children (50 males, 47 females; age range 8-18y; mean age 12y 3mo, SD 3y1mo) with recent-onset epilepsy including idiopathic generalized (n=43) and idiopathic localization-related epilepsies (n=54); 69 healthy comparison children (38 females, 31 males; age range 8-18y; mean age 12y 8mo, SD 3y 2mo), and one biological parent per child. All participants were administered the Wechsler Abbreviated Scale of Intelligence (WASI). FSIQ was compared in children with epilepsy and typically developing children; FSIQ was compared in the parents of typically developing children and the parents of participants with epilepsy; parent-child FSIQ differences were compared between the groups.

RESULTS

FSIQ was lower in children with epilepsy than in comparison children (p<0.001). FSIQ of parents of children with epilepsy did not differ from the FSIQ of the parents of typically developing children. Children with epilepsy had significantly lower FSIQ than their parents (p<0.001), whereas comparison children did not. The parent-child IQ difference was significantly higher in the group with epilepsy than the comparison group (p=0.043). Epilepsy characteristics were not related to parent-child IQ difference.

INTERPRETATION

Parent-child IQ difference appears to be a marker of epilepsy impact independent of familial IQ, epilepsy syndrome, and clinical seizure features. This marker is evident early in the course of idiopathic epilepsies and can be tracked over time.

Brain structure and aging in chronic temporal lobe epilepsy

PURPOSE

To characterize differences in brain structure and their patterns of age-related change in individuals with chronic childhood/adolescent onset temporal lobe epilepsy compared with healthy controls.

METHODS

Subjects included participants with chronic temporal lobe epilepsy (n = 55) of mean childhood/adolescent onset and healthy controls (n = 53), age 14-60 years. Brain magnetic resonance imaging (MRI) studies (1.5 T) were processed using FreeSurfer to obtain measures of lobar thickness, area, and volume as well as volumes of diverse subcortical structures and cerebellum. Group differences were explored followed by cross-sectional lifespan modeling as a function of age.

KEY FINDINGS

Anatomic abnormalities were extensive in participants with chronic temporal lobe epilepsy including distributed subcortical structures (hippocampus, thalamus, caudate, and pallidum), cerebellar gray and white matter, total cerebral gray and white matter; and measures of cortical gray matter thickness, area, or volume in temporal (medial, lateral) and extratemporal lobes (frontal, parietal). Increasing chronologic age was associated with progressive changes in diverse cortical, subcortical, and cerebellar regions for both participants with epilepsy and controls. Age-accelerated changes in epilepsy participants were seen in selected areas (third and lateral ventricles), with largely comparable patterns of age-related change across other regions of interest.

SIGNIFICANCE

Extensive cortical, subcortical, and cerebellar abnormalities are present in participants with mean chronic childhood/adolescent onset temporal lobe epilepsy implicating a significant neurodevelopmental impact on brain structure. With increasing chronologic age, the brain changes occurring in epilepsy appear to proceed in a largely age-appropriate fashion compared to healthy controls, the primary exception being age-accelerated ventricular expansion (lateral and third ventricles). These cumulative structural abnormalities appear to represent a significant anatomic burden for persons with epilepsy, the consequences of which remain to be determined as they progress into elder years.

Striatal hypertrophy and its cognitive effects in new-onset benign epilepsy with centrotemporal spikes

PURPOSE

Benign epilepsy with centrotemporal spikes (BECTS), the most common childhood epilepsy syndrome, is a neurodevelopmental disorder with a genetic influence. Despite its signature electroencephalographic pattern and distinct focal motor seizure semiology, little is known about the underlying brain anatomic alteration and the corresponding cognitive consequences. Given the motor manifestations of seizures in BECTS, we hypothesize that anatomic networks in BECTS involve a distributed corticostriatal circuit.

METHODS

We investigated volumetric differences and shape deformities of caudate, putamen, pallidum, and thalamus in a group of children with new- and recent-onset BECTS (N =  3) compared to healthy controls (N = 54). We correlated specific subcortical volumes in BECTS that were significantly different from those in healthy controls with performances in executive function.

KEY FINDINGS

Children with BECTS demonstrated significantly hypertrophied putamen, which was selective among the subcortical regions examined. Shape analysis showed dorsoventral elongation of the left caudate and bilateral putamen, with subnuclei expansion in ventral and dorsal striatum. Larger putamen volumes were linked to better cognitive performances on two complementary executive function tests.

SIGNIFICANCE

Children with BECTS showed aberrant volume and shape in subcortical regions that are critical for both motor processing and executive function. It is of importance to note that the hypertrophy appears to be cognitively adaptive, as enlargement was associated with improved cognitive performances. The anatomic abnormalities and their cognitive effects are evident in a group of children with new- and recent-onset epilepsy, suggesting that the structural brain anomalies occurred before the diagnosis of epilepsy.

Ventricular enlargement in new-onset pediatric epilepsies

PURPOSE

To examine baseline and prospective (2-year) changes in third, fourth, and lateral ventricle volumes in children with new-onset idiopathic epilepsies and controls (age 8-18 years).

METHODS

Structural magnetic resonance imaging (MRI) were collected from children with idiopathic generalized epilepsy (IGE, n = 29), idiopathic localization-related epilepsy (ILRE, n = 30), and healthy controls (HCs, n = 49). Volumes of the third, fourth, and lateral ventricles were derived and compared across groups, followed by shape analyses, to identify specific regions of ventricular abnormality. Of the initial cohort, a consecutive sample of 71 children returned 2 years later for reimaging and determination of progressive changes in the ventricular system.

KEY FINDINGS

At baseline, children with new-onset IGE had significantly larger lateral and third ventricle volumes relative to the HC group. In addition, lateral ventricle enlargement in IGE was significantly greater compared to new-onset ILRE. Shape analysis of the lateral ventricles revealed that volume expansion in IGE was selective for the anterior horn, a region surrounded by the lateral and medial frontal lobes as well as basal ganglia. These abnormalities did not progress over a 2-year interval.

SIGNIFICANCE

Abnormalities in brain development prior to onset and diagnosis of epilepsy are evident and reflected in expansion of the ventricular system, especially among children with IGE. These abnormalities appear to represent an antecedent and possibly static finding given the lack of progressive ventricular expansion over the 2-year interval following diagnosis and treatment.

Deformation-based morphometry of prospective neurodevelopmental changes in new onset paediatric epilepsy

Epilepsy is a prevalent childhood neurological disorder, but there are few prospective quantitative magnetic resonance imaging studies examining patterns of brain development compared to healthy controls. Controlled prospective investigations initiated at or near epilepsy onset would best characterize the nature, timing and course of neuroimaging abnormalities in paediatric epilepsy. In this study, we report the results of a deformation-based morphometry technique to examine baseline and 2-year prospective neurodevelopmental brain changes in children with new and recent onset localization-related epilepsies (n = 24) and idiopathic generalized epilepsies (n = 20) compared to healthy controls (n = 36). Children with epilepsy demonstrated differences from controls in baseline grey and white matter volumes suggesting antecedent anomalies in brain development, as well as abnormal patterns of prospective brain development that involved not only slowed white matter expansion, but also abnormalities of cortical grey matter development involving both greater and lesser volume changes compared to controls. Furthermore, abnormal neurodevelopmental changes extended outside the cortex affecting several subcortical structures including thalamus, cerebellum, brainstem and pons. Finally, there were significant differences between the epilepsy syndromes (localization-related epilepsies and idiopathic generalized epilepsies) with the idiopathic generalized epilepsies group showing a more disrupted pattern of brain structure both at baseline and over the 2-year interval.

Thalamofrontal neurodevelopment in new-onset pediatric idiopathic generalized epilepsy

BACKGROUND

Quantitative MRI techniques have demonstrated thalamocortical abnormalities in idiopathic generalized epilepsy (IGE). However, there are few studies examining IGE early in its course and the neurodevelopmental course of this region is not adequately defined.

OBJECTIVE

We examined the 2-year developmental course of the thalamus and frontal lobes in pediatric new-onset IGE (i.e., within 12 months of diagnosis).

METHODS

We performed whole-brain MRI in 22 patients with new-onset IGE and 36 age-matched healthy controls. MRI was repeated 24 months after baseline MRI. Quantitative volumetrics were used to examine thalamic and frontal lobe volumes.

RESULTS

The IGE group showed significant differences in thalamic volume within 1 year of seizure onset (baseline) and went on to show thalamic volume loss at a significantly faster rate than healthy control children over the 2-year interval. The control group also showed a significantly greater increase in frontal white matter expansion than the IGE group. In contrast, frontal lobe gray matter volume differences were moderate at baseline and persisted over time, indicating similar developmental trajectories with differences early in the disease process that are maintained.

CONCLUSIONS

Brain tissue abnormalities in thalamic and frontal regions can be identified very early in the course of IGE and an abnormal trajectory of growth continues over a 2-year interval.

The nature and extent of cerebellar atrophy in chronic temporal lobe epilepsy

PURPOSE

Research indicates that patients with chronic temporal lobe epilepsy (TLE) exhibit cerebellar atrophy compared to healthy controls, but the degree to which specific regions of the cerebellum are affected remains unclear. The purpose of this study was to characterize the extent and lateralization of atrophy in individual cerebellar lobes and subregions in unilateral TLE using advanced quantitative magnetic resonance imaging (MRI) techniques.

METHODS

Study participants were 46 persons with TLE and 31 age- and gender- matched healthy controls. All participants underwent high-resolution MRI with manual tracing of the cerebellum yielding gray and white matter volumes of the right and left anterior lobes, superior posterior lobes, inferior posterior lobes, and corpus medullare. The degree to which asymmetric versus generalized abnormalities was evident in unilateral chronic TLE was determined and related to selected clinical seizure features (age of onset, duration of disorder).

KEY FINDINGS

There were no lateralized abnormalities in cerebellar gray matter or white matter in patients with right or left TLE (all p's > 0.2). Compared with controls, unilateral TLE was associated with significant bilateral reductions in the superior (p = 0.032) and inferior (p = 0.023) posterior lobes, whereas volume was significantly increased in the anterior lobes (p = 0.002), especially in patients with early onset TLE, and not significantly different in the corpus medullare (p = 0.71). Total superior cerebellar tissue volumes were reduced in association with increasing duration of epilepsy.

SIGNIFICANCE

Patients with unilateral TLE exhibit a pattern of bilateral cerebellar pathology characterized by atrophy of the superior and inferior posterior lobes, hypertrophy of the anterior lobe, and no effect on the corpus medullare. Cross-sectional analyses show that specific aspects of cerebellar pathology are associated with neurodevelopmental (anterior lobe) or chronicity-related (superior posterior lobe) features of the disorder.

Brain development in children with new onset epilepsy: a prospective controlled cohort investigation

PURPOSE

To characterize prospective neurodevelopmental changes in brain structure in children with new and recent-onset epilepsy compared to healthy controls.

METHODS

Thirty-four healthy controls (mean age 12.9 years) and 38 children with new/recent-onset idiopathic epilepsy (mean age 12.9 years) underwent 1.5 T magnetic resonance imaging (MRI) at baseline and 2 years later. Prospective changes in total cerebral and lobar gray and white matter volumes were compared within and between groups.

RESULTS

Prospective changes in gray matter volume were comparable for the epilepsy and control groups, with significant (p < 0.0001) reduction in total cerebral gray matter, due primarily to significant (p < 0.001) reductions in frontal and parietal gray matter. Prospective white matter volume changes differed between groups. Controls exhibited a significant (p = 0.0012) increase in total cerebral white matter volume due to significant (p < 0.001) volume increases in the frontal, parietal, and temporal lobes. In contrast, the epilepsy group exhibited nonsignificant white matter volume change in the total cerebrum (p = 0.51) as well as across all lobes (all p's > 0.06). The group by white matter volume change interactions were significant for total cerebrum (p = 0.04) and frontal lobe (p = 0.04).

DISCUSSION

Children with new and recent-onset epilepsy exhibit an altered pattern of brain development characterized by delayed age-appropriate increase in white matter volume. These findings may affect cognitive development through reduced brain connectivity and may also be related to the impairments in executive function commonly reported in this population.

Synoptic operative record for point of care outcomes: a leap forward in knowledge translation

INTRODUCTION

Modern information technology coupled with synoptic methodology allows point of care, real time outcomes generation. Our objective was to review province-wide breast cancer surgery outcomes from a prospective synoptic operative record to demonstrate its value in knowledge translation.

METHODS

All synoptic reports for breast cancer procedures from 2006 until March 2010 were reviewed and descriptively analyzed. Key outcomes included frequency of breast cancer procedures captured over time, methods of breast cancer detection, clinical staging, method of axillary staging, breast conservation and reconstruction rates. Further analysis involved important decision-making for mastectomy and resource allocation for surgery.

RESULTS

Four thousand nine hundred fifty-five breast cancer procedures were recorded synoptically; greater than 80% of cases provincially. Method of breast cancer detection was 49%, 45% and 4% by screening radiology, patient or family, and physician, respectively. Pathologic diagnoses were via core or mammotome biopsy in 94%; nearly half of all patients were clinical Stage I at time of operation. Overall rate of breast conservation was 48%. Of the 65% who had no contra-indication to breast conservation surgery, 76% had breast conservation and 4% had primary reconstruction. Of those having mastectomy, one third were due to patient choice. Seventy-nine percent had sentinel node staging, 18% had full axillary dissection and 3% had no axillary staging.

CONCLUSION

A new paradigm of creating medical records using synoptic electronic templates allows prospective outcomes generation at point of care by the surgeon which is unparalleled in its depth of surgical detail capturing surgical decision-making.

Children with new-onset epilepsy exhibit diffusion abnormalities in cerebral white matter in the absence of volumetric differences

The purpose of this investigation was to examine the diffusion properties of cerebral white matter in children with recent onset epilepsy (n=19) compared to healthy controls (n=11). Subjects underwent DTI with quantification of mean diffusion (MD), fractional anisotropy (FA), axial diffusivity (D(ax)) and radial diffusivity (D(rad)) for regions of interest including anterior and posterior corpus callosum, fornix, cingulum, and internal and external capsules. Quantitative volumetrics were also performed for the corpus callosum and its subregions (anterior, midbody and posterior) and total lobar white and gray matter for the frontal, parietal, temporal and occipital lobes. The results demonstrated no group differences in total lobar gray or white matter volumes or volume of the corpus callosum and its subregions, but did show reduced FA and increased D(rad) in the posterior corpus callosum and cingulum. These results provide the earliest indication of microstructural abnormality in cerebral white matter among children with idiopathic epilepsies. This abnormality occurs in the context of normal volumetrics and suggests disruption in myelination processes.

Neuroanatomical correlates of cognitive phenotypes in temporal lobe epilepsy

OBJECTIVE

Previous research characterized three cognitive phenotypes in temporal lobe epilepsy, each associated with a different profile of clinical seizure and demographic characteristics, total cerebral (gray, white, cerebrospinal fluid) and hippocampal volumes, and prospective cognitive trajectories. The objective of this investigation was to characterize in detail the specific neuroanatomical abnormalities associated with each cognitive phenotype.

METHODS

High-resolution MRI scans of healthy controls (n=53) and patients with temporal lobe epilepsy (n=55), grouped by cognitive phenotype (minimally impaired; memory impaired; memory, executive function, and speed impaired), were examined with respect to patterns of gray matter thickness throughout the cortical mantle, as well as volumes of subcortical structures, corpus callosum, and regions of the cerebellum.

RESULTS

Increasing abnormalities in temporal and extratemporal cortical thickness, volumes of subcortical structures (hippocampus, thalamus, basal ganglia), all regions of the corpus callosum, and bilateral cerebellar gray matter distinguish the cognitive phenotypes in a generally stepwise fashion. The most intact anatomy is observed in the minimally impaired epilepsy group and the most abnormal anatomy is evident in the epilepsy group with impairments in memory, executive function, and speed.

CONCLUSION

Empirically derived cognitive phenotypes are associated with the presence, severity, and distribution of anatomic abnormalities in widely distributed cortical, subcortical, callosal, and cerebellar networks.

Bilateral breast cancer in northern Alberta: risk factors and survival patterns

Of 2231 women with stage I, II or III breast cancer who were registered and seen between 1971 and 1979 and followed to the end of 1981, 48 (2.2%) had synchronous and 58 (2.6%) asynchronous bilateral breast cancer. The unadjusted incidence rate for a second breast cancer was 6.4/1000 breast-years at risk, compared with a rate of 0.70 for the risk of a first breast cancer in women. When calculated from the date of diagnosis of the first breast cancer the survival rate was better for the group with asynchronous disease than for the group with synchronous disease or for a group with unilateral disease, but when calculated from the date of diagnosis of the second cancer the rate was the same in all three groups. Comparison of known risk factors showed a significant association between the development of bilateral cancer and a later age at the birth of the first child and a longer interval between menarche and that birth. There was a trend towards greater age and more stage III cancer in the group with synchronous disease. There was no correlation between receiving radiotherapy for the first breast cancer and development of the second cancer. Annual mammography and clinical examination of asymptomatic women at a cancer centre resulted in the detection of a significantly higher proportion of minimal breast cancers in the second breast compared with the first. Such screening practices should be even more valuable in the earlier detection of unilateral breast cancer in asymptomatic women who have not had breast cancer.