Emotional facial expression and perioral motor functions of the human auditory cortex.

OBJECTIVE: We investigated the role of transverse temporal gyrus and adjacent cortex (TTG+) in facial expressions and perioral movements. METHODS: In 31 patients undergoing stereo-electroencephalography monitoring, we describe behavioral responses elicited by electrical stimulation within the TTG+. Task-induced high-gamma modulation (HGM), auditory evoked responses, and resting-state connectivity were used to investigate the cortical sites having different types of responses on electrical stimulation. RESULTS: Changes in facial expressions and perioral movements were elicited on electrical stimulation within TTG+ in 9 (29%) and 10 (32%) patients, respectively, in addition to the more common language responses (naming interruptions, auditory hallucinations, paraphasic errors). All functional sites showed auditory task induced HGM and evoked responses validating their location within the auditory cortex, however, motor sites showed lower peak amplitudes and longer peak latencies compared to language sites. Significant first-degree connections for motor sites included precentral, anterior cingulate, parahippocampal, and anterior insular gyri, whereas those for language sites included posterior superior temporal, posterior middle temporal, inferior frontal, supramarginal, and angular gyri. CONCLUSIONS: Multimodal data suggests that TTG+ may participate in auditory-motor integration. SIGNIFICANCE: TTG+ likely participates in facial expressions in response to emotional cues during an auditory discourse.

Long-term characterization of cognitive phenotypes in children with seizures over 36 months.

RATIONALE: Children with new-onset epilepsies often exhibit co-morbidities including cognitive dysfunction, which adversely affects academic performance. Application of unsupervised machine learning techniques has demonstrated the presence of discrete cognitive phenotypes at or near the time of diagnosis, but there is limited knowledge of their longitudinal trajectories. Here we investigate longitudinally the presence and progression of cognitive phenotypes and academic status in youth with new-onset seizures as sibling controls. METHODS: 282 subjects (6-16 years) were recruited within 6 weeks of their first recognized seizure along with 167 unaffected siblings. Each child underwent a comprehensive neuropsychological assessment at baseline, 18 and 36 months later. Factor analysis of the neuropsychological tests revealed four underlying domains - language, processing speed, executive function, and verbal memory. Latent trajectory analysis of the mean factor scores over 36 months identified clusters with prototypical cognitive trajectories. RESULTS: Three unique phenotypic groups with distinct cognitive trajectories over the 36-month period were identified: Resilient, Average, and Impaired phenotypes. The Resilient phenotype exhibited the highest neuropsychological factor scores and academic performance that were all similar to controls; while the Impaired phenotype showed the polar opposite with the worst performances across all test metrics. These findings remained significant and stable over 36 months. Multivariate logistic regression indicated that age of onset, EEG, neurological examination, and sociodemographic disadvantage were associated with phenotype classification. CONCLUSIONS: This study demonstrates the presence of diverse latent cognitive trajectory phenotypes over 36 months in youth with new-onset seizures that are associated with a stable neuropsychological and academic performance longitudinally.

International consensus recommendations for the identification and treatment of tuberous sclerosis complex-associated neuropsychiatric disorders (TAND).

BACKGROUND: Tuberous sclerosis complex (TSC) is associated with a wide range of physical manifestations for which international clinical recommendations for diagnosis and management have been established. TSC is, however, also associated with a wide range of TSC-Associated Neuropsychiatric Disorders (TAND) that are typically under-identified and under-treated yet associated with a profound burden of disease. The contemporary evidence base for the identification and treatment of TAND is much more limited and, to date, consensus recommendations for the diagnosis and management of TAND have also been limited and non-specific. METHODS: The TANDem project was launched with an international, interdisciplinary, and participatory consortium of 24 individuals, including TSC family representatives, from all World Health Organization (WHO) regions but one. One of the aims of the TANDem project was to generate consensus recommendations for the identification and treatment of TAND. At the time of this project, no internationally adopted standard methodology and methodological checklists existed for the generation of clinical practice recommendations. We therefore developed our own systematic procedure for evidence review and consensus-building to generate evidence-informed consensus recommendations of relevance to the global TSC community. RESULTS: At the heart of the consensus recommendations are ten core principles surrounded by cluster-specific recommendations for each of the seven natural TAND clusters identified in the literature (autism-like, dysregulated behavior, eat/sleep, mood/anxiety, neuropsychological, overactive/impulsive, and scholastic) and a set of wraparound psychosocial cluster recommendations. The overarching recommendation is to "screen" for TAND at least annually, to "act" using appropriate next steps for evaluation and treatment, and to "repeat" the process to ensure early identification and early intervention with the most appropriate biological, psychological, and social evidence-informed approaches to support individuals with TSC and their families. CONCLUSIONS: The consensus recommendations should provide a systematic framework to approach the identification and treatment of TAND for health, educational, social care teams and families who live with TSC. To ensure global dissemination and implementation of these recommendations, partnerships with the international TSC community will be important. One of these steps will include the generation of a "TAND toolkit" of "what to seek" and "what to do" when difficulties are identified in TAND clusters.

The Impact of Sociodemographic Disadvantage on Cognitive Outcomes in Children With Newly Diagnosed Seizures and Their Unaffected Siblings Over 36 Months.

BACKGROUND: Accumulating evidence indicates that children with newly diagnosed epilepsy have comorbidities including cognitive challenges. Research investigating comorbidities has focused on clinical epilepsy characteristics and neurobiological/genetic correlates. The role that sociodemographic disadvantage (SD) may play has received less attention. We investigated the role of SD in cognitive status in youth with newly diagnosed epilepsy over a follow-up of 36 months to determine the degree, extent, and duration of the role of disadvantage. METHODS: A total of 289 children (six to 16 years) within six weeks of their first seizure along with 167 siblings underwent comprehensive neuropsychological assessments (intelligence, language, memory, executive function, processing speed, and academic achievement) at baseline, 18 months later, and at 36 months from baseline. Baseline demographic information (race, caregivers education, household income, and parental marital status), clinical epilepsy characteristics (e.g., age of onset), and magnetic resonance imaging (MRI) and electroencephalographic (EEG) information was collected. RESULTS: An SD index was computed for each family and categorized into four groups by level of disadvantage. In children and siblings, the least disadvantaged group exhibited the highest Full-Scale IQ, neuropsychological factor scores, and academic performances, whereas the most disadvantaged showed the polar opposite with the worst performances across all tests. Findings remained stable and significant over 36 months. Linear regression analyses indicated that disadvantage was a more constant and stable predictor of cognitive and academic performance over time compared with clinical epilepsy characteristics and MRI/EEG abnormalities. CONCLUSIONS: This study indicates the strong association between SD and cognitive/academic performance in children with newly diagnosed epilepsy and their siblings is significant and predictive of three-year cognitive outcomes.

Development and Feasibility of the Self-Report Quantified Tuberous Sclerosis Complex-Associated Neuropsychiatric Disorders Checklist (TAND-SQ).

BACKGROUND: Tuberous sclerosis complex-associated neuropsychiatric disorders (TAND) are often present but underidentified and undertreated in individuals with tuberous sclerosis complex (TSC). The clinician-completed TAND-Lifetime Checklist (TAND-L) was developed to address this identification and treatment gap. Stakeholder engagement identified the need for a TAND Checklist that can (1) be completed by caregivers or individuals with TSC and (2) quantify TAND difficulties. The aim of this study was to develop a self-report quantified TAND Checklist (TAND-SQ) and conduct feasibility and acceptability testing. METHODS: This aim was addressed in three phases: (1) development of the TAND-SQ Checklist, (2) feasibility and acceptability testing of the "near-final" TAND-SQ Checklist, and (3) preparation of the final TAND-SQ Checklist. Participants included 23 technical experts from the TAND consortium in all phases and 58 lived experts (caregivers and individuals with TSC) in phase 2. All participants completed a TAND-SQ Checklist and a checklist feedback form. RESULTS: Phase 1 additions to the TAND-SQ, when compared with the TAND-L, included four new items and a quantification rating. Phase 2 showed high ratings for the "near-final" TAND-SQ Checklist on comprehensiveness, clarity, ease of use, and overall acceptability. In phase 3, questions on strengths, strategies, and a TAND Cluster Profile were added. CONCLUSION: The TAND-SQ Checklist is presented here for use by individuals with TSC and their caregivers. The next steps as part of the TANDem project include internal and external validation of the checklist and linking of TAND Cluster Profiles generated from the checklist to evidence-informed consensus recommendations within a smartphone application.

Neuropsychological outcomes after epilepsy surgery: A comparison of stereo electroencephalography and subdural electrodes.

BACKGROUND AND PURPOSE: We analyzed the association of neuropsychological outcomes after epilepsy surgery with the intracranial electrode type (stereo electroencephalography [SEEG] and subdural electrodes [SDE]), and electrical stimulation mapping (ESM) of speech/language. METHODS: Drug-resistant epilepsy patients who underwent comprehensive neuropsychological evaluation before and 1 year after epilepsy surgery were included. SEEG and SDE subgroups were matched by age, handedness, operated hemisphere, and seizure freedom. Postsurgical neuropsychological outcomes (adjusted for presurgical scores) and reliable change indices were analyzed as functions of electrode type and ESM. RESULTS: Ninety-nine patients aged 6-29 years were included with similar surgical resection/ablation volumes in the SEEG and SDE subgroups. Most of the neuropsychological outcomes were comparable between SEEG and SDE subgroups; however, Working Memory and Processing Speed were significantly improved in the SEEG subgroup. Undergoing language ESM was associated with significant improvements in Spelling, Letter-Word Identification, Vocabulary, Verbal Comprehension, Verbal Learning, and Story Memory scores, but a decline in Calculation scores. CONCLUSIONS: Intracranial evaluations with SEEG and SDE are comparable in terms of long-term postsurgical neuropsychological outcomes. Our data suggest that SEEG may be associated with improvements in working memory and processing speed, representing cognitive domains served by spatially distributed networks. Our study also supports wider use of language ESM before epilepsy surgery, preferably using other language tasks in addition to visual naming. Rather than the type of electrode, postsurgical neuropsychological outcomes are driven by whether language ESM was performed or not, with beneficial effects of language mapping.

Impact of sociodemographic disadvantage on neurobehavioral outcomes in children with newly diagnosed seizures and their unaffected siblings over 36 months.

OBJECTIVE: This study was undertaken to determine the short-term and longer term impact of sociodemographic disadvantage on the emotional-behavioral status of youths with new onset epilepsy and their unaffected siblings at the time of diagnosis and the subsequent 3 years. METHODS: Three hundred twelve youths with newly diagnosed epilepsies and 223 unaffected siblings, aged 6-16 years, were independently assessed regarding their emotional and behavioral status by their parents and teachers at baseline, and at 18 at 36 months later; youths with seizures also completed self-report measures of depression, anxiety, and hostility at those three time points. A sociodemographic disadvantage score was computed for each family (children with newly diagnosed seizures and their siblings), and families were separated into four categories from most disadvantaged to least disadvantaged. RESULTS: In both children and siblings, the least disadvantaged group exhibited the lowest level of neurobehavioral problems, whereas the most disadvantaged group showed a higher level of neurobehavioral problems across all the same behavior metrics. Findings remained stable and significant across all informants (parent, teacher, child) and across all time periods (throughout the 3-year period). Furthermore, both corrected and uncorrected linear regression analyses indicated that disadvantage was a more constant and stable predictor of behavioral and emotional problems over time compared to clinical seizure characteristics and abnormalities in magnetic resonance imaging and electroencephalographic testing. SIGNIFICANCE: Sociodemographic disadvantage bears a strong relationship to youths with emotional and behavioral problems both at the time of diagnosis as well as prospectively. The relationship is robust and reflected in reports from multiple informants (parent, teacher, child self-report), evident in siblings as well, and possibly more explanatory than traditional clinical seizure variables. Future studies will be needed to determine whether this disadvantage factor is modifiable with early intervention.

Comparing electrical stimulation functional mapping with subdural electrodes and stereoelectroencephalography.

OBJECTIVE: Electrical stimulation mapping (ESM) is the clinical standard for functional localization with subdural electrodes (SDE). As stereoelectroencephalography (SEEG) has emerged as an alternative option, we compared functional responses, afterdischarges (ADs), and unwanted ESM-induced seizures (EISs) between the two electrode types. METHODS: Incidence and current thresholds for functional responses (sensory, motor, speech/language), ADs, and EISs were compared between SDE and SEEG using mixed models incorporating relevant covariates. RESULTS: We identified 67 SEEG ESM and 106 SDE ESM patients (7207 and 4980 stimulated contacts, respectively). We found similar incidence of language and motor responses between electrode types; however, more SEEG patients reported sensory responses. ADs and EISs occurred less commonly with SEEG than SDE. Current thresholds for language, face motor, and upper extremity (UE) motor responses and EIS significantly decreased with age. However, they were not affected by electrode type, premedication, or dominant hemispheric stimulation. AD thresholds were higher with SEEG than with SDE. For SEEG ESM, language thresholds remained below AD thresholds up to 26 years of age, whereas this relationship was inverse for SDE. Also, face and UE motor thresholds fell below AD thresholds at earlier ages for SEEG than SDE. AD and EIS thresholds were not affected by premedication. SIGNIFICANCE: SEEG and SDE have clinically relevant differences for functional brain mapping with electrical stimulation. Although evaluation of language and motor regions is comparable between SEEG and SDE, SEEG offers a higher likelihood of identifying sensory areas. A lower incidence of ADs and EISs, and a favorable relationship between functional and AD thresholds suggest superior safety and neurophysiologic validity for SEEG ESM than SDE ESM.

Characterizing Sleep Phenotypes in Children With Newly Diagnosed Epilepsy.

BACKGROUND: Children with epilepsy frequently have sleep, behavior, and cognitive problems at the time of or before the epilepsy diagnosis. The primary goal of this study was to determine if specific sleep disturbance phenotypes exist in a large cohort of children with new-onset epilepsy and if these phenotypes are associated with specific cognitive and behavioral signatures. METHODS: A total of354 children with new-onset epilepsy, aged six to 16 years, were recruited within six weeks of initial seizure onset. Each child underwent evaluation of their sleep along with self, parent, and teacher ratings of emotional-behavioral status. Two-step clustering using sleep disturbance (Sleep Behavior Questionnaire), naps, and sleep latency was employed to determine phenotype clusters. RESULTS: Analysis showed three distinct sleep disturbance phenotypes-minimal sleep disturbance, moderate sleep disturbance, and severe sleep disturbance phenotypes. Children who fell into the minimal sleep disturbance phenotype had an older age of onset with the best cognitive performance compared with the other phenotypes and the lowest levels of emotional-behavioral problems. In contrast, children who fell into the severe sleep disturbance phenotype had the youngest age of onset of epilepsy with poor cognitive performance and highest levels of emotional-behavioral problems. CONCLUSIONS: This study indicates that there are indeed specific sleep disturbance phenotypes that are apparent in children with newly diagnosed epilepsy and are associated with specific comorbidities. Future research should determine if these phenotypic groups persist over time and are predictive of long-term difficulties, as these subgroups may benefit from targeted therapy and intervention.

Functional MRI and electrical stimulation mapping for language localization: A comparative meta-analysis.

OBJECTIVE: This systematic review and meta-analysis evaluated the diagnostic validity of functional magnetic resonance imaging (fMRI) compared to electrical stimulation mapping (ESM) for pre-surgical language mapping. METHODS: A structured literature search was performed and studies with electrode-level data comparing fMRI and ESM for language localization were analyzed. Outcome measures included pooled estimates of diagnostic odds ratio (DOR), sensitivity, and specificity. Sources of heterogeneity were explored with a meta-regression framework. RESULTS: Nine studies were included in the analysis having 5-40 patients with mean age 11.3-43.4 years. Verb generation and picture naming were the most common fMRI tasks, while picture naming was the most common ESM task. Sensitivity (0.37-0.95), specificity (0.36-0.97), and DOR (1.9-44.6) for fMRI compared to ESM varied widely across studies with statistically significant heterogeneities. Pooled estimates were: sensitivity 0.71 (95% confidence interval 0.54, 0.83), specificity 0.74 (0.58, 0.85), and DOR 7.0 (3.5, 13.8), from a valid meta-analysis (area under the summary receiver-operating-curve 0.78). fMRI was noted to have higher sensitivity in studies using higher maximal ESM currents. fMRI variables could not be included in the meta-regression because of substantial methodological differences among studies. CONCLUSIONS: fMRI is moderately sensitive and moderately specific for language localization compared to ESM in well-designed studies. However, because the confidence limits for sensitivity and DOR are close to the line of no effect, and there is high unmeasured heterogeneity, fMRI cannot perhaps be used as the only modality for language localization to inform neurosurgical decisions at present.

The Relationship Between Sleep, Cognition and Behavior in Children With Newly-Diagnosed Epilepsy Over 36 Months.

Introduction: There is substantial evidence that children with epilepsy experience more sleep, behavior and cognitive challenges than children without epilepsy. However, the literature is limited in describing the relationship between sleep, epilepsy, cognition and behavioral challenges and the interactions amongst these factors over time. This study aims to understand the nature and strength of the relationship between sleep, cognition, mood and behavior in children with new-onset epilepsy as assessed by multiple informants at multiple time periods using multiple different dependent measures. Methods: 332 participants (6-16years) were recruited within 6 weeks of their first recognized seizure. The comparison group was comprised of 266 healthy siblings. Participants underwent sleep evaluation by a parent using the Sleep Behavioral Questionnaire (SBQ), cognitive evaluation using a comprehensive neuropsychological test battery, a behavioral evaluation using the Child Behavior Checklist (CBCL from parents and TRF from teachers) and the Children's Depression Inventory (CDI). These evaluations were completed at baseline (B), at 18 months, and at 36 months. Results: Compared to siblings, children with new-onset epilepsy had more sleep disturbance (SBQ), higher rates of behavioral problems (CBCL and TRF), lower cognitive testing scores, and higher rates of depression; which persisted over the 36-month study. Sleep significantly correlated with behavioral problems, cognitive scores and depression. When divided into categories based of sleep disturbance scores, 39.7% of children with epilepsy experienced "Persistently Abnormal Sleep", while 14.8% experienced "Persistently Normal Sleep". Children with persistently abnormal sleep experienced the highest rates of behavioral problems, depression and cognitive impairment compared to those with persistently normal sleep, regardless of epilepsy syndrome. Younger age of seizure onset, younger age at testing, and lower grade level at baseline were associated with persistently abnormal sleep. Conclusions: To our knowledge, this is the first demonstration of the nature, strength, reliability, stability and persistence of the relationship between sleep, cognition, and behavioral problems over time in a large cohort of children with newly diagnosed epilepsy, as assessed by multiple informants at different timepoints. The results of this study indicate that children with epilepsy are at a high risk of significant persisting neurobehavioral multimorbidity. Therefore, early screening for these challenges may be essential for optimizing quality of life long-term.

Neuronal Circuits Supporting Development of Visual Naming Revealed by Intracranial Coherence Modulations.

Background: Improvement in visual naming abilities throughout the childhood and adolescence supports development of higher-order linguistic skills. We investigated neuronal circuits underlying improvement in the speed of visual naming with age, and age-related dynamics of these circuits. Methods: Response times were electronically measured during an overt visual naming task in epilepsy patients undergoing stereo-EEG monitoring. Coherence modulations among pairs of neuroanatomic parcels were computed and analyzed for relationship with response time and age. Results: During the overt visual naming task, mean response time (latency) significantly decreased from 4 to 23 years of age. Coherence modulations during visual naming showed that increased connectivity between certain brain regions, particularly that between left fusiform gyrus/left parahippocampal gyrus and left frontal operculum, is associated with improvement in naming speed. Also, decreased connectivity in other brain regions, particularly between left angular and supramarginal gyri, is associated with decreased mean response time. Further, coherence modulations between left frontal operculum and both left fusiform and left posterior cingulate gyri significantly increase, while that between left angular and supramarginal gyri significantly decrease, with age. Conclusion: Naming speed continues to improve from pre-school years into young adulthood. This age-related improvement in efficiency of naming environmental objects occurs likely because of strengthened direct connectivity between semantic and phonological nodes, and elimination of intermediate higher-order cognitive steps.

Empowering Families Through Technology: A Mobile-Health Project to Reduce the TAND Identification and Treatment Gap (TANDem).

Introduction: Tuberous Sclerosis Complex (TSC) is a multi-system genetic disorder with various TSC-Associated Neuropsychiatric Disorders (TAND) that significantly impact the mental health and wellbeing of individuals with TSC and their caregivers. TAND represents the number one concern to families worldwide, yet is highly under-identified and under-treated. The clinician-administered TAND-Checklist (Lifetime version, TAND-L) has improved identification of TAND in clinical settings. However, many individuals with TSC and their caregivers still have difficulty accessing suitable support for diagnosis and evidence-informed interventions. The TANDem study is a community-based participatory research project with a broad range of TSC stakeholders aimed at reducing the TAND identification and treatment gap. Objectives: Participatory research identified three priority next steps: 1) development and validation of a self-report, quantified version of the TAND Checklist (TAND-SQ) and building the TAND-SQ into a smartphone application, 2) generation of consensus clinical recommendations for the identification and treatment of TAND, to be incorporated as a TAND toolkit on the app, and 3) establishment of a global TAND consortium through networking, capacity-building and public engagement activities. Methods: TANDem is a four-year project, and includes 24 consortium members from 10 countries representing all World Health Organization regions. Collaborators represent five stakeholder groups (family representatives, technology experts, clinical experts, non-profit organisations and researchers). Here we outline the project study protocol in detail, describing the scientific rationale, the project aims and objectives, the methods involved in participant recruitment, multi-site and multi-phase data collection, data analysis, ethical considerations including informed consent, data protection, privacy and confidentiality considerations related to the European Union General Data Protection Regulation and the USA Health Insurance Portability and Accountability Act. The expected outcomes and potential impact on the TSC community, implementation and dissemination of results, as well as future scale-up and scale-out plans are also discussed. Conclusions: The TANDem project has the potential to transform the global TSC community by empowering families living with TSC through an easily accessible digital solution to allow them to document their own TAND needs linked to an evidence-informed toolkit to enhance personalised healthcare, and by providing healthcare professionals with consensus clinical recommendations to prevent, identify and manage TAND manifestations.

The research landscape of tuberous sclerosis complex-associated neuropsychiatric disorders (TAND)-a comprehensive scoping review.

BACKGROUND: Tuberous sclerosis complex (TSC)-associated neuropsychiatric disorders (TAND) is an umbrella term for the behavioural, psychiatric, intellectual, academic, neuropsychological and psychosocial manifestations of TSC. Although TAND affects 90% of individuals with TSC during their lifetime, these manifestations are relatively under-assessed, under-treated and under-researched. We performed a comprehensive scoping review of all TAND research to date (a) to describe the existing TAND research landscape and (b) to identify knowledge gaps to guide future TAND research. METHODS: The study was conducted in accordance with stages outlined within the Arksey and O'Malley scoping review framework. Ten research questions relating to study characteristics, research design and research content of TAND levels and clusters were examined. RESULTS: Of the 2841 returned searches, 230 articles published between 1987 and 2020 were included (animal studies = 30, case studies = 47, cohort studies = 153), with more than half published since the term TAND was coined in 2012 (118/230; 51%). Cohort studies largely involved children and/or adolescents (63%) as opposed to older adults (16%). Studies were represented across 341 individual research sites from 45 countries, the majority from the USA (89/341; 26%) and the UK (50/341; 15%). Only 48 research sites (14%) were within low-middle income countries (LMICs). Animal studies and case studies were of relatively high/high quality, but cohort studies showed significant variability. Of the 153 cohort studies, only 16 (10%) included interventions. None of these were non-pharmacological, and only 13 employed remote methodologies (e.g. telephone interviews, online surveys). Of all TAND clusters, the autism spectrum disorder-like cluster was the most widely researched (138/230; 60%) and the scholastic cluster the least (53/200; 27%). CONCLUSIONS: Despite the recent increase in TAND research, studies that represent participants across the lifespan, LMIC research sites and non-pharmacological interventions were identified as future priorities. The quality of cohort studies requires improvement, to which the use of standardised direct behavioural assessments may contribute. In human studies, the academic level in particular warrants further investigation. Remote technologies could help to address many of the TAND knowledge gaps identified.

A distributed network supports spatiotemporal cerebral dynamics of visual naming.

OBJECTIVE: Cerebral spatiotemporal dynamics of visual naming were investigated in epilepsy patients undergoing stereo-electroencephalography (SEEG) monitoring. METHODS: Brain networks were defined by Parcel-Activation-Resection-Symptom matching (PARS) approach by matching high-gamma (50-150 Hz) modulations (HGM) in neuroanatomic parcels during visual naming, with neuropsychological outcomes after resection/ablation of those parcels. Brain parcels with >50% electrode contacts simultaneously showing significant HGM were aligned, to delineate spatiotemporal course of naming-related HGM. RESULTS: In 41 epilepsy patients, neuroanatomic parcels showed sequential yet temporally overlapping HGM course during visual naming. From bilateral occipital lobes, HGM became increasingly left lateralized, coursing through limbic system. Bilateral superior temporal HGM was noted around response time, and right frontal HGM thereafter. Correlations between resected/ablated parcels, and post-surgical neuropsychological outcomes showed specific regional groupings. CONCLUSIONS: Convergence of data from spatiotemporal course of HGM during visual naming, and functional role of specific parcels inferred from neuropsychological deficits after resection/ablation of those parcels, support a model with six cognitive subcomponents of visual naming having overlapping temporal profiles. SIGNIFICANCE: Cerebral substrates supporting visual naming are bilaterally distributed with relative hemispheric contribution dependent on cognitive demands at a specific time. PARS approach can be extended to study other cognitive and functional brain networks.

Case Report: Cerebral Revascularization in a Child With Mucopolysaccharidosis Type I.

Mucopolysaccharidosis (MPS) type I is a rare lysosomal storage disorder caused by an accumulation of glycosaminoglycans (GAGs) resulting in multisystem disease. Neurological morbidity includes hydrocephalus, spinal cord compression, and cognitive decline. While many neurological symptoms have been described, stroke is not a widely-recognized manifestation of MPS I. Accordingly, patients with MPS I are not routinely evaluated for stroke, and there are no guidelines for managing stroke in patients with this disease. We report the case of a child diagnosed with MPS I who presented with overt stroke and repeated neurological symptoms with imaging findings for severe ventriculomegaly, infarction, and bilateral terminal carotid artery stenosis. Direct intracranial pressure evaluation proved negative for hydrocephalus. The patient was subsequently treated with cerebral revascularization and at a 3-year follow-up, the patient reported no further neurological events or new ischemia on cerebral imaging. Cerebral arteriopathy in patients with MPS I may be associated with GAG accumulation within the cerebrovascular system and may predispose patients to recurrent strokes. However, further studies are required to elucidate the etiology of cerebrovascular arteriopathy in the setting of MPS I. Although the natural history of steno-occlusive arteriopathy in patients with MPS I remains unclear, our findings suggest that cerebral revascularization is a safe treatment option that may mitigate the risk of future strokes and should be strongly considered within the overall management guidelines for patients with MPS I.

Sirolimus Treatment in Sturge-Weber Syndrome.

BACKGROUND: Sturge-Weber syndrome is a rare neurovascular disorder associated with capillary malformation, seizures, cognitive impairments, and stroke-like episodes (SLEs), arising from a somatic activating mutation in GNAQ. Studies suggest this mutation may cause hyperactivation of the mammalian target of rapamycin pathway. Sirolimus is an mammalian target of rapamycin inhibitor studied in other vascular anomalies and a potentially promising therapy in Sturge-Weber syndrome. METHODS: Ten patients with Sturge-Weber syndrome brain involvement and cognitive impairments were enrolled. Oral sirolimus was taken for six months (maximum dose: 2 mg/day, target trough level: 4-6 ng/mL). Neuropsychological testing, electroencephalography, and port-wine score were performed at baseline and after six months on sirolimus. Neuroquality of life, adverse events, and Sturge-Weber Syndrome Neurological Score (neuroscore) were recorded at each visit. RESULTS: Sirolimus was generally well tolerated; one subject withdrew early. Adverse events considered related to sirolimus were mostly (15/16) grade 1. A significant increase in processing speed was seen in the overall group (P = 0.031); five of nine patients with available data demonstrated statistically rare improvement in processing speed. Improvements were seen in the neuroquality of life subscales measuring anger (P = 0.011), cognitive function (P = 0.015), and depression (P = 0.046). Three subjects experiencing SLEs before and during the study reported shortened recovery times while on sirolimus. CONCLUSIONS: Sirolimus was well tolerated in individuals with Sturge-Weber syndrome and may be beneficial for cognitive impairments, especially in patients with impaired processing speed or a history of SLE. A future, randomized, placebo-controlled trial of sirolimus in patients with Sturge-Weber syndrome is needed to further understand these potentially beneficial effects.

High-gamma modulation language mapping with stereo-EEG: A novel analytic approach and diagnostic validation.

OBJECTIVE: A novel analytic approach for task-related high-gamma modulation (HGM) in stereo-electroencephalography (SEEG) was developed and evaluated for language mapping. METHODS: SEEG signals, acquired from drug-resistant epilepsy patients during a visual naming task, were analyzed to find clusters of 50-150 Hz power modulations in time-frequency domain. Classifier models to identify electrode contacts within the reference neuroanatomy and electrical stimulation mapping (ESM) speech/language sites were developed and validated. RESULTS: In 21 patients (9 females), aged 4.8-21.2 years, SEEG HGM model predicted electrode locations within Neurosynth language parcels with high diagnostic odds ratio (DOR 10.9, p < 0.0001), high specificity (0.85), and fair sensitivity (0.66). Another SEEG HGM model classified ESM speech/language sites with significant DOR (5.0, p < 0.0001), high specificity (0.74), but insufficient sensitivity. Time to largest power change reliably localized electrodes within Neurosynth language parcels, while, time to center-of-mass power change identified ESM sites. CONCLUSIONS: SEEG HGM mapping can accurately localize neuroanatomic and ESM language sites. SIGNIFICANCE: Predictive modelling incorporating time, frequency, and magnitude of power change is a useful methodology for task-related HGM, which offers insights into discrepancies between HGM language maps and neuroanatomy or ESM.

Neuropsychological outcomes after pediatric epilepsy surgery: Role of electrical stimulation language mapping.

PURPOSE: We studied the association between electrical stimulation mapping (ESM) with a visual naming task and post-operative neuropsychological outcomes after pediatric epilepsy surgery. METHODS: Children who underwent epilepsy surgery, having pre- and 1-year post-surgery neuropsychological evaluation (NPE) available, were included. NPE scores were transformed using principal components (PC) analysis. The relationship between post-surgical PC scores, adjusted for pre-surgery PC scores, and ESM was analyzed. Clinical variables influencing this relationship were also sought. RESULTS: One hundred and four children (89 patients >5 years-old, and 15 patients 3-5 years-old) were included. Among children >5 years-of-age, a significant effect of language ESM was observed on all 3 post-surgery PC scores adjusted for respective pre-surgery PC scores. Specifically, only 30 % patients who underwent language ESM had a decrease in PC1 scores ≥1-year after epilepsy surgery, compared to 68 % those who did not undergo language ESM (p = 0.001). Seizure outcomes, age at the time of surgery, predominant seizure type, and family history of epilepsy were other significant determinants of post-surgical PC scores including a change in PC scores from pre-surgery baseline. Combinations of pre-surgical variables were able to predict post-surgical PC scores with high specificity. In children aged 3-5 years, no significant effect of language ESM was seen on post-surgery PC scores adjusted for respective pre-surgery PC scores. CONCLUSIONS: Speech/language ESM should be performed more widely in patients >5 years-of-age undergoing epilepsy surgery. Also, more efficient brain mapping techniques and language paradigms are needed for younger children.

Electrical stimulation sensorimotor mapping with stereo-EEG.

OBJECTIVE: We evaluated stereo-EEG electrical stimulation mapping (ESM) for localization of anatomic sensorimotor parcels in pediatric patients with drug-resistant epilepsy. We also analyzed sensorimotor and after-discharge thresholds, and the somatotopy of sensorimotor responses. METHODS: ESM was performed with 50 Hz, biphasic, 2-3 s trains, using 1-9 mA current. Pre- and post-implant neuroimaging was co-registered and intersected with Neurosynth reference, to classify each electrode contact as lying within/outside an anatomic sensorimotor parcel. Indices of diagnostic performance were computed. Sensorimotor and after-discharge thresholds were analyzed using multivariable linear mixed models. RESULTS: In 15 patients (6 females), aged 5.5-21.2 years, ESM showed high accuracy (0.80), high specificity (0.86), and diagnostic odds ratio (11.4, p < 0.0001) for localization of sensorimotor parcels. Mean sensorimotor threshold (3.4 mA) was below mean after-discharge threshold (4.2 mA, p = 0.0004). Sensorimotor and after-discharge thresholds showed a significant decrease with increasing intelligence quotient. Somatotopy of sensorimotor responses was mapped to standardized brain parcels. CONCLUSIONS: We provide evidence for diagnostic validity and safety of stereo-EEG sensorimotor ESM. SIGNIFICANCE: The somatotopy of sensorimotor responses elicited with electrical stimulation provide new insights into mechanisms of motor control and sensory perception.