Falls in oxygen saturations accompany electrographic seizures in term neonates: an observational study.

BACKGROUND: Effective seizure detection is important however, clinical signs of seizure activity may be subtle in neonates. This study aimed to systematically investigate SpO2 and respiratory pattern changes associated with EEG seizures in term-born neonates. METHOD: An observational study in term neonates at risk of seizures admitted to a single tertiary level neonatal intensive care unit. Synchronised high-resolution physiological data (ECG, pulse oximetry, respiration) and EEG/amplitude-integrated EEG (aEEG) monitoring were recorded. Sections of traces with evidence of clear EEG seizure activity were compared with physiological data recorded at the same time. RESULTS: 22/44 (50%) neonates who had aEEG monitoring were noted to have electrographic seizures. Physiologic download measurements were available for 11 of these neonates. In nine of these, an acute drop in oxygen saturation (SpO2) of at least 5% was noted in at least one seizure. Accompanying apnoeas were noted in three neonates. CONCLUSION: Acute decreases in SpO2 were seen in term neonates associated with seizures and these were not always accompanied by an apnoeic episode. Physiologic download in association with EEG monitoring may assist in improving seizure detection. Unexplained drops in SpO2 could indicate further investigation for possible seizures in at-risk neonates. IMPACT: A decrease in blood oxygen saturation (SpO2) associated with EEG seizures can occur in term infants with HIE or perinatal stroke. Drops in SpO2 associated with EEG seizures in term infants with HIE or stroke may occur in the absence of apnoeas. Unexplained acute falls in SpO2 in sick neonates may suggest possible seizures. Drops in SpO2 associated with seizures in term infants can occur over less than 3 minutes. Physiological monitoring alongside EEG monitoring could help to improve seizure detection.

Neurological manifestations of SARS-CoV-2 infection in hospitalised children and adolescents in the UK: a prospective national cohort study.

BACKGROUND: The spectrum of neurological and psychiatric complications associated with paediatric SARS-CoV-2 infection is poorly understood. We aimed to analyse the range and prevalence of these complications in hospitalised children and adolescents. METHODS: We did a prospective national cohort study in the UK using an online network of secure rapid-response notification portals established by the CoroNerve study group. Paediatric neurologists were invited to notify any children and adolescents (age <18 years) admitted to hospital with neurological or psychiatric disorders in whom they considered SARS-CoV-2 infection to be relevant to the presentation. Patients were excluded if they did not have a neurological consultation or neurological investigations or both, or did not meet the definition for confirmed SARS-CoV-2 infection (a positive PCR of respiratory or spinal fluid samples, serology for anti-SARS-CoV-2 IgG, or both), or the Royal College of Paediatrics and Child Health criteria for paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS). Individuals were classified as having either a primary neurological disorder associated with COVID-19 (COVID-19 neurology group) or PIMS-TS with neurological features (PIMS-TS neurology group). The denominator of all hospitalised children and adolescents with COVID-19 was collated from National Health Service England data. FINDINGS: Between April 2, 2020, and Feb 1, 2021, 52 cases were identified; in England, there were 51 cases among 1334 children and adolescents hospitalised with COVID-19, giving an estimated prevalence of 3·8 (95% CI 2·9-5·0) cases per 100 paediatric patients. 22 (42%) patients were female and 30 (58%) were male; the median age was 9 years (range 1-17). 36 (69%) patients were Black or Asian, 16 (31%) were White. 27 (52%) of 52 patients were classified into the COVID-19 neurology group and 25 (48%) were classified into the PIMS-TS neurology group. In the COVID-19 neurology group, diagnoses included status epilepticus (n=7), encephalitis (n=5), Guillain-Barré syndrome (n=5), acute demyelinating syndrome (n=3), chorea (n=2), psychosis (n=2), isolated encephalopathy (n=2), and transient ischaemic attack (n=1). The PIMS-TS neurology group more often had multiple features, which included encephalopathy (n=22 [88%]), peripheral nervous system involvement (n=10 [40%]), behavioural change (n=9 [36%]), and hallucinations at presentation (n=6 [24%]). Recognised neuroimmune disorders were more common in the COVID-19 neurology group than in the PIMS-TS neurology group (13 [48%] of 27 patients vs 1 [<1%] of 25 patients, p=0·0003). Compared with the COVID-19 neurology group, more patients in the PIMS-TS neurology group were admitted to intensive care (20 [80%] of 25 patients vs six [22%] of 27 patients, p=0·0001) and received immunomodulatory treatment (22 [88%] patients vs 12 [44%] patients, p=0·045). 17 (33%) patients (10 [37%] in the COVID-19 neurology group and 7 [28%] in the PIMS-TS neurology group) were discharged with disability; one (2%) died (who had stroke, in the PIMS-TS neurology group). INTERPRETATION: This study identified key differences between those with a primary neurological disorder versus those with PIMS-TS. Compared with patients with a primary neurological disorder, more patients with PIMS-TS needed intensive care, but outcomes were similar overall. Further studies should investigate underlying mechanisms for neurological involvement in COVID-19 and the longer-term outcomes. FUNDING: UK Research and Innovation, Medical Research Council, Wellcome Trust, National Institute for Health Research.

Severe cortical damage associated with COVID-19 case report.

Symptoms of COVID-19, as reported during the SARS-CoV-2 pandemic in 2019-2020, are primarily respiratory and gastrointestinal, with sparse reports on neurological manifestations. We describe the case of a 17-year old female with Cornelia de Lange syndrome and well controlled epilepsy, who sustained significant cortical injury during a COVID-19 associated multi-inflammatory syndrome.

The emerging spectrum of COVID-19 neurology: clinical, radiological and laboratory findings.

Preliminary clinical data indicate that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with neurological and neuropsychiatric illness. Responding to this, a weekly virtual coronavirus disease 19 (COVID-19) neurology multi-disciplinary meeting was established at the National Hospital, Queen Square, in early March 2020 in order to discuss and begin to understand neurological presentations in patients with suspected COVID-19-related neurological disorders. Detailed clinical and paraclinical data were collected from cases where the diagnosis of COVID-19 was confirmed through RNA PCR, or where the diagnosis was probable/possible according to World Health Organization criteria. Of 43 patients, 29 were SARS-CoV-2 PCR positive and definite, eight probable and six possible. Five major categories emerged: (i) encephalopathies (n = 10) with delirium/psychosis and no distinct MRI or CSF abnormalities, and with 9/10 making a full or partial recovery with supportive care only; (ii) inflammatory CNS syndromes (n = 12) including encephalitis (n = 2, para- or post-infectious), acute disseminated encephalomyelitis (n = 9), with haemorrhage in five, necrosis in one, and myelitis in two, and isolated myelitis (n = 1). Of these, 10 were treated with corticosteroids, and three of these patients also received intravenous immunoglobulin; one made a full recovery, 10 of 12 made a partial recovery, and one patient died; (iii) ischaemic strokes (n = 8) associated with a pro-thrombotic state (four with pulmonary thromboembolism), one of whom died; (iv) peripheral neurological disorders (n = 8), seven with Guillain-Barré syndrome, one with brachial plexopathy, six of eight making a partial and ongoing recovery; and (v) five patients with miscellaneous central disorders who did not fit these categories. SARS-CoV-2 infection is associated with a wide spectrum of neurological syndromes affecting the whole neuraxis, including the cerebral vasculature and, in some cases, responding to immunotherapies. The high incidence of acute disseminated encephalomyelitis, particularly with haemorrhagic change, is striking. This complication was not related to the severity of the respiratory COVID-19 disease. Early recognition, investigation and management of COVID-19-related neurological disease is challenging. Further clinical, neuroradiological, biomarker and neuropathological studies are essential to determine the underlying pathobiological mechanisms that will guide treatment. Longitudinal follow-up studies will be necessary to ascertain the long-term neurological and neuropsychological consequences of this pandemic.

Subcortical nuclei volumes are associated with cognition in children post-convulsive status epilepticus: Results at nine years follow-up.

PURPOSE: The purpose of the present study was to investigate the relationship between subcortical nuclei volume and cognition in children with post-convulsive status epilepticus (CSE). METHODS: Structural T1-weighted magnetic resonance imaging (MRI) scans (Siemens Avanto, 1.5 T) and neuropsychological assessments (full-scale intelligence quotient (FSIQ) and Global Memory Scores (GMS)) were collected from subjects at a mean 8.5 years post-CSE (prolonged febrile seizures (PFS), n = 30; symptomatic/known, n = 28; and other, n = 12) and from age- and sex-matched healthy controls (HC). Subjects with CSE were stratified into those with lower cognitive ability (LCA) (CSE+, n = 22) and those without (CSE-, n = 48). Quantitative volumetric analysis using Functional MRI of the Brain Software Library (FSL) (Analysis Group, FMRIB, Oxford) provided segmented MRI brain volumes. Univariate analysis of covariance (ANCOVA) was performed to compare subcortical nuclei volumes across subgroups. Multivariable linear regression was performed for each subcortical structure and for total subcortical volume (SCV) to identify significant predictors of LCA (FSIQ <85) while adjusting for etiology, age, socioeconomic status, sex, CSE duration, and intracranial volume (ICV); Bonferroni correction was applied for the analysis of individual subcortical nuclei. RESULTS: Seventy subjects (11.8 ±â€¯3.4 standard deviation (SD) years; 34 males) and 72 controls (12.1 ±â€¯3.0SD years; 29 males) underwent analysis. Significantly smaller volumes of the left thalamus, left caudate, right caudate, and SCV were found in subjects with CSE+ compared with HC, after adjustment for intracranial, gray matter (GM), or cortical/cerebellar volume. When compared with subjects with CSE-, subjects with CSE+ also had smaller volumes of the left thalamus, left pallidum, right pallidum, and SCV. Individual subcortical nuclei were not associated, but SCV was associated with FSIQ (p = 0.005) and GMS (p = 0.014). Intracranial volume and etiology were similarly predictive. CONCLUSIONS: Nine years post-CSE, SCV is significantly lower in children who have LCA compared with those that do not. However, in this cohort, we are unable to determine whether the relationship is independent of ICV or etiology. Future, larger scale studies may help tease this out.

Incidence of early-onset epilepsy: A prospective population-based study.

PURPOSE: The first five years of life reflect a critical period of development prior to formal education yet few epidemiological studies focus on children with early-onset epilepsy (CWEOE; onset <60 months). This study aimed to determine early-onset epilepsy incidence using a comprehensive case identification strategy, and examined socioeconomic status (SES) and ethnicity as risk factors. METHODS: Through a prospective, population-based study, newly diagnosed CWEOE from Fife and Lothian, Scotland, were identified using multiple-source, active surveillance capture-recapture between May 2013 and June 2015. Crude, ascertainment-adjusted, age-adjusted, age- and gender-specific, and epilepsy-type incidence rates were determined. Risk ratios (RR) were calculated to examine SES and ethnicity as risk factors. RESULTS: 59 (36 Male) CWEOE were identified. Ascertainment was 98% (95% CI 94-103). Crude annual incidence of epilepsy in children 0-59 months was 60.2 (95% CI 44.8-75.5) per 100,000 per year; ascertainment-adjusted annual incidence was 61.7 (95% CI 46.2-77.3) per year. Cumulative incidence of West Syndrome/Infantile Spasms was 6.7 per 10,000 live births (95% CI 3.6-12.3). Aetiology was unknown in almost two-thirds of CWEOE. Compared to White-British Isles (BI) children, Asian children (RR 2.6 [95% CI 1.2-5.7], p = .02) and White-non-BI children (RR 2.5 [95% CI 1.2-5.2], p = .02) had increased risk. SES was not a risk factor. CONCLUSION: The high incidence of early-onset epilepsy is similar to previous studies and demonstrates a substantial disease burden. Cause of epilepsy remains unknown in almost two thirds of CWEOE. Ethnicity but not SES affects early-onset epilepsy risk.

Neurobehavioral problems in children with early-onset epilepsy: A population-based study.

PURPOSE: Neurobehavioral problems (i.e., cognitive impairment/behavior problems) are a major challenge in childhood epilepsy. Yet there are limited data in children with early-onset epilepsy (CWEOE; onset ≤4 years), the period in which the incidence of childhood epilepsy is highest. This study aimed to determine the prevalence, spectrum, and risk factors for neurobehavioral problems CWEOE. METHODS: This prospective, population-based, case-controlled study identified children with newly diagnosed early-onset epilepsy in South East Scotland using active multisource capture-recapture surveillance (May 2013 - June 2015). The CWEOE and controls completed an age-appropriate neurobehavioral assessment battery across seven domains: general cognitive ability (GCA), adaptive behavior, externalizing, internalizing, executive functioning, social functioning, and Autism Spectrum Disorder (ASD) risk. RESULTS: Fifty-nine CWEOE were identified with an ascertainment of 98% (95% confidence interval [CI] 94, 103). Forty-six (78% [95% CI 65.9, 86.6]) CWEOE (27 male, median age 25.5, range 1-59, months) and 37 controls (18 male, median age 31.5, range 3-59, months) consented for study entry. The CWEOE were similar to controls in gender, age, prematurity, and family history of psychopathology, but not socioeconomic status (Fisher's exact test [FET] < .001). Neurobehavioral assessments were carried out a median of 2.97 (Interquartile range [IQR] 1.51-4.95) months post epilepsy diagnosis. More CWEOE (63% [95% CI 48.6, 75.5]) had neurobehavioral problems compared with controls (27% [95% CI 15.4, 43.0]); p < 0.01. This observation was independent of socioeconomic status. Multidimensional problems were prevalent in CWEOE with 43% having two or more different domain-level problems; GCA impairment, adaptive behavior, internalizing, social functioning, and ASD risk were particularly marked. Risk factors varied by domain. DISCUSSION: This novel study using comprehensive psychometric assessments found that neurobehavioral problems in CWEOE were detectable, common, and multidimensional. The degree of cooccurrence implies that problems are the norm, and multidimensional screening should be considered at epilepsy onset. The findings could aid policy development on health and educational provision in CWEOE.

Analysis of EEG networks and their correlation with cognitive impairment in preschool children with epilepsy.

OBJECTIVE: Cognitive impairment (CI) is common in children with epilepsy and can have devastating effects on their quality of life. Early identification of CI is a priority to improve outcomes, but the current gold standard of detection with psychometric assessment is resource intensive and not always available. This paper proposes exploiting network analysis techniques to characterize routine clinical electroencephalography (EEG) to help identify CI in children with early-onset epilepsy (CWEOE) (0-5 years old). METHODS: Functional networks from routinely acquired EEGs of 51 newly diagnosed CWEOE were analyzed. Combinations of connectivity metrics with subnetwork analysis identified significant correlations between network properties and cognition scores via rank correlation analysis (Kendall's τ). Predictive properties were investigated using a cross-validated classification model with healthy cognition, mild/moderate CI, and severe CI classes. RESULTS: Network analysis revealed phase-dependent connectivity having higher sensitivity to CI and significant functional network changes across EEG frequencies. Nearly 70.5% of CWEOE were aptly classified as having healthy cognition, mild/moderate CI, or severe CI using network features. These features predicted CI classes 55% better than chance and halved misclassification penalties. CONCLUSIONS: Cognitive impairment in CWEOE can be detected with sensitivity at 85% (in identifying mild/moderate or severe CI) and specificity of 84%, by network analysis. SIGNIFICANCE: This study outlines a data-driven methodology for identifying candidate biomarkers of CI in CWEOE from network features. Following additional replication, the proposed method and its use of routinely acquired EEG forms an attractive proposition for supporting clinical assessment of CI.

Cognitive impairment in early onset epilepsy is associated with reduced left thalamic volume.

OBJECTIVE: The objective of this study was to investigate whether reduction of thalamic volumes in children with early onset epilepsy (CWEOE) is associated with cognitive impairment. METHODS: This is a nested case-control study including a prospectively recruited cohort of 76 children with newly-diagnosed early onset epilepsy (onset <5years age) and 14 healthy controls presenting to hospitals within NHS Lothian and Fife. Quantitative volumetric analysis of subcortical structures was performed using volumetric T1-weighted magnetic resonance imaging (MRI) and correlated with the results of formal neurocognitive and clinical assessment. False discovery rate was used to correct for multiple comparisons as appropriate with q<0.05 used to define statistical significance. RESULTS: Age, gender, and intracranial volume (ICV)-adjusted left thalamic volumes were significantly reduced in CWEOE with cognitive impairment compared to CWEOE without impairment (5295mm3 vs 6418mm3, q=0.008) or healthy controls (5295mm3 vs 6410mm3, q<0.001). The differences in left thalamic volume remained if gray matter or cortical/cerebellar volumes were used as covariates rather than ICV (q<0.05). The degree of volume reduction correlated with the severity of cognitive impairment (q=0.048). SIGNIFICANCE: Reduced left thalamic volume may be a biomarker for cognitive impairment in CWEOE and could help inform the need for further formal cognitive evaluations and interventions.

Quantifying the deficit-imaging neurobehavioural impairment in childhood epilepsy.

BACKGROUND: Neurobehavioral impairments such as learning difficulty, autism, attention deficit hyperactivity disorder (ADHD) and mood or behavioural problems are known to be increased in children with epilepsy; however, they remain under-recognised and often cause considerable morbidity. Quantitative neuroimaging techniques offer a potential avenue to improving our understanding of the underlying pathological basis for these disorders, aiding with diagnosis and risk stratification. METHODS: A systematic review was undertaken for original research articles involving magnetic resonance imaging in children with epilepsy and one or more neurobehavioural impairments. Studies were reviewed with respect to patient population, methodology and magnetic resonance imaging (MRI) findings. RESULTS: A total of 25 studies were identified and included in this review. The majority of studies looked at single impairments, commonly cognitive impairment or ADHD, with few studies reporting on other impairments. Reductions in cortical grey matter and disruptions of functional and structural brain networks were associated with poorer cognitive performance and disruptions of grey and white matter within a fronto-striatal-cerebellar network associated with ADHD. Insufficient studies were available to report on other impairments. CONCLUSIONS: Relatively few studies exist in this field and those that do are methodologically diverse. Further investigation is required to determine if the changes reported to date are epilepsy syndrome specific or have broader applicability.

Estimating intracranial volume using intracranial area in healthy children and those with childhood status epilepticus.

BACKGROUND: Correcting volumetric measurements of brain structures for intracranial volume (ICV) is important in comparing volumes across subjects with different ICV. The aim of this study was to investigate whether intracranial area (ICA) reliably predicts actual ICV in a healthy pediatric cohort and in children with convulsive status epilepticus (CSE). METHODS: T1-weighted volumetric MRI was performed on 20 healthy children (control group), 10 with CSE with structurally normal MRI (CSE/MR-), and 12 with CSE with structurally abnormal MRI (CSE/MR+). ICA, using a mid-sagittal slice, and the actual ICV were measured. RESULTS: A high Spearman correlation was found between the ICA and ICV measurements in the control (r = 0.96; P < 0.0001), CSE/MR- (r = 0.93; P = 0.0003), and CSE/MR+ (r = 0.94; P < 0.0001) groups. On comparison of predicted and actual ICV, there was no significant difference in the CSE/MR- group (P = 0.77). However, the comparison between predicted and actual ICV was significantly different in the CSE/MR+ (P = 0.001) group. Our Bland-Altman plot showed that the ICA method consistently overestimated ICV in children in the CSE/MR+ group, especially in those with small ICV or widespread structural abnormalities. CONCLUSIONS: After further validation, ICA measurement may be a reliable alternative to measuring actual ICV when correcting volume measurements for ICV, even in children with localized MRI abnormalities. Caution should be applied when the method is used in children with small ICV and those with multilobar brain pathology.

Application of diffusion tensor imaging and tractography of the optic radiation in anterior temporal lobe resection for epilepsy: a systematic review.

BACKGROUND: Approximately 50-100% of patients with temporal lobe epilepsy undergoing anterior temporal lobe resection (ATLR) will suffer a postoperative visual field defect (VFD) due to disruption of the optic radiation (OpR). OBJECTIVE: We conducted a systematic review of the literature to examine the role of DTI and tractography in ATLR and its potential in reducing the incidence of postoperative VFD. METHODS: We conducted an electronic literature search using PubMed, Embase, Web of Science and BMJ case report databases. Eligibility for study inclusion was determined on abstract screening using the following criteria: the study must have been (1) an original investigation or case report in humans; (2) investigating the OpR with DTI in cases of ATLR in temporal lobe epilepsy; (3) investigating postoperative VFD. All forms of ATLR and ways of assessing VFD were included to reflect clinical practice. RESULTS: 13 studies (four case reports, eight prospective observational studies, one prospective comparative trial) were included in the review, 179 (mean±SD, 13.8±12.6; range, 1-48) subjects were investigated using DTI. The time of postoperative VFD measurement differed between the detected studies, ranging from two weeks to nine years following ATLR. A modest number of studies and insufficient statistical homogeneity precluded meta-analysis. However, DTI methods were consistently accurate at quantifying and predicting postoperative damage to the OpR. These methods revealed a correlation between the extent of OpR damage and the severity of postoperative VFD. The first and only trial with 15 subjects compared to 23 controls reported that using intraoperative tractography in ATLR significantly reduces the occurrence of postoperative VFD on comparison to conventional surgical planning. CONCLUSIONS: DTI shows potential to be an effective method used in planning ATLR. Findings from a single modest sized study suggest that tractography may be employed as part of intraoperative navigation techniques in order to avoid injury to the OpR. Further research needs to be conducted to ensure the applicability and effectiveness of this technology before implementation in routine clinical practice.

Hippocampal volume loss following childhood convulsive status epilepticus is not limited to prolonged febrile seizures.

PURPOSE: Childhood convulsive status epilepticus (CSE), in particular prolonged febrile seizures (PFS), has been linked with mesial temporal sclerosis (MTS). Previous studies have shown that hippocampal injury occurs in the acute phase immediately following CSE, but little is known about the longer term evolution of such injury. This study aimed to investigate the longer term outcome of childhood CSE with sequential magnetic resonance imaging (MRI) looking for progressive hippocampal injury during the first year post-CSE. METHODS: Eighty children (0.18-15.5 years) underwent brain MRI 1 month post-CSE, 50 with a repeat MRI at 6 months and 46 with repeat MRI at 12 months post-CSE. Thirty-one control subjects without neurologic problems had a single brain MRI for comparison. Hippocampal volumes were measured from each MRI scan by two independent observers, and hippocampal growth rates were estimated in each patient with suitable imaging. KEY FINDINGS: Hippocampal volume loss was found in 20-30% of patients and was not associated with the etiology or clinical features of CSE, including seizure duration or focality. A borderline association was found between a history of previous seizures (p = 0.063) and the number of previous febrile seizures (p = 0.051), suggesting that multiple insults may be important in the pathogenesis of progressive hippocampal injury. SIGNIFICANCE: It is apparent that progressive hippocampal damage can occur after CSE of any etiology and is not limited to PFS. Repeated seizures may play an important role, but further follow-up is needed to determine any other risk factors and proportion of children showing initial volume loss progress to clinical MTS and temporal lobe epilepsy.

Early developmental outcomes in children following convulsive status epilepticus: a longitudinal study.

PURPOSE: Convulsive status epilepticus (CSE) is the most common pediatric neurologic emergency and is often associated with unfavorable neurodevelopmental outcomes. The early developmental trajectory of children following CSE has not been previously investigated, leaving a gap in our understanding of how these adverse long-term outcomes emerge. METHODS: We prospectively recruited children aged between 1 and 42 months from a predefined geographic region of North London who had at least one episode of CSE and classified them as prolonged febrile seizures (PFS) or nonfebrile CSE. Neuropsychological and imaging investigations were conducted within 6 weeks of CSE (baseline) and were repeated a year later (follow-up). Neurodevelopment was assessed using the Bayley Scales of Infant Development III and compared to normally developing children. Predictors of neurodevelopmental scores at baseline and follow-up were investigated using regression analyses. KEY FINDINGS: Of the 54 children that underwent investigations a mean of 38 days following CSE, 27 had PFS (mean age 18.4 months) and 27 had nonfebrile CSE (mean age 15.5 months). In addition, 17 healthy controls were assessed (mean age 20.49 months). Children with nonfebrile CSE had a worse developmental outcome than children with PFS (p < 0.002), despite there being no differences in seizure characteristics. In contrast to expectations, the PFS group had a worse developmental outcome than controls (p = 0.002). There were no significant differences in performance from baseline to 1-year follow-up for the 70.4% of children who provided data. Seizure characteristics were not shown to be significant predictors of performance. SIGNIFICANCE: CSE is associated with developmental impairments within 6 weeks of the acute event that continue to be present a year onward. This is also true of PFS cases that under-perform relative to controls despite mean scores within the clinically normal range. The absence of a change in performance from baseline to follow-up as well as the lack of a relationship between seizure characteristics and developmental outcomes supports the notion that premorbid abilities may be overshadowing any direct effects of CSE itself on outcome.

Recognition memory is impaired in children after prolonged febrile seizures.

Children with a history of a prolonged febrile seizure show signs of acute hippocampal injury on magnetic resonance imaging. In addition, animal studies have shown that adult rats who suffered febrile seizures during development reveal memory impairments. Together, these lines of evidence suggest that memory impairments related to hippocampal injury may be evident in human children after prolonged febrile seizures. The current study addressed this question by investigating memory abilities in 26 children soon after a prolonged febrile seizure (median: 37.5 days) and compared their results to those of 37 normally developing children. Fifteen patients were reassessed at a mean of 12.5 months after their first assessment to determine the transiency of any observed effects. We used the visual paired comparison task to test memory abilities in our group, as this task does not depend on verbal abilities and also because successful performance on the task has been proven to depend on the presence of functional hippocampi. Our findings show that patients perform as well as controls in the absence of a delay between the learning phase and the memory test, suggesting that both groups are able to form representations of the presented stimulus. However, after a 5-min delay, patients' recognition memory is not different from chance, and comparison of patients and controls points to an accelerated forgetting rate in the prolonged febrile seizure group. The patients' performance was not related to the time elapsed from the acute event or the duration of the prolonged febrile seizure, suggesting that the observed effect is not a by-product of the seizure itself or a delayed effect of medication administered to terminate the seizure. By contrast, performance was related to hippocampal size; participants with the smallest mean hippocampal volumes revealed the biggest drop in performance from the immediate to the delayed paradigm. At follow-up, children were still showing deficiencies in recognizing a face after a 5-min delay. Similarly, this suggests that the observed memory impairments are not a transient effect of the prolonged febrile seizures. This is the first report of such impairments in humans, and it is clinically significant given the links between mesial temporal sclerosis and prolonged febrile seizures. The persistence of these impairments a year onwards signals the potential benefits of intervention in these children who run the risk of developing episodic memory deficits in later childhood.

The role of magnetic resonance imaging in the follow-up of children with convulsive status epilepticus.

AIM: The aim of this study was to determine the yield of magnetic resonance imaging (MRI) after an episode of childhood convulsive status epilepticus (CSE) and to identify the clinical predictors of an abnormal brain scan. METHOD: Children were recruited following an episode of CSE from an established clinical network in north London. Eighty children (age range 1mo-16y; 39 males; 41 females) were enrolled and seen for clinical assessment and brain MRI within 13 weeks of suffering from an episode of CSE. Scans were reviewed by two neuroradiologists and classified as normal (normal/normal-variant) or abnormal (minor/major abnormality). Factors predictive of an abnormal scan were investigated using logistic regression. RESULTS: Eighty children were recruited at a mean of 31.8 days (5-90d) after suffering from CSE. Structural abnormalities were found in 31%. Abnormal neurological examination at assessment (odds ratio [OR] 190.46), CSE that was not a prolonged febrile seizure (OR 77.12), and a continuous rather than an intermittent seizure (OR 29.98) were all predictive of an abnormal scan. No children with previous neuroimaging had new findings that altered their clinical management. INTERPRETATION: Brain MRI should be considered for all children with a history of CSE who have not previously undergone MRI, especially those with non-prolonged febrile seizure CSE, those with persisting neurological abnormalities 2 to 13 weeks after CSE, and those with continuous CSE.