Volumetric magnetic resonance imaging differences between complex febrile seizure and recurrent simple febrile seizure.

PURPOSE: We investigated the volumetric differences in cortical and subcortical structures between patients with complex febrile seizure (FS) and recurrent simple FS. We aimed to identify the brain morphological patterns of children with complex FS. METHODS: Twenty-five patients with complex FS and age- and sex-matched 25 patients with recurrent simple FS with structural magnetic resonance imaging (MRI) scans were studied. Cortical volumetric analysis was performed using a voxel-based morphometry method with the CAT12 toolbox within SPM12. FSL-FIRST was used to obtain volume measures of subcortical deep grey matter structures (amygdala, caudate nucleus, thalamus, nucleus accumbens, putamen, globus pallidus, and hippocampus). The volumetric asymmetry index (AI) and laterality index (LI) were calculated for each subcortical structure. RESULTS: Compared with recurrent simple FS, complex FS demonstrated lower volume in the left putamen (p = .003) and right nucleus accumbens (p = .001). Additionally, patients with complex FS presented a higher magnitude of AI of the nucleus accumbens (p < .001) compared with recurrent simple FS. CONCLUSIONS: The findings indicate that volumetric analysis may be a useful marker for the detection of FS-induced changes that reflect microstructural alterations. This study is the first to report on alterations in the putamen and nucleus accumbens in FS.

[Clinical and imaging features of acute encephalopathy with biphasic seizures and late reduced diffusion in children].

Objective: To explore the clinical and imaging features of acute encephalopathy with biphasic seizures and late reduced diffusion(AESD) in children. Methods: For the case series study, 21 children with AESD from Peking University First Hospital, Provincial Children's Hospital Affiliated to Anhui Medical University, Children's Hospital of Fudan University, and Shanxi Children's Hospital who were diagnosed and treated from October 2021 to July 2023 were selected. Clinical data were collected to summarize their clinical information, imaging, and laboratory tests, as well as treatment and prognostic characteristics. Descriptive statistical analysis was applicated. Results: Of the 21 cases with AESD, 11 were males and 10 were females, with the age of onset of 2 years and 6 months (1 year and 7 months, 3 years and 6 months). Of the 21 cases, 18 were typical cases with biphasic seizures. All typical cases had early seizures within 24 hours before or after fever onset. Among them, 16 cases had generalized seizures, 2 cases had focal seizures, and 7 cases reached the status epilepticus. Of the 21 cases, 3 atypical cases had late seizures in biphasic only. The late seizures in the 21 cases occurred on days 3 to 9. The types of late seizures included focal seizures in 12 cases, generalized seizures in 6 cases, and both focal and generalized seizures in 3 cases. Diffusion-weighted imaging (DWI) test on days 3 to 11 showed reduced diffusion of subcortical white matter which was named "bright tree sign" in all cases. The diffuse cerebral atrophy predominantly presented in the front-parietal-temporal lobes was found in 19 cases between day 12 and 3 months after the onset of the disease. Among 21 cases, 20 had been misdiagnosed as autoimmune encephalitis, central nervous system infection, febrile convulsions, posterior reversible encephalopathy syndrome, acute disseminated encephalomyelitis, and hemiconvulsion-hemiplegia-epilepsy syndrome. All the cases received high-dose gammaglobulin and methylprednisolone pulse therapy with poor therapeutic effect. By July 2023, 18 cases were under follow-up. Among them, 17 cases were left with varying degrees of neurologic sequelae, including 11 cases with post-encephalopathic epilepsy; 1 recovered completely. Conclusions: AESD is characterized by biphasic seizures clinically and "bright tree sign" on DWI images. Symptomatic and supportive treatments are recommended. The immunotherapy is ineffective. The prognosis of AESD is poor, with a high incidence of neurological sequelae and a low mortality.

Morphometry and network-based atrophy patterns in SCN1A-related Dravet syndrome.

Mutations of the voltage-gated sodium channel SCN1A gene (MIM#182389) are among the most clinically relevant epilepsy-related genetic mutations and present variable phenotypes, from the milder genetic epilepsy with febrile seizures plus to Dravet syndrome, a severe developmental and epileptic encephalopathy. Qualitative neuroimaging studies have identified malformations of cortical development in some patients and mild atrophic changes, partially confirmed by quantitative studies. Precise correlations between MRI findings and clinical variables have not been addressed. We used morphometric methods and network-based models to detect abnormal brain structural patterns in 34 patients with SCN1A-related epilepsy, including 22 with Dravet syndrome. By measuring the morphometric characteristics of the cortical mantle and volume of subcortical structures, we found bilateral atrophic changes in the hippocampus, amygdala, and the temporo-limbic cortex (P-value < 0.05). By correlating atrophic patterns with brain connectivity profiles, we found the region of the hippocampal formation as the epicenter of the structural changes. We also observed that Dravet syndrome was associated with more severe atrophy patterns with respect to the genetic epilepsy with febrile seizures plus phenotype (r = -0.0613, P-value = 0.03), thus suggesting that both the underlying mutation and seizure severity contribute to determine atrophic changes.

Focality in Febrile Seizures: A Retrospective Assessment Using Arterial Spin Labeling MRI.

PURPOSE: Defining focality of febrile seizures (FS) in clinical practice remains controversial. We investigated focality issues in FS with a postictal arterial spin labeling (ASL) sequence. METHODS: We retrospectively reviewed 77 children (median: 19.0 months, range: 15.0-33.0 months) who consecutively visited our emergency room for FS and underwent brain magnetic resonance imaging (MRI), including the ASL sequence, within 24 hours of seizure onset. ASL data were visually analyzed to assess perfusion changes. Factors related to the perfusion changes were investigated. RESULTS: The mean time to ASL acquisition was 7.0 (interquartile range: 4.0-11.0) hours. The most common seizure classification was unknown-onset seizures (n = 37, 48%), followed by focal-onset (n = 26, 34%) and generalized-onset seizures (n = 14, 18%). Perfusion changes were observed in 43 (57%) patients: most were hypoperfusion (n = 35, 83%). The temporal regions were the most common location of perfusion changes (n = 26, 60%); the majority of these were distributed in the unilateral hemisphere. Perfusion changes were independently associated with seizure classification (focal-onset seizures, adjusted odds ratio [aOR]: 9.6, p = 0.01; unknown-onset seizures aOR: 10.4, p < 0.01), and prolonged seizures (aOR: 3.1, p = 0.04), but not with other factors (age, sex, time to MRI acquisition, previous FS, repeated FS within 24 hour, family history of FS, structural abnormality on MRI, and developmental delay). The focality scale of seizure semiology positively correlated with perfusion changes (R = 0.334, p < 0.01). CONCLUSION: Focality in FS may be common, and its primary origin might be the temporal regions. ASL can be useful for assessing focality in FS, particularly when seizure onset is unknown.

The Utility of Infectious and Neurodiagnostic Testing in Children With Complex Febrile Seizures Requiring Mechanical Ventilation.

A retrospective cohort analysis was performed on 79 consecutive patients between 6 months and 5 years admitted to a tertiary hospital with a diagnosis of complex febrile seizures requiring mechanical ventilation from 2011 to 2017 to determine the utility of infectious and neurologic diagnostics. Intubation was used as a proxy for severity of illness. The overall intensive care unit stay was short (95% intubated <24 hours, 88% admitted <3 days). No life-threatening infections were identified, and none required surgical interventions. Electroencephalogram (EEG) was obtained on 43%, 26% of which were abnormal. Sixty-six percent of patients were discharged on rescue benzodiazepine and 20% with maintenance antiseizure medications. Duration of follow-up averaged 4 years (range 1 month to 9 years); 8 patients (10%) were subsequently diagnosed with epilepsy. Our findings suggest that extensive diagnostic evaluations may not be necessary for children with complex febrile seizures requiring mechanical ventilation although the role of EEG is less understood.

Organic Lesions in the Brain MRI of Children with Febrile Seizure.

OBJECTIVE: Seizure is the most common neurological disorders in children, where 4-10% of the cases experience at least one seizure before the age of 16. The most frequent causes of seizures in children are fever, epilepsy, infection and brain damage. The aim of this study was to investigate the frequency of organic lesions in MRI of children with seizures unrelated to fever. MATERIALS AND METHODS: This cross-sectional study included children presented with fever-unrelated seizures. The MRI was examined by a radiologist to identify abnormal findings in each patient. A researcher-made questionnaire including general information, history of head trauma, obstructed labor and the history of seizure was completed for the patients. RESULTS: Of 287 children with fever-related seizure, 127 (45.7%) were male and 151 (54.3%) were female. History of seizure, history of obstructed labor, abnormal MRI, complete delay, use of antiepileptic drug and history of trauma were 22(9.9%), 1 (0.4%), 11(4%), 5(1.8%), 259(93.2%) and 12 (4.3%), respectively. Of 11 patients with abnormal MRI, 4 had MTS lesions, 2 had tumor lesions, 2 had scarring trauma, 1 had an epidural abscess and 1 had meningitis. The frequency of organic lesions had no significant differences based on gender, use of antiepileptic drug and traumatic history, but it had a significant relation with obstructed labor andthehistory of seizure. CONCLUSION: The results showed that organic brain lesions in children with fever-unrelated seizure had a significant relationship with the history of seizure and obstructed maternal labor.

Transient cortical diffusion restriction in children immediately after prolonged febrile seizures.

AIM: Little is known about acute febrile status epilepticus-induced injury of extrahippocampal structures. To clarify the presence and clinical significance of acute extrahippocampal injuries, we performed diffusion-weighted imaging (DWI) in children immediately after prolonged febrile seizure (PFS). METHOD: We performed a retrospective cohort study in children younger than 6 years old who visited one of two hospitals due to PFSs between January 2013 and October 2018. PFS was defined as a febrile seizure that persisted for 15 min or longer. We collected brain DWI data within 6 h of the end of PFS. When the initial DWI detected an abnormality, a follow-up DWI was performed a few days later. RESULTS: The study population consisted of 101 patients with PFSs. DWI was performed within 6 h in 51 patients, while the remaining 50 patients did not undergo imaging because of good recovery of consciousness. Restricted cortical diffusion was evident in 9 (18%) patients on initial DWI. All of them underwent DWI within 100 min after PFS. Restricted cortical diffusion was associated with male sex, asymmetrical PFS symptoms, and a shorter duration between the end of the seizure and DWI, but was not associated with seizure duration. All cortical abnormalities had resolved on follow-up DWI of these patients within 72 h after the initial imaging, but ipsilateral hippocampal hyperintensity appeared in one patient. All 9 patients with restricted cortical diffusion were finally diagnosed with PFS and discharged without sequelae. CONCLUSIONS: Some children with PFSs exhibit transient restricted diffusion in the regional cortex on DWI performed immediately after the end of PFS. These transient diffusion changes were not associated with unfavorable epileptic sequelae or neuroimaging in the short-term.

Two Different Manifestations of Neonatal Vascular Injury: Dyke-Davidoff-Masson Syndrome and Crossed Cerebellar Atrophy.

Dyke-Davidoff-Masson syndrome (DDMS) was first described in 1933 as a clinical condition characterized by hemiatrophy, hyperpneumatization of paranasal sinuses, contralateral hemiparesis, facial asymmetry, seizures, and mental retardation.1 DDMS can be of 2 types: congenital and acquired. The congenital type can be caused by various conditions experienced during fetal or early childhood development, including ischemia, infarction, trauma, infections, and hemorrhage. The acquired type is mostly associated with hemorrhage, trauma, and infections experienced after 1 month of age. DDMS can manifest alone or can be accompanied by crossed cerebellar atrophy (CCA) which is a newly discovered radiological marker characterized by prominent cortical sulci and loss of cerebellar parenchyma. The congenital type of DDMS is known to be accompanied by ipsilateral cerebellar atrophy and the acquired type is known to be accompanied by contralateral cerebellar atrophy.2,3 Supratentorial events may lead to destruction in the cortico-ponto-cerebellar pathways, mostly in the contralateral side of the body (80%) due to decussation.4 In this report, we present 2 cases of DDMS accompanied by CCA to emphasize the possibility that the DDMS cases with severe intrauterine hemorrhage can be accompanied by contralateral CCA and migratory abnormalities rather than ipsilateral CCA and clinical survey.

Predictors of clinically urgent intracranial pathology at neuroimaging in children with complex febrile seizures: a retrospective cross-sectional study.

AIM: To assess the prevalence of clinically urgent intracranial pathology (CUIP) in children visiting the emergency department with a complex febrile seizure (CFS). METHODS: Retrospective cohort review. We analysed the visits of patients for a CFS from January 2007 to December 2011 in seven paediatric emergency departments. Our main outcomes were the proportions of CUIP diagnosed between day 0 and 1 and within 30 days after the index visit. RESULTS: From 1 183 487 visits, 839 were for a CFS and 130 (15.5%) of these had a neuroimaging performed within 30 days (CT scan for 75 visits [8.9%], MRI for 30 visits [3.6%] and both for 25 visits [3.0%]). Three CUIP were diagnosed between day 0 and 1 (0.4% [CI-95%: 0.1-1.3]), 5 within 30 days after the index visit (0.7% [CI-95%: 0.2-1.7]) but none among the 630 visits of children presenting with a normal neurological clinical examination (0% [95% CI: 0.0-0.7]), nor among the 468 presenting only with multiple seizure (0% [95% CI: 0.0-1.0]). CONCLUSION: In children with a CFS, CUIP is rare event in the subgroup of children with a normal neurological clinical examination and in those with brief generalised multiple seizures.

Severe Factor X Deficiency Presenting as Febrile Seizure in an Infant.

Factor X deficiency is a severe inherited coagulation disorder, which is characterized by severe systemic bleeding manifestations in affected individuals. It is a rare disorder with a frequency of around 1:1,000,000 in the general population. We present the case of an infant with factor X deficiency who presented with complex febrile seizure. Although febrile seizures are very common in children, a closer scrutiny leads to neuroimaging and finding of intracranial bleed. Hematologic and genetic investigations confirmed the diagnosis. A high index of suspicion should be maintained to diagnose uncommon bleeding disorders in children.

Hippocampal diffusion abnormality after febrile status epilepticus is related to subsequent epilepsy.

OBJECTIVE: To assess hippocampal signal changes on diffusion-weighted imaging (DWI) during the acute period after febrile status epilepticus (FSE) and to examine the relationship between DWI and subsequent epilepsy. METHODS: A prospective, multicenter study of children with a first episode of FSE was performed. The patients underwent magnetic resonance imaging (MRI) within 3 days of FSE, and signal intensity was evaluated on DWI. Electroencephalography studies within 3 days of FSE were also assessed. Nine to 13 years after FSE, information on subsequent epilepsy was obtained. RESULTS: Twenty-two children with FSE were evaluated. DWI showed unilateral hippocampal hyperintensity in six patients (27%). Three of six patients with hippocampal hyperintensity had ipsilateral thalamic hyperintensity. On EEG within 3 days of FSE, five of six patients with hippocampal hyperintensity had ipsilateral focal slowing, spikes, or attenuation. Nine to 13 years later, the outcomes could be determined in five patients with hippocampal hyperintensity and in 10 without. All 5 patients with hippocampal hyperintensity had hippocampal atrophy and developed focal epilepsy, whereas only 1 of 10 patients without hippocampal hyperintensity developed epilepsy (P = 0.002). Ictal semiology was concordant with temporal lobe seizures in all patients. Ipsilateral temporal epileptiform abnormalities were seen on EEG in four of five at last follow-up. SIGNIFICANCE: Acute DWI hippocampal hyperintensity was seen in 27% of patients with FSE. Acute DWI hyperintensity suggests cytotoxic edema caused by prolonged seizure activity. Hippocampal DWI hyperintensity is related to mesial temporal lobe epilepsy and can be a target of neuroprotective treatments to prevent the onset of epilepsy.

Infantile epilepsy with multifocal myoclonus caused by TBC1D24 mutations.

PURPOSE: To summarize the clinical features and neuroimaging changes of epilepsy associated with TBC1D24 mutations. METHODS: Genetic testing was conducted in all epilepsy patients without acquired risk factors for epilepsy. Epilepsy patients identified with TBC1D24 compound heterozygous mutations by next-generation sequencing (NGS) epilepsy panel or whole exome sequencing (WES) were enrolled. The enrolled patients were followed up to summarize the clinical features. RESULTS: Nineteen patients were identified with TBC1D24 compound heterozygous mutations. Nine patients carried the same pathogenic variant c.241_252del. The seizure onset age ranged from 1 day to 8 months of age (median age 75 days). The most prominent features were multifocal myoclonus and epilepsia partialis continua (EPC). Myoclonus could be triggered by fever or infection in 15 patients, and could be terminated by sleep or sedation drugs. Psychomotor developmental delay was presented in 11 patients. Six patients exhibited hearing loss. Brain MRIs were abnormal in eight patients. Twelve patients were diagnosed with epilepsy syndromes including one patient who was diagnosed with Dravet syndrome. Two patients died due to status epilepticus at 4 months and 19 months of age, respectively. CONCLUSION: TBC1D24 mutation related epilepsy was drug-resistant. Multifocal myoclonus, EPC, and fever-induced seizures were common clinical features. Most patients presented psychomotor developmental delay. The neuroimaging abnormality and hearing loss could exacerbate during follow-up.

The spectrum of neuroimaging findings in febrile infection-related epilepsy syndrome (FIRES): A literature review.

Febrile infection-related epilepsy syndrome (FIRES) is a rare severe epileptic syndrome occurring in previously healthy children and characterized by refractory status epilepticus (SE) following a febrile illness. Brain imaging findings in affected patients have been reported in few case series and some case reports. This article is a comprehensive review of the magnetic resonance imaging (MRI) characteristics in all reported patients with a diagnosis of FIRES, describing the findings in the acute and chronic phases of the disease, and discussing possible pathogenesis and radiologic differential diagnoses. Most of the patients had normal brain scans in the acute phase (61%) and about 25% of the patients reported in literature had abnormalities in the temporal lobes. Changes in the basal ganglia and rarely in thalami or brainstem have also been described, as well as diffuse cerebral edema in a minority of patients during the acute phase. The chronic phase of the disease was characterized by atrophic changes and evidence of mesiotemporal sclerosis. An understanding of these MRI abnormalities is necessary to support the diagnosis of FIRES and exclude mimics.

Improved chemical exchange saturation transfer imaging with real-time frequency drift correction.

PURPOSE: To investigate the effects of frequency drift on chemical exchange saturation transfer (CEST) imaging at 3T, and to propose a new sequence for correcting artifacts attributed to B0 drift in real time. THEORY AND METHODS: A frequency-stabilized CEST (FS-CEST) imaging sequence was proposed by adding a frequency stabilization module to the conventional non-frequency-stabilized CEST (NFS-CEST) sequence, which consisted of a small tip angle radiofrequency excitation pulse and readout of three non-phase-encoded k-space lines. Experiments were performed on an egg white phantom and 26 human subjects on a heavy-duty clinical scanner, in order to compare the difference of FS-CEST and NFS-CEST sequences for generating the z-spectrum, magnetization transfer ratio asymmetry (MTRasym ) spectrum, and amide proton transfer weighted (APTw) image. RESULTS: The B0 drift in CEST imaging, if not corrected, would cause APTw images and MTRasym spectra from both the phantom and volunteers to be either significantly higher or lower than the true values, depending on the status of the scanner. The FS-CEST sequence generated substantially more stable MTRasym spectra and APTw images than the conventional NFS-CEST sequence. Quantitatively, the compartmental-average APTw signals (mean ± standard deviation) from frontal white matter regions of all 26 human subjects were -0.32% ± 2.32% for the NFS-CEST sequence and -0.14% ± 0.37% for the FS-CEST sequence. CONCLUSIONS: The proposed FS-CEST sequence provides an effective approach for B0 drift correction without additional scan time and should be adopted on heavy-duty MRI scanners.

Myelin water fraction changes in febrile seizures.

OBJECTIVE: The objective of this feasibility study was to investigate whether myelin water fraction (MWF) patterns can differentiate children presenting with febrile seizures who will go on to develop nonfebrile epilepsy from those who will not. PATIENTS AND METHODS: As part of a prospective study of myelination patterns in pediatric epilepsy, seven subjects with febrile seizures underwent magnetic resonance imaging (MRI) including the following standard sequences-T1-weighted, T2-weighted, fluid-attenuated inversion recovery (FLAIR)-and an additional experimental sequence, multicomponent-derived equilibrium single-pulse observation of T1 and T2 (mcDESPOT) to quantify MWF. For each of these subjects, MWF maps were derived and compared with an age-matched population-averaged MWF atlas. RESULTS: All seven subjects (<5 years old) initially presented with febrile seizures. Of the seven, four had complex seizures and three had simple seizures. All of the children with simple febrile seizures had higher MWF compared with model-derived controls and did not develop epilepsy. All of the children with complex febrile seizures had lower MWF than their model-derived control, and two of these subjects later developed epilepsy. CONCLUSION: This is the first study in which MWF maps were used to study children with febrile *seizures. This data suggests that relatively higher or stable MWF compared with normative data indicates a lower risk of nonfebrile epilepsy while relatively lower MWF may indicate a pathological condition that could lead to nonfebrile epilepsy.

Intermittent oral levetiracetam reduced recurrence of febrile seizure accompanied with epileptiform discharge: a pilot study.

BACKGROUND: In previous study, we have found intermittent oral levetiracetam (LEV) can effectively prevent recurrence of febrile seizure (FS). This study aimed to analyze the effects of the preventive on the patients with frequent FS accompanied with epileptiform discharge. METHODS: Patients with frequent FS were assigned to undergo Electroencephalogram (EEG). At the onset of fever, the patients who presented epileptiform discharge were orally administered with LEV with a dose of 15-30 mg/kg per day twice daily for 1 week, thereafter, the dosage was gradually reduced until totally discontinued in the second week. The seizure frequency associated with febrile events and FS recurrence rate during a 48-week follow-up were analyzed. RESULTS: among the 19 patients presented epileptiform discharge on EEG, 31.58% (6 of 19) had complex FS, 68.42% (13 of 19) had simple FS. Up to 57.89% (11 of 19) had a family history of seizure disorder and 36.84% (7 of 19) had a family history of FS in first-degree relatives. 42.11% (8 of 19) happened the first FS episode at the age < 18 months. 36.84% (7/19) presented generalized spikes, 63.16% (12/19) showed focal spikes. During the 48-week follow-up period, the patients experienced 26 febrile episodes, none of them presented seizure recurrence. CONCLUSION: Intermittent oral LEV can prevent the seizure recurrence of FS accompanied with epileptiform discharge in 48-week. However, further randomized controlled trials should be conducted. TRIAL REGISTRATION: ChiCTR-IPR-15007241 ; Registered 1 January 2014 - Retrospectively registered.

Spinal Fluid Cytokine Levels and Single-Photon Emission Computed Tomography Findings in Complex Febrile Seizures.

In this study, the authors assessed cerebrospinal fluid cytokine levels and single-photon emission computed tomography (SPECT) findings in complex febrile seizures. This study included 23 Japanese patients with complex febrile seizures. Twenty patients underwent SPECT and 12 underwent analysis of cerebrospinal fluid cytokine levels (interleukin [IL]-6, interleukin-10, interleukin-17, interleukin-1ß, tumor necrosis factor-α, and interferon-γ); 9 patients underwent both studies. Cerebrospinal fluid cytokine levels were compared between the current complex febrile seizure patients and 30 patients with acute encephalopathy. In 17 of 20 patients, SPECT findings revealed areas of hypoperfusion, including the frontal (5), occipital (4), and lobular (4) regions, overlapping with other areas. Relative to patients with acute encephalopathy, those with complex febrile seizures exhibited significantly lower cerebrospinal fluid interleukin-6, interleukin-1ß, tumor necrosis factor-α, and interleukin-10 levels and significantly higher interleukin-17 levels. As patients with complex febrile seizures frequently exhibit abnormal SPECT findings, cerebrospinal fluid interleukin-17 levels might provide a valid biomarker to discriminate complex febrile seizures and acute encephalopathy, regardless of SPECT findings.

Neuroinflammation imaging markers for epileptogenesis.

Epilepsy can be a devastating disorder. In addition to debilitating seizures, epilepsy can cause cognitive and emotional problems with reduced quality of life. Therefore, the major aim is to prevent the disorder in the first place: identify, detect, and reverse the processes responsible for its onset, and monitor and treat its progression. Epilepsy often occurs following a latent period of months to years (epileptogenesis) as a consequence of a brain insult, such as head trauma, stroke, or status epilepticus. Although this latent period clearly represents a therapeutic window, we are not able to stratify patients at risk for long-term epilepsy, which is prerequisite for preventative clinical trials. Moreover, because of the length of the latent period, an early biomarker for treatment response would be of high value. Finally, mechanistic biomarkers of epileptogenesis may provide more profound insight in the process of disease development.