Diagnosis and treatment of late-onset myoclonic epilepsy in Down syndrome (LOMEDS): A systematic review with individual patients' data analysis.

INTRODUCTION: The late onset myoclonic epilepsy in Down Syndrome (LOMEDS) is a peculiar epilepsy type characterized by cortical myoclonus and generalized tonic-clonic seizures (GTCS), in people suffering from cognitive decline in Down syndrome (DS). In this review, we analyzed available data on the diagnostic and therapeutic management of individuals with LOMEDS. METHODS: We performed a systematic search of the literature to identify the diagnostic and therapeutic management of patients with LOMEDS. The following databases were used: PubMed, Google Scholar, EMBASE, CrossRef. The protocol was registered on PROSPERO (registration code: CRD42023390748). RESULTS: Data from 46 patients were included. DS was diagnosed according to the patient's clinical and genetic characteristics. Diagnosis of Alzheimer's dementia (AD) preceded the onset of epilepsy in all cases. Both myoclonic seizures (MS) and generalized tonic-clonic seizures (GTCS) were reported, the latter preceding the onset of MS in 28 cases. EEG was performed in 45 patients, showing diffuse theta/delta slowing with superimposed generalized spike-and-wave or polyspike-and-wave. A diffuse cortical atrophy was detected in 34 patients on neuroimaging. Twenty-seven patients were treated with antiseizure medication (ASM) monotherapy, with reduced seizure frequency in 17 patients. Levetiracetam and valproic acid were the most used ASMs. Up to 41% of patients were unresponsive to first-line treatment and needed adjunctive therapy for seizure control. CONCLUSIONS: AD-related pathological changes in the brain may play a role in LOMEDS onset, although the mechanism underlying this phenomenon is still unknown. EEG remains the most relevant investigation to be performed. A significant percentage of patients developed a first-line ASM refractory epilepsy. ASMs which modulate the glutamatergic system may represent a good therapeutic option.

A Single-center Analysis of Three Japanese Patients with Mahjong-related Seizures.

Mahjong is one of the most popular Chinese tile games played in Japan. Mahjong-related seizures (MRS) are rare praxis-induced seizures. We identified three patients with MRS from February 2000 to February 2021. All cases were men, with a middle-age onset, generalized convulsive seizures, and lack of non-provoked, myoclonic, and absence seizures. All patients had no or non-specific neuroimaging or electroencephalogram abnormalities. They did not have features linked to idiopathic generalized epilepsy. All patients were seizure-free after behavioral adjustments, although one patient required anti-seizure medication and avoided long duration games. These changes may help other patients with MRS continue playing Mahjong.

CSNK2B: A broad spectrum of neurodevelopmental disability and epilepsy severity.

CSNK2B has recently been implicated as a disease gene for neurodevelopmental disability (NDD) and epilepsy. Information about developmental outcomes has been limited by the young age and short follow-up for many of the previously reported cases, and further delineation of the spectrum of associated phenotypes is needed. We present 25 new patients with variants in CSNK2B and refine the associated NDD and epilepsy phenotypes. CSNK2B variants were identified by research or clinical exome sequencing, and investigators from different centers were connected via GeneMatcher. Most individuals had developmental delay and generalized epilepsy with onset in the first 2 years. However, we found a broad spectrum of phenotypic severity, ranging from early normal development with pharmacoresponsive seizures to profound intellectual disability with intractable epilepsy and recurrent refractory status epilepticus. These findings suggest that CSNK2B should be considered in the diagnostic evaluation of patients with a broad range of NDD with treatable or intractable seizures.

Epileptic phenotype in late-onset hyperinsulinemic hypoglycemia successfully treated by diazoxide.

OBJECTIVES: Serious hyperinsulinemic hypoglycemia (HH) is generally the main initial symptom of hyperinsulinism. Epilepsy, without any overt feature of hypoglycemia, might be a very rare initial presentation of late-onset isolated hyperinsulinism. CASE PRESENTATION: We describe a case of late-onset HH in a 15-year-old boy with a history of idiopathic generalized epilepsy, now named genetic generalized epilepsy (IGE/GGE), beginning with a tonic-clonic seizure at the age of 11 years. Subsequently, absences with rare eyelid myoclonia were recorded on electroencephalogram (EEG), followed by episodes of impaired consciousness with facial myoclonia. Neurological status was normal except attention-deficit hyperactivity disorder (ADHD). At the age of 15 years, an episode of slight alteration of consciousness with neurovegetative signs could be recorded, which did not correspond to an absence status. Hypoglycemia due to hyperinsulinism was documented (clinically, biologically, and genetically). Diazoxide treatment resolved the glycopenic symptoms, the non-hypoglycemic seizures and normalized brain electrical activity allowing complete withdrawal of antiepileptic medication. CONCLUSIONS: Epilepsy can be a very rare initial feature of HH starting in childhood. The occurrence of atypical features in the context of GGE as "absence statuses" with unusual vegetative symptoms and facial myoclonia might be suggestive for HH. Careful assessment and specific treatment are necessary to prevent hyperinsulinism related brain damage. Our case showed that diazoxide might also resolve seizures and normalize EEG.

Clinical spectrum and treatment outcome of 95 children with continuous spikes and waves during sleep (CSWS).

OBJECTIVE: Continuous spikes and waves during sleep (CSWS) is an epileptic encephalopathy characterized by generalised epileptiform activity and neurocognitive dysfunction. Causes and outcome are diverse and treatment is mainly empirical. METHODS: Retrospective descriptive analysis of clinical and EEG data of children with CSWS diagnosed between 1998 and 2018 at the University Hospital Heidelberg. RESULTS: Ninety-five children were included with a median age at diagnosis of 5.4 years. A structural/metabolic aetiology was found in 43.2%, genetic alterations in 17.9%, while it remained unknown in 38.9%. The proportion of patients with genetic aetiology increased from 10.3% (1998-2007) to 22.8% (2008-2018). On average, each patient received 5 different treatments. CSWS was refractory in >70% of cases, steroids and neurosurgery were most effective. No difference was observed between children with CSWS or Near-CSWS (Spike-Wave-Index 40-85%). CONCLUSIONS: Our cohort confirms CSWS as an age-dependent epileptic encephalopathy. Structural brain abnormalities were most frequent, but genetic causes are increasingly identified. More specific criteria for the diagnosis and treatment goals should be elaborated and implemented based on evidence. SIGNIFICANCE: This study is the largest monocentric observational study on treatment effects in children with CSWS, providing data for diagnostic and therapeutic decisions.

Frequent epileptic apnoea in a patient with Pitt-Hopkins syndrome.

Pitt-Hopkins syndrome is a rare genetic disease, characterised by severe intellectual disability, distinctive dysmorphic features, epilepsy and distinctive breathing abnormalities during wakefulness. Here, we describe the case of a 22-year-old woman with Pitt-Hopkins syndrome who presented with intractable generalised tonic seizures from the age of 11 years, which increased in frequency with age and onset of menstruation despite usage of some anticonvulsant drugs. From the age of 16 years, polysomnography and video-EEG led to the detection of frequent epileptic apnoea during sleep. Although the frequency of generalised tonic seizure clusters was reduced by treatment with phenobarbital and potassium bromide, epileptic apnoea persisted. Furthermore, frequent epileptic apnoea observed in our patient was regarded as a factor for aspiration and deterioration of respiratory function. This study indicates that patients with Pitt-Hopkins syndrome require close monitoring for epileptic apnoea. Moreover, long-term EEG and respiratory monitoring are necessary to distinguish epileptic apnoea from other respiratory disorders in patients with Pitt-Hopkins syndrome.

Clinical characterization of status epilepticus in childhood: a retrospective study in 124 patients.

PURPOSE: The aim of this study is to describe demographic data, semiology and etiology in a pediatric population with status epilepticus (SE) and refractory SE (RSE). METHOD: We retrospectively reviewed patients with the following inclusion criteria: i) age between two months and eighteen years; ii) SE diagnosis; iii) admission from January 2001 to December 2016; iv) available clinical data. RESULTS: We enrolled 124 patients. Mean and median age was 4.6 ± 4.2 years and 3.3 [1.2-7.5] years respectively. SE had a "de novo" onset in 66.9%. Focal convulsive-SE was the most common semiology (50.8%) whilst generalised (32.3%) and nonconvulsive-SE (NCSE) (16.9%) were less represented. Some etiologies showed a different age distribution: febrile in youngest age (p = 0.002, phi 0.3) and idiopathic-cryptogenic in older children (p = 0.016, phi 0.2). A statistical significance correlation was detected between semiology and etiology (p < 0.001, Cramer's V 0.4), chemotherapy and NCSE (n = 6/21 vs 3/103, p < 0.001) as well as PRES and NCSE (n = 7/21 vs 5/103, p < 0.001). Only 17.7% had a RSE. No correlation was found in demographic and clinical data, but NCSE, acute and idiopathic-cryptogenic etiologies were more frequently associated to RSE. Encephalitis was the most common diagnosis in acute etiologies whereas unknown epilepsy in idiopathic-cryptogenic group. CONCLUSION: Most of our findings were previously described however we found a significant role of non-antiepileptic treatments (chemotherapy-dialysis) and comorbidity (PRES) determining acute etiology and NCSE. Acute (mostly encephalitis), idiopathic-cryptogenic (mainly unknown-epilepsy) and NCSE were frequently detected in RSE. In the above mentioned conditions a high level of suspicion was recommended.

A knock-in mouse model for KCNQ2-related epileptic encephalopathy displays spontaneous generalized seizures and cognitive impairment.

OBJECTIVE: Early onset epileptic encephalopathy with suppression-burst is one of the most severe epilepsy phenotypes in human patients. A significant proportion of cases have a genetic origin, and the most frequently mutated gene is KCNQ2, encoding Kv7.2, a voltage-dependent potassium channel subunit, leading to so-called KCNQ2-related epileptic encephalopathy (KCNQ2-REE). To study the pathophysiology of KCNQ2-REE in detail and to provide a relevant preclinical model, we generated and described a knock-in mouse model carrying the recurrent p.(Thr274Met) variant. METHODS: We introduced the p.(Thr274Met) variant by homologous recombination in embryonic stem cells, injected into C57Bl/6N blastocysts and implanted in pseudopregnant mice. Mice were then bred with 129Sv Cre-deleter to generate heterozygous mice carrying the p.(Thr274Met), and animals were maintained on the 129Sv genetic background. We studied the development of this new model and performed in vivo electroencephalographic (EEG) recordings, neuroanatomical studies at different time points, and multiple behavioral tests. RESULTS: The Kcnq2Thr274Met/+ mice are viable and display generalized spontaneous seizures first observed between postnatal day 20 (P20) and P30. In vivo EEG recordings show that the paroxysmal events observed macroscopically are epileptic seizures. The brain of the Kcnq2Thr274Met/+ animals does not display major structural defects, similar to humans, and their body weight is normal. Kcnq2Thr274Met/+ mice have a reduced life span, with a peak of unexpected death occurring for 25% of the animals by 3 months of age. Epileptic seizures were generally not observed when animals grew older. Behavioral characterization reveals important deficits in spatial learning and memory in adults but no gross abnormality during early neurosensory development. SIGNIFICANCE: Taken together, our results indicate that we have generated a relevant model to study the pathophysiology of KCNQ2-related epileptic encephalopathy and perform preclinical research for that devastating and currently intractable disease.

Generalized Epileptic Seizure Induced by the Stroboscopic Effect of Helicopter Blades.

BACKGROUND: The stroboscopic effect made by helicopter blades passing through rays of sunlight is known as a factor that can induce an epileptic seizure.CASE REPORT: We report a case of inaugural tonic-clonic generalized seizure while refueling an NH 90 helicopter by an aeronautical technician standing under the rotating main rotor on a sunny day at a South of France naval air station. The stroboscopic effect of the helicopter blades was identified as one of the factors involved in the induction of this seizure.DISCUSSION: This aeronautical factor identified here during ground hot refueling must be considered for patients predisposed to epileptic seizures who are being evacuated by helicopter, but also for the medical screening of flight members. This is even more important within the military aeronautical environment, justifying electroencephalogram testing implementation on initial aeronautical medical evaluation in France.Corgie L, Huiban N, Quesnel L, Brocq F-X, Boulard J-F, Monteil M. Generalized epileptic seizure induced by the stroboscopic effect of helicopter blades. Aerosp Med Hum Perform. 2019; 90(10):891-895.

Seizures in Down Syndrome: An Update.

The prevalence of seizures in individuals with Down Syndrome (DS) is higher than in the general population. Rates of epilepsy in DS range from 1-13%. Forty percent of individuals develop seizures before 1 year of age and another 40% develop in their thirties or later. Boys have an earlier age of onset. The prevalence of epilepsy increases with age. Types of seizures are: 47% partial seizures, 32% infantile spasms and 21% generalized tonic-clonic seizures. Sex distribution for epilepsy in children with DS varies. Males have a younger age at onset. Trisomy 21 is common among epileptic children with DS but mosaicism or translocation has also been documented. The mechanisms underlying the increased seizure susceptibility in DS have not yet been completely explained. Seizures in infancy may be due to inherent structural brain abnormalities, like fewer inhibitory neurons, abnormal cortical lamination, persistent fetal dendritic morphology, underdeveloped synaptic profiles. Concentrations of carbonic anhydrase II are increased in the brains of young children with DS. It potentially increases seizure susceptibility. The pharmacological treatment of epilepsy in DS is same as that of other patients diagnosed with epilepsy. Individuals with DS have an unusually high number of side-effects from phenytoin. The diagnosis, classification and treatment of epilepsy in DS follow the guidelines applied to the general population. Review of literatures from 1960 to 2017 and electronically identified articles on epilepsy in Down syndrome in children in English are searched from internet and pub med to describe features of seizures in children with DS.

[Difficulties in distinguishing abnormal intensities associated with convulsion from tumor on MRI: a case report].

A 48-year-old man was admitted to our department with generalized convulsive seizures followed by recurrent partial clonic convulsions in the left face and arm. Convulsions stopped temporarily after administration of diazepam, fosphenytoin, and levetiracetam. However, frequent partial seizures occurred repeatedly and general anesthesia was required to control seizures. Diffusion-weighted and T2-weighted images revealed a high-intensity lesion in the right frontal lobe. A tumor-like area in the white matter showed high intensity on T2-weighted images with ring enhancement on gadolinium-enhanced T1-weighted images. An area of frontal cortex near the tumor was also enhanced. Brain surgery was performed for the purposes of diagnosis, seizure control and tumor resection. Histological findings demonstrated oligodendroglioma in the ring-enhancing area, but not in the frontal cortex. This fact indicated that contrast enhancement of the frontal cortex was caused by status epilepticus. It is important to recognize that status epilepticus could cause contrast enhancement on magnetic resonance imaging.

[A rare form of ion channel gene mutation identified as underlying cause of generalized epilepsy]. / Generalizált epilepszia hátterében azonosított ioncsatorna-génmutáció ritka formája.

The advances in molecular genetic methods has lead to the discovery of the genetic alterations that underlie the etiology of most diseases previously held to be idiopathic. Targeted genetic examination of a pediatric male patient showing a normal intellect, an extended area of skin hypopigmentation, and suffering from generalized epilepsy displaying a switch in epilepsy syndrome during the course of the disease towards a neurocutaneous syndrome was unsuccessful. Whole-exome sequencing identified a heterozygous missense mutation in a potassium chloride cotransporter gene, which together with the phenotype underscores the diagnosis of an epilepsy syndrome known in the literature as idiopathic generalized epilepsy type 14. Orv Hetil. 2019; 160(21): 835-838.

Etiology, seizure type, and prognosis of epileptic seizures in the emergency department.

Epileptic seizures are a common reason for emergency department (ED) admittance. We aimed to describe the etiological distribution of epileptic seizures and the relationships between etiology and semiology in patients admitted to the emergency room, and to identify early prognostic factors for recurrence and mortality. METHODS: A retrospective observational study was conducted in adult patients consecutively attended in the emergency room with epileptic seizures over a 2-year period. We recorded data on the etiological and syndromic classification of the seizure, and on recurrence and mortality at 1 year of follow-up. RESULTS: In total, 289 patients were included. Mean age was 55.9 (±21.9 years). There were 38.6% with a previous diagnosis of epilepsy and 49.8% with new-onset seizures. Among structural epilepsies, a vascular etiology was the most common overall (28.3%) but particularly in elderly (>65 years) patients (50.9%), followed by brain tumors (15.5%). In both etiologies, most patients presented with nonconvulsive seizures. Seizure recurrence during follow-up was reported in 37.1% and was most common in patients with symptomatic remote seizures (50 patients, 41%). Brain tumors (odds ratio (OR): 5.1, confidence interval (CI): 1.7-11.8; p < 0.01), younger age (OR: 0.9, CI: 0.97-0.99; p < 0.05), and a previous diagnosis of epilepsy (OR: 3.5, CI: 1.9-6.3; p < 0.01) were independent predictors of recurrence. Overall mortality was 8.6%. Symptomatic epilepsy was an independent predictor of mortality (hazard ratio (HR): 6.3, CI 1.4-23.4; p < 0.05). CONCLUSIONS: The most common etiologies of seizures in patients admitted to the ED are seizures of unknown cause and vascular disorder-related seizures. Seizures are more likely to recur in younger patients with a tumor whereas symptomatic epilepsy is associated with a higher risk of death at a 1-year follow-up.

Epilepsy Surgery for Children With Low-Grade Epilepsy-Associated Tumors: Factors Associated With Seizure Recurrence and Cognitive Function.

OBJECTIVE: Low-grade epilepsy-associated tumors (LEATs) are associated with childhood seizures that are typically drug-resistant, necessitating surgical interventions. In this study, we aimed to investigate the efficacy of surgical intervention in children with LEATs and to identify factors associated with seizure and cognitive outcomes. METHODS: We reviewed 58 children less than 18 years of age who underwent epilepsy surgery due to histopathologically confirmed LEATs and had a minimum postoperative follow-up duration of 24 months. RESULTS: Of the 58 patients who were followed for a median duration of 5.6 (IQR 3.2 to 10.0) years, 51 (87.9%) were seizure-free after surgery. In univariate analysis, shorter epilepsy duration, fewer antiepileptic drugs at time of surgery, gross total resection, and unilobar tumor involvement were associated with seizure freedom. In multivariate analysis, gross total resection was independently associated with seizure freedom. The preoperative and postoperative full-scale intelligence quotient (FSIQ) scores were 78.9 ± 27.1 and 80.9 ± 28.7, respectively. In univariate analysis, younger age at seizure onset, longer epilepsy duration, more antiepileptic drugs at time of surgery, multilobar tumor involvement, and presence of generalized epileptic discharges were associated with lower preoperative FSIQ. In multivariate analysis, longer epilepsy duration was independently associated with lower preoperative FSIQ scores. Postoperative FSIQ scores were significantly influenced by preoperative FSIQ scores. CONCLUSIONS: Epilepsy surgery for LEATs in children resulted in excellent seizure outcome. Gross total resection was the only independent factor associated with favorable seizure outcome. Preoperative and postoperative cognitive abilities were significantly influenced by epilepsy duration, so early surgical intervention should be considered.

[Calcifying pseudoneoplasm of the neuraxis]. / Pseudo-tumeur calcifiante du névraxe.

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare lesions of the central nervous system. To date, about 60 cases have been reported in literature. We present a case that had the peculiarity to occur in a pregnant woman. At 32 weeks of gestation, a 26-year-old woman was hospitalized to explore nocturnal epigastralgia. During the hospitalisation, the patient presented generalised seizures. As an eclampsia had been suspected, a caesarean delivery was performed. Post-operatively, the patient harboured memory disorders and neuro-imaging explorations were done. They showed an intracerebral calcified mass located in the left frontal lobe and surrounded by an oedema. A complete surgical resection was performed. Histological examination of the surgical specimen showed a calcified tissue containing a fibrillary or granular material. A dense and hyalinised eosinophilic material focally surrounded the calcifications and contained regular fusiform cells of fibroblastic type. Foci of lipomatous and osseous metaplasia were present. Immunohistochemical staining for EMA and STAT6 was negative. There was no associated meningioangiomatosis nor tumour proliferation. Forty-five months after surgery, the patient did not present any seizures and had no sequelae. CAPNON are rare lesions occurring at any age. Their location in the central nervous system is ubiquitous and they can be intra or extra axial. The treatment is surgical and the prognosis excellent. CAPNON must be recognized and distinguished from the other calcified lesions, tumoural or non-tumoural, to avoid an inadequate and potentially harmful treatment.

Genetic (idiopathic) epilepsy with photosensitive seizures includes features of both focal and generalized seizures.

Clinically, some patients having genetic (idiopathic) epilepsy with photosensitive seizures were difficult to be diagnosed. We aimed to discuss whether the genetic (idiopathic) epilepsy with photosensitive seizures is a focal entity, a generalized entity or a continuum. Twenty-two patients with idiopathic epilepsies and photoconvulsive response (PCR) were retrospectively recruited. In the medical records, the seizure types included "generalized tonic-clonic seizures (GTCS)" in 15, "partial secondarily GTCS (PGTCS)" in 3, partial seizures (PS) in 3, myoclonic seizures in 2, eyelid myoclonus in one, and only febrile seizures in one. Seizure types of PCR included GTCS (1/22), PGTCS (6/22), PS (9/22), electrical seizures (ES) (3/22) and GTCS/PGTCS (3/22). Combined the medical history with PCR results, they were diagnosed as: idiopathic (photosensitive) occipital lobe epilepsy (I(P)OE) in 12, genetic (idiopathic) generalized epilepsy (GGE) in one, GGE/I(P)OE in 5, pure photosensitive seizure in one, and epilepsy with undetermined generalized or focal seizure in 3. So, the dichotomy between generalized and focal seizures might have been out of date regarding to pathophysiological advances in epileptology. To some extent, it would be better to recognize the idiopathic epilepsy with photosensitive seizures as a continuum between focal and generalized seizures.