Abstract Background and Objectives Muscle‐Eye‐Brain disease (MEB) is a dystroglycanopathy that belongs to the congenital muscular dystrophies. Central nervous system manifestations include congenital brain abnormalities, neurodevelopmental delay, and epilepsy, making it a rare but important cause of developmental and epileptic encephalopathy. This systematic review aims to explore all current literature data regarding clinical and electroencephalographic features of MEB cases with epilepsy. Materials and Methods We conducted a literature review of previously published cases of patients with MEB and epilepsy in the PubMed and Scopus databases in the English language, focusing on seizure semiology and electroencephalographic features. Results We included 52 studies with 80 patients. The clinical spectrum of patients with MEB is broad, including hypotonia at birth, ocular symptoms, delay of motor milestones, and intellectual disability. Serum creatine kinase levels are significantly elevated (median value 1600 IU/L). POMGnT1 mutation is, by far, the most common mutation in MEB patients, reported in 38.8% of cases, followed by GMPPB (10%), FKTN, POMT2, or DPM2 mutations (less than 10%, respectively). Epilepsy is a common feature, with onset usually in the first 6 months of life. Absences are the most common seizure type (58.8% of patients), followed by generalized tonic–clonic (33.8%) and focal seizures (21.3%). Patients present with drug‐resistant epilepsy in approximately one fourth of cases (21.3%). Electroencephalogram (EEG) shows focal or multifocal discharges in approximately half of the cases, with a predominance over frontal or temporal regions. Slow and disorganized EEG background activity is commonly observed in 92.9% of cases. Conclusion Epilepsy is a common feature in MEB patients; its age of onset is usually in the first months of life, and it is often drug‐resistant. It can manifest with all seizure types, with absences being the most common type. EEG shows focal or multifocal discharges with a slow and disorganized EEG background. The POMGnT1 mutation is the most common in MEB patients with epilepsy. A clear understanding of the electroclinical patterns in MEB patients can contribute to improved diagnostic precision and management.

Although inborn errors of metabolism (IEM) are a rare cause of epilepsy, seizures are a common presentation in these disorders. Seizures in IEM are frequently refractory to conventional anti‐seizure medication and might warrant initiation of specific treatments based on vitamins or dietary modifications or provision of alternative substrates (to bypass a block). In most IEMs, seizures present with variable and non‐specific semiology and EEG findings. Nevertheless, certain distinctive electro‐clinical features might suggest an underlying IEM and even point towards the etiology. Even though biochemical and genetic tests will confirm the definitive diagnosis, EEG has the great advantage of being rapidly available, before the results of these tests. This article aims to describe through a literature review, illustrated by videos and EEGs from personal cases, seizures, and EEG patterns in IEM. We will focus on distinctive electro‐clinical features that may help the clinician to establish an appropriate diagnosis allowing a prompt and specific treatment in order to improve outcome.

Status epilepticus (SE) can be regarded as the most severe expression of seizure activity characterized by a low probability of spontaneous cessation and mechanisms leading to metabolic and inflammatory derangements with increased risk of brain damage, alterations of neural networks, and potentially life‐threatening systemic complications. Time‐based criteria are fundamental in diagnosing SE as response to treatment and outcomes worsen with increasing duration in terms of neurological impairment and mortality. Classification of status epilepticus includes four axes: semiology, EEG correlates, etiology, and age. Semiology, especially when evolving from SE with prominent motor phenomena (SE‐PM) to nonconvulsive status epilepticus (NCSE) with impaired consciousness, is associated with drug resistance and poor prognosis. The Salzburg EEG criteria define four subcategories of NCSE. The umbrella term ictal‐interictal continuum (IIC) includes a wide spectrum of EEG changes ranging from almost non‐epileptic situations to conditions that just fail to fulfill the criteria of NCSE. From a pathophysiologic point of view, EEG patterns on the IIC might be generated by both the underlying etiology and the superimposed hypersynchronous epileptic activity. It is impossible to disentangle their relative contributions by visual inspection of the EEG. However, it is essential to identify the contribution of ictal activity in an individual patient as it may be amenable to treatment with antiseizure medication (ASM). The main approach is to perform a diagnostic intravenous ASM trial (diagnostic IV‐ASM trial) during EEG recording and to assess for both EEG and clinical response. Furthermore, CT‐ and MRI‐perfusion studies help to clarify the diagnosis. Early and consequent treatment is necessary to minimize the total time spent in status, also called seizure burden. This educational review focuses on the diagnosis of status epilepticus in children and adults, excluding neonatal status.

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Objective(1) To compare use, benefits, and complications of stereo‐EEG (SEEG) and subdural EEG (SD) in presurgical epilepsy candidates. (2) To evaluate the effectiveness of both methods in delineation of the epileptogenic zone (EZ) and guiding tailored resective surgery.MethodsWe included patients with SEEG or SD evaluations in children and adults at the Bethel Epilepsy Centre, Germany, between 2000 and 2020. We retrospectively assessed epilepsy related parameters, main indication of iEEG (intracranial EEG, for identification of the EZ and functional mapping), complications, seizure, and functional outcome. The second objective was addressed by a subgroup analysis in patients with focal cortical dysplasia (FCD) and mild malformation of cortical development with oligodendroglial hyperplasia (MOGHE) for delineation of the EZ.ResultsTwo hundred and nineteen iEEG explorations in 215 patients (age range: 1.3–64.6 years) were assessed (SEEG, n = 78; SD, n = 141). We observed a change in iEEG usage away from SD towards SEEG. In the SEEG group, the decision rate against surgery was higher (SEEG: 23.1% vs. SE: 3.5%, p < .001) and more patients achieved seizure freedom 2 years after surgery (SEEG: 67.8% vs. SD: 46.5%, p = .008). For all iEEG, complications were rare; symptomatic intracranial bleeding only occurred in the SD group (n = 6, 4.3%). In patients with FCD/MOGHE for delineation of the EZ, all patients were operated with favorable seizure freedom after SEEG, but with acceptance of planned neurological deficits (SEEG n = 8, SD n = 20, seizure freedom rate SEEG 87.5% vs. SD 30%, p = .011; neurological deficits: SEEG n = 3 planned motor deficits vs. SD n = 1 unplanned motor deficit due to ischemia).SignificanceSEEG has largely replaced SD in iEEG for the identification of the EZ. It is better tolerated and allows more freedom of choice with respect to resective surgery, resulting in the better identification of surgical candidates and delineation of the EZ with favorable seizure outcomes.

IntroductionClonic seizures are characterized by twitching movements at a frequency of 0.2–5 Hz. The clonic “twitch” is produced by a brief synchronized contraction of agonist and antagonist muscles, followed by a synchronized silent period. In this study, we aimed to compare the surface‐electromyography (sEMG) characteristics of scalp‐EEG negative clonic seizures with those of nonepileptic movements like tremors that can resemble clonic seizures.MethodsWe retrospectively identified patients who were diagnosed with scalp‐EEG negative clonic seizures or tremors. We only included patients (n = 6) who were monitored simultaneously with video‐EEG and sEMG electrodes. sEMG was placed on agonist and antagonist muscles of the affected extremity using a standardized placement system developed at our institution. We analyzed the following characteristics of sEMG bursts: the relationship between agonist and antagonist muscles and the temporal evolution of burst duration, burst amplitude, and burst frequency.ResultsThe following sEMG characteristics were observed: (i) sEMG bursts and corresponding silent periods were synchronous between agonist and antagonist muscles in clonic seizures. In tremors, an alternating pattern was seen. (ii) sEMG burst amplitude increased during the first 10 s of clonic seizures. There was no significant change in tremors. (iii) sEMG burst duration increased from the beginning to end of clonic seizures. There was no significant change in tremors. (iv) sEMG burst frequency decreased from the beginning to end of clonic seizures due to increased burst and silent period duration. There was no consistent change in burst frequency in tremors. (v) sEMG burst duration of ≥250 ms was indicative of a clonic seizure with a >90% positive predictive value.ConclusionsOur study describes characteristic sEMG features of clonic seizures without scalp‐EEG correlates, which can be used as an objective biomarker in distinguishing these from nonepileptic movements such as tremors.