To date, few analyses of the electroclinical features and prognosis of patients with epilepsy with myoclonic absences (EMA) have been performed. We reviewed the clinical and electroencephalography (EEG) features, response to antiseizure medications, and long-term prognosis of patients with EMA in a single center in Southwest China, with the goal of increasing the understanding of the disease, strengthening early clinical diagnosis and treatment, and improving prognosis. We retrospectively analyzed the data of 11 children with EMA at the Epilepsy Center of Children's Hospital of Chongqing Medical University. The patients' history of EEG (including ictal EEG), medical history, head magnetic resonance imaging (MRI), medication, cognition and development were retrospectively analyzed. Eleven patients (7:4 male:female) with an onset age of 7.18 ± 3.72 years had myoclonic-absence (MA) seizures, and four (36.36 %) had asymmetrical features. Nine (75 %) had multiple seizure types, including MA, myoclonic, absence, and generalized tonic-clonic seizures. During the interictal period, generalized 3 Hz spike-slow wave complexes were rhythmically emitted, with two having a small amount of focal discharge. In eight patients, bilateral symmetrically synchronized 3 Hz rhythmic spike-slow wave complex bursts, which showed a lock-in relationship with myoclonic, were recorded. All patients were treated with new or adjusted antiseizure medications and were followed up for 15-44 months. Five patients (45.45 %) had no seizures and no cognitive impairment; and 4/5 (80 %) were treated with valproic acid alone. During follow-up, the EEG results of four patients showed normal. The remaining six patients had drug-resistant epilepsy. Five had daily MA seizures, and one had daily myoclonic seizures. Among these six patients, four (66.67 %) exhibited developmental delay before disease onset, three experienced language delay, one experienced motor delay at follow-up. The clinical manifestations of EMA are highly heterogeneous. Some patients experience seizures with atypical characteristics and exhibit significant clinical heterogeneity in response to antiseizure medications and cognitive impairment. Some patients have a better prognosis, and developmental delay before disease onset may be associated with a poor prognosis.

The primary purpose was to assess the diagnostic performance of investigations in children with myoclonic epilepsy. The secondary objectives were to examine the definitive syndromic diagnoses and report the outcomes of pediatric myoclonic epilepsies. We conducted a retrospective monocentric study from a pediatric center for rare epilepsies. We included pediatric patients investigated for myoclonic epilepsy at our center from 2009 to 2022. Data were collected from their medical records. Forty-one children were included; 32 (78%) underwent untargeted etiological investigations, including brain magnetic resonance imaging and diverse laboratory tests to rule out an underlying etiology for progressive myoclonus epilepsy (PME). These investigations led to an etiological diagnosis of epilepsy for two patients, exclusively based on genetic investigations. At the final follow-up, an underlying etiology for epilepsy was established for nine patients (22%). The definitive syndromic diagnoses were diverse, comprising myoclonic epilepsy in infancy, epilepsy with myoclonic absences, Rasmussen syndrome, and PME. Some patients were diagnosed with nonsyndromic developmental and epileptic encephalopathy or unclassified nonsyndromic myoclonic epilepsy. Developmental delay or regression at the initial evaluation was found to be significantly associated with an unfavorable neurological outcome, the total number of antiseizure medications (ASMs) prescribed, and the unlikelihood of achieving ASM freedom. No patients with an abnormal head circumference or born of a consanguineous union were in the favorable neurological outcome group, although this finding did not reach statistical significance. Except for the need to promptly identify diseases for which precision medicine treatments are available, a first-line genetic approach seems reasonable to investigate children diagnosed with epileptic myoclonus.

In childhood absence epilepsy, pharmaco-resistance occurs in 20-30% of patients. In that situation, glucose transporter type 1 deficiency has to be ruled out, especially if absences started before the age of four years and if neurological signs are present. If ethosuximide, valproate and lamotrigine have failed in monotherapy or in association, there are currently no valuable therapeutic options. The same rules apply for epilepsy with myoclonic absences. Importantly, arguments supporting that making the patient seizure-free will improve eventual associated cognitive deficits such as attention deficit are very weak. Therefore, limiting the cognitive side effects of the anti-epileptic drugs has always to be a priority when faced with typical refractory absences in childhood. In epilepsy with eyelid myoclonia, the majority of patients are pharmaco-resistant. However, absence seizures, if present, tend to be very brief, and seizures are limited in many patients to eyelid myoclonia that eventually do not affect their quality of life and are well attenuated by wearing blue lenses. Atypical absences occurring in the course a developmental and/or epileptic encephalopathy are often pharmaco-resistant. In that situation, characterizing the type of epilepsy syndrome and searching for a specific genetic or structural etiology are needed to offer the best therapeutic options to the patient.

Pathogenic variants of the GABRG2 gene, encoding a GABAA receptor subunit, have been associated with various epileptic syndromes and drug-resistant epilepsy. Vinpocetine has been previously reported efficacious in a patient harboring a GABRB3 pathogenic variant, encoding another GABAA receptor subunit. We describe a patient with GABRG2-related drug-resistant epilepsy who improved after vinpocetine treatment. An 8-year-old boy with a family history of epilepsy was diagnosed with early onset absence epilepsy at 6 months of age and was treated unsuccessfully with sodium valproate and ethosuximide. At 6 years of age, he developed generalized tonic-clonic seizures and increasing absences despite lamotrigine add-on as well as learning difficulties. Brain MRI was normal and video-EEG telemetry showed multiple myoclonic absences. An epilepsy gene panel analysis showed a GABRG2 pathogenic variant, c.254 T > A p.(Ile85Lys) (NM_198903.2), inherited from the proband's father. Seizures were resistant to several medications. After treatment with vinpocetine add-on, the patient showed a dramatic initial response, further reduction of seizures, and improvement of his cognitive functions. This case illustrates that vinpocetine could be considered in drug-resistant epilepsies related to GABRG2 in accordance with the principles of precision medicine.