A case of perioral myoclonia with absences and its evolution in adulthood?

The rare syndrome of perioral myoclonia with absences (POMA) is described as a specific type of idiopathic generalized epilepsy in which absence seizures are accompanied by prominent perioral myoclonus as a consistent symptom. We present a 52‐year‐old man who was referred to our department due to treatment‐resistant epilepsy. Typical seizures were described as rhythmic twitching of the lips which started at six years old, and his first convulsive seizure occurred at around 20 years old. Based on video‐EEG recordings, we present two distinct EEG patterns accompanied by slight differences in clinical manifestations, which appear to be atypical of POMA. Firstly, consciousness was preserved during seizures, with no manifestation of absences. Secondly, regarding the EEG features, in some of the seizures, the perioral motor symptoms were tonic rather than myoclonic. The defining features of POMA are discussed in relation to this case.     

Clinical and neurophysiologic features of progressive myoclonus epilepsy without renal failure caused by SCARB2 mutations

Purpose: Mutations of the SCARB2 gene cause action myoclonus renal failure syndrome (AMRF), a rare condition that combines progressive myoclonus epilepsy (PME) with severe renal dysfunction. We describe the clinical and neurophysiologic features of PME associated with SCARB2 mutations without renal impairment. Methods: Clinical and neurophysiologic investigations, including wakefulness and sleep electroencephalography (EEG), polygraphic recording (with jerk‐locked back‐averaging and analysis of the EEG–EMG (electromyography) relationship by coherence spectra and phase calculation), multimodal evoked potentials, and electromyography were performed on five Italian patients with SCARB2 mutations. Key Findings: The main clinical features were adolescent–young adulthood onset, progressive action myoclonus, ataxia, absence of cognitive deterioration and, in most cases, epilepsy. The severity of the epilepsy could vary from uncontrolled seizures and status epilepticus in patients with adolescent onset to absent or rare seizures in patients with adult onset. Relevant neurophysiologic findings were a pronounced photosensitivity and massive action myoclonus associated with rhythmic myoclonic jerks at a frequency of 12–20 Hz, clinically resembling a postural tremor. The cortical origin of rhythmic myoclonus was demonstrated mainly by coherence and phase analysis of EEG–EMG signals indicating a significant EEG–EMG coupling and a direct corticospinal transfer. Significance: Our patients with SCARB2 mutations showed the clinical and neurophysiologic phenotype of PME, in which epilepsy could be extremely severe, extending the spectrum reported in the typical AMRF syndrome. Patients with PME of unknown origin of adolescent or young adult onset, with these neurophysiologic features, should be tested for SCARB2 mutations, even in the absence of renal impairment.     

Magnetoencephalography localizing spike sources of atypical benign partial epilepsy

Rationale: Atypical benign partial epilepsy (ABPE) is characterized by centro-temporal electroencephalography (EEG) spikes, continuous spike and waves during sleep (CSWS), and multiple seizure types including epileptic negative myoclonus (ENM), but not tonic seizures. This study evaluated the localization of magnetoencephalography (MEG) spike sources (MEGSSs) to investigate the clinical features and mechanism underlying ABPE. Methods: We retrospectively analyzed seizure profiles, scalp video EEG (VEEG) and MEG in ABPE patients. Results: Eighteen ABPE patients were identified (nine girls and nine boys). Seizure onset ranged from 1.3 to 8.8 years (median, 2.9 years). Initial seizures consisted of focal motor seizures (15 patients) and absences/atypical absences (3). Seventeen patients had multiple seizure types including drop attacks (16), focal motor seizures (16), ENM (14), absences/atypical absences (11) and focal myoclonic seizures (10). VEEG showed centro-temporal spikes and CSWS in all patients. Magnetic resonance imaging (MRI) was reported as normal in all patients. MEGSSs were localized over the following regions: both Rolandic and sylvian (8), peri-sylvian (5), peri-Rolandic (4), parieto-occipital (1), bilateral (10) and unilateral (8). All patients were on more than two antiepileptic medications. ENM and absences/atypical absences were controlled in 14 patients treated with adjunctive ethosuximide. Conclusion: MEG localized the source of centro-temporal spikes and CSWS in the Rolandic-sylvian regions. Centro-temporal spikes, Rolandic-sylvian spike sources and focal motor seizures are evidence that ABPE presents with Rolandic-sylvian onset seizures. ABPE is therefore a unique, age-related and localization-related epilepsy with a Rolandic-sylvian epileptic focus plus possible thalamo-cortical epileptic networks in the developing brain of children.     

Neurophysiology of myoclonus and progressive myoclonus epilepsies

The high temporal resolution of neurophysiological recordings makes them particularly suited to faithfully describing the time course of rapid events such as myoclonus and to precisely measure its time relationship with other related activities. In progressive myoclonus epilepsies (PMEs) polygraphy with simultaneous EMG‐EEG recordings is a crucial tool for defining the characteristic of myoclonic jerks their topography over different muscles (namely antagonists), their time course and relationship with vigilance muscle activation and stimulations. Moreover on polygraphic recordings it is possible to detect EEG activities associated to myoclonic jerks and define their time relationship with myoclonus thus differentiating cortical types of myoclonus from subcorticallly generated ones. Tanks to the back averaging technique non obvious time‐locked EEG potentials can be detected on polygraphy, furthermore in stimulus sensitive myoclonus the analysis can include the potential evoked by the somatosensory stimulus (SEP). The polygraphic recording also gives information on muscle activity suppression occurring after jerk or as pure negative myoclonus. Besides the time domain analysis, techniques based on frequency analysis have been developed to evaluate EEG‐EMG coherence. The neurophysiological techniques provide investigators and clinicians with an invaluable information to define the type of myoclonus and its generating circuitry thus substantially contributing in the diagnosis and management of PMEs.     

Clinical and Neurophysiological Development of Unverricht-Lundborg Disease in Four Swedish Siblings

Four siblings aged 12-18 years with progressive myoclonus epilepsy demonstrated a subclinical stage at the age of 9-11 years, with visual blackouts and polyspike electroencephalographic (EEG) activity on photic stimulation, an early myoclonic stage at the age of 12-15 years, with increasing segmental, stimulus-sensitive myoclonus, occasional nocturnal buildup myoclonic "cascade" seizures, slowing of EEG alpha-activity, episodic 4-6 Hz bilateral sharp waves and polyspikes with myoclonias on photic stimulation, and a disabling myoclonic stage at the age of 16-18 years, with periodic generalized myoclonias, nocturnal myoclonic "cascade" seizures, ataxia, dysarthria, mental changes, intermittent wheelchair dependency, and continuous EEG slow waves with polyspikes and intense myoclonias on photic stimulation. One of the siblings died at the age of 18 years with no apparent cause of death. Treatment with antiepileptic drugs other than valproate may have contributed but none of the siblings were ever treated with phenytoin. Extensive clinical and laboratory investigations revealed no abnormalities and excluded other known possible causes of progressive myoclonus epilepsy. The diagnosis was consistent with Unverricht-Lundborg disease and rested on typical age of onset, clinical signs, EEG, and evoked response abnormalities. Buildup myoclonic seizures are typical in advanced stages of Unverricht-Lundborg disease. We have labeled these myoclonic "cascade" seizures. A typical seizure was studied with video-EEG and cardiorespiratory monitoring. Characteristics revealed were onset with continuous arrhythmic myoclonic jerks followed by intense rhythmic myoclonus with increasing muscle tone that successively reduced the amplitude of the jerks. The EEG during the whole seizure showed intense polyspike activity. Obstructive apnea was seen at the peak of the seizure. There were no cardiac dysrhythmias. Consciousness was normal or only slightly impaired. Postictal drowsiness was not observed. Myoclonic "cascade" seizures are easily confused with generalized tonic-clonic seizures.     

Early childhood myoclonic epilepsy: An independent genetic generalized epilepsy with myoclonic seizures as the main seizure type

Objective

To elucidate the characteristics of the myoclonic seizures alone, or predominant myoclonus combined with generalized tonic-clonic seizures (GTCS) and/or absences, in early childhood, and discuss its classification.

Absence seizures in the first 3 years of life: an electroclinical study of 46 cases

Purpose: Early onset absence seizures have been considered a rare heterogeneous group with a poor prognosis. Only few patients may be categorized into well‐known syndromes. We have evaluated electroclinical features, evolution, and the nosologic boundaries of early onset absence seizures. Methods: Forty‐six neurologically normal patients with absence seizures associated with bilateral, synchronic, or asynchronic, and symmetric or asymmetric spike‐and‐wave paroxysms with onset in the first 3 years of life were included. Patients with abnormal neurologic examination and brain imaging were excluded from the study. Key Findings: In our study, 39 patients met the clinical and electroencephalography (EEG) criteria of well‐defined epileptic syndromes. Childhood absence epilepsy was found in 11 patients, benign myoclonic epilepsy in infancy in 18 patients, eyelid myoclonic epilepsy in 4, and epilepsy with myoclonic absences in 6. We did not find clinical and EEG criteria of well‐recognized epileptic syndromes in seven children. Nine of 11 patients with simple absence seizures became seizure free. All these patients had normal neurologic and neuropsychological evaluations. Of the 35 patients who had absence seizures associated with myoclonic seizures, 20 became seizure free. Fifteen of 35 children continue having seizures. At the last visit, 20 of these 35 patients had normal neurologic and neuropsychological evaluations, 11 presented with mild mental retardation, and 4 with severe mental retardation. Significance: Epilepsies with absence seizures of early onset are relatively uncommon. Most of the patients had well‐defined epileptic syndromes with a variable evolution. The evolution depended on the epileptic syndromes.     

Crossing the lines between epilepsy syndromes: a myoclonic epilepsy variant with prominent eyelid myoclonia and atonic components

Accurate diagnosis of a distinct epilepsy syndrome is based on well‐defined electroclinical features that differentiate separate nosological entities. In clinical practice, however, syndromes may overlap and cases may present with unusual manifestations posing a diagnostic challenge. This heterogeneity has been documented in several cases presenting with eyelid myoclonia with or without absences (EMA) diagnosed either as Jeavons syndrome (JS) variants or as genetic generalised epilepsies defined by the presence of this unique clinical entity. The hallmark of JS is the triad: (1) eyelid myoclonia with or without absences, (2) eye closure‐induced paroxysms, and (3) photosensitivity. The presence of massive myoclonus, intellectual disability, or slowing of the EEG background are not typical features of the syndrome and may cause delay in making the correct diagnosis. Adding to the variability of clinical features, we describe two female paediatric patients with probable genetic epilepsy who presented with EMA but demonstrated clear atypical features, such as prominent myoclonic seizures, atonic components on video‐EEG, and cognitive impairment. We also note the presence of interictal and ictal posterior discharges during eyelid myoclonia in one, supporting similar previous observations leading to consideration of EMA as an occipital cortex‐initiated seizure activity. [Published with video sequences on www.epilepticdisorders.com ].     

Myoclonus in Creutzfeldt‐Jakob disease: Polygraphic and video‐electroencephalography assessment of 109 patients

We used electroencephalography (EEG)‐polygraphic recordings to classify myoclonus in 109 patients with Creutzfeldt‐Jakob disease (CJD) on the basis of its electromyography (EMG) pattern, time course, distribution, and EEG correlates. We recorded myoclonic jerks in 55 patients (50.4%), and we classified them as periodic myoclonus in 28, rhythmic in 13, and irregular in 20 (6 patients showed two types of myoclonus). Myoclonus occurred as a prominently negative event (interrupting the EMG discharge) in 10. Periodic sharp‐wave complexes (PSWCs) were present in all but one patient with myoclonic jerks but were time‐locked with EMG‐bursts only in case of periodic myoclonus. Jerk‐locked back averaging revealed a variable EEG‐EMG transfer‐time commonly exceeding that characterizing cortical myoclonus. Myoclonus was frequently associated with Met/Met polymorphism at codon 129 of the prion protein gene, but it was also observed in association with Met/Val or Val/Val polymorphisms provided that the EEG showed the presence of the PSWC pattern. The presence of enlarged somatosensory evoked potentials significantly correlated with the myoclonic presentation, as did MR signal hyperintensity involving the cortical mantle. Our observations on the basis of standard polygraphic criteria suggest that CJD associates with a remarkable variety of myoclonic jerks, and therefore different brain structures are probably involved as generators. The significant association between the presence of all myoclonus types with PSWCs suggests that hyperexcitable corticosubcortical loops are always required to generate (or allow) both myoclonus and the EEG complexes, either they are time locked or not. © 2010 Movement Disorder Society     

Myoclonic Absence-Like Seizures and Chromosome Abnormality Syndromes

Summary: Purpose: We explored the relationship between myoclonic absence seizures (MAS) and underlying chromosome disorders.
Methods: Among 14 patients with MAS observed in three centers, 5 had typical cryptogenic myoclonic absence epilepsy (MAE), 2 had MAS associated with other seizure types (1 with signs of a neuronal migration abnormality and 1 with signs of a metabolic disorder), and 7 had MAS, with or without other seizure types, complicating a chromosome abnormality syndrome-2 with trisomy 12p, 4 with Angelman syndrome, and 1 with inv dup (15).
Results: In the 7 patients with chromosomopathy, MAS appeared at a mean age of 2.9 years (range 4 months to 6 years 6 months), had a duration of 4–20 s, and were accompanied by reduced awareness and rhythmic myoclonic jerks involving proximal limb muscles. Ictal EEG showed 2- to 3-Hz generalized spike-and-wave discharges.
Conclusions: In these patients, MAS differed slightly from those of typical MAE: age of onset was earlier, absences were of shorter duration, and no clear increase in muscular tone was noted. Abnormal expression of genes codifying for the subfamily of K⁺ channels and for γ-aminobutyric acid-3 subunit receptors (GABRBS), both located in the chromosome segments involved in the chromosomopathies presented by our patients, could be responsible for the same generalized seizure type. Chromosome analysis should be performed in patients with mental retardation and MAS, especially when the ictal pattern does not completely overlap that observed in MAE.     

Pitfalls in the diagnosis of Jeavons syndrome: a study of 32 cases and review of the literature

Aims. Jeavons syndrome (JS) is mainly characterized by eyelid myoclonia with or without absences. It is thought to be underdiagnosed rather than have a rare prevalence. We aimed to investigate the electroclinical features of JS to determine possible factors influencing the diagnosis. Methods. We retrospectively identified the medical records of 32 cases (0.55%) from 5,796 patients with epilepsy. The inclusion criteria were: (1) eyelid myoclonia with or without absences; (2) generalized paroxysmal activity on EEG; and (3) discharges triggered by eyelid closure and/or intermittent photic stimulation. Results. Eighteen (56.2%) of the patients were female. The mean age at seizure onset was 8.7±5.3 years and the mean age at admission to hospital was 17.8±10.7 years. A family history of epilepsy was present in 15 (46.8%) patients. Eyelid myoclonias were noticed in six (18.7%) patients by themselves. Based on the analysis of video‐EEG recordings, 26 (81.2%) patients were sensitive to eye closure, 22 (68.7%) had photoparoxysmal responses, and 16 (50%) presented with absence seizures. Ten (31.2%) patients had focal epileptic discharges. Eight (25%) patients were on monotherapy. Seven (21.8%) patients achieved seizure freedom. Three patients underwent ketogenic diet therapy, which was effective in two patients. A vagus nerve stimulator was implanted into three patients, one of whom reported seizure reduction. Conclusions. Eyelid myoclonias are the main seizure type of JS but are usually overlooked. The time interval between seizure onset and clinical diagnosis suggests that this syndrome continues to be under‐recognized. The genetic heterogeneity and phenotypic variability are likely to be more extensive than currently recognized, making the diagnosis more phalangine. [Published with video sequence].     

Symptoms and clinical course of epilepsy with myoclonic absences

There is no comprehensive study so far in Japan on epilepsy with myoclonic absences (EMA), characterized by myoclonic absences (MA) as a specific seizure type. We retrospectively studied 9 patients (4 males and 5 females) with EMA confirmed by ictal video EEG and polygraph (EEG+EMG) recordings. The age at MA onset ranged from 18 to 92 months and the age at the last follow-up ranged from 3 to 39 years. The patients had IQ of 40 to 79. Eight patients had been free from seizures for more than one year at the last follow up. MA was controlled by valproate sodium monotherapy or combination of valproate sodium and ethosuximide with appropriate plasma levels. Generalized tonic clonic seizures and severe mental retardation were not necessarily associated with poor seizure outcome. Patients with long MA duration or MA status epilepticus were prone to be refractory to medication. EMA can be divided into two subgroups based on the seizure outcome, favorable and unfavorable. Further large-scale study is required.     

CDKL5 gene-related epileptic encephalopathy: electroclinical findings in the first year of life

Aim Cyclin‐dependent kinase‐like 5 (CDKL5) gene abnormalities cause an early‐onset epileptic encephalopathy. We performed video‐electroencephalography (video‐EEG) monitoring early in the course of CDKL5‐related epileptic encephalopathy in order to examine the early electroclinical characteristics of the condition. Method We used video‐EEG to monitor six infants (five females, one male) with CDKL5‐related epileptic encephalopathy (five mutations; one deletion), at ages 45 days to 12 months and followed them up to the ages of 14 months to 5 years (mean age 23mo). We focused our analysis on the first year of life. The results were evaluated against those of a comparison group of nine infants (aged below 1y) with epileptic encephalography who had tested negative for CDKL5 mutations and deletions. Results One infant exhibited normal background activity, three exhibited moderate slowing, and two exhibited a suppression burst pattern. Two participants had epileptic spasms and four had a stereotyped complex seizure pattern, which we defined as a ‘prolonged’ generalized tonic–clonic event consisting of a tonic–tonic/vibratory contraction, followed by a clonic phase with series of spasms, gradually translating into repetitive distal myoclonic jerks. Seizure duration ranged from 2 to 4 minutes. The EEG correlate of each clinical phase included an initial electrodecremental event (tonic vibratory phase), irregular series of sharp waves and spike slow waves (clonic phase with series of spasms), and bilateral rhythmic sharp waves (time locked with myoclonus). Interpretation Infants with CDKL5‐related early epileptic encephalopathy can present in the first year of life with an unusual electroclinical pattern of ‘prolonged’ generalized tonic–clonic seizures.     

Low-dose phenobarbital for epilepsy with myoclonic absences: A case report

BackgroundEpilepsy with myoclonic absences (EMA) is a rare childhood-onset syndrome characterized by absences of responsiveness accompanied by bilateral rhythmic clonic-like myoclonic jerks. Herein, we describe the case of a child with EMA, resistant to multiple commonly used antiepileptic drugs, in whom low-dose phenobarbital unexpectedly achieved complete remission of epilepsy.Case reportA 10-year-old boy was referred to our hospital because of pharmaco-resistant frequent myoclonic absence seizures (MASs) and occasional generalized tonic-clonic seizures (GTCSs) that had commenced at the age of 7 years. Antiepileptic drugs including valproate sodium (VPA), levetiracetam, ethosuximide (ESM), clobazam, zonisamide, topiramate, clonazepam and lamotrigine were tested without significant effects. At the age of 8 years, phenobarbital was added to the VPA and ESM and increased to 1.2 mg/kg/day (blood concentration 8.6 µg/mL), which suppressed MASs completely within 1 month, and epileptic discharges on electroencephalography (EEG) within 5 months. To date, the boy has been seizure-free with normal EEG for 2 years.ConclusionPhenobarbital is a potential therapeutic option for pharmaco-resistant EMA.     

Epilepsy with myoclonic absences in siblings

Background: Epilepsy with myoclonic absences (EMAs) is a distinct form of childhood epilepsy characterized by a peculiar seizure type that identifies this condition. Purpose: To describe the clinical, electroencephalographic features, treatment strategies and outcome in this first case series of two siblings with normal intelligence presenting with EMAs. Materials and methods: Both siblings underwent video-polygraphic investigations (simultaneous recording of electroencephalogram [EEG] and electromyogram [EMG] from deltoids), high-resolution magnetic resonance imaging (MRI), karyotyping, neuropsychological evaluation and language assessment. Results: Both the children had a mean age of onset of prototype seizures by 3.5 years. Myoclonic absences (MAs) were characterized by rhythmic, bilateral, synchronous, symmetric 3-Hz spike–wave discharges, associated with EMG myoclonic bursts at 3 Hz, superimposed on a progressively increasing tonic muscle contraction. The interictal EEG showed a normal background activity with bursts of generalized spike and waves (SWs) as well as rare focal SWs independently over bilateral temporal and frontal regions. Increase in the seizure frequency from 5 to 100/day was observed due to use of carbamazepine and phenobarbitone which decreased with its withdrawal and introduction of valproate. Though lamotrigine was given as an add on to valproate, it did not benefit them and was therefore replaced by topiramate at 3.5 mg/kg/day which has maintained them on remission at one year follow up. Conclusions: Recognition of this ictal pattern allows identification and differentiation of EMAs from other seizure types. Idiopathic and symptomatic EMAs need to be differentiated from childhood absence epilepsy with myoclonia. MAs are worsened by drugs like carbamazepine while valproate either alone or in combination with topiramate (preferred to lamotrigine) gives excellent outcome.     

Diaphragm myoclonus followed by generalised atonia in a patient with trisomy 4p: unusual semiology in an unusual condition

In this report, we describe a female patient with trisomy 4p, a rare genetic condition, with unusual seizure semiology. The patient is one of the oldest reported survivors with this condition. This semiology was noted while she was being monitored by inpatient video telemetry. We observed a series of myoclonic shoulder jerks, followed by hiccup‐like episodes, and finally an atonic head drop. Corresponding ictal EEG showed semi‐rhythmic high‐amplitude slow waves with spikes superimposed over the frontotemporal areas. This semiology was confirmed as habitual by her parents. Subsequent hiccup‐like episodes had no EEG correlate, and the head drop was again associated with semi‐rhythmic high‐amplitude slow waves and superimposed spikes, more prominent over the right hemisphere. In addition, we review the several cases in which hiccups have been associated with seizures and how this may relate to the neural pathways involved in the pathophysiology of hiccups. We believe the ictal hiccup‐like episodes followed by atonia to be a seizure semiology that has not previously been documented. [Published with video sequence]     

Idiopathic epilepsy with generalized tonic–clonic seizures only versus idiopathic epilepsy with phantom absences and generalized tonic–clonic seizures: One or two syndromes?

Purpose: To define the relationship between two syndromes of idiopathic generalized epilepsy (IGE) with apparently similar phenotypes: The form with generalized tonic–clonic seizures only (IGE‐GTCS) and that with phantom absences (IGE‐PA). Methods: We compared the electroclinical features of 33 consecutive patients with GTCS and generalized spike wave (GSW); 18 had only GTCS and were diagnosed as IGE‐GTCS, and 15 had hitherto unnoticed mild absences on the electroencephalography (EEG) and were diagnosed as IGE‐PA. All patients were subjected to the same diagnostic workout, including video EEG during hyperventilation with breath counting (HBC). Patients with a clinical history of absences or myoclonic seizures were excluded. Results: PA were easily identified with the first or second EEG in 14 of 15 patients with IGE‐PA and always with sleep‐deprived EEGs; conversely, PA did not occur in the IGE‐GTCS patients despite using more EEGs. GTCS were twice as frequent in the IGE‐GTCS group and tended to occur on awakening, whereas episodes of absence status affected twice as many patients with IGE‐PA. The hereditary risk was 30% in the IGE‐GTCS and 6.7% in IGE‐PA. GSW had a strong polyspike component in IGE‐PA and were briefer in IGE‐GTCS. There is no evidence for a maturational influence on the duration of GSW in either syndrome. Conclusion: Our findings clearly indicate that IGE‐GTCS and IGE‐PA are two distinct IGE syndromes and emphasize the role of PA for patients' diagnosis and management and for syndromic classification. They also appear to validate HBC as a simple, sensitive, and pragmatic method for the clinical identification of typical absences.     

Characteristic phasic evolution of convulsive seizure in PCDH19‐related epilepsy

PCDH19‐related epilepsy is a genetic disorder that was first described in 1971, then referred to as “epilepsy and mental retardation limited to females”. PCDH19 has recently been identified as the responsible gene, but a detailed characterization of the seizure manifestation based on video‐EEG recording is still limited. The purpose of this study was to elucidate features of the seizure semiology in children with PCDH19‐related epilepsy. To do this, ictal video‐EEG recordings of 26 convulsive seizures in three girls with PCDH19‐related epilepsy were analysed. All seizures occurred in clusters, mainly during sleep accompanied by fever. The motor manifestations consisted of six sequential phases: “jerk”, “reactive”, “mild tonic”, “fluttering”, “mild clonic”, and “postictal”. Some phases were brief or lacking in some seizures, whereas others were long or pronounced. In the reactive phase, the patients looked fearful or startled with sudden jerks and turned over reactively. The tonic and clonic components were less intense compared with those of typical tonic‐clonic seizures in other types of epilepsy. The fluttering phase was characterised initially by asymmetric, less rhythmic, and less synchronous tremulous movement and was then followed by the subtle clonic phase. Subtle oral automatism was observed in the postictal phase. The reactive, mild tonic, fluttering and mild clonic phases were most characteristic of seizures of PCDH19‐related epilepsy. Ictal EEG started bilaterally and was symmetric in some patients but asymmetric in others. It showed asymmetric rhythmic discharges in some seizures at later phases. The electroclinical pattern of the phasic evolution of convulsive seizure suggests a focal onset seizure with secondary generalisation. Based on our findings, we propose that the six unique sequential phases in convulsive seizures suggest the diagnosis of PCDH19‐related epilepsy when occurring in clusters with or without high fever in girls. [Published with video sequences online]     

Myoclonic jerks are commonly associated with absence seizures in early‐onset absence epilepsy

Aim. Typical absence seizures are observed in various epilepsy syndromes, however, few series have focused on early‐onset absence epilepsy (EOAE). We aimed to evaluate the occurrence of this seizure type in children under 4 years of age in order to evaluate their electroclinical characteristics and outcome. Methods. We retrospectively studied (2006–2014) the electroclinical features of children with normal development and typical absence seizures starting before the age of 4 (with available pre‐treatment video‐EEG). Results. Nine patients were included. Among them, eight patients had rhythmic myoclonic jerks involving the muscles of the upper face (eyebrows and eyelids) or neck, present from the onset to the end of the typical absence discharge. The myoclonia were synchronous with spike‐wave complexes. One patient with GLUT‐1 deficiency was refractory to antiepileptic polytherapy. The other eight became seizure‐free; five with one antiepileptic drug and three with a combination of two drugs. The treatment was successfully withdrawn in five of the six patients who achieved two years of seizure freedom. None of them exhibited any other seizure type. Four of the eight patients with normal schooling required some support. We observed a positive correlation between the duration of absence seizure and the age of the patient at examination. Conclusion. Most of the patients under four years with only typical absence seizures had EOAE, and the motor symptoms may represent a distinctive age‐related feature of EOAE. Further investigations are required to better correlate the role of brain maturation with the duration of the absence. [Published with video sequence on www.epilepticdisorders.com ]