Levetiracetam in a neonate with malignant migrating partial seizures

Efficacy of levetiracetam as first-line therapy for neonatal clinical seizures and neurodevelopmental outcome at 12 months of age

Appropriate treatment of neonatal seizures with an effective therapy is important in reducing long-term neurologic disabilities. Sixty-seven neonates, who received intravenous (IV) levetiracetam (LEV) as first-line therapy for treating seizures between 2013 and 2017 were evaluated retrospectively to investigate the efficacy of LEV and its neurodevelopmental outcome at 12 months of age. Of the 67 neonates (44 preterm and 23 term babies) evaluated for seizures, 55 (82%) had a defined etiology. EEG confirmation was obtained in 36 (57.1%) of the neonates with clinical seizures. On the 7th day of the treatment (mean seizure control time 7.4 ± 15.1 days), LEV was effective as monotherapy in 43 (64%), whereas add-on therapy was required in 24 (36%) neonates. At the 1-year follow-up, 76% of infants achieved drug-free state, nine (18%) infants remained on LEV monotherapy and three (6%) needed add-on therapy. Neurodevelopmental outcome of the infants was assessed with Ankara Development Screening Inventory and results suggested favorable neurodevelopmental outcome in 69.7% of the infants with at the end of the 1-year follow-up with LEV monotherapy. In conclusion, this retrospective cross-sectional study demonstrated that IV LEV is an effective first-line therapy for treating neonatal clinical seizures and LEV monotherapy effect was sustained during the first year follow-up.

KCNT1-Related Epilepsy: A Review

KCNT1 gene encodes the sodium-dependent potassium channel reported as a causal factor for several different epileptic disorders. The gene has been also linked with cardiac disorders and in a family to sudden unexpected death in epilepsy. KCNT1 mutations, in most cases, result in a gain of function causing a neuronal hyperpolarization with loss of inhibition. Many early-onset epileptic encephalopathies related to gain of function of KCNT1 gene have been described, most often associated with two phenotypes: malignant migrating focal seizures of infancy and familial autosomal-dominant nocturnal frontal lobe epilepsy; however, there is no clear phenotype–genotype correlation, in fact same mutations have been represented in patients with West syndrome, Ohtahara syndrome, and early myoclonic encephalopathy. Additional neurologic features include intellectual disability, psychiatric disorders, hypotonia, microcephaly, strabismus, and movement disorders. Conventional anticonvulsant, vagal stimulation, and ketogenic diet have been used in the absence of clinical benefit in individuals with KCNT1-related epilepsy; in some patients, quinidine therapy off-label has been practiced successfully. This review aims to describe the characteristics of the gene, the phenotypes related to genetic mutations with the possible genotype–phenotype correlations and the treatments proposed to date, discussing the comorbidities reported in the literature.

Treating the symptom or treating the disease in neonatal seizures: a systematic review of the literature

Aim

The existing treatment options for neonatal seizures have expanded over the last few decades, but no consensus has been reached regarding the optimal therapeutic protocols. We systematically reviewed the available literature examining neonatal seizure treatments to clarify which drugs are the most effective for the treatment of specific neurologic disorders in newborns.

Method

We reviewed all available, published, literature, identified using PubMed (published between August 1949 and November 2020), that focused on the pharmacological treatment of electroencephalogram (EEG)-confirmed neonatal seizures.

Results

Our search identified 427 articles, of which 67 were included in this review. Current knowledge allowed us to highlight the good clinical and electrographic responses of genetic early-onset epilepsies to sodium channel blockers and the overall good response to levetiracetam, whose administration has also been demonstrated to be safe in both full-term and preterm newborns.

Interpretation

Our work contributes by confirming the limited availability of evidence that can be used to guide the use of anticonvulsants to treat newborns in clinical practice and examining the efficacy and potentially harmful side effects of currently available drugs when used to treat the developing newborn brain; therefore, our work might also serve as a clinical reference for future studies.

Intravenous Levetiracetam for Treatment of Seizures in Term and Preterm Neonates

Context:

Seizures are the most frequent neurological disturbance in the neonatal period, and there are no evidence-based guidelines for the treatment of neonatal seizures. Here we report a study on the use of levetiracetam as second-line therapy in the treatment of seizures in term and preterm neonates.

Aim:

The aim of this study was to assess the efficacy and safety of levetiracetam for seizures of term and preterm neonates.

Settings and Design:

We retrospectively analyzed data of the patients who had seizures and who were treated with levetiracetam as an add-on therapy to phenobarbital during the neonatal period.

Statistical Analysis:

The Statistical Package for the Social Sciences (SPSS) software, version 15.0 (SPSS, Chicago, Illinois), was used for statistical analysis. Continuous variables were expressed as mean values and standard deviations.

Results:

Thirty-six patients (8 term and 28 preterm) received levetiracetam. Mean dose of levetiracetam was 31.67 ± 14.83mg/kg/day. Twenty-five of the patients (69.4%) were seizure free with levetiracetam treatment. Electroencephalography recordings improved in 28 (77.8%) of the patients after levetiracetam. No severe adverse effects were observed.

Conclusion:

Our data suggest that levetiracetam may be a safe and effective treatment for neonatal seizures, which are unresponsive to phenobarbital.

Neonatal Developmental and Epileptic Encephalopathies

The new concept of developmental and epileptic encephalopathy is based on the understanding that many genetic epilepsies are associated with developmental impairment as a direct consequence of the genetic mutation, in addition to the effect of the frequent epileptic activity on brain development. As an example, in infants with KCNQ2 or STXBP1 encephalopathy, seizures may be controlled early after onset or cease spontaneously after a few years, but the developmental consequences tend to remain profound. The term "developmental and epileptic encephalopathy" expresses the concept that the genetic defect may be responsible for both the epilepsy and adverse development which is crucial to understanding the disease process for both families and clinicians. The increased use of EEG monitoring, neuroimaging, and metabolic and genetic testing in the Neonatal Intensive Care Unit has greatly improved our understanding of neonatal-onset epilepsies as seen with the syndromes Ohtahara and Early Myoclonic Encephalopathy outlined in the 1970s into distinct etiology-specific electroclinical phenotypes.

KCNT1 epilepsy with migrating focal seizures shows a temporal sequence with poor outcome, high mortality and SUDEP

Data on KCNT1 epilepsy of infancy with migrating focal seizures are heterogeneous and incomplete. Kuchenbuch et al. refine the syndrome phenotype, showing a three-step temporal sequence, poor prognosis with acquired microcephaly, high prevalence of extra-neurological manifestations and early mortality, particularly due to SUDEP. Refining the electro-clinical spectrum should facilitate early diagnosis.

Short-Term Neurodevelopmental Outcome in Term Neonates Treated with Phenobarbital versus Levetiracetam: A Single-Center Experience

Background

Phenobarbital (PB) has been traditionally used as the first-line treatment for neonatal seizures. More recently, levetiracetam (LEV) has been increasingly used as a promising newer antiepileptic medication for treatment of seizures in neonates.

Objectives

The aim of our study was to compare the effect of PB vs. LEV on short-term neurodevelopmental outcome in infants treated for neonatal seizures.

Method

This randomized, one-blind prospective study was conducted on term neonates admitted to the Neonatal Intensive Care Unit of S. Bambino Hospital, University Hospital "Policlinico-Vittorio Emanuele," Catania, Italy, from February 2016 to February 2018. Thirty term neonates with seizures were randomized to receive PB or LEV; the Hammersmith Neonatal Neurological Examination (HNNE) was used at baseline (T0) and again one month after the initial treatment (T1).

Results

We found a significantly positive HNNE score for the developmental outcomes, specifically tone and posture, in neonates treated with LEV. There was no significant improvement in the HNNE score at T1 in the neonates treated with PB.

Conclusion

This study suggests a positive effect of levetiracetam on tone and posture in term newborns treated for neonatal seizures. If future randomized-controlled studies also show better efficacy of LEV in the treatment of neonatal seizures, LEV might potentially be considered as the first-line anticonvulsant in this age group.

Genetics of neonatal-onset epilepsies

Although the majority of seizures in neonates are related to acute brain injury, a substantial minority are the first symptom of a neonatal-onset epilepsy often linked to a pathogenic genetic variant. Historically, studies on neonatal seizures including treatment response and long-term consequences have lumped all etiologies together. However, etiology has been consistently shown to be the most important determinant of outcome. In the past few years, an increasing number of monogenic disorders have been described and might explain up to a third of neonatal-onset epilepsy syndromes previously included under the umbrella of Ohtahara syndrome and early myoclonic encephalopathy. In this chapter, we define the concept of genetic epilepsy and review the classification. Then, we review the most relevant monogenic neonatal-onset epilepsies, detail their underlying pathophysiologic mechanisms, and present their electroclinical phenotypes. We highlight that, in some cases, such as neonates with KCNQ2 or KCNT1 gene mutations, the early recognition of the electroclinical phenotype can lead to targeted diagnostic testing and precision medicine treatment, enabling the possibility of improved outcome.

Neonatal epilepsies: Clinical management

Whereas the majority of seizures in neonates are related to acute brain injury, a substantial minority are the first symptom of a neonatal-onset epilepsy, often linked to a pathogenic genetic variant. This defect may disrupt cortical development (e.g., lissencephaly, focal cortical dysplasia), lead to metabolic changes (e.g., pyridoxine-dependent epilepsy, sulfite oxidase deficiency) or lead to cortical dysfunction without metabolic or macroscopic structural changes (e.g., channelopathies, STXBP1). Historically, studies on treatment response and long-term consequences of neonatal seizures have lumped all etiologies together. However, etiology has been consistently shown to be the most important determinant of outcome. Here, we address the elements differentiating neonatal-onset epilepsies from acute symptomatic seizures. We review some common neonatal-onset epilepsies and emphasize how pathognomonic electro-clinical phenotypes such as the ones associated with KCNQ2 or KCNT1 gene mutation, when recognized early, can lead to targeted diagnostic testing and precision medicine treatment, enabling the possibility of improved outcome.

Levetiracetam in neonatal seizures: a review

Phenobarbital and phenytoin have been the mainstay treatment modalities for neonatal seizures. Studies have revealed these agents control seizures in less than half of neonates, can cause neuronal apoptosis in vitro, and have highly variable pharmacokinetics in neonates. In contrast, there have been no reports of levetiracetam causing these neurotoxic effects. Due to its favorable side effect and pharmacokinetic profiles and positive efficacy outcomes in neonatal studies to date, there is great interest in the use of levetiracetam for neonatal seizures. This article reviews the literature regarding the safety of levetiracetam in neonates and its efficacy in neonatal seizures.

Emerging role of the KCNT1 Slack channel in intellectual disability

The sodium-activated potassium KNa channels Slack and Slick are encoded by KCNT1 and KCNT2, respectively. These channels are found in neurons throughout the brain, and are responsible for a delayed outward current termed I KNa. These currents integrate into shaping neuronal excitability, as well as adaptation in response to maintained stimulation. Abnormal Slack channel activity may play a role in Fragile X syndrome, the most common cause for intellectual disability and inherited autism. Slack channels interact directly with the fragile X mental retardation protein (FMRP) and I KNa is reduced in animal models of Fragile X syndrome that lack FMRP. Human Slack mutations that alter channel activity can also lead to intellectual disability, as has been found for several childhood epileptic disorders. Ongoing research is elucidating the relationship between mutant Slack channel activity, development of early onset epilepsies and intellectual impairment. This review describes the emerging role of Slack channels in intellectual disability, coupled with an overview of the physiological role of neuronal I KNa currents.

Electroencephalogram of age-dependent epileptic encephalopathies in infancy and early childhood

Epileptic encephalopathy syndromes are disorders in which the epileptiform abnormalities are thought to contribute to a progressive cerebral dysfunction. Characteristic electroencephalogram findings have an important diagnostic value in classification of epileptic encephalopathy syndromes. In this paper, we focus on electroencephalogram findings of childhood epileptic encephalopathy syndromes and provide sample illustrations.

Efficacy and tolerability of intravenous levetiracetam in childrens

Intractable epilepsy in children poses a serious medical challenge. Acute repetitive seizures and status epilepticus leads to frequent emergency room visits and hospital admissions. Delay of treatment may lead to resistance to the first-line anticonvulsant therapies. It has been shown that these children continue to remain intractable even after acute seizure management with approved Food and Drug Administration (FDA) agents. Intravenous levetiracetam, a second-generation anticonvulsant was approved by the FDA in 2006 in patients 16 years and older as an alternative when oral treatment is not an option. Data have been published showing that intravenous levetiracetam is safe and efficacious, and can be used in an acute inpatient setting. This current review will discuss the recent data about the safety and tolerability of intravenous levetiracetam in children and neonates, and emphasize the need for a larger prospective multicenter trial to prove the efficacy of this agent in acute seizure management.

Migrating partial seizures of infancy: expansion of the electroclinical, radiological and pathological disease spectrum

Migrating partial seizures of infancy, also known as epilepsy of infancy with migrating focal seizures, is a rare early infantile epileptic encephalopathy with poor prognosis, presenting with focal seizures in the first year of life. A national surveillance study was undertaken in conjunction with the British Paediatric Neurology Surveillance Unit to further define the clinical, pathological and molecular genetic features of this disorder. Fourteen children with migrating partial seizures of infancy were reported during the 2 year study period (estimated prevalence 0.11 per 100,000 children). The study has revealed that migrating partial seizures of infancy is associated with an expanded spectrum of clinical features (including severe gut dysmotility and a movement disorder) and electrographic features including hypsarrhythmia (associated with infantile spasms) and burst suppression. We also report novel brain imaging findings including delayed myelination with white matter hyperintensity on brain magnetic resonance imaging in one-third of the cohort, and decreased N-acetyl aspartate on magnetic resonance spectroscopy. Putaminal atrophy (on both magnetic resonance imaging and at post-mortem) was evident in one patient. Additional neuropathological findings included bilateral hippocampal gliosis and neuronal loss in two patients who had post-mortem examinations. Within this cohort, we identified two patients with mutations in the newly discovered KCNT1 gene. Comparative genomic hybridization array, SCN1A testing and genetic testing for other currently known early infantile epileptic encephalopathy genes (including PLCB1 and SLC25A22) was non-informative for the rest of the cohort.

Epileptic encephalopathies (including severe epilepsy syndromes)

Epileptic encephalopathies represent a group of devastating epileptic disorders that appear early in life and are characterized by pharmacoresistant generalized or focal seizures, persistent severe electroencephalography (EEG) abnormalities, and cognitive dysfunction or decline. The ictal and interictal epileptic discharges are age-specific and are the main etiologic factors causing cognitive deterioration. This is most obvious in the idiopathic group. In the symptomatic group, the most common causes are structural, congenital, or acquired and rarely some metabolic disorders. In certain cases, clinical and EEG abnormalities persist and may evolve from one type to another as the child grows older. Various factors trigger and sustain the underlying pathophysiologic process and the ongoing epileptic and epileptiform activity during the most critical periods of brain maturation, perpetuating their deleterious effect on the brain. Immune-mediated mechanisms may have a role, suggested by certain encephalopathies responding to immune-modulating treatments and by the finding of various autoimmune antibodies. The chance of a better cognitive outcome improves with early diagnosis and treatment that is appropriate and effective. Current antiepileptic drugs are, in general, not effective: we urgently need new trials in this very special epileptic category. This article briefly reviews the most common epileptic encephalopathies and analyzes the most important clinical issues.

De novo gain-of-function KCNT1 channel mutations cause malignant migrating partial seizures of infancy

Malignant migrating partial seizures of infancy (MMPSI) is a rare epileptic encephalopathy of infancy that combines pharmacoresistant seizures with developmental delay. We performed exome sequencing in three probands with MMPSI and identified de novo gain-of-function mutations affecting the C-terminal domain of the KCNT1 potassium channel. We sequenced KCNT1 in 9 additional individuals with MMPSI and identified mutations in 4 of them, in total identifying mutations in 6 out of 12 unrelated affected individuals. Functional studies showed that the mutations led to constitutive activation of the channel, mimicking the effects of phosphorylation of the C-terminal domain by protein kinase C. In addition to regulating ion flux, KCNT1 has a non-conducting function, as its C terminus interacts with cytoplasmic proteins involved in developmental signaling pathways. These results provide a focus for future diagnostic approaches and research for this devastating condition.

A case of malignant migrating partial seizures in infancy as a continuum of infantile epileptic encephalopathy

The syndrome of malignant migrating partial seizures in infancy (MMPSI) is characterized by onset before the age of 6 months, nearly continuous electrographic seizures involving multiple independent areas of onset in both hemispheres, and poor developmental outcome. This report presents a case involving a patient with MMPSI, who later developed West syndrome. At the age of 2 months old, he showed multifocal partial seizures, which were refractory to antiepileptic drugs. His electroencephalogram (EEG) revealed characteristic migrating multifocal epileptiform activities and neuroimaging finding was normal. The focal seizures were refractory to antiepileptic drugs and ketogenic diet. When he was 9 months old, epilepic spasms were observed with hypsarrhythmia on EEG. He also showed severe developmental delay. MMPSI may be a continuum of infantile epileptic encephalpathy and could evolve to West syndrome.

Migrating focal seizures during infancy: a case report and pathologic study

Migrating focal seizures in infancy are an unusual and often overlooked epilepsy syndrome, with onset before age 6 months, in which nearly continuous seizures involve multiple, independent areas of both hemispheres with an arrest of psychomotor development. We describe a patient with migrating focal seizures in infancy whose seizures began at age 45 days. The seizures were refractory to common antiepileptic drugs. At age 6 months, the infant received potassium bromide and became almost seizure-free. The infant developed severe neurologic impairment, with marked axial hypotonia and an absence of visual contact and head control. At age 8 months, the child suddenly died. Pathologic findings included multiple malformations of cortical development, polymicrogyria, and focal cortical dysplasia associated with hippocampal sclerosis.

Levetiracetam for treatment of neonatal seizures

Neonatal seizures are often refractory to treatment with initial antiseizure medications. Consequently, clinicians turn to alternatives such as levetiracetam, despite the lack of published data regarding its safety, tolerability, or efficacy in the neonatal population. We report a retrospectively identified cohort of 23 neonates with electroencephalographically confirmed seizures who received levetiracetam. Levetiracetam was considered effective if administration was associated with a greater than 50% seizure reduction within 24 hours. Levetiracetam was initiated at a mean conceptional age of 41 weeks. The mean initial dose was 16 ± 6 mg/kg and the mean maximum dose was 45 ± 19 mg/kg/day. No respiratory or cardiovascular adverse effects were reported or detected. Levetiracetam was associated with a greater than 50% seizure reduction in 35% (8 of 23), including seizure termination in 7. Further study is warranted to determine optimal levetiracetam dosing in neonates and to compare efficacy with other antiseizure medications.

Ictal patterns in children: an illustrated review

Detailed knowledge of electroencephalographic patterns accompanying epileptic seizures in children is paramount to the correct identification of epileptic seizures and syndromes. In this article, we present a review of ictal patterns of different seizure types in children, illustrating with examples collected in our video-EEG laboratory at Pequeno Príncipe Hospital.

Update on rufinamide in childhood epilepsy

Rufinamide is an orally active, structurally novel compound (1-[(2,6-difluorophenil1) methyl1]-1 hydro 1,2,3-triazole-4 carboxamide), which is structurally distinct from other anticonvulsant drugs. It was granted orphan drug status for the adjunctive treatment of Lennox-Gastaut syndrome (LGS) in the United States in 2004, and released for use in Europe in 2007. In January 2009, rufinamide was approved by the United States Food and Drug Administration for treatment of LGS in children 4 years of age and older. It is also approved for adjunctive treatment for partial seizures in adults and adolescents. Rufinamide's efficacy mainly against atonic/tonic seizures in patients with LGS seems nowadays indubitable and has been confirmed both in randomized controlled trial and in open label extension studies. More recently, rufinamide was evaluated for the adjunctive treatment of childhood-onset epileptic encephalopathies and epileptic syndromes other than LGS, including epileptic spasms, multifocal epileptic encephalopathy with spasm/tonic seizures, myoclonic-astatic epilepsy, Dravet syndrome and malignant migrating partial seizures in infancy. This review updates the existing literature data on the efficacy and safety/tolerability of rufinamide in childhood-onset epilepsy syndromes.

Efficacy and safety of levetiracetam as an add-on therapy in children aged less than 4 years with refractory epilepsy

In the past decade, most studies on levetiracetam were conducted on patients aged > or = 4 years of age. The authors sought to assess the efficacy and safety of levetiracetam as an adjunctive treatment of children <4 years of age with refractory epilepsy. The mean levetiracetam dosage used on the 24 patients in this study was 38.85 mg/kg per day, and the mean duration of treatment was 40 weeks. During the study, levetiracetam was tapered off in 2 patients due to seizure worsening and was discontinued in other 2 patients due to unacceptable adverse effects. Levetiracetam therapy was effective in 58.3% of patients, with 20.8% achieving seizure freedom. Eight patients showed no obvious response and the remaining 2 patients showed divergent responses. Although adverse effects were seen in 37.5% of patients, all adverse effects were tolerable or resolved with time or discontinuation. Therefore, the authors conclude that levetiracetam treatment is effective and safe in young children with refractory epilepsy.

Neonatal seizures: an update on mechanisms and management

The lifespan risk of seizures is highest in the neonatal period. Current therapies have limited efficacy. Although the treatment of neonatal seizures has not changed significantly in the last several decades, there has been substantial progress in understanding developmental mechanisms that influence seizure generation and responsiveness to anticonvulsants. This article provides an overview of current approaches to the diagnosis and treatment of neonatal seizures, and some of the recent insights about the pathophysiology of neonatal seizures that may provide the foundation for better treatment are identified.

Controversies in neonatal seizure management

Seizures in the newborn period are common and frequently indicate serious underlying brain injury. Although accumulating evidence suggests that they may impair brain development, there are currently no evidence-based guidelines for evaluation and management of neonatal seizures. In this review, we will address some of the current controversies facing child neurologists and neonatologists, including how to define, monitor, and treat neonatal seizures.

Partial seizures and atypical absence seizures as a single ictal event in a patient with Lennox-Gastaut syndrome

The authors report a patient with Lennox-Gastaut syndrome who was a fraternal twin. The twins encountered myoclonic seizures at the age of 4 years, but the seizures in the other patient were controlled very quickly without intellectual development damage. With the disease evolving, other characteristic seizures of Lennox-Gastaut syndrome appeared and failed to be controlled by multiple antiepileptic drugs, so levetiracetam was added on. At this time, frequent partial seizures from the left occipital and posterior temporal regions occurred, which always intermixed with atypical absence seizures in a single ictal event. To control the status epilepticus, levetiracetam was withdrawn immediately, and clonazepam, midazolam, and corticotropin in turn were used. The partial seizures were gradually alleviated. The results obtained in this study suggest that there might be some correlative mechanisms between partial seizures and atypical absence seizures in a single event. There is a temporal relationship between the occurrence of partial seizures and the introduction of levetiracetam.

Malignant migrating partial seizures in Aicardi syndrome

This article reports on a female infant with Aicardi syndrome presenting with malignant migrating partial seizures from her first day of life. Initially, unilateral tonic seizures were seen with contralateral ictal electroencephalogram findings. Typically, these tonic seizures were accompanied by head and eye deviation and were followed by a tonic seizure on the other side of the body. At 6 months of age she developed epileptic spasms. She showed no motor development, did not respond to eye contact, and was nasogastric tube-fed. The epilepsy syndrome in this child is refractory to antiepileptic treatment and there is no psychomotor development. This case expands the phenotype of this catastrophic epileptic encephalopathy and suggests that the corpus callosum is not necessary for the 'migration' of partial seizures in this syndrome.

Epileptic syndromes in infancy and childhood

PURPOSE OF REVIEW

The aim of this article is to review new epilepsy syndromes, acquire a new understanding of older ones and emphasize the impact of this concept on basic research regarding aetiology and treatment.

RECENT FINDINGS

In addition to those included in the classification of the International League Against Epilepsy, new epilepsy syndromes comprise febrile seizures plus, benign familial neonatal-infantile seizures (BFNIS), benign infantile focal epilepsy with midline spikes and waves during sleep (BFIS), malignant migrating partial seizures in infancy, devastating epilepsy in school age children and late onset cryptogenic spasms. Genetics played a central role in identifying some new entities (BFNIS, BFIS with choreoathetosis), to delineate older syndromes (Dravet syndrome and myoclonic astatic epilepsy) and determine their mechanisms (infantile spasms, pyridoxine dependent seizures, neonatal encephalopathy with suppression bursts).

SUMMARY

A significant number of children, mainly infants, do not fit in any of the described epilepsy syndromes. Still many patients with infantile epilepsy require the identification of cause or recognition of an epilepsy syndrome.

Migrating focal seizures in infancy: analysis of the electroclinical patterns in 17 patients

We describe the electroclinical features, therapy, and long-term evolution of 17 patients with migrating focal seizures in infancy, and analyzed the charts of these patients seen between February 1985 and July 2005. Three different electroclinical patterns were recognized: (1) 8 cases with alternating simple focal motor seizures at onset. The ictal electroencephalography (EEG) pattern was characterized by recurrence of rhythmic focal spikes or rhythmic sharp activity in the Rolandic region; (2) 5 cases with complex focal seizures and progressive appearance of polymorphic delta- activity in 1 temporo-occipital region recurring independently; (3) 4 cases with focal complex seizures with motor manifestations. Ictal EEG showed flattening or fast activity in 1 frontotemporal region followed by unilateral fast poly-spikes in alternating clusters in both hemispheres. The focal seizures were refractory to antiepileptic drugs, and all patients except 3 had severe developmental delay. Migrating focal seizures in infancy is a newly defined and rare, but underrecognized, epileptic encephalopathy.