Benign myoclonus of early infancy

The assessment of the knowledge and practices of healthcare providers regarding paroxysmal non-epileptic events (PNES) in children: A cross-sectional study

OBJECTIVE

Paroxysmal non-epileptic events (PNEs) are a group of disorders that may be misdiagnosed as epilepsy. This study has aimed to assess the knowledge and practices of family physicians and pediatricians regarding the diagnosis, treatment, and follow-up of PNEs in children.

METHODS

The study was designed as a prospective cross-sectional study that was conducted between March 1, 2022, and June 1, 2022, by reaching pediatric specialists and assistants, family physicians, subspecialty assistants, and subspecialists using a Google questionnaire. The survey consists of 26 questions. The questionnaire used by the researchers was prepared in accordance with the literature search and it included detailed questions on the diagnosis, treatment, and differential diagnosis of PNEs.

RESULTS

A total of 37.3% worked as specialists. Most of the participants (41.3%) have worked in training and research hospitals, and 44.3% have been physicians for 6-10 years. The mean and standard deviation for the total score were 10.1 ± 2.6. The scores of family physicians were statistically lower than those of specialists, subspecialty assistants, and subspecialists. A total of 67.2% left the decision of whether the patient should stop taking their medication to another clinician. 45% of the doctors said that they were uncomfortable with the diagnosis.

SIGNIFICANCE

The study findings emphasized the significant knowledge gap among healthcare providers regarding PNEs in children, highlighting the need for targeted educational interventions to improve their understanding and diagnostic skills in this area.

Clinical and Genetic Overview of Paroxysmal Movement Disorders and Episodic Ataxias

Paroxysmal movement disorders (PMDs) are rare neurological diseases typically manifesting with intermittent attacks of abnormal involuntary movements. Two main categories of PMDs are recognized based on the phenomenology: Paroxysmal dyskinesias (PxDs) are characterized by transient episodes hyperkinetic movement disorders, while attacks of cerebellar dysfunction are the hallmark of episodic ataxias (EAs). From an etiological point of view, both primary (genetic) and secondary (acquired) causes of PMDs are known. Recognition and diagnosis of PMDs is based on personal and familial medical history, physical examination, detailed reconstruction of ictal phenomenology, neuroimaging, and genetic analysis. Neurophysiological or laboratory tests are reserved for selected cases. Genetic knowledge of PMDs has been largely incremented by the advent of next generation sequencing (NGS) methodologies. The wide number of genes involved in the pathogenesis of PMDs reflects a high complexity of molecular bases of neurotransmission in cerebellar and basal ganglia circuits. In consideration of the broad genetic and phenotypic heterogeneity, a NGS approach by targeted panel for movement disorders, clinical or whole exome sequencing should be preferred, whenever possible, to a single gene approach, in order to increase diagnostic rate. This review is focused on clinical and genetic features of PMDs with the aim to (1) help clinicians to recognize, diagnose and treat patients with PMDs as well as to (2) provide an overview of genes and molecular mechanisms underlying these intriguing neurogenetic disorders.

Transient benign paroxysmal movement disorders in infancy

This review summarizes the current empirical and clinical literature on benign paroxysmal movement disorders in infancy most relevant to practitioners. Paroxysmal benign movement disorders are a heterogeneous group of movement disorders characterized by their favourable outcome. We pay special attention to the recognition and management of these abnormal motor conditions strongly suggestive of epileptic disorders. They include: neonatal jitteriness; benign neonatal sleep myoclonus; benign paroxysmal tonic upgaze; paroxysmal tonic downgaze, benign paroxysmal torticollis and benign polymorphous movement disorder of infancy.

Benign neonatal sleep myoclonus: our experience of 15 Japanese cases

PURPOSE

Benign neonatal sleep myoclonus is a non-epileptic movement disorder that may mimic neonatal seizures. The aim of this study was to clarify the clinical manifestations and outcomes in Japanese infants with benign neonatal sleep myoclonus.

METHODS

We reviewed the clinical manifestations and outcomes in 15 consecutive patients with benign neonatal sleep myoclonus (males: 10), including three paired familial cases, referred to our center between 1996 and 2011. The diagnosis of benign neonatal sleep myoclonus was based on a neonatal onset, characteristic myoclonic jerks that occurred during sleep, and normal electroencephalogram findings.

RESULTS

All were healthy full-term neonates at birth. The age at onset ranged from 1 to 18 days (median: 7 days). Prior to referral to our center (3-8 weeks), two infants had been placed on antiepileptic drugs, without effects. During the clinical course, the myoclonic jerks resolved by 6 months in 14 of the 15 patients. On follow-up (final evaluation, mean: 38 months), all but one patient (speech delay) showed normal development. None developed epilepsy. Of note, migraine occurred after 5 years of age in three children, including one who developed cyclic vomiting syndrome, evolving to migraine. Another boy developed cyclic vomiting syndrome, a precursor of migraine, before 1 year, and was being followed. A high incidence of migraine was observed in five (42%) of 12 parents whose detailed family history was available.

CONCLUSION

Our study suggests that benign neonatal sleep myoclonus is related to migraine. With the high rate of familial cases, further genetic study, including migraine-related gene analysis, is necessary to determine the underlying mechanism responsible for benign neonatal sleep myoclonus.

Infantile spasms syndrome, West syndrome and related phenotypes: what we know in 2013

The current spectrum of disorders associated to clinical spasms with onset in infancy is wider than previously thought; accordingly, its terminology has changed. Nowadays, the term Infantile spasms syndrome (ISs) defines an epileptic syndrome occurring in children younger than 1 year (rarely older than 2 years), with clinical (epileptic: i.e., associated to an epileptiform EEG) spasms usually occurring in clusters whose most characteristic EEG finding is hypsarrhythmia [the spasms are often associated with developmental arrest or regression]. The term West syndrome (WS) refers to a form (a subset) of ISs, characterised by the combination of clustered spasms and hypsarrhythmia on an EEG and delayed brain development or regression [currently, it is no longer required that delayed development occur before the onset of spasms]. Less usually, spasms may occur singly rather than in clusters [infantile spasms single-spasm variant (ISSV)], hypsarrhythmia can be (incidentally) recorded without any evidence of clinical spasms [hypsarrhythmia without infantile spasms (HWIS)] or typical clinical spasms may manifest in absence of hypsarrhythmia [infantile spasms without hypsarrhythmia (ISW)]. There is a growing evidence that ISs and related phenotypes may result, besides from acquired events, from disturbances in key genetic pathways of brain development: specifically, in the gene regulatory network of GABAergic forebrain dorsal-ventral development, and abnormalities in molecules expressed at the synapse. Children with these genetic associations also have phenotypes beyond epilepsy, including dysmorphic features, autism, movement disorders and systemic malformations. The prognosis depends on: (a) the cause, which gives origin to the attacks (the complex malformation forms being more severe); (b) the EEG pattern(s); (c) the appearance of seizures prior to the spasms; and (d) the rapid response to treatment. Currently, the first-line treatment includes the adrenocorticotropic hormone ACTH and vigabatrin. In the near future the gold standard could be the development of new therapies that target specific pathways of pathogenesis. In this article we review the past and growing number of clinical, genetic, molecular and therapeutic discoveries on this expanding topic.

Paroxysmal non-epileptic motor events in childhood: a clinical and video-EEG-polymyographic study

AIM

The aim of this article was to describe the phenomenology and polymyographic features of paroxysmal non-epileptic motor events (PNMEs) observed in a series of typically developing and children with neurological impairment.

METHOD

We conducted a retrospective evaluation of 63 individuals (29 females; 34 males) affected by PNMEs at the National Neurological Institute 'C. Besta' between 2006 and 2008. Individuals were included in the study if they had PNMEs documented by a video-electroencephalography-polymyographic study and were aged between 1 month and 18 years (mean age at the time of video-electroencephalography-polymyography: 5y 10mo).

RESULTS

In 45 of the 63 participants (71%), PNMEs were associated with other neurological conditions (secondary) including epilepsy, whereas in 18 participants PNME was the only neurological symptom (primary). Clinical features allowed classification of the motor disturbance into usual movement disorder categories in 31 individuals (49%); in the remaining 32 (51%), the movement disorder was characterized on the basis of polymyographic pattern of 'jerks' or 'sustained contraction'. The most frequent PNMEs were paroxysmal dyskinesias, followed by startle, stereotypies, shuddering, sleep myoclonus, psychogenic movement disorders, and benign myoclonus of early infancy; the last syndrome was also observed in children with neurological impairment. In eight participants, PNMEs remained unclassified.

INTERPRETATION

PNMEs may occur in both healthy and children with neurological impairment and are caused by a wide range of static and progressive conditions. In the majority of children with neurological impairment with associated epilepsy, the PNMEs do not fit into the usual movement disorders categories. A video-electroencephalography-polymyography is therefore useful for characterizing them.

Benign convulsions in newborns and infants: occurrence, clinical course and prognosis

BACKGROUND

During early development severe epilepsies may appear, some with well established occurrence. Benign non-epileptic and epileptic paroxysmal syndromes with excellent prognosis occur in the same period. There are no exact data on their occurrence.

AIM

We have reviewed medical histories of children with benign non-epileptic or benign epileptic events: benign myoclonus of early infancy, benign neonatal sleep myoclonus, benign sleep myoclonus in infancy, benign partial epilepsy in infancy (BPEI) and benign infantile familial convulsions (BIFC) were established. The occurrence, clinical characteristics and prognosis of these syndromes were evaluated.

METHODS

Inclusion criteria were met in 31 children. Research included retrospective analysis of clinical characteristics, laboratory values, neuroimaging and neurophysiological assessments, followed by evaluation of psychosocial development with the use of the Strengths and Difficulties Questionnaire (SDQ), fulfilled by parents.

RESULTS

In our group the incidence of benign non-epileptic convulsions was 6.69 per 10 000 live births and the incidence of benign epileptic convulsions was 1.35 per 10 000. Male/female ratio in the group of children with non-epileptic events was 2.1:1. Among non-epileptic group 5 out of 23 children and among epileptic group 3 out of 8 children had minimal, mild or moderate abnormalities at neurological assessment at the time of the first clinical examination. Nonspecific changes in laboratory values were seen in 6 out of 23 in the non-epileptic and in 1 out of 8 children in the epileptic group. Neurophysiological assessments showed subtle changes in 4/23 in the non-epileptic and 6/8 in the epileptic group. Neuroimaging was not optimal in 5/23 with non-epileptic and 3/8 with epileptic events. Analysis of SDQ did not show significant deviations in psyhosocial development. Statistically significant deviation was observed only in relations with peers (p = 0.009).

CONCLUSIONS

Benign neonatal and infantile convulsions are more frequent than severe epilepsies of the same age period. Results show higher proportion of males with benign non-epileptic conditions. No deviations in further development was found. Laboratory values, neuroimaging and neurophysiological assessments were normal or nonspecifically changed.

Mouvements anormaux paroxystiques non épileptiques de l'enfant

Paroxysmal movement disorders are not uncommon in childhood, but are probably under-recognised. Paroxysmal movement disorders are a distinctive group of disorders that represents various clinical situations, characterised by intermittent and episodic disturbances of movement. Diagnosis relies on semiological analysis, mainly based on parental description of the manifestations; video recording (during an EEG-video monitoring or home made video) are often helpful to establish the correct diagnosis. In the large majority of the cases, paroxysmal movement disorders are benign situations. Some of them are transient, as they spontaneously stop over time (benign torticolis of infancy, paroxysmal tonic upgaze). Being familiar with these disorders will lead to accurate diagnosis, so avoiding useless investigations. Most of the time, no treatment will be required, and the families will be informed of the good prognosis.

Paroxysmal nonepileptic events of childhood

The paroxysmal nonepileptic events of childhood are a group of disorders, syndromes, and phenomena that mimic true epileptic seizures. Clinical experience and a clear description of the event in question will usually lead to a correct categorization. They span in age from neonate to young adult and are apt to be the most common diagnostic challenges clinicians face regularly. The key to diagnosis is a detailed history and careful observation. Despite the large number of discrete entities enumerated herein, common principles in clinical approach are successful and described. Each entity can pose a significant clinical challenge in identification, etiologic pathophysiology, genetics, and management. A simple division is offered here separating those episodes that are associated with an altered mental status or occurring during sleep and those without an altered mental status or occurring while awake.

Idiopathic generalized epilepsies: clinical and electroencephalogram diagnosis and treatment

This review concentrates on the principles of the clinical and electroencephalogram diagnosis of idiopathic generalized epilepsies and their treatment. The electroclinical variability of the main seizure types is detailed and particular emphasis is placed on the differential diagnosis from other seizures and nonepileptic conditions that is essential for the optimal management of these patients. The authors review the various idiopathic generalized epilepsy subsyndromes and conditions that are included in both the 1989 International League Against Epilepsy classification system and the recently proposed International League Against Epilepsy scheme, but also syndromes and forms that have not been formally recognized. Finally, the authors describe the principles of antiepileptic drug treatment with the old and newer drugs, and their specific indications and contraindications in the various syndromes and seizure types.

Clinical evaluation of idiopathic paroxysmal kinesigenic dyskinesia: new diagnostic criteria

BACKGROUND

Paroxysmal kinesigenic dyskinesia (PKD) is a rare disorder characterized by short episodes of involuntary movement attacks triggered by sudden voluntary movements. Although a genetic basis is suspected in idiopathic cases, the gene has not been discovered. Establishing strict diagnostic criteria will help genetic studies.

METHODS

The authors reviewed the clinical features of 121 affected individuals, who were referred for genetic study with a presumptive diagnosis of idiopathic PKD.

RESULTS

The majority (79%) of affected subjects had a distinctive homogeneous phenotype. The authors propose the following diagnostic criteria for idiopathic PKD based on this phenotype: identified trigger for the attacks (sudden movements), short duration of attacks (<1 minute), lack of loss of consciousness or pain during attacks, antiepileptic drug responsiveness, exclusion of other organic diseases, and age at onset between 1 and 20 years if there is no family history (age at onset may be applied less stringently in those with family history). In comparing familial and sporadic cases, sporadic cases were more frequently male, and infantile convulsions were more common in the familial kindreds. Females had a higher remission rate than males. An infantile-onset group with a different set of characteristics was identified. A clear kinesigenic trigger was not elicited in all cases, antiepileptic response was not universal, and some infants had attacks while asleep.

CONCLUSIONS

The diagnosis of idiopathic paroxysmal kinesigenic dyskinesia (PKD) can be made based on historical features. The correct diagnosis has implications for treatment and prognosis, and the diagnostic scheme may allow better focus in the search for the PKD gene(s).

Benign febrile myoclonus in childhood

BACKGROUND

Myoclonus is often associated with progressive myoclonic epilepsy or neurodegenerative conditions. Febrile myoclonus is a benign phenomenon, which has only been reported previously in one child.

METHODS

The clinical features of three children with fever-induced myoclonus are described.

RESULTS

Fever-induced myoclonus is characterized by frequent myoclonus, which resolves with resolution of the fever in otherwise healthy children.

CONCLUSIONS

Recognition of fever-induced myoclonus as a benign phenomenon may prevent unnecessary investigations and interventions.

Infantile spasms: therapy and outcome

Up-to date information about corticotropin (ACTH) in the treatment of infantile spasms and evaluation of the long-term outcome was provided to answer questions about (1) the efficacy of doses of ACTH in comparison with other drugs, especially with vigabatrin, and the efficacy in patients with tuberous sclerosis; (2) tolerability; and (3) long-term outcome. In two studies, high doses were not more effective than low doses but were more effective in another study. In the follow-up of the studies, there was no difference. In an open, randomized, prospective study, the efficacy and relapse rates of ACTH and vigabatrin treatment did not differ significantly. The high response rates in tuberous sclerosis complex were similar. Both drugs had severe side effects. In the long-term follow-up of 20 to 35 years, one third of the patients died, the intellectual outcome of the remaining patients was normal or slightly subnormal, and one quarter and one third of the patients were seizure free. ACTH should be the first choice for treatment of infantile spasms. The side effects of ACTH, unlike those of vigabatrin, are well known, treatable, and reversible. However, an open, prospective study to compare the efficacy, relapse rate, and long-term outcome of treatment with ACTH and vigabatrin is urgently needed. The frequency of visual field defects after vigabatrin therapy should be evaluated.

Infantile spasms versus myoclonus: is there a connection?

Infantile spasms (IS) is usually classified as a form of "myoclonic epilepsy," but the nosology of this whole group of disorders is unclear. Evidence suggests that the spasms are subcortically mediated, but can be modified by input from the cortex, which is believed to be abnormally excitable and disorganized. The latter features may give rise to hypsarrhythmia. The whole issue of myoclonus rests on the phenotype of IS and precise measurements of the length of electromyographic (EMG) bursts. Based on scant EMG data, it would appear that the bursts during flexor spasms are too long for epileptic myoclonus. The nature of tonic spasms of even longer duration is not myoclonic. However, the infrequent spontaneous myoclonic jerks, which can occur without spasms, and head nodding could represent positive and negative myoclonus, respectively. Data can be collected easily through techniques such as back-averaging to resolve the issue of classification and localization of motor phenomena.

The spectrum of nonepileptic events in children

Nonepileptic events (NEE) are common in children, and can be difficult to distinguish from epileptic events. Several strategies can assist in differentiation. The first is an age-based approach to the differential of commonly presenting EEs in neonates, infants, and adolescents. The next strategy is to identify key elements of the patient's history to narrow the possibilities, and third is a rational approach to ancillary testing. There are additional challenges to the diagnosis and evaluation of NEEs in patients with cognitive impairments or mental retardation (MR). Twenty to 25% of neurologically normal patients (34), and up to 60% of children with MR (35) referred for an evaluation of seizures, have NEE. In most instances, the clinical history leads to the diagnosis, and ancillary testing serves as confirmation. But in certain populations, neonates, children with concurrent epilepsy, children in whom pseudoseizures are suspected, and children with MR, early use of video-EEG telemetry is indicated to establish the diagnosis and avoid overtreatment with antiepileptic drugs (AEDs).

Infantile spasms

Infantile spasms constitute both a distinctive seizure type and an age-specific epilepsy syndrome that have been extensively described for over a century. Standardization of the classification of infantile spasms has evolved, culminating in recent recommendations for separately recognizing and distinguishing the seizure type (spasms or epileptic spasms) and the epilepsy syndrome of infantile spasms (West syndrome). More-detailed descriptions of the clinical and electrographic features of epileptic spasms and hypsarrhythmia have emerged. Advances in neuroimaging techniques have revealed clues about pathophysiology and increased the etiologic yield of the diagnostic evaluation of patients with infantile spasms. Adrenocorticotrophic hormone remains the treatment of choice for many neurologists. Recent controlled studies support vigabatrin as first-line therapy, and open-label studies suggest that topiramate, lamotrigine, and zonisamide may be useful in treating spasms. Recent reports of visual-field constriction with vigabatrin may limit its use. Surgical treatment has been used successfully in a select subgroup of patients with secondarily generalized spasms from a single epileptogenic zone. Although the prognosis for most patients with infantile spasms remains poor, further studies identifying predictors of favorable prognosis and recent advances in understanding the pathophysiology of infantile spasms offer hope of safer and more-effective therapies that improve long-term outcome.

Benign myoclonus of early infancy: an imitator of West's syndrome

Benign myoclonus of early infancy is a rare condition characterized by nonepileptic spasms that may resemble the epileptic spasms seen in West's syndrome. The spells in benign myoclonus of early infancy begin before age 1 year and are self-limited. The electroencephalogram (EEG) is invariably normal, and neurologic development is not affected. West's syndrome is characterized by infantile spasms that appear before 1 year of age, an abnormal EEG with hypsarrhythmia, and a poor prognosis. We describe six infants who presented for evaluation of clusters of head, trunk or extremity spasms, eye blinking, brief jerking of upper extremities or trunk, and head nodding episodes. In most, a presumptive diagnosis of West's syndrome was made prior to the referral. One infant had been placed on valproate. Routine EEG recordings or prolonged video EEG monitoring were normal both during and between episodes. After the negative evaluations, the diagnosis of benign myoclonus of early infancy was made in each infant. Subsequently, no infant was treated with anticonvulsants. Follow-up revealed complete resolution of the episodes in all children within 2 weeks to 8 months of onset. All had normal neurologic development. Based on our cases and review of the literature, the prognosis for this disorder is excellent. Care should be taken to recognize this rare entity and avoid unnecessary and potentially harmful antiepileptic therapy.

Understanding sleep ontogeny to assess brain dysfunction in neonates and infants

The ontogenetic framework onto which a child's sleep is constructed undergoes significant developmental alterations during early life. Sleep state behaviors, in large part, reflect continuities from fetal through neonatal time periods. Major changes in sleep organization subsequently occur throughout infancy. Maturational expressions of sleep behaviors must be understood by the pediatric neurologist before specific physiologic phenomena can be assessed as transient sleep disturbances or clinically relevant sleep disorders. The first part of this two-part review article focuses on the major aspects of developmental sleep physiology in the first few months of life. Recognition of age-specific electroencephalographic/polysomnographic patterns will facilitate the child neurologist's evaluation of the newborn with suspected seizures and interictal encephalopathies, as well as the prediction of neurologic sequelae.

Myoclonus and epilepsies

The possible associations of myoclonic phenomenae, progressive or non-progressive encephalopathies and epileptic features are reviewed, with special emphasis on pediatric age. This leads to recognize the following five groups of conditions: (1) Myoclonus without encephalopathy and without epilepsy; (2) Encephalopathies with non-epileptic myoclonus; (3) Progressive encephalopathies presenting myoclonus seizures of epileptic syndromes (Progressive myoclonus epilepsies); (4) Epileptic encephalopathies with myoclonic seizures; (5) Myoclonic epilepsies. Within the first group, which also includes physiologic myoclonus, a more thorough description of "Benign sleep myoclonus of newborn" and "Benign myoclonus of early infancy" is given. Characteristics of group 2 are "Kinsbourne Syndrome" and certain types of "Hyperekplexia" which pose interesting differential diagnosis with stimulus-sensitive epilepsies. In group 3, the concept of progressive encephalopathies is stressed. The fourth group refers to severe epilepsies, mainly on infancy and childhood, which lead to mental retardation irrespective of their aetiology. Group 5 comprises the true myoclonic epilepsies, differentiating syndromes recognized as idiopathic--such as "Benign myoclonic epilepsy of infancy" and "Juvenile myoclonic epilepsy"--from those which are cryptogenic and carry a more cautious prognosis--as "Cryptogenic myoclonic and myoclonoastatic epilepsies" and "Severe myoclonic epilepsy of infancy". Other epileptic syndromes not usually considered as myoclonic epilepsies, but presenting sometimes as myoclonic seizures, are finally referred.

[Benign reflex myoclonic epilepsy in infants]

BACKGROUND

Myoclonic epilepsy of infancy are seldom benign.

CASE REPORT

A 25-month old girl developed myoclonic jerks either spontaneously either as reflex responses to auditory and tactile stimuli, such as sudden touching of the face or trunk from the age of 4 months. The jerks disappeared after valproate therapy. Neurological examination was normal with a follow-up of 9 months.

CONCLUSION

This condition resembles that described in 1995 by Ricci et al. In must be differentiated from other myoclonic epilepsies of infancy, reflex epilepsies and hyperekplexia. It could be the earliest from of idiopathic generalized epilepsy.

Problems of differentiation between epilepsy and non-epileptic paroxysmal events in the first year of life

Twenty two babies under 1 year old were referred for evaluation of suspected epileptic seizures. Nine were found to have epilepsy. In the other 13--all developing normally, aged up to 10 months--the spells were non-epileptic paroxysmal events (NEPE). They consisted of five patterns of movement: (1) eye blinking; (2) 'no' movements; (3) body posturing with head and arm jerks; (4) masturbation-like movements; and (5) myoclonic head flexion. The NEPE were present for a period of two weeks to seven months. Although some NEPE cannot be clinically differentiated from true epilepsy, in these infants at least four interictal EEGs were normal, the spells completely resolved after a relatively short period without antiepileptic treatment, and the infants continued to develop normally with no evidence of epilepsy during a follow up period of 28 to 38 months. This sample indicates that the frequency of NEPE in the first year of life may be high. Cautious clinical consideration, repeat EEGs and, when appropriate, a few weeks' observation are recommended. Awareness of these benign behavioural spells in this young age group is important, and parents can be reassured. Nevertheless, the spells may illustrate a 'foggy frontier' between NEPE and epilepsy. The lack of evidence for any other disease process in affected infants, as well as the disappearance of the NEPE without any intervention, indicates that a maturational process may be involved.

Reappraisal of interictal electroencephalograms in infantile spasms

To delineate interictal electroencephalographic (EEG) features before treatment of patients with clinically defined infantile spasms, EEGs of 82 infants having tonic spasms in clusters were analyzed by type of paroxysmal abnormalities, continuity, interhemispheric synchrony, topography, and wave component of hypsarrhythmia during wakefulness and sleep. Hypsarrhythmia occurred less frequently in wakefulness than in non-rapid eye movement (NREM) sleep at any age, least frequently in wakefulness after 1 year of age, and disappeared in rapid eye movement (REM) sleep at any age. The continuity of hypsarrhythmia changed with states, but did not change with age, and was greatest in wakefulness and stage 1 and decreased in stage 2-3. Interhemispheric synchrony increased with increasing age but decreased with advancing sleep stage. The term modified hypsarrhythmia should be discarded, and unusual features, if present, should be specified.

Benign neonatal sleep myoclonus: clinical features and video-polygraphic recordings

Benign neonatal sleep myoclonus is a syndrome characterized by the occurrence of repetitive myoclonic jerks of the extremities exclusively during non-rapid eye movement sleep in the early life of healthy newborns. No etiological factors are present. The onset is within the first 15 days of life with spontaneous disappearance within 3-4 months. These myoclonic events are commonly diagnosed as epileptic seizures. We observed 12 newborns with this clinical pattern; the follow-up ranges from 12 to 60 months. Long-term videopolygraphic electroencephalographic (EEG) monitoring demonstrated normal EEG activity, thus confirming that these unusual events were nonepileptic.

Clinical imitators of infantile spasms

We report 53 infants who by clinical history were thought to have infantile spasms but who video-electroencephalograms showed were having other episodes that closely mimicked infantile spasms. Nine patients had other types of seizures. Forty-five patients had episodic symptoms that were not seizures: 11 patients had spasticity, four had gastroesophageal reflux, and the other patients had nonepileptic myoclonus, including 19 patients with benign neonatal sleep myoclonus. Three patients had more than one type of symptom. Infantile spasms imitators occurred in neurologically normal or abnormal infants, in patients with normal or abnormal interictal electroencephalograms, and in patients who also had previous or current infantile spasms. Differentiation of these episodes from infantile spasms prevented the initiation or continuation of anticonvulsant treatment appropriate for infantile spasms but inappropriate for these other behaviors.

Movement disorders of children

Abnormal movements occur in many of the neurologic disorders affecting children and in certain conditions are the presenting major manifestations. In children abnormal movements may be transient and benign and do not necessarily indicate a progressive degeneration of the central nervous system. Clinical observations and appropriate laboratory investigation will frequently lead to a neurologic diagnosis that in many instances will respond to specific pharmacologic treatment.

The child with spells

The purpose of this article was to discuss paroxysms, both neurologic and non-neurologic, that can mimic seizures. This is summarized in Table 4. It should be clear that the evaluation of any spell in a child should begin with a detailed and complete history. Historical features should focus on all aspects of the event--length of time, situation, appearance, quantity, as well as other features not directly pertaining to the event. Physical and neurologic examinations are frequently normal. Ancillary testing that may prove valuable include routine and video EEG monitoring as well as home video recording.

Neonatal sleep myoclonus followed by myoclonic-astatic epilepsy: a case report

Neonatal sleep myoclonus documented polygraphically during the second month of life and subsequent development of a seizure disorder are reported in a 3-year-old boy. Several generalized tonic-clonic seizures associated with febrile illnesses occurred during the first year of life; astatic and myoclonic attacks began at age 13 months. A complex partial seizure occurred for the first time at age 3 years. Differential diagnosis of age-related generalized myoclonic epileptic syndromes and various forms of neonatal myoclonus were considered in this unusual case.

Familial occurrence of benign myoclonus of early infancy

Three cases of benign myoclonus of early infancy (BMEI) were observed in the same family. Previously, only sporadic cases have been reported. Electroencephalogram (EEG) recordings were consistently normal, and the affected girls had normal neurological development. Therapy was not administered and the episodes spontaneously disappeared within the first months of life. While etiological mechanisms of BMEI are still unknown, a hereditary mechanism is now hypothesized on the basis of these cases.

Experience with the International League against Epilepsy proposals for classification of epileptic seizures and the epilepsies and epileptic syndromes in a pediatric outpatient epilepsy clinic

The International League Against Epilepsy proposals for classification of epileptic seizures (1981) and of the epilepsies and epileptic syndromes (1985) have been used in daily practice in a pediatric epilepsy clinic in Bogota, Colombia. Most patients can be classified by these schemes, and the classifications are useful in everyday diagnosis and management. However, there are some drawbacks and difficulties with the classifications. Some syndromes are unnecessarily separated as different entities, artificially contributing to the complexity of the Classification.

New anticonvulsants in pediatrics: carbamazepine and valproate

The majority of patients with epilepsy have their first seizure during childhood and are first evaluated and diagnosed by their pediatrician. For many patients the medication selected by the pediatrician will be taken for an extended time period, perhaps even for a lifetime. The first job of the pediatrician is to be sure that the patient's recurrent attacks represent genuine epilepsy and not some other paroxysmal medical disorder such as migraine or cardiac arrhythmias. Epileptic seizures are then classified by a careful clinical description of the attacks in conjunction with the results of the physical and EEG examinations. Based on all of the information at hand, the clinician chooses the drug that is most likely to reduce or eliminate further seizures without exposing the child to unnecessary medical risk or behavioral-cognitive adverse effects. In properly selected patients, both carbamazepine and valproate are safe, physically well tolerated, and less likely to provoke chronic mental side effects than the pediatrician's "traditional" choices: phenobarbital or phenytoin. Although carbamazepine and valproate have been widely acclaimed by neurologists and epileptologists, practicing pediatricians have heretofore been less likely to initiate treatment with these drugs. Yet pediatricians have something of priceless value to offer the child with epilepsy: seizure control and a clear mind. The information in this monograph should assist the practicing pediatrician in the rational choice, initiation, and follow-up of treatment with these two excellent anticonvulsants.

Benign infantile nocturnal myoclonus

Myoclonic jerks during sleep is a normal phenomenon seen also in infancy. Sometimes the episodes can be extended both in duration and seizure type. When this happens it should be differentiated from epilepsy and treatment is not needed. Five cases are reported.

Infantile spasms: modern practical aspects

Data on incidence, aetiology, therapy and prognosis of infantile spasms are reviewed. In a large proportion of cases the aetiological factors of infantile spasms can now be established with some certainty. Especially the new neuroradiological and virological investigative methods have enabled a more accurate diagnosis. There have been changes in the aetiologic pattern over the years. The optimal dosage and duration of ACTH or glucocorticoid therapy have not yet been established. In the Finnish study the large ACTH doses (120-160 IE) generally used in many Nordic countries did not carry a better prognosis than the smaller doses (20-40 IE). Side-effects of ACTH therapy are relatively common. They are more frequent with large doses than with smaller ones. Measures can be taken to prevent or treat part of them. The prognosis and related factors in infantile spasms as well as some recommendations to improve them are reviewed.