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

Electrographic screening for infantile epileptic spasms syndrome in a single sleep-wake cycle

OBJECTIVE

Infantile epileptic spasms syndrome (IESS) is a common and urgent diagnosis with seizure and nonseizure mimics. Evaluation with prolonged video-electroencephalography (EEG) can be time-consuming and costly. This study investigated the use of EEG review of a single sleep-wake cycle to exclude IESS.

METHODS

We retrospectively reviewed video-EEG studies to rule out IESS in children between the ages of 2 months and 2 years in the period from January 2019 through June 2020. EEG studies were reviewed from the start of the recording through the first sleep-wake cycle and scored as "normal," "consistent with IESS," or "abnormal but not diagnostic of IESS." Scores were compared to the clinical report created by analysis of the entire video-EEG.

RESULTS

Inclusion criteria were met in 238 EEG studies. The mean patient age was 7.6 months. The median duration of the full study was 908 min, compared to 107.5 min for the first sleep-wake cycle only. The median difference in recording time was 801 min, p-value < .01. Scored outcomes were similar. Sixty-eight percent of EEG studies were scored as "normal" on first sleep-wake cycle review as compared to 63% on full study review, 13% scored as "consistent with IESS" compared to 16% and 19% scored as "abnormal but not diagnostic of IESS" compared to 21%. Sensitivity and specificity of the first sleep-wake cycle review for studies "consistent with IESS" was 84% and 100%, respectively. No cases of IESS were scored as normal on first sleep-wake cycle review.

SIGNIFICANCE

A single sleep-wake cycle captured on EEG can triage studies when IESS is suspected. A normal first sleep-wake cycle did not miss cases of IESS and could result in reduced EEG recording time. Because most of these cases presented to an emergency department, a normal first sleep-wake cycle may help providers determine the acuity, or necessity, of further testing.

Idiopathic and structural episodic nonintentional head tremor in dogs: 100 cases (2004-2022)

BACKGROUND

Although idiopathic episodic head tremor (IEHT) in dogs is well-known, little is known about structural brain lesions causing structural episodic head tremor (SEHT).

HYPOTHESIS/OBJECTIVES

Describe semiology, magnetic resonance imaging (MRI) findings and outcome of dogs with IEHT or SEHT. We hypothesized that structural lesions affecting the middle cranial fossa or mesencephalic aqueduct could lead to SEHT.

ANIMALS

One hundred dogs with IEHT (n = 71) or SEHT (n = 29).

METHODS

Retrospective, multicenter, study of dogs with episodic (nonintentional) head tremor and brain MRI between 2004 and 2022.

RESULTS

Lesions on MRI in SEHT dogs were localized to the middle cranial fossa (15/29), cerebrocortex (3/29), brainstem (2/29), fourth ventricle (1/29) or multifocal (8/29) with thalamus involvement (6/8). Secondary compression of the mesencephalic aqueduct (19/29), third ventricle or interthalamic adhesion or both (14/29) was common. The most common underlying condition in dogs with SEHT was a pituitary mass. Dogs with SEHT were older, had additional neurological signs and were more likely to be euthanized after diagnosis (P < .001 for all) compared to IEHT dogs. Two SEHT dogs had only tremor. In IEHT dogs, 8/10 owners reported that the tremor decreased or abated over time (range, 106-2315 days) without treatment. Tremor remission occurred in SEHT dogs treated for underlying meningoencephalitis.

CONCLUSIONS AND CLINICAL IMPORTANCE

Presence of additional neurological signs and older age may indicate an underlying structural cause for episodic (nonintentional) head tremor involving the mesencephalic aqueduct, third ventricle, interthalamic adhesion or some combination of these. An intracranial structural abnormality cannot be excluded in dogs with normal neurological examination.

Early-onset spontaneously relieved spasms of infancy in sleep: Electroclinical characteristics and differential diagnoses

PURPOSE

Infantile spasm-like paroxysms are often difficult to classify as epileptic or non-epileptic. We aimed to study spontaneously relieved (non-epileptic) spasms of infancy in sleep. Elucidation of the electroclinical characteristics and differential diagnoses of such spasms could facilitate accurate diagnosis in the future.

METHODS

We retrospectively analyzed the clinical data, video-EEG recordings, and other laboratory test results of patients with spontaneously relieved spasms of infancy during sleep. All the enrolled patients were followed up for at least 5 months.

RESULTS

Seven infants were included in this study. The median age at spasm onset was 0.5 months (range: 0.1-2 months). The episodes were characterized by clusters of non-epileptic spasms of the head, trunk, or extremities lasting approximately 0.5-2 s, and were validated by ictal electromyography (EMG)/video EEG. Episodes occurred several times daily in clusters, particularly during sleep; two patients also experienced episodes while awake. Additionally, non-epileptic jerks were recorded in 3 patients. All non-epileptic spasms were completely resolved 2 weeks to 3 months after onset. Moreover, neuropsychomotor development in all patients was normal at the last follow-up (5 to 12 months).

CONCLUSIONS

Spontaneously relieved spasms of infancy in sleep is a self-limiting movement disorder characterized by onset between 0.1 and 2 months of age, and by clusters of spasms occurring in sleep. Correct differential diagnosis relies on familiar clinical and electrophysiological features.

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.

Diagnosing infantile spasms: Accuracy of the internet

Infantile spasms, one of the catastrophic epilepsies, can be a diagnostic challenge since the clinical manifestations may be subtle and may mimic benign conditions. Because of the rarity of the condition, primary care physicians and pediatricians may never see a case of infantile spasms during their career and may be unfamiliar with the seizure semiology. This is a serious issue since there is evidence that early diagnosis and treatment may improve outcome. Patients and families are increasingly using the internet more than their physician as a source of medical information about epilepsy. The reliance on using the internet for diagnostic information raises concerns about the accuracy of posted material that has not undergone professional review. To assess the quality of information being obtained about infantile spasms, we reviewed written and video content addressing infantile spasms on the internet. A total of 135 websites and 156 videos were reviewed for accuracy. Using the search terms Infantile Spasms and West Syndrome, we report that the majority of the written and video information provided was accurate and provided important and pertinent information. We conclude that internet searches provide accurate and pragmatic information about infantile spasms that has the potential for reducing the delay between the onset of the spasms and medical intervention.

Polymicrogyria and myoclonic epilepsy in autosomal recessive cutis laxa type 2A

Cutis laxa syndromes are rare inherited disorders of skin and connective tissue metabolism associated with variable systemic involvement. The main clinical manifestation is loose, wrinkled, redundant, inelastic skin, hypotonia, typical facies including short nose and down-slanting palpebral fissures, and varying degrees of developmental delay. The aim of this report is to describe two siblings diagnosed with a moderate form of ATP6V0A2-related cutis laxa with polymicrogyria (cobblestone-like brain dysgenesis). One of the patients has myoclonic epilepsy which may have contributed to his more severe clinical presentation. The literature on cutis laxa syndromes is reviewed.

Fifteen-minute consultation: when is a seizure not a seizure? Part 1, the younger child

Paroxysmal non-epileptic events (PNEs) are common, and occur in all age groups ranging from neonates to young adults. The key to diagnosis in the majority is a detailed history and careful observation. However, a few can pose diagnostic challenges for the paediatrician to differentiate them from epileptic seizures. PNEs are usually recurrent, stereotyped and some of them tend to repeatedly occur within the same context. Although the vast majority have a benign nature, they can be a source of parental anxiety, unnecessary investigations and even potentially harmful treatments. In this review, we have described the common PNEs occurring in infants and preschool children. This will be followed by a second review for older children and adolescents. We have provided a practical diagnostic approach by dividing these events into three broad categories: PNEs associated with altered consciousness, PNEs not associated with apparently altered consciousness and sleep-related PNEs.

Neonatal seizures-part 1: Not everything that jerks, stiffens and shakes is a fit

The neonatal period is the most frequent time of life to have epileptic seizures. However, neonates can also exhibit unusual movements that are not epileptic seizures. Differentiating between epileptic and non-epileptic movements can be difficult. Many neonatal seizures exhibit few or no clinical features at all. This article is for the benefit of paediatric trainees and reviews the published evidence on which neonatal movements are likely to be epileptic seizures and which are not. We also discuss epileptic seizure classification.

Paroxysmal nonepileptic events in infancy, childhood, and adolescence

There are a wide variety of paroxysmal nonepileptic events (PNEEs) in children that can mimic seizures. The type of PNEEs that need to be considered in the differential diagnosis depends on the age of symptom onset and the clinical features. In infants and toddlers, conditions that are relatively common in clinical practice such as apnea, jitteriness, shuddering attacks, and breath-holding spells may not present much of a diagnostic conundrum, whereas unusual conditions such as hyperekplexia may cause concern. Similarly, although most types of migraine are easily distinguished from seizures in school-aged children, certain variants such as the "Alice in Wonderland" syndrome or basilar migraine can create diagnostic confusion. Most types of PNEE are exclusive to childhood; therefore, the pediatrician must be familiar with a variety of physiological processes and pathological entities that can raise concern in parents. The pediatrician is in the unique position of being able to reassure families and/or guide further work-up. Many of the PNEEs in young children require no treatment and resolve spontaneously. It is important to distinguish these episodes from true seizures as to avoid unnecessary testing and pharmacological treatment. This review highlights common PNEEs in children, beginning with the neonatal age group and moving upward to adolescence.

"3 . . 2 . . 1 . . Impact [factor]: target [academic career] destroyed!": just another statistical casualty

"Publish or perish" is the time-honored "principle" for academicians who race to accumulate lines under the "publications" section of a curriculum vitae. The original intent of publication-to inform others of findings and further scientific knowledge-has been corrupted by factors including (1) exponential growth of journals and the journal industry, fueled in part by intrusion of the Internet into all aspects of academic life; and (2) adoption of journal metrics (rather than written content) as the measure of scientific quality. The proprietary Thomson Reuters Impact Factor is the most pernicious metric, having caused editors and publishers to change editorial practices to boost the number. At the same time, gullible administrators and government agencies have been persuaded that metrics for the journal in which materials are published can be used as a measure of the worth of individual investigators (and institutions) and their research efforts: simple numbers can be substituted for the burdensome effort required to read and assess research quality. Thus, granting of research funds, awarding of academic rank and tenure, and determination of salaries (including bonus payments) have become tied to manipulable journal metrics rather than the significance or quality of reported research. Therefore, it is no wonder that the integrity of science is more often being questioned. How should a young investigator approach the "publish or perish" dilemma? Performing sound research and preparing optimal materials for publication must remain the overriding goals: properly articulate the question addressed by the study; thoroughly document all methods and case information; carefully describe results including any conflicting or negative findings; discuss the importance of the findings along with how the results address the initial question and whether findings refute or confirm previous studies; prepare properly cited bibliographic references; list all author contributions, potential conflicts of interest, financial support, and required ethical approvals; and provide a catchy title and an abstract containing sufficient information that other investigators perusing scientific indices will be enticed to read the published article. Submit the completed manuscript to the most appropriate journal based on that journal's previously published content and relevance to the field of study regardless of journal metrics. On publication, notify investigators in the same field to ask for their comments on the work. Thus, an individual will become known for the quality of his or her work product and the worshiping of publication metrics will be unnecessary.

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.

Benign neonatal sleep myoclonus: a review of the literature

OBJECTIVE

Neurologically normal term infants sometimes present with repetitive, rhythmic myoclonic jerks that occur during sleep. The condition, which is traditionally resolved by 3 months of age with no sequelae, is termed benign neonatal sleep myoclonus. The goal of this review was to synthesize the published literature on benign neonatal sleep myoclonus.

METHODS

The US National Library of Medicine database and the Web-based search engine Google, through June 2009, were used as data sources. All articles published after the seminal description in 1982 as full-length articles or letters were collected. Reports that were published in languages other than English, French, German, Italian, Portuguese, or Spanish were not considered.

RESULTS

We included 24 reports in which 164 term-born (96%) or near-term-born (4%) infants were described. Neonatal sleep myoclonus occurred in all sleep stages, disappeared after arousal, and was induced by rocking the infant or repetitive sound stimuli. Furthermore, in affected infants, jerks stopped or even worsened by holding the limbs or on medication with antiepileptic drugs. Finally, benign neonatal sleep myoclonus did not resolve by 3 months of age in one-third of the infants.

CONCLUSIONS

This review provides new insights into the clinical features and natural course of benign neonatal sleep myoclonus. The most significant limitation of the review comes from the small number of reported cases.

The differential diagnosis of epilepsy: a critical review

The wrong diagnosis of epilepsy is common. At referral epilepsy centers, psychogenic non-epileptic attacks are by far the most common condition found to have been misdiagnosed as epilepsy, with an average delay of 7-10 years. There are many "red flags" that can raise the suspicion of psychogenic non-epileptic attacks. Syncope is the second most common condition misdiagnosed as epilepsy, and it is probably more common in outpatient populations. Other conditions more rarely misdiagnosed as epilepsy include hypoglycemia, panic attacks, paroxysmal movement disorders, paroxysmal sleep disorders, TIAs, migraines, and TGA. Conditions specific to children include nonepileptic staring spells, breath-holding spells, and shudder attacks. At all ages, the over-interpretation of EEGs plays an important part in the misdiagnosis of epilepsy.

The head nodding syndrome--clinical classification and possible causes

PURPOSE

In the 1960s in Tanzania, L. Jilek-Aall observed a seizure disorder characterized by head nodding (HN). Decades later, "nodding disease," reminiscent of what was seen in Tanzania, was reported from Sudan. To date this seizure disorder has not been classified and possible causes still remain obscure.

METHODS

In a prospective study in southern Tanzania, we evaluated 62 patients with HN. Selected patients underwent blood (n = 51) and cerebrospinal fluid (CSF) (n = 48) analyses. Others were chosen for MRI (n = 12) and EEG (n = 10).

RESULTS

Seizure type was classified as "head nodding only" and "head nodding plus," the latter being combined with other types of seizure (n =34). During HN, consciousness was impaired in 11 patients (17.7%) and supportive signs of epileptic seizures were described by 15 (24.2%) patients. Precipitating factors were confirmed by 11 (17.7%) patients. Fifty-six (90.3%) patients had at least one relative with epilepsy. EEG confirmed interictal epileptic activity in two patients and unspecific changes in four patients. MRI showed hippocampus pathologies (n = 5) and gliotic changes (n = 5). Skin polymerase chain reaction (PCR) positivity for Onchocerca volvulus was significantly associated with lesions on MRI. However, PCR of the CSF was negative in all cases.

CONCLUSIONS

We present a comprehensive clinical description of the "HN syndrome," possibly a new epilepsy disorder in sub-Saharan Africa. MRI lesions and their association with positive skin PCR for O. volvulus despite negative PCR of the CSF is intriguing and deserves attention. Furthermore, the high prevalence of hippocampus sclerosis and familial clustering of epilepsy may point toward other potential pathogenetic mechanisms.

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.

Myoclonus in childhood

The term "myoclonus" sounds esoteric, yet it is part of our normal physiology, occurring as a muscle jerk on drowsiness or falling asleep, during rapid eye movement (REM) sleep, and as hiccoughs. Myoclonus is also a developmental feature of the human nervous system, comprising some of the earliest fetal movements. In pathologic settings, myoclonus may be the only neurologic abnormality, as in essential myoclonus, but more often it is one symptom of a larger neurologic problem. The vast etiologic spectrum of symptomatic myoclonus can be bewildering, but defining the underlying problem may provide the opportunity to develop specific therapies. Otherwise, treatment is merely symptomatic. The approach to the patient should be to verify the nature of the movement disorder and establish a specific etiologic diagnosis. A battery of neurophysiologic, neuroradiologic, and other laboratory studies is needed to localize the origin of the myoclonus and identify causative lesions. Drug treatment is largely empiric but must be systematic and aimed at restoring activities of everyday living. Unlike in epilepsies, in myoclonus multiple drugs usually must be combined to attain functional improvement.