Sleep Myoclonus Research Articles

Benign neonatal sleep myoclonus

Benign neonatal sleep myoclonus is a non-epileptic disorder. This phenomenon of the first weeks of life is characterized by erratic myoclonic jerks occurring only during sleep and with no electroencephalographic changes. It is not associated with perinatal complications, disappears spontaneously within two to four months, and it does not compromise future development. We illustrate with a video this relatively frequent condition, which is often misdiagnosed as epileptic in nature, and discuss the clinical characteristics and differential diagnosis.

Benign neonatal sleep myoclonus: Experience from the study of 38 infants

Background Benign neonatal sleep myoclonus (BNSM) is characterised by myoclonic jerks that occur only during sleep and stop abruptly when the child is aroused. It is a benign condition that is frequently confused with epileptic seizures during infancy. Aims The purpose of this study was to examine the clinical characteristics of newborns and infants with BNSM. Methods In a retrospective study of 38 newborns with BNSM, the entire inpatient charts were reviewed and data on the clinical picture and results of investigations were studied. The data for analysis of the children's neurological development and the time at which myoclonic jerks ceased were provided from outpatient files and parental interviews. Results Myoclonic jerks started between day 1 and day 16 (median 3 days, 95% confidence interval 2–4 days); they were mostly bilateral synchronous and symmetrical in distribution and never involved the facial muscles. An episode of jerks lasted from a few seconds up to 20 min. In every instance, the jerks occurred only during sleep: when the child was drowsy or fell asleep in 20, when the child had been asleep for more than 20 min in 5, before awaking in 3 and in different stages of sleep in 5 infants. In the majority of cases (32), the jerks were reported to stop spontaneously, and in 6 on arousal. Neurological evaluation revealed optimal results in the majority of infants (22), hyperexcitability in 11 and mild abnormalities of muscle tone in 5. In two infants electroencephalography (EEG) performed during the attack of jerks showed no paroxysmal activity. In the remainder EEG performed between the episodes of jerks was normal, apart from mild abnormalities found in six infants. US revealed normal results in all except eight infants, in whom mild abnormalities were found. Myoclonic jerks remitted between the age of 2 weeks and 10 months (median 2 months, 95% confidence interval 1–2 months). Follow-up between 3 and 12 months of age revealed optimal results of neurological assessment in 30 infants and mildly abnormal neurological signs in 8. Conclusion In the studied group, myoclonic jerks occurred within the first 16 days (median 3 days) of life irrespective of other conditions. They were predominantly observed at the beginning of the sleep and disappeared spontaneously in the first 10 months (median 2 months) of life.

Familial Benign Neonatal Sleep Myoclonus

Benign neonatal sleep myoclonus is a nonepileptic syndrome characterized by myoclonic jerks during sleep. It occurs in the first weeks of life and disappears, in most cases, within 3 months. There are no sequelae, and psychomotor and cognitive development are normal. The syndrome is usually sporadic; only a few familial cases have been reported in the literature. This case report describes three members of a single family with benign neonatal sleep myoclonus and discusses its differentiation from other types of myoclonus.

Sleep‐related stridor due to dystonic vocal cord motion and neurogenic tachypnea/tachycardia in multiple system atrophy

Sleep-disordered breathing and sleep-related motor phenomena are part of the clinical spectrum of multiple system atrophy (MSA). Stridor has been attributed to denervation of laryngeal muscles or instead to dystonic vocal cord motion. We studied 3 patients with nocturnal stridor in the setting of MSA. All patients underwent nocturnal videopolysomnography (VPSG) with breathing and heart rate, O(2) saturation and intra-esophageal pressure recordings, and simultaneous EMG recordings of the posterior cricoarytenoid, cricothyroid, and thyroarytenoid muscles and continuous vocal cord motion evaluation by means of fiberoptic laryngoscopy. VPSG/EMG and fiberoptic laryngoscopy documented normal vocal cord motion without denervation during wake and stridor only during sleep when hyperactivation of vocal cords adductors appeared in the absence of significant O(2) desaturation. All patients had tachycardia and tachypnea and paradoxical breathing during sleep, erratic intercostalis and diaphragmatic EMG activity and Rem sleep behavior disorder. One of the patients had restless legs syndrome with periodic limb movement during sleep and excessive fragmentary hypnic myoclonus. In conclusion, our patients with MSA had nocturnal stridor due to sleep-related laryngeal dystonia. Stridor was associated with other abnormal sleep-related respiratory and motor disorders, suggesting an impairment of homeostatic brainstem integration in MSA.

Clinical Identification of the Simple Sleep-Related Movement Disorders

Simple sleep-related movement disorders must be distinguished from daytime movement disorders that persist during sleep, sleep-related epilepsy, and parasomnias, which are generally characterized by activity that appears to be simultaneously complex, goal-directed, and purposeful but is outside the conscious awareness of the patient and, therefore, inappropriate. Once it is determined that the patient has a simple sleep-related movement disorder, the part of the body affected by the movement and the age of the patient give clues as to which sleep-related movement disorder is present. In some cases, all-night polysomnography with accompanying video may be necessary to make the diagnosis. Hypnic jerks (ie, sleep starts), bruxism, rhythmic movement disorder (ie, head banging/body rocking), and nocturnal leg cramps are discussed in addition to less well-appreciated disorders such as benign sleep myoclonus of infancy, excessive fragmentary myoclonus, and hypnagogic foot tremor/alternating leg muscle activation.

Seizure-like States

Seizure-like States

Age-related electrical status epilepticus during sleep and epileptic negative myoclonus in DRPLA

Hereditary dentatorubral-pallidoluysian atrophy (DRPLA) (MIM 125370)1 is a rare autosomal dominant neurodegenerative disorder found mostly in Japanese people and caused by an expansion of the CAG repeat in the DRPLA gene on chromosome 12p.2 Childhood-onset patients generally have a phenotype of progressive myoclonus epilepsy (PME) with a large expansion of the CAG repeat.2 In the present study, we report a patient with DRPLA who showed epilepsy with electrical status epilepticus during slow sleep (ESES) or the extraordinary EEG abnormality of continuous spike-waves during slow wave sleep (CSWS) and epileptic negative myoclonus in childhood. Epilepsy with CSWS generally occurs in cryptogenic patients or symptomatic ones with nonprogressive brain pathology and is an age-related and self-limited disorder.3 Remarkably, his CSWS on EEG remitted spontaneously with age, as it does in other patients without progressive disorder, although the underlying degeneration of the brain continued relentlessly. This patient, who was born after an uneventful pregnancy, had a father with ataxia and dementia and a diagnosis of DRPLA in later life. The patient's early …

Idiopathic Generalized Epilepsies: A Review and Modern Approach

Idiopathic Generalized Epilepsies: A Review and Modern Approach

Nonepileptic Disorders Imitating Generalized Idiopathic Epilepsies

Differential diagnosis between epileptic and nonepileptic paroxysmal disorders is fundamental not only to allow correct management of patients but also to avoid the burden of unnecessary antiepileptic medication. The focus of this chapter is limited to imitators of idiopathic generalized epilepsies (IGE) which are expressed through myoclonic, tonic-clonic, tonic, atonic, and absence seizures. Apparent losses of consciousness and drop attacks also have to be considered. Benign myoclonus of early infancy is the main nonepileptic disorder in the differential diagnosis of infantile spasms, but is not dealt with here because West syndrome is not an IGE. Hyperekplexia, metabolic disorders, hypnagogic myoclonus, and disturbed responsiveness caused by the use of drugs are listed in Table 1. Other conditions that may imitate more focal epileptic seizures are omitted. Benign neonatal sleep myoclonus, apnea and apparent life-threatening events in infants, cyanotic and pallid breath-holding spells, syncope, staring spells, psychogenic seizures, hyperventilation syndrome, and narcolepsy have been selected based on frequency or difficulties in differential diagnosis with the intention to cover the most conspicuous imitators of IGE in different ages.

Benign neonatal sleep myoclonus: An under‐recognized, non‐epileptic condition

During a 3-y period 13 newborns were referred for investigation of jerks. The events were epileptic in six children. The diagnosis of benign neonatal sleep myoclonus was made in the remaining seven children. Benign neonatal sleep myoclonus is an important neonatal entity that can be mistaken for epilepsy.

Index of Suspicion in the Nursery

A 3-day-old male infant in the nursery presents with repetitive jerking of his arms and twitching of the chin. The baby was born at term after an uneventful pregnancy. Delivery had been complicated by shoulder dystocia, with a low first Apgar score (4 at 1 min), but the score was 8 at 5 minutes.On physical examination just after birth, no abnormalities were detected except for some jitteriness, and the baby was kept for further observation. A complete blood count and measurement of serum glucose and ionized calcium showed normal values. Ultrasonography of the brain revealed no abnormalities.Now the baby lies in his mother’s arms, appearing asleep, while the continuous jerking movements lead to a mild oxygen desaturation (85% on the oxygen saturation monitor). The mother states that over the past 2 days she has seen similar shorter episodes (lasting 10 to 20 sec) of symmetric jerks of the arms and twitching of the mouth, especially just after feeding, when the baby started dozing off. She denies any (ab)use of drugs during pregnancy, and the family history is negative for epilepsy, although an older sibling also experienced exaggerated jitteriness during the first few months after birth.A bedside maneuver reveals the cause of the condition and, at the same time, extinguishes the movements.A gentle squeeze of the arms of the baby woke him and immediately stopped the seizures, leading to the diagnosis of benign neonatal sleep myoclonus (BNSM).BNSM, first described by Coulter and Allen in 1982, is a distinctive disorder of quiet sleep that frequently is mistaken for true neonatal seizures. (1)(2) The condition usually starts within 3 days after birth and, according to some authors, could be as frequent as neonatal epilepsy. The rhythmic myoclonic movements typically appear when the child is asleep or drowsy and tend to last a few minutes to occasionally 30 minutes. The myoclonic jerks may be partial, multifocal, or generalized, with a frequency of 1 to 15 per second, and immediately stop if the child is awakened. The general condition of the child is unaffected, even during prolonged episodes of myoclonic jerks, and there are no associated abnormalities on neurologic or developmental examination. Neonatal sleep myoclonus by definition is a benign disorder; spontaneous resolution occurs between 2 and 6 months of age, as the sleep pattern matures.A detailed history often is all that is needed to make the diagnosis, especially if findings on the physical examination are unremarkable. In selected cases, electroencephalography (EEG) may be helpful to differentiate BNSM from “true” neonatal seizures. BNSM abnormalities on EEG are conspicuous by their absence. (3)There is no indication for antiepileptic drugs in BNSM because they are not effective and may worsen the condition by inducing drowsiness. (4) Neurologic and developmental deficits do not occur on follow-up.BNSM must be differentiated from neonatal seizures and jitteriness. True neonatal seizures often occur in the setting of a perinatal, metabolic, or infectious insult. Neurologic and developmental assessments frequently reveal abnormalities. True neonatal seizures also may occur during sleep, but a quick arousal of the patient accompanied by abrupt and consistent cessation of the movements strongly speaks against an epileptic origin. Jitteriness consists of symmetric fine rapid movements of the hands and feet (not affecting the eyes) that frequently are stimulus-sensitive and stop if the involved hands or feet are grasped.Myoclonic jerks in a neonate should raise the question of whether the origin is epileptic or nonepileptic. Although this question initially may be difficult to answer, the clinician should evaluate whether the movements occur exclusively during sleep. In this situation, an attempt should be made to awaken the baby. Consideration of BNSM at the initial evaluation of a suspected neonatal seizure disorder, rather than making it a diagnosis of exclusion, can prevent unnecessary investigations, treatment, and parental anxiety.See also Hahn J, Sanger T. Neonatal movement disorders. NeoReviews. 2004;5:e321–e326.

Neonatal Movement Disorders

After completing this article, readers should be able to: 1. Delineate the characteristics that differentiate hyperkinetic neonatal movement disorders from neonatal seizures. 2. Describe the primary characteristics of and treatment for hyperekplexia. 3. Explain the relationship between gastroesophageal reflux and movement disorders in neonates. 4. Describe the primary ocular movement disorders in neonates. Neonates often exhibit paroxysmal behaviors that are nonepileptic in nature, such as oral-buccal-lingual movements, pedaling, stepping, and rotatory arm movements. The electroencephalogram (EEG) is of particular value for distinguishing these nonepileptic behaviors from subtle seizures. EEG and video-EEG studies in such movement disorders do not exhibit seizure discharges during the events. This distinction is important because nonepileptic events do not require treatment with anticonvulsants. Although the absence of surface ictal activity does not exclude entirely the possibility of seizures arising from deeper structures, it generally is accepted that these disorders are not epileptic. For the purposes of this review, we include common nonepileptic paroxysmal (episodic) movements that occur from birth to early infancy (onset between birth and 3 months of age). Many of these movement disorders may persist during infancy or early childhood. We do not discuss more persistent motor problems, such as spasticity, hypotonia, or myotonia. Also, disorders that occur after 3 months of age are not included. We have classified the movement disorders into two major categories: 1) hyperkinetic movements and 2) dystonic or extrapyramidal type of movements. Because the pathophysiologic mechanisms underlying neonatal movement disorders often are unknown, they are categorized on the basis of phenomenology, rather than presumed cause. Some of these disorders may have overlapping symptomatology. A third category encompasses “ocular movement disorders.” ### Jitteriness of the Newborn Jitteriness may be due to many factors, including metabolic disturbance, hypoxic-ischemic encephalopathy, drug withdrawal, hypoglycemia, and hypocalcemia. Although jitteriness may be mistaken for neonatal seizures, a distinguishing feature of jitteriness is that the …

Sleep-related non epileptic motor disorders

Sleep-related non epileptic motor disorders represent a frequent but often neglected or trivialized source of neurological disability. In recent decades, the widespread adoption of videopolygraphic techniques has better characterized already known nosographic entities and described a bewildering variety of previously unrecognized clinical entities (such as REM sleep behaviour disorder, sleep-related eating disorder, benign neonatal sleep myoclonus, facio-mandibular myoclonus during sleep, fragmentary hypnic myoclonus, propriospinal myoclonus at the wake-sleep transition, rhythmic feet movements during sleep, etc). The scope of the neurophysiological investigations of sleep related disorders has therefore been much expanded. However, advances in the semeiology and clinical description of sleep-related movement disorders has rarely been matched by adequate understanding of the underlying pathophysiological mechanisms, or by major advances in treatment. The main sleep-related motor disorders are described here, following the only classification currently available, e. g. that offered by the International Sleep Disorders Classification of the American Sleep Disorders Association, which is more a classification of diseases of sleep than of movement disorders. The increasing use of functional neuroimaging in vivo and of updated neurophysiological and molecular techniques in man and in the experimental animal will hopefully lead to a better understanding of these disorders in terms of pathophysiology of disordered motor control.

Benign neonatal sleep myoclonus mimicking status epilepticus.

Benign neonatal sleep myoclonus is a self-limited movement disorder characterized by neonatal-onset myoclonic jerks only during sleep, abrupt and consistent cessation with arousal, and absence of concomitant electrographic changes suggestive of seizures. It has a good outcome and was included in the differential diagnosis of neonatal seizures. A presumed transient serotonin imbalance and genetic factors may play a role in the pathogenesis of this disorder. We report a case of benign neonatal sleep myoclonus mimicking status epilepticus in an infant with a family history of nocturnal myoclonus, tic disorder, and sleep disturbance. We suggest that this benign entity should be included in the differential diagnosis of status epilepticus during the newborn period.

Circadian abnormalities in older adults.

This study examined the circadian phase adjustment of symptomatic elders ages 60-79 years in comparison with that of young, healthy adults ages 20-40 years. Seventy-two elders with complaints of insomnia or depression, and 30 young, healthy adults were assessed for 5-7 days at home. Sleep and illumination were recorded with Actillume wrist monitors and sleep diaries. Urine was collected over two 24-hr periods and assayed for 6-sulphatoxymelatonin (6-smt). The volunteers were then observed continuously for 5 nights and 4 days in the laboratory. In the laboratory, sleep periods were fixed at 8 hr with polysomnographic assessment of sleep, apnea-hypopnea, and nocturnal myoclonus. Circadian dispersion, defined as the mean variation of 6-smt acrophase from the median age-specific acrophase, was significantly greater in the older vs. young adults. Likewise, circadian malsynchronization, defined as the absolute number of hours (advance or delay) between the 6-smt acrophase and the middle of the sleep period, was significantly greater in the older vs. young volunteers. For the older volunteers, multiple regressions were calculated associating sleep with potential correlates of sleep disturbance. Nocturnal myoclonus and circadian malsynchronization were more strongly associated with sleep impairment than other factors (e.g., sleep apnea, depression). These observations suggest that circadian malsynchronization might be a common and significant cause of disturbed sleep among adults over age 60.

Synkinetic Blepharoclonus

To analyze the clinical data and test results collected in a group of patients exhibiting eyelid-closure blepharoclonus (BLC) on clinical neurologic examination. Thirty-five patients were referred for neurologic evaluation for reasons other than BLC. Clinical electrophysiologic evaluations, including cranial nerve testing and electromyograms, were done according to standards. All patients had neuroimaging studies, including brain magnetic resonance imaging and head computerized tomography, or both, and many had electroencephalograms. Additional tests were done based on the patient's symptoms or reasons for referral. Eight patients had reflex BLC. Two cases were precipitated by vertical gaze; one of these patients had hereditary palmoplantar keratoderma and cataplexy, and the other patient had Ehlers-Danlos syndrome and familial BLC. Other precipitants included speech in four cases, postural changes in two cases, and light stimulation in one case. Two patients had generalized myoclonus independent of their BLC, two patients had a history of sleep myoclonus, and several patients had BLC-associated facial myoclonus. One patient had BLC-associated myoclonus of the right shoulder. Synkinetic cranial movements were detected in 11 patients (four oculofacial, three oculopterygoid, one oculolingual, two dual cases, and one case of imitation synkinesis.) Three patients had familial BLC, seven patients had congenital developmental disorders, six patients had synkinetic tremors, and six patients had restless feet. Some indication of peripheral neuropathy was evident in eight patients. Eyelid-closure BLC is an underrecognized, sporadic or familial, mostly benign, chronic eyelid-movement disorder that may be associated with tremors, myoclonus, cranial synkinesis, and restless feet. Reflex mechanisms may be identified in some patients. Gaze-induced BLC seems to have the greatest clinical relevance. In the current series, there were no examples of posttraumatic BLC, multiple sclerosis, hydrocephalus, or blepharospasm conditions previously reported to be associated with BLC. No electroencephalographic abnormalities were recorded during BLC, ruling out eyelid-closure epilepsy.

Paroxysmal non-epileptic events in children: a retrospective study over a period of 10 years.

To determine the frequency, nature and clinical characteristics of paroxysmal non-epileptic events in children diagnosed by video electroencephalogram (EEG) monitoring at a tertiary referral centre. A retrospective study of children with paroxysmal non-epileptic events, aged 2 weeks to 17 years inclusive was undertaken. The study group consisted of children who had video EEG monitoring during a 10-year period (1988-99). Telemetry files, medical charts, events recorded on video and record sheets were reviewed. A total of 666 children were analysed, 269 had epileptic events recorded, 285 had non-epileptic events and 112 had no events recorded. In children with non-epileptic events, 43% were developmentally delayed, 25% had an abnormal neurological examination and 40% had epilepsy. In the study sample an epileptiform interictal EEG was common (24%). The major subgroups of non-epileptic events were: staring (34%), sleep phenomena - benign sleep myoclonus (15%), arousals (13%), motor tics (11%) and shuddering (7%). Developmental delay (57%) was common in children who presented with staring spells. A diagnosis of a specific non-epileptic event was reached in 96% of cases. Paroxysmal non-epileptic events can cause diagnostic confusion, particularly in children with developmental delay, epilepsy or an epileptiform EEG. Accurate diagnosis can be reached in the majority of cases using video EEG monitoring.

Alcohol and sleep disturbances

Despite an initial sedative effect, alcohol disrupts sleep persistently and should not be used as a sleeping aid. Nocturnal withdrawal symptoms may lead to an increased duration of wakefulness, and to tachycardia and sweating in the second half of the night. It is not known by which mechanism alcohol affects sleep; however, effects do not appear to depend on the stimulation of benzodiazepine receptors or the antagonism at adenosine receptors. Alcohol can exacerbate primary sleep disturbances such as sleep apnea and nocturnal myoclonus, and thereby contribute to excessive daytime sleepiness. The sleep of alcoholic patients is characterized by increased sleep latency, and reduced sleep efficiency, total sleep time, slow wave sleep and non-REM sleep. Even during abstinence, the changes in sleep architecture can persist for months or years, and might contribute to a relapse into alcoholism. The use of benzodiazepines or other hypnotics to treat alcohol-related sleep disturbances is not recommended.

Understanding Fibromyalgia Syndrome

Fibromyalgia syndrome (FMS) is characterized by generalized pain and musculoskeletal tenderness, fatigue, nonrestorative sleep, and morning stiffness. People with FMS often report that they hurt all over. Many describe the pain as aching, exhausting, or nagging. Pain is most commonly associated with tender points in the suboccipital area of the neck, shoulders, chest wall, elbows, knees, hips, and back (see illustration at right). Muscle cramping and spasms are common. Although classified as a chronic pain syndrome, FMS may produce flares of acute pain. In fact, pain may become so severe that it limits range of motion and functional ability. Often denied or misunderstood, FMS has been described as an invisible illness. Because people with the syndrome don't look sick, their clinicians, family, and friends may fail to respond empathetically. Over time, such insensitivity may produce selfdoubt and diminished self-worth. The condition often is mislabeled as rheumatism, fibromyositis, and myositis. Unlike stiffness associated with arthritis, pain from FMS doesn't diminish with activity. In addition to pain, signs and symptoms of FMS include dry eyes and mouth, swelling, sleep myoclonus, paresthesias, poor posture, weight gain, cold sensitivity, exercise intolerance, difficulty concentrating, visual deficits, balance disturbances, and anxiety. Febrile Low cervic Occiput

Mioclonías neonatales benignas del sueño

To evaluate the clinical, electro-encephalographic and evolutionary characteristics of a series of patients diagnosed as having benign neonatal sleep myoclonus (BNSM). The clinical histories of 21 patients with BNSM were analyzed. Criteria for inclusion in the study were: neonates who had had more than one episode of myoclonia during sleep and in whom neurological examination and psychomotor development were normal. CRITERIA FOR EXCLUSION: Patients with myoclonia while awake, a perinatal history which included significant pathology and/or the diagnosis of epilepsy. The period of evolution varied from 6 months to 5 years, and the following parameters were considered: clinical features of the myoclonia, neurological examination, psychomotor development and evolution. EEG were done between crises in all patients. In 5 cases we recorded EEG during crises and in 2 cases video-EEG were done. The study group was made up of 11 girls and 10 boys. The myoclonia started between the first and twenty third day of age (average = 7 days). Fifteen (71.4%) of the patients had generalized myoclonia, mainly in the distal part of the upper limbs in 13 and in the lower limbs in two. In 20 cases (95.2%) jerking was of short duration, lasting 10 to 20 seconds. In one case, the jerks were repeated in series lasting 30 minutes. Two patients later developed benign myoclonia of early infancy. The myoclonia disappeared before the age of 7 months in all cases. BNSM is seen in healthy newborns and disappear spontaneously during the first months of live. Differential diagnosis with epileptic seizures is imperative in order to avoid unnecessary medication.