[Benign reflex myoclonic epilepsy in infants]

Reflex Myoclonic Epilepsy of Infancy: Seizures Induced by Tactile Stimulation

Myoclonic epilepsy with reflex seizures in infancy is an extremely rare condition, in which seizures are provoked mainly by auditory or auditory-tactile stimuli. To increase the awareness of pediatricians regarding this underrecognized condition, we describe a child with seizures provoked only by the tactile stimulation of specific areas of the head and face.

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.

Treatment options for epileptic myoclonus and epilepsy syndromes associated with myoclonus

BACKGROUND

Myoclonus is a brief shock-like movement that has many different etiologies. The degree to which it disturbs quality of life is extremely variable, as is its response to treatment.

OBJECTIVE

In this review, we focus on the treatment strategies for epileptic myoclonus in some common disorders, and in others that are not so common but where myoclonus is a prominent feature and has been studied more.

METHODS

An extended literature review in the English language was conducted through PubMed and text books.

CONCLUSION

Epileptic myoclonus is a manifestation of cortical irritability. The precise etiology is important when determining the best course of treatment. Response to treatment is variable and usually depends on the epileptic syndrome. Some antiepileptic drugs may worsen myoclonus even in patients with syndromes where most patients have a good response to that same drug. Therefore, clinicians must always have in mind that worsening in myoclonus may be ameliorated by decrease or withdrawal rather than increase of medication.

Developmental outcome in benign myoclonic epilepsy in infancy and reflex myoclonic epilepsy in infancy: A literature review and six new cases

Benign myoclonic epilepsy in infancy is a rare syndrome with just over 100 cases reported since the first syndromic description by Dravet and Bureau [Dravet, C., Bureau, M., 1981. The benign myoclonic epilepsy of infancy. Rev. Elecroencephalogr. Neurophysiol. Clin. 11, 438-444]. This includes 23 infants with reflex myoclonic epilepsy whose inclusion in the wider syndrome remains debatable. We have reviewed the literature and present data from six further cases. Prognosis in respect of long term seizure freedom is good with sodium valproate being the most effective medication. However, the cognitive outcome is much less certain with cognitive problems present in one-third of children who have long term follow up. The cognitive outcome in reflex myoclonic epilepsy of infancy is normal in all reported cases. The term benign may be appropriately used to describe the myoclonic seizures but must be used cautiously when counselling families about cognitive outcome. The clinical heterogeneity within this syndrome suggests that there may be a variety of genetic mechanisms that underlie the presentation. Clinicians should distinguish the syndrome of reflex myoclonic epilepsy in infancy from benign myoclonic epilepsy of infancy and all patients should continue developmental follow up for several years after diagnosis.

Benign Myoclonic Epilepsy in Infants: Electroclinical Features and Long-term Follow-up of 34 Patients

PURPOSE

Benign myoclonic epilepsy in infants (BMEI) is a rare epileptic syndrome characterized only by generalized myoclonic seizures (MSs) in normal children during the first 2 years. Our aim was to assess the electroclinical features and the follow-up of this syndrome.

METHODS

BMEI was confirmed by electroencephalogram (EEG) in four neuropediatric units in France between 1981 and 2002. Clinical and electroencephalographic findings at diagnosis and during the follow-up were collected. The Vineland scale or Wechsler scale or both were used to perform neuropsychological evaluations.

RESULTS

We report 34 patients with BMEI characterized by MSs occurring many times a day. The ictal EEG showed a generalized discharge of polyspikes, polyspikes-and-waves, or spikes-and-waves. The interictal EEG was usually normal. A family history of febrile seizures (FSs) or epilepsy was noted in six patients. A history of FSs was noted in 11 patients. Eleven patients had reflex MSs. Monotherapy with valproic acid was effective in 23 of 30 treated patients. The onset of epilepsy was known in all patients. Four patients had seizures after the initial symptoms. Juvenile myoclonic epilepsy developed in two patients, and cryptogenic partial epilepsy in another. Neuropsychological outcome was evaluated in 20 patients (10 with Wechsler scales and 17 with the Vineland scale). Cognitive functions were normal in 17 patients, whereas developmental delay was observed in three others.

CONCLUSIONS

BMEI is clinically characterized by myoclonic seizures involving the upper part of the body, occurring many times a day. The ictal EEG showed a generalized discharge of polyspikes, polyspikes-and-waves, or spikes-and-waves. The interictal EEG was usually normal. Reflex MSs were frequently observed, suggesting that two distinctive syndromes are not necessary. BMEI may be followed by juvenile myoclonic epilepsy. Despite a generally favorable neuropsychological outcome, mental retardation can be observed more frequently than in the general population.