Reflex myoclonic epilepsy in infancy: a critical review

Abstract

Benign myoclonic epilepsy in infancy, classified among the generalised idiopathic epilepsies, is characterised by the occurrence of myoclonic seizures in the first three years of life in otherwise normal infants. Some authors have described cases of myoclonic seizures as a reflex response to sudden unexpected tactile or acoustic stimuli and this clinical entity has been proposed as a separate nosographic syndrome, referred to as “reflex myoclonic epilepsy in infancy” (RMEI). We reviewed all published articles and case reports on RMEI in order to clarify clinical and electroencephalographic findings, with particular attention to outcome and treatment. RMEI appears to be a benign variant of idiopathic myoclonic epilepsy in infancy with specific features that occur in neurologically and developmentally normal children. This rare clinical entity is often under‐described and under‐diagnosed, and for this reason should be brought to the attention of paediatricians in order to avoid extensive investigations and reassure parents of the lack of long‐term complications.

The role of EEG in the diagnosis and classification of the epilepsy syndromes: a tool for clinical practice by the ILAE Neurophysiology Task Force (Part 2)

“…There are no other seizure types. This presentation has been considered as a variant, termed "reflex myoclonic epilepsy in infancy (RMEI)", with some differentiating features (Ricci et al, 1995;Verrotti et al, 2013) that include: earlier mean age at onset (10 months, compared to 20 months for MEI), shorter duration of the MS, most of which are provoked by sudden and unexpected stimuli, better response to antiepileptic medication, and better cognitive outcome. Although these children usually have good prognosis for seizures, cognitive and behavioural disturbances have been reported in around 40% of patients (Zuberi and O'Regan, 2006;Guerrini et al, 2012;Auvin et al, 2013).…”

Early infancy‐onset stimulation‐induced myoclonic seizures in three siblings with inherited glycosylphosphatidylinositol (GPI) anchor deficiency

“…During the course of the disease, a variety of seizures, including generalized seizures (tonic, atonic, and absence seizures) and/or focal seizures, occurred in all patients. However, some authors claim that this group of infants with reflex myoclonic seizures should be considered as a variant of myoclonic epilepsy in infancy rather than a distinct epileptic syndrome (Verrotti et al, 2013). Of note, the myoclonic seizures occurred mostly spontaneously, but sometimes appeared in response to sudden unexpected acoustic or tactile stimuli.…”

“…Between one week and 3 months of life, our patients developed daily myoclonic jerks which were associated with irregular spike-and-wave complexes on EEG. To date, 80 cases with RMEI have been reported in the literature (Verrotti et al, 2013). All seizures were refractory to antiepileptic drug treatment.…”

“…All seizures were refractory to antiepileptic drug treatment. However, these myoclonic seizures are usually spontaneous (Verrotti et al, 2013). Myoclonic jerks provoked by stimuli are extremely rare events.…”

“…To date, epileptic myoclonic jerks provoked by stimuli have been reported exclusively in infants with RMEI (Verrotti et al, 2013). Myoclonic seizures were easily evoked by sudden unexpected acoustic or tactile stimuli.…”