Eyelid myoclonia with absences: phenomenology in children

Abstract

The aim of this study is to describe the phenomenology of children with eyelid myoclonia with absences (EMA) in relation to EEG findings and diagnosis, with particular reference to the issue of self-induction. Case notes of all children with a diagnosis of EMA within a regional paediatric neurology clinic were identified. Each child was interviewed by a paediatric neurologist with or without a child psychiatrist and their EEG reviewed by a clinical neurophysiologist. Six patients (five female, one male) were identified. Clinical and EEG features and treatment responses were in keeping with the established literature. Five of the six patients demonstrated various compulsive or tic-like symptoms including premonitory sensations, compulsive, difficult to resist urges and a sense of relief associated with the absence attacks. Separate facial tics not associated with absences were also evident in at least two children. The argument that self-induction does not occur in EMA assumes its deliberate nature, which may not necessarily be the case for a proportion of these children. Compulsive 'self-induction' may be similar to the phenomenology described in Tourette's syndrome (TS) where individuals experience motor and vocal tics and obsessive compulsive symptoms. The relationship between this argument and EEG findings in EMA would presume that the initial eye ball roll/eye closure and eye blinking (tics seen in TS) are tic-like symptoms which cause the absences and discharges of EMA in those who are photosensitive. In this model the self-induction of discharges in an individual may or may not be deliberate, or even go unnoticed by the patient. The beneficial response of some so-called 'self-inducers' to the proconvulsive dopamine antagonists (commonly prescribed for TS) lends further support to this argument.