Syndrome of rapid irregular movements of eyes and limbs in childhood.

Electroencephalographic (E.E.G.), polyelectromyographic (poly-E.M.G.), and electro-oculographic (E.O.G.) studies were made of 16 young children and babies referred because of prolonged episodes of rapid irregular movements of eyes and limbs (R.I.M.E.L.) sometimes involving also the trunk and head. This unusual syndrome of unknown aetiology developed over a period of a few days and persisted for months or years. In the E.E.G. there were only minor changes, without discharges of any kind during the episodes of involuntary movements, and during sleep the spindles were unusually fast. In the poly-E.M.G. single or multiple spikes appeared as electrical concomitants of brief myoclonic phenomena at irregular intervals and independently in the various groups of muscles examined. In the E.O.G. the frequent episodes of irregular jerky movements of the eyeballs occurred at various intervals and without rhythmicity. On clinical observation alone this syndrome may not be easily separated from other conditions such as myoclonic epilepsy, gross ataxia, tremors, or choreiform syndromes in young children; the peculiar combination of neurophysiological findings is essential in the identification of this unusual disorder.