The jittery newborn and infant: a review.

Jitteriness is an involuntary movement that is particularly frequent in the newborn. Its hallmark is tremor. The pathogenesis is poorly understood. Jitteriness is often accompanied by other signs of central nervous system excitation, such as hypermotility, hypertonicity, and ease of startle. It must be differentiated from myoclonus and seizure, although they may coexist. Jitteriness can be caused by a variety of pre-, peri-, and postnatal insults, and it is the nature and treatability of these, rather than the tremor itself, that are the major determinants of the ultimate prognosis. "Coarse" tremor is probably more often abnormal than "fine" tremor, and appears to bear some relationship to the later development of a choreiform syndrome. The evaluation of the jittery infant must be individualized and management aimed at reversing any remediable causes.