[Kearns' syndrome: a case study (author's transl)].

An anatomoclinical study of a case of Kearns' syndrome is reported. Neuro-ophthalmic symptoms appeared when the child was 13 year-old. Two and a half years later occurred an episode of paroxystic atrioventricular block, after which the triad characterising the syndrome was completed: retinitis pigmentosa, ophthalmoplegia, disorder of heart conduction. The course was unfavorable despite pacemaker insertion. Study of the central nervous system showed spongiosis of the subcortical white substance, of the basal ganglia and of the cranial nerve nuclei. The specialized heart conduction tissue was the site of apparently primary degeneration. The extension of the visceral involvement is discussed in the light of published data.