Abrupt neurological deterioration in children with Kearns-Sayre syndrome.

The conditions of a young woman and a boy with Kearns-Sayre syndrome (KSS) deteriorated abruptly; they died despite pacemaker control of complete heart block (case 1) and without evidence of arrhythmia or asystole. Extensive spongy vacuolization of the brainstem was shown by serial computerized tomographic scanning (case 2) and at autopsy (case 1). A review of the literature indicated that KSS in childhood is particularly severe and is associated with diffuse, progressive, spongy degeneration of the brain. Children with KSS have clinical, roentgenographic, and neuropathological evidence of spongy degeneration of the brain, which may be related to abrupt deterioration and death despite adequate control of heart block. Periodic brainstem auditory evoked response studies may allow early recognition of this process.