In two children, ages 22 months and 4 years, after slight trauma, flaccid weakness of both arms developed, followed by flaccid quadriplegia with sphincter involvement. No vertebral fracture or dislocation was found, myelograms were negative, and diagnosis was made only after the full clinical syndrome developed. Pathologic studies revealed ischemic infarction involving the cervical cord and low medulla in one patient, and central gray matter of low cervical cord in the other, without hematomyelia or external compressive lesions. The pattern of infarction may be related to spasm of distal branches of the central sulcal arteries in a terminal arterial bed.