Intraventricular blood after "traumatic" lumbar puncture: a report of two cases.

Blood was detected in the lateral ventricles on head computed tomograms performed after "traumatic" lumbar punctures in two children. This finding has not previously been observed or reported. The likely mechanisms by which blood from the spinal thecal sac reached the ventricles are discussed. This potentially confusing observation, if not correctly accounted for, may lead to an unnecessary, fruitless search for the site of a supposed "primary" intraventricular haemorrhage.