Kinking of the medulla in children with acute cerebral oedema and hydrocephalus and its relationship to the dentate ligaments.

While developing a method for doing perinatal necropsies some 4,000 necropsies ago, we were disturbed about the contamination of the cerebrospinal fluid with blood whilst opening the skull, and a technique was devised of opening the dura over the base of the skull, sampling the cerebrospinal fluid and inspecting the foramenmagnum frombelow before the skull was touched. That method (Emery, 1960) has been applied as a routine procedure at the Sheffield Children's Hospital for over 10 years. It enabled us to find the severe brain swelling that sometimes occurs in children following relatively minor bums (Emery and Reid, 1962). The technique has also brought to our notice instances in which death was apparently associated with kinking of the brain-stem at its junction with the spinal cord, a lesion that we have not found described previously in presumably healthy children. This bending of the brain-stem appears to be due to a downward and backward displacement of the intracerebral brain-stem while the spinal cord is held rigid by the dentate ligaments. This deformity is seen as an acute lesion in children dying in a variety of diseases associated with unconsciousness and convulsions. It also has close analogies with the spur and 'Knickung' defotmity forming part of the 'Cleland' or 'Arnold-Chiari' malformation (Cleland, 1883; Schwalbe and Gredig, 1906). It seems likely that the post-natal acute lesions may illustrate the mechanism by which the spur part of the Chiari type II deformity develops in utero. In this paper, illustrative cases only are described for which photographs are available. Only two cases of Arnold-Cbiari deformity are illustrated from a series of over 200 brains of this type that we have examined.