Microscopic lesions in the brain following head injury.

In cases of head injury with more than a few hours' survival, microscopic examination of the brain may reveal lesions which are not apparent on naked-eye inspection. In the first place, anoxic cell changes are frequently seen in cases where the injury has been complicated by respiratory troubles. Secondly, there are diffuse microscopic lesions attributable to accelerations within the brain substance at the time of injury. These may be in the form of multiple capillary haemorrhages-which to the naked eye are often indistinguishable from the normal vascular markings of a congested brain-or in the form of microscopic disruptions of nervous tissue, without haemorrhage. It is the purpose of this paper to show that the use of a simple silver impregnation enables one to pick out these tiny lesions with the scanning power of the microscope. It is suggested that a study of the sites, numbers and distribution of these lesions might throw useful light on the mechanisms of acceleration injuries to the brain.