Intracranial volume, brain volume, reserve volume and morphological signs of increased intracranial pressure--a post-mortem analysis.

In a series of 93 unselected forensic autopsies of adults the following volumes were measured: skull volume by filling a sac of synthetic material with water, placed intracranially, after removal of the brain and brain volume by its water displacement. Objective was to demonstrate if generally is there a relation between reduced difference of skull volume minus cerebral volume ("reserve volume"=RV, predominantly identical with cerebrospinal fluid compartment) and the presence of pressure marks (grooves) on the basis of temporal lobes (uncal grooves) and cerebellum (cerebellar cone). These alterations in post-mortem examination were usually regarded as signs of increased intracranial pressure during life. The obtained data were presented in diagrams. Most of the intracranial volumes were in the range 1200-1600 ml and brain volumes in the range 1200-1500 ml. The actual brain volume can be estimated by the multiplication brain weight *0.957. The RV in most cases was situated between 25 and 150 ml, corresponding 2-10% of the cranial cavity--increasing with increasing age of the persons. Clear uncal grooves (less distinct: cerebellar grooves) relate to significant decrease of the RV and the conclusion seems acceptable that this is indicative for intracranial displacement during life and is therefore an indirect sign of - at least local - brain swelling and increased intracranial pressure. However, to provide a well-founded basis for such a conclusion in a case under investigation a (semi quantitative) graduation of the intensity of such actual grooves seems to be recommendable.