The driving forces of cranial extra-axial space morphology: age, sex, and drugs

Abstract

Surrounding the brain but contained within the skull is a dynamic organ that functions to physically and chemically maintain the typical functioning of the brain. This organ is usually appreciated only as a series of layered supportive tissues, and a substantial collection of fluid suspended within them. In understanding it as such, the potential insights that its distinctive morphology has on our understanding of human anatomy have gone essentially unexamined. From here on out this organ or the collection of tissues that separate the brain from the skull will be referred to as the cranial extra-axial space (cEAS). In the research that follows, the normal morphology of the cEAS is examined with respect to variation with age, sex, body size, and marijuana use in an attempt to better characterize its normal morphology. Size, shape, and distribution of the cEAS were found to be highly variable in response to a number of individualistic characteristics. More absolute space was seen in taller, older, and male individuals than those that were shorter, younger, and/or female. Overall morphologic interactions of the cEAS are however complex, and cannot be explained by these characteristics alone.