The influence of methylmethacrylate on brain elastic responsein vivo

Abstract

In controlled experiments in six dogs, we have studied the influence of acrylic cement (applied to the skull) on the mechanical response properties of the brainin vivo. In particular we have been concerned with the brain elastic response which reflects that property of the brain usually referred to by the generic terms “stiff” or “soft.” This response property is directly proportional to the instantaneous elastic modulus, a characteristic response property of viscoelastic materials. As anin vivo response property it was measured as the short-time pressure-depth response using a pressure-depth transducer inserted a short distance (less than 1 mm) into the subpial region, maintaining an intact dura. This quantity was determined before and after the application of the acrylic cement. The results show that the acrylic cement lowered the cerebrospinal fluid (CSF) pressure at the cranial vault, increased the depth of the position δ _s , which represents substantial brain contact, and increased the brain elastic response.