Monro kellie hypothesis history book

Abstract for 200 years, the closed box analogy of intracranial pressure icp has underpinned neurosurgery and neurocritical care. Management of intracranial pressure in traumatic brain. Pdf continuous monitoring of the monrokellie doctrine. Intracranial pressure and cerebral blood flow sciencedirect. More than two centuries ago, alexander monro applied some of the principles of physics to the intracranial contents and for the first time hypothesized that the blood circulating in the cranium was of constant volume at all times. The monrokellie doctrine describes the principle of homeostatic intracerebral volume regulation, which stipulates that the total volume of the parenchyma, cerebrospinal fluid, and blood remains. The monrokellie doctrine or hypothesis states that the sum of volumes of brain, cerebrospinal fluid csf and intracerebral blood is constant.

Appearances observed in the dissection of two individuals. The pressurevolume relationship between icp, volume of csf, blood, and brain tissue, and cerebral perfusion pressure cpp is known as the monrokellie doctrine or hypothesis. As stated by the monrokellie hypothesis, the totality of elements inside the skull is composed of the brain, csf, and blood 36. The monrokellie hypothesis states that an increase in volume of one of these components must be compensated for by a reduction in volume of one or both of the others. The monro kellie hypothesis was proposed by doctors alexander monro and george kellie in correspondence to the impact cerebrospinal fluid csf has on the pressurevolume relationship within the cranium. That is, the total volumes of the brain tissues, cerebrospinal fluid csf, and intracranial blood are fixed. If one component increases, one or both of the other two decrease. An increase in one should cause a reciprocal decrease in either one or both of the remaining two. The monroekellie doctrine states that the contents of the cranium are in a state of the constant volume. These three entities need to remain constant because of the skull. The monrokellie hypothesis states that the cranial compartment is inelastic and that the volume inside the cranium is fixed. The sum of the volume of the brain, blood, and csf within the skull must remain constant.

This particular hypothesis describes the intracranial volumepressure relationship, which we briefly mentioned above. In 1783, alexander monro first articulated this in his observations on the structure and function of the nervous system and later was supported by kellie in 1824 by his observation in two humans. Monro kellie hypothesis is a pressurevolume relationship that aims to keep a dynamic equilibrium among the essential noncompressible components inside the rigid compartment of the skull. This hypothesis was supported by experiments by kellie. If this compensation is insufficient, then potentially fatal increases in icp can occur. Therefore, an increase in one of the above must be offset by an decreased volume of the others. Cushing conceptualised the monrokellie doctrine stating that a change in blood, brain or csf volume resulted in reciprocal changes in one or both of the other two. Maintenance of relatively constant icp is essential for normal perfusion of the brain. More than two centuries ago, alexander monro applied some of the principles of physics to the cranial cavity and for the first time hypothesized that the blood circulating in the cranium was of constant volume at all times. Increased intracranial pressure statpearls ncbi bookshelf. Monrokellie hypothesis radiology reference article. An increase in the volume of one component will result in the decrease of volume in 1 or 2 of the other components.