Monro-Kellie hypothesis

Monro-Kellie hypothesis is a pressure-volume relationship that aims to keep a dynamic equilibrium among the essential non-compressible components inside the rigid compartment of the skull .

The average intracranial volume in the adult is around 1700 mL, composed of brain tissue (~1400 mL), CSF (~150 mL), and blood (~150 mL) . The volume of these three components remains nearly constant in a state of dynamic equilibrium (figures 1 and 2). Thus, a decrease in one component should be compensated by the increase in other and vice-a-versa (figures 3, 4 and 5).

It is important to note that most of the blood in the cranial cavity is contained in the low-pressure venous system, so venous compression serves as a means of displacing blood volume .

There are many classic brain imaging findings that this theoretical hypothesis can explain:

• venous distention in intracranial hypotension
• sulcal effacement in brain edema or expansive lesion
• brain shift with intracranial hypertension

History and etymology

Named after Alexander Monro (1733-1817), a Scottish physician, and George Kellie, a Scottish surgeon (1720–1779).

Siehe auch:

• Liquorunterdrucksyndrom