Discuss the determinants of intracranial pressure (80% marks) and outline how it can be measured (20% marks).
In the good answers to this question, and there were a number, the candidates included the volumes of the cranium and a correct description of the Monroe Kellie doctrine. A good answer should have included the compensations and consequences of increases in intra-cranial volumes; a discussion of all three components (brain tissue, blood, and CSF) and how they affect intracranial pressure; and then information on intra-ventricular and parenchymal devices in measuring ICP, briefly including their pros and cons. A common issue was writing quite a lot more than was needed on the relationship of cerebral blood flow to cerebral blood volume, and/or on the physiological consequences of raised ICP, which seemed to leave little time for discussion elsewhere. A few candidates did not provide any response for ICP measurement (worth 20% of the marks). Few candidates provided the intra-cranial elastance equation. A significant proportion of candidates missed out a part of the question, either the factors that affect CBV or ICP measurement.
Gomes, Joao A., and Anish Bhardwaj. "Normal intracranial pressure physiology." Cerebrospinal fluid in clinical practice (2008): 19-25.
Timofeev, Ivan. "The intracranial compartment and intracranial pressure." Essentials of Neuroanesthesia and Neurointensive Care. WB Saunders, 2008. 26-31.
Gergelé, Laurent, and Romain Manet. "Postural Regulation of Intracranial Pressure: A Critical Review of the Literature." Acta neurochirurgica. Supplement 131 (2021): 339-342.
Boulton, M., et al. "Raised intracranial pressure increases CSF drainage through arachnoid villi and extracranial lymphatics." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 275.3 (1998): R889-R896.
Mann, J. Douglas, et al. "Regulation of intracranial pressure in rat, dog, and man." Annals of Neurology: Official Journal of the American Neurological Association and the Child Neurology Society 3.2 (1978): 156-165.
Czosnyka, Marek, and John D. Pickard. "Monitoring and interpretation of intracranial pressure." Journal of Neurology, Neurosurgery & Psychiatry 75.6 (2004): 813-821.
Khan, S. H., et al. "Comparison of percutaneous ventriculostomies and intraparenchymal monitor: a retrospective evaluation of 156 patients."Intracranial Pressure and Neuromonitoring in Brain Injury. Springer Vienna, 1998. 50-52.