The Historical Evolution of Intracranial Pressure Monitoring.

Intracranial pressure (ICP) monitoring has become an important tool in neurocritical care. Despite being used in ICUs all over the world, many are unfamiliar with its origins and the people and events that shaped the development of this technique. Herein, we provide a comprehensive historical review of the evolution of ICP monitoring, beginning with the earliest descriptions of the cerebrospinal fluid. We conducted a database search in PubMed, Google Scholar, and Google Books for relevant articles using the keywords "cerebrospinal fluid", "intracranial pressure" and "monitoring". Articles were further snowballed using reference lists of relevant papers. Although the earliest descriptions of the CSF date back several hundred years B.C., the history of ICP monitoring itself is not a long one. Alexander Monro and his student George Kellie laid the foundation of CSF physiology in the early 1800s through the Monro-Kellie doctrine. Their principles were later consolidated by John Abercrombie and Harvey Cushing. However, ten years earlier than Cushing's work on CSF physiology, Hans Queckenstedt's utilization of a lumbar needle to measure the pressure in the CSF marked the beginning of the era of ICP monitoring. Thenceforward, ICP monitoring technology underwent progressive improvements through the contributions of French scientists Guillaume and Janny, Swedish neurosurgeon Nils Lundberg, among others. Nowadays, ICP monitoring can be performed via direct and indirect methods using a potpourri of devices such as, but not limited to, subarachnoid bolts, microtransducer catheters and telemetric monitors. Nevertheless, despite advancements in ICP monitoring technology, the gold standard remains an extra-ventricular drain catheter connected to an external pressure transducer.