Neuronavigation

The term neuronavigation is a neologism used to describe the set of computer assisted technologies used by neurosurgeons to guide or “navigate” within the confines of the skull or vertebral column during surgery. The term is also used in a more universal form outside the field of neurosurgery in other areas of medicine such as otorhinolaryngology (ENT), orthopedics, general surgery and urology with similar purposes on different anatomical areas. The set of hardware for these purposes is referred to as a "neuronavigator".

Neuronavigation is recognized as the next evolutionary step of stereotactic surgery that dates back to the early 1900’s and gained popularity during the 1940’s particularly in Germany, France and the U.S. with the development of surgery for the treatment of movement disorders such as Parkinson’s disease and dystonias. In its infancy the purpose of this technology was to create a mathematical model describing a proposed coordinate system for the space within a closed structure e.g., the skull. This “fiducial spatial coordinate system” is used as a reference to describe the position of specific structures within this arbitrary defined space with high accuracy. The surgeon then referred to that data to target particular structures within the brain. This technology was boosted by the collection of data on human anatomy in “stereotactic atlases” expanding the quantitatively defined “targets” that could be easily used for surgery. Finally, the advent of modern neuro-imaging technologies, such as computer tomography (CT) and magnetic resonance imaging (MRI) along with the ever increasing capabilities of digitalization, computer graphic modelling and accelerated manipulation of data through complex mathematical algorithms via robust computer technologies made possible the real-time quantitative spatial fusion of images of the patient's brain with the created “fiducial coordinate system” for the purpose of guiding the surgeon's instrument or probe to a selected target. In this way the observations done via highly sophisticated neuro-imaging technologies (CT, MRI, Angiography) are related to the real patient at surgery time.

The ability to relate the position of a real surgical instrument in the surgeon’s hand or microscope’s focal point to the location of the imaged pathology updated in “real time” in an "Integrated Operating Room" - highlights the modern version of this set of technologies at its finest. In its current form neuronavigation began about 1990's and has ever since evolved to adapt to new neuro-imaging technologies, real-time imaging capabilities, new technologies to transfer the information in the operating room for 3D localization, real-time neuro-monitoring, robotics and new and better algorithms to handle the data via new and more sophisticated computer technology.

In its later conceptualization the term neuronavigation has started to fuse with that of “surgical-virtualization” eg, DextroscopeTM in which a neurosurgeon is able to recreate the scenario for a surgery in a 3-D model of manipulable computer data "to practice and check" the surgery -alternative approaches, assess possible difficulties, etc.- before the real surgery takes place.