Neuronavigation is the set of computer-assisted technologies used by neurosurgeons to guide or "navigate" within the confines of the skull or vertebral column during surgery, and used by psychiatrists to accurately target rTMS (

transcranial magnetic stimulation Transcranial magnetic stimulation (TMS) is a noninvasive form of brain stimulation in which a changing magnetic field is used to induce an electric current at a specific area of the brain through electromagnetic induction. An electric pulse gener ...

). The set of hardware for these purposes is referred to as a neuronavigator.

Stereotactic surgery

Neuronavigation is recognized as the next evolutionary step of

stereotactic surgery Stereotactic surgery is a minimally invasive form of surgical intervention that makes use of a three-dimensional coordinate system to locate small targets inside the body and to perform on them some action such as ablation, biopsy, lesion, injec ...

, a set of techniques that dates back to the early 1900s and that gained popularity during the 1940s, particularly in Germany, France and the U.S., with the development of surgery for the treatment of movement disorders such as

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...

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” uses

fiducial marker A fiducial marker or fiducial is an object placed in the field of view of an imaging system that appears in the image produced, for use as a point of reference or a measure. It may be either something placed into or on the imaging subject, or a ...

s as a reference to describe with high accuracy the position of specific structures within this arbitrarily defined space. The surgeon then refers 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 readily used in surgery. Finally, the advent of modern neuro-imaging technologies such as

computed tomography A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...

(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 Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is perfo ...

) are related to the actual patient during surgery.

Neuro imaging

The ability to relate the position of a real surgical instrument in the surgeon's hand or the 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. In its current form, neuronavigation began in the 1990s and has adapted to new neuro-imaging technologies, real-time imaging capabilities, new technologies to transfer the information in the operating room for 3-D localization, real-time neuro-monitoring,

robotics Robotics is an interdisciplinarity, interdisciplinary branch of computer science and engineering. Robotics involves design, construction, operation, and use of robots. The goal of robotics is to design machines that can help and assist human ...

, and new and better algorithms to handle data via more sophisticated computer technology.

Surgical virtualization

In its later conceptualization, the term ''neuronavigation'' has started to overlap fuse with ''surgical-virtualization'' in which a neurosurgeon is able to visualize the scenario for surgery in a 3-D model of manipulable computer data. In this way the physician can "practice and check" the surgery, try alternative approaches, assess possible difficulties, etc., before the real surgery takes place. MRI image of human cerebral cortex with stereotaxic localization of DLPFC

MRI image of human cerebral cortex with stereotaxic localization of DLPFC

Neuronavigation for transcranial magnetic stimulation

The standard TMS protocol which was FDA approved in 2008 estimates the location of the

DLPFC The dorsolateral prefrontal cortex (DLPFC or DL-PFC) is an area in the prefrontal cortex of the primate brain. It is one of the most recently derived parts of the human brain. It undergoes a prolonged period of maturation which lasts until adultho ...

by finding the left motor cortex and marking a spot 5 cm anterior to it. Later two more methods were introduced using measurements of the head and calculating the location of the

as 1) the F3 (EEG 10/20 system) or 2) the Beam method. Both were estimations with some limitations. With the introduction of Neuronavigation, direct visualization of structures can be achieved either with an individual's (specially ordered) MRI or an average brain (MNI) stretched to the dimensions of the individual. There is now greater significance of this increased accuracy due to recent evidence that stimulation of the gyral crown is less effective than stimulation of the sulcal bank. The introduction of robotic controlled TMS also may make Neuronavigation more important. Several manufacturers offer complete systems including Ant Neuro or Axilum Robotics. 3d printed TMS guide

Neuronavigation for spine surgery

Assistive technologies are used during spinal fusion surgery to increase accuracy, especially for the placement of

pedicle Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

screws. A review of navigation techniques for spine surgery published in 2019 listed four currently available options: *

Medtronic Medtronic plc is an American medical device company. The company's operational and executive headquarters are in Minneapolis, Minnesota, and its legal headquarters are in Ireland due to its acquisition of Irish-based Covidien in 2015. While it ...

stealth system *

BrainLab Brainlab is a privately held German medical technology company headquartered in Munich, Bavaria. Brainlab develops software and hardware for radiotherapy and radiosurgery, and the surgical fields of neurosurgery, ENT and craniomaxillofacial, spi ...

Stryker The Stryker is a family of eight-wheeled armored fighting vehicles derived from the Canadian LAV III. Stryker vehicles are produced by General Dynamics Land Systems-Canada (GDLS-C) for the United States Army in a plant in London, Ontario. It ...

navigation *

7D Surgical 7D or 7-D may refer to: *7D (Argentina), a political scandal in Argentina *7D (Long Island bus) *''The 7D'', an animated series for Disney XD *7D, the production code for the 1987 ''Doctor Who'' serial ''Time and the Rani'' *Canon EOS 7D, a 2009 18 ...

system

External links

American Association of Neurological Surgeons (AANS.org) , Library.
Research List. * {{cite journal , vauthors=Neggers SF, Langerak TR, Schutter DJ, etal , title=A stereotactic method for image-guided transcranial magnetic stimulation validated with fMRI and motor-evoked potentials , journal=NeuroImage , volume=21 , issue=4 , pages=1805–17 , date=April 2004 , pmid=15050601 , doi=10.1016/j.neuroimage.2003.12.006, s2cid=25409984

References

Neurosurgery