Stereotactic neurosurgery is a rapidly growing aspect of treatment for nervous system disorders. It typically involves the use of advanced imaging techniques (CT, MRI) and devices to translate the imaging information into guidance for the neurosurgical procedure. Stereotactic neurosurgery has progressed from the use of a cumbersome frame placed on the patient’s head under anesthesia for simple probe (eg, biopsy needle, electrode) localization to a multifaceted set of techniques that can incorporate various anatomic, metabolic, and functional data sets to permit precise interventions on any area of the brain or spinal cord. Future developments will include neurosurgical robots to minimize human error and physiological shortcomings in stereotactic neurosurgery as well as precisely implanted multifunctional “effectors” (micro- and nano- devices such as electrodes, infusion catheters, and controlled-release capsules) to greatly expand the types of disorders benefiting from stereotactic neurosurgery.
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• Stereotactic neurosurgery (3-dimensional localization in the nervous system) began with animal research early in the 20th century; procedures in humans began in the middle of the 20th century.
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• Until the 1990s, stereotactic neurosurgery usually involved placing a frame on the patient’s head under local anesthesia.
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• Frameless stereotactic neurosurgery register points on the patient’s face, skull, or spine with imaging (CT or MRI scan) to allow precise localization of the desired target in the central nervous system.
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• Major applications of stereotactic neurosurgery include stereotactic radiosurgery (over the past 40 years) and deep brain stimulation (over the past 20 years).
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• The integration of stereotactic neurosurgery with robots is at present the most rapidly developing aspect of the field, resulting in more precise and minimally invasive neurosurgical procedures involving the brain and spine.
Historical note and terminology
Early in the 20th century, Horsley and Clarke devised a stereotaxic system for studying neurophysiology (20). Mussen devised the first stereotactic frame intended for human use in 1918. Although the frame was never used, Mussen presciently described minimally invasive stereotactic surgery for the diagnosis and treatment of brain tumors (35). In a 1971 letter to his son, an engineer, Mussen wrote,
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My idea…was to make a complete instrument of the human brain and then make an atlas of the human brain like in the cat. Then you could locate any structure in the human brain by looking at the atlas and it was my thought that if there was a tumor in the brain that could not be located, you could send an electrode in and get the reaction of a normal brain and the difference if you came to the tumor. And then by making a number of degenerations with the galvanic current you might be able to destroy the tumor. And all this could be done through a 5 mm trephine in the skull and puncturing the dura without exposing the brain at all.
However, it was not until the World War II era that stereotaxic techniques were developed to explore the deep brain nuclei in both animals and humans (40). Following World War II, the Temple University team in the United States and the Talairach team in France continued working on stereotactic frames for use in man. The Temple team was first in publishing their work; the initial stereotactic target was the globus pallidus in patients with Huntington chorea (41; 14).
Initially, stereotaxic neurosurgery relied on a referential system called a "stereotaxic frame.” The frame is attached to the skull, and serves to position the necessary instruments.
In 1950 Talairach proposed the bicommissural line of the third ventricle (anterior commissure to posterior commissure), visualized by means of ventriculography, as the zero or reference plane. In 1956 during the First International Congress of Neurology, Talairach and colleagues presented their first stereotactic atlas based on the bicommissural line (47). Stereotactic approaches to spinal lesions were proposed in 1969 (17) and have undergone considerable development (23; 05; 32).
A subset of stereotactic neurosurgery is stereotactic radiosurgery, the use of stereotactic techniques to direct multiple doses of radiation toward a specific target (usually from 2 mm to 3 mm up to 2 cm to 3 cm in diameter). Stereotactic radiosurgery is the subject of another article (titled Stereotactic radiosurgery) and will not be discussed here.
Regarding nomenclature, the technique was initially called "stereotaxic,” but during the 1970s the term "stereotactic” came into use. The terms have since been differentiated: "stereotaxic" when used in animals and "stereotactic" when used in humans. “Stereotaxy" is applied to both (12).
A compendium of stereotactic neurosurgery has been edited by 3 of the most significant contributors to the field (27). The role of psychosurgery in the evolution of stereotactic and functional neurosurgery during the second half of the 20th century has been published (37).