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Biomedical subjects

Michael L J Apuzzo

Publications and source records attributed to Michael L J Apuzzo.

At least 19 recordsLinked to original sources

Gamma knife radiosurgery for trigeminal neuralgia.

OBJECTIVE: The purpose of this study was to assess outcomes in patients treated with gamma knife radiosurgery for trigeminal neuralgia. METHODS: From 1997 to 2003, a total of 49 patients with trigeminal neuralgia underwent gamma knife radiosurgery. The trigeminal root entry zone immediately adjacent to the pons was targeted by use of a 4-mm collimator to deliver 40 Gy to the 50% isodose line (maximum dose, 80 Gy). Special care was taken to limit radiation dose to the adjacent pons to 12 Gy. Of the 49 study patients, all had undergone previous medical therapy, 8 (16%) had undergone microvascular decompression, 8 (16%) had undergone percutaneous rhizotomy, 2 (4%) had undergone linear accelerator-based radiosurgery, and 5 (10%) presented with multiple sclerosis. The median duration of symptoms was 6 years. There were 29 female patients (59%) and 20 male patients (41%). Facial pain outcomes were assessed by use of the Barrow Neurological Institute pain score. Other outcomes assessed included recurrence of symptoms and treatment toxicity. The median follow-up period was 49 months. RESULTS: At last evaluation, a total of 27 patients (61%) with idiopathic trigeminal neuralgia reported pain relief (scores of IIIb or less). This included 14 patients (32%) who reported complete pain relief when not receiving medications. Significant recurrence of pain after an initial interval of relief was reported by 10 patients (23%). Mean time to pain recurrence was 9.6 months (range, 2-36 mo). Mild to moderate facial numbness was experienced by 13 patients (29%), whereas 8 (18%) reported mild dysesthesias. CONCLUSION: Gamma knife radiosurgery established durable pain relief in 61% of patients with medically refractory idiopathic trigeminal neuralgia. A longer follow-up period is necessary to fully assess the incidence of late complications and recurrences.

Adult↗

A fantastic voyage: a personal perspective on involvement in the development of modern stereotactic and functional neurosurgery (1974-2004).

Stressing environments, individuals, ideas, and global events, this historical stereotactic and functional neurosurgical vignette initially presents a review of factors in the genesis of personal interest and the foundations of involvement in the discipline of neurological surgery. The vignette then traces the development of concepts and instrumentation and their ultimate practical utilization in patient care on the neurosurgical services at the Keck School of Medicine at the University of Southern California over the course of a 3-decade period (1974-2004). The article summarizes and elaborates details of contributions to the literature and complex involvement on the national and international levels as the refinements and capabilities of stereotactic and functional neurosurgery have been reinvented over a generation through the emergence of new technology, ideas, individual ingenuity, and active collegial exchange.

Europe↗

The physics of image formation in the neuroendoscope.

INTRODUCTION: The development of the neuroendoscope has allowed neurosurgeons to visualize anatomic structures deep within the nervous system with minimal disruption of the critical overlying structures. This has enabled the development of an entire system of tools and techniques for maximum effective action at the target point through minimal corridors for the treatment of an entire spectrum of pathologies. DISCUSSION: The design of an optical instrument with the ability to illuminate deep, hidden anatomic structures and transmit those images accurately and brightly to the eye of the neurosurgeon poses several challenges. These challenges have been met by advances in lens design and optical systems engineering over a period of several decades leading up to emergence of the modern neuroendoscope. In this paper, the basic concepts of the physics of image formation in optical systems are reviewed with emphasis on those elements critical to the endoscope. CONCLUSION: A consideration of these basic concepts is critical to the understanding of the limitations and capabilities of the key instrument for neuroendoscopy.

Humans↗

The evolution and future of minimalism in neurological surgery.

INTRODUCTION: The evolution of the field of neurological surgery has been marked by a progressive minimalism. This has been evident in the development of an entire arsenal of modern neurosurgical enterprises, including microneurosurgery, neuroendoscopy, stereotactic neurosurgery, endovascular techniques, radiosurgical systems, intraoperative and navigational devices, and in the last decade, cellular and molecular adjuvants. AIMS: In addition to reviewing the major developments and paradigm shifts in the cyclic reinvention of the field as it currently stands, this paper attempts to identify forces and developments that are likely to fuel the irresistible escalation of minimalism into the future. These forces include discoveries in computational science, imaging, molecular science, biomedical engineering, and information processing as they relate to the theme of minimalism. DISCUSSION: These areas are explained in the light of future possibilities offered by the emerging field of nanotechnology with molecular engineering.

Biomedical Engineering↗

Measurements of the relative output factors for CyberKnife collimators.

OBJECTIVE: To determine accurately the relative output factors, defined as the ratio of the nominal dose rate for a given collimator to that of the 60-mm collimator. This is particularly important for radiosurgical treatment of functional disorders, such as trigeminal neuralgia, in which a single large radiation dose is delivered to the target with a small collimator, such as the 5-mm collimator for CyberKnife radiosurgery. Numerous studies on the output factors have been reported for the Leksell gamma knife unit but none for the CyberKnife system. METHODS: Measurements of the relative output factors for all 12 collimators were performed by three different methods: silicon diode, radiographic film, and thermoluminescent dosimetry microcubes. The silicon diode is designed for measurements in small (1-50 MV) photon beams performed in water or air. Film and thermoluminescent dosimetry measurements were performed in a plastic phantom. RESULTS: The measured relative output factors for the three methods were very similar except for the three smallest collimators (5, 7.5, and 10 mm). The measured difference between the above methods was approximately 2%. The mean value of the output factor for the 5-mm collimator was 0.686 +/- 0.024. The uncertainties of the output factors are expected to increase with the decrease of collimator diameter. They range from approximately 1 to 4% of the relative output factor. CONCLUSION: The relative output factor can be measured with an acceptable accuracy even for the smallest (5-mm) CyberKnife collimators. This requires the selection of appropriate dosimetric detectors and measuring procedures. The results obtained with the diode are considered more accurate than with the other two methods.

Film Dosimetry↗

Virtual reality neurosurgery: a simulator blueprint.

OBJECTIVE: This article details preliminary studies undertaken to integrate the most relevant advancements across multiple disciplines in an effort to construct a highly realistic neurosurgical simulator based on a distributed computer architecture. Techniques based on modified computational modeling paradigms incorporating finite element analysis are presented, as are current and projected efforts directed toward the implementation of a novel bidirectional haptic device. METHODS: Patient-specific data derived from noninvasive magnetic resonance imaging sequences are used to construct a computational model of the surgical region of interest. Magnetic resonance images of the brain may be coregistered with those obtained from magnetic resonance angiography, magnetic resonance venography, and diffusion tensor imaging to formulate models of varying anatomic complexity. RESULTS: The majority of the computational burden is encountered in the presimulation reduction of the computational model and allows realization of the required threshold rates for the accurate and realistic representation of real-time visual animations. CONCLUSION: Intracranial neurosurgical procedures offer an ideal testing site for the development of a totally immersive virtual reality surgical simulator when compared with the simulations required in other surgical subspecialties. The material properties of the brain as well as the typically small volumes of tissue exposed in the surgical field, coupled with techniques and strategies to minimize computational demands, provide unique opportunities for the development of such a simulator. Incorporation of real-time haptic and visual feedback is approached here and likely will be accomplished soon.

Computer Simulation↗

Study of magnetic resonance imaging-based arteriovenous malformation delineation without conventional angiography.

OBJECTIVE: In this study, we aimed to assess the feasibility of arteriovenous malformation (AVM) delineation for gamma knife radiosurgery without conventional angiography and to correlate factors that may affect AVM delineation. METHODS: A series of 57 consecutive patients with AVMs treated with gamma knife radiosurgery from August 1994 to December 2000 were reviewed. All patients in the study had undergone pretreatment angiography. The mean AVM volume was 2.8 cm(3), with a median of 2.0 cm(3) (range, 0.04-22 cm(3)). All AVMs were delineated on the original frame-based magnetic resonance imaging (MRI) scans by a vascular neurosurgeon without the assistance of angiography and then compared with the actual AVM delineation on the basis of previously performed angiography and MRI. Univariate correlation analysis was used to determine the relationship of AVM coverage, size, diffuseness, previous embolization, and hemorrhage parameters. RESULTS: The study volume or MRI-based volume alone coincided with the actual treatment volume by a mean of 58% for diffuse and 87% for nondiffuse AVMs (P = 0.0005). At AVM volume greater than 2 cm(3), the median percentage of coinciding volume was 63% for embolized AVMs and 82% for nonembolized AVMs (P = 0.0315). Conversely, the study volume overestimated the actual treatment volume by a mean of 57% for AVMs larger than 2 cm(3) versus 25% for AVMs smaller than 2 cm(3) (P = 0.0012). In general, the percentage of the coinciding volume was inversely related to that of the excess volume, whereas both the study volume and the coinciding volume were proportionate to AVM volume at treatment. CONCLUSION: MRI-based AVM delineation without conventional angiography may be feasible only for selected patients, such as those with nondiffuse and large nonembolized AVMs.

Adolescent↗

Reliability of three-dimensional fluoroscopy for detecting pedicle screw violations in the thoracic and lumbar spine.

OBJECTIVE: Thoracic and lumbar pedicle screws have become popular because of their biomechanical superiority over other methods of spinal fixation. However, the safety and efficacy of transpedicular screws depend on their proper placement. Recent advances in imaging have resulted in the ability to acquire three-dimensional (3-D) axial images of the spine during surgery, and this study was undertaken to assess the reliability of this technology to detect pedicle violations. METHODS: Pedicle screws were placed in six human cadaver spines from T1 to S1 using standard techniques. Intentional pedicle violations were created in 74 of 216 pedicles, and violations were graded on a four-point scale (range, 0-3). Radiographic images were then obtained using a conventional spiral computed tomographic scanner and the Siremobil Iso-C 3D (Siemens Medical Solutions, Erlangen, Germany) 3-D fluoroscopy unit. An independent neuroradiologist then graded pedicle violations as ascertained by the two imaging modalities. RESULTS: Using direct inspection of the pedicles as the "gold standard," the overall sensitivity and specificity for detecting pedicle violations were 0.716 and 0.789, respectively, with 3-D fluoroscopy. The overall sensitivity and specificity for detecting pedicle violations were 0.608 and 0.937, respectively, with conventional computed tomography. All Grade 2 pedicle violations were detected in the thoracic spine by both modalities, and all Grade 3 violations were detected by both modalities. CONCLUSION: Axial images obtained with 3-D fluoroscopy demonstrate a higher sensitivity but lower specificity than conventional computed tomographic scanning for assessing pedicle violations. By providing real-time intraoperative imaging, 3-D fluoroscopy may enhance the safety of thoracic transpedicular instrumentation.

Bone Screws↗

Gamma knife radiosurgery for benign cavernous sinus tumors: quantitative analysis of treatment outcomes.

OBJECTIVE: We review our 8-year experience with gamma knife radiosurgery (GKRS) for the treatment of patients with benign cavernous sinus tumors and present a quantitative analysis of factors relevant to treatment outcomes. METHODS: From 1994 to 2002, a total of 139 patients with benign cavernous sinus tumors were treated in 145 sessions. Their median age was 53 years, and the median follow-up was 3.5 years. The tumors included 57 meningiomas, 76 pituitary tumors (49 nonfunctional adenomas, 15 prolactinomas, 5 adrenocorticotropic hormone-secreting tumors, 6 growth hormone-secreting tumors, and 1 plurihormone-secreting tumor), 4 schwannomas, 1 hemangioma, and 1 paraganglioma. Sekhar tumor grades were as follows: I, n = 28 (20%); II, n = 42 (30%); III, n = 42 (30%); IV, n = 19 (14%); and V, n = 8 (6%). The median tumor volume was 3.4 cm(3), and the median prescribed dose was 15 Gy defined to the 50% isodose line. RESULTS: A total of 136 treated tumors (97.8%) were well controlled by GKRS, with low morbidity. For meningiomas, 29 tumors (51%) were unchanged and 26 (46%) were smaller at a median of 15.2 months. For pituitary tumors, 50 (66%) were unchanged and 25 (33%) were smaller at a median of 20.6 months. Improvement in cranial nerve (CN) function was seen in 19 (36.5%) of 52 patients with pre-GKRS deficits, and 3 patients (2.2%) developed new stable CN deficits after GKRS: 1 patient developed IVth CN palsy at 9 months, and 2 developed persistent VIth CN palsies at 43 and 45 months, respectively, that required surgical correction. Two patients developed transient VIth CN palsies at 48 months that self-resolved after another year. Endocrine function normalized for all 6 treated patients with a growth hormone-secreting tumor at a median of 18 months. One of the 5 adrenocorticotropic hormone-secreting tumors required retreatment after 17 months because of continued cortisol elevation. Thirteen (87%) of 15 prolactinoma patients had normalized prolactin levels within 2 years of the procedure; 2 patients relapsed by endocrine criteria at 18 and 22 months after GKRS. Two patients with normalized prolactin levels completed three normal pregnancies within 3 years of treatment. Six patients (4.3%) with a median tumor volume of 8 cm(3) developed radiation-induced injury at a median of 36 months after GKRS. Five of these patients also underwent external beam radiotherapy and received a median dose of 52.2 Gy in 30 fractions. Quantitative analysis revealed that the radiation dose to critical structures (optic apparatus and pons) is correlated with their distance from tumor margins. Underdosed tumor volume, tumor volume, and total treated volume are correlated with treatment outcomes. CONCLUSION: GKRS is a safe and effective treatment for selected patients with benign cavernous sinus tumors and is an important adjunct for treating postoperative tumor residual and/or recurrent tumor. Continued analysis of treated patients over an extended time is needed to evaluate long-term disease control and potential late GKRS complications.

Adolescent↗

The Leksell gamma knife Model U versus Model C: a quantitative comparison of radiosurgical treatment parameters.

OBJECTIVE: We present a quantitative comparison of radiosurgery treatments for cavernous sinus tumors using the Leksell gamma knife Model U versus the Model C with automatic positioning system (APS) (Elekta Instruments, Norcross, GA). METHODS: At our medical center from August 1994 through May 2000, the Model U was used to treat 96 patients (37 men [39%] and 59 women [61%]; median age, 54.5 yr) with benign cavernous sinus tumors: 43 meningiomas (45%), 48 pituitary tumors (50%), and 5 others (5%). From June 2000 through April 2002, the Model C with APS treated 45 patients (20 men [44%] and 25 women [56%]; median age, 51.4 yr) with 15 meningiomas (33%), 29 pituitary tumors (65%), and 1 schwannoma (2%). The two groups had similar treated tumor volumes (Model U mean, 4.3 cm(3); Model C mean, 4.2 cm(3)), equivalent tumor distances from critical structures (optic nerve, chiasm, and pons), comparable distributions in Sekhar tumor grades, and the same median prescribed dose of 15 Gy to the 50% isodose line at the tumor periphery. All planning and treatments were performed by the same radiosurgery team to minimize dosage to adjacent critical tissues and to optimize conformity index. RESULTS: Analysis of multiple treatment parameters showed that the Model C plans were superior. Model C treatments had an improved conformity index (Model U mean, 1.7; Model C mean, 1.6; P < 0.02) and a lower underdosed tumor volume (Model U mean, 0.4 cm(3); Model C mean, 0.1 cm(3); P < 0.004). The total treated volume and the excess treated volume were similar. The Model C group had a reduction in optic chiasm dose (Model C mean dose, 3.8 Gy; Model U mean dose, 5.3 Gy; P < 0.0001). The average number of isocenters was slightly higher for the Model C group (6.7 versus 6 for the Model U), but with a lower mean number of collimator sizes (1 versus 2 for the Model U). Model C plans required a mean of 93 fewer plugs per treatment, thus contributing to an estimated 67.6 minutes saved per treatment session. CONCLUSION: Comparison of radiosurgery treatments using the Leksell gamma knife Model U versus the Model C with APS was performed by quantitative analysis of treatment parameters on a cohort of benign cavernous sinus tumors. Treatment plans using the Model C resulted in better tumor coverage (improved conformity, less underdosed tumor volume) and decreased optic chiasm dose. An estimated average of 1 hour was saved per treatment when using the Model C with APS.

Adolescent↗

Analysis and evolution of head injury in football.

OBJECTIVE: To review head injury in football through historical, anatomic, and physiological analysis. METHODS: We obtained data from a thorough review of the literature. RESULTS: The reported incidence of concussion among high school football players dropped from 19% in 1983 to 4% in 1999. During the 1997 Canadian Football League season, players with a previous loss of consciousness in football were 6.15 times more likely to experience a concussion than players without a previous loss of consciousness (P < 0.05). Players with a previous concussion in football were 5.10 times more likely to experience a concussion than players without a previous concussion (P = 0.0001). With the implementation of National Operating Committee on Standards for Athletic Equipment standards, fatalities decreased by 74% and serious head injuries decreased from 4.25 per 100,000 to 0.68 per 100,000. CONCLUSION: Significant declines in both the incidence and severity of head injury have been observed. The enhanced safety records in football can be attributed to the application of more stringent tackling regulations as well as the evolving football helmet. The role of a neurosurgeon is critical in further head injury prevention and guidelines in sport.

Adolescent↗

Birth and evolution of the football helmet.

OBJECTIVE: To review the advent and evolution of the football helmet through historical, physiological, and biomechanical analysis. METHODS: We obtained data from a thorough review of the literature. RESULTS: Significant correlation exists between head injuries and the advent of the football helmet in 1896, through its evolution in the early to mid-1900s, and regulatory standards for both helmet use and design and tackling rules and regulations. With the implementation of National Operating Committee on Standards for Athletic Equipment standards, fatalities decreased by 74% and serious head injuries decreased from 4.25 per 100,000 to 0.68 per 100,000. Not only is the material used important, but the protective design also proves essential in head injury prevention. Competition among leading helmet manufacturers has benefited the ultimate goal of injury prevention. However, just as significant in decreasing the incidence and severity of head injury is the implementation of newer rules and regulations in teaching, coaching, and governing tackling techniques. CONCLUSION: Helmet use in conjunction with more stringent head injury guidelines and rules has had a tremendous impact in decreasing head injury severity in football. Modifications of current testing models may further improve helmet design and hence further decrease the incidence and severity of head injury sustained while playing football.

Athletic Injuries↗

Vagus nerve stimulation therapy after failed cranial surgery for intractable epilepsy: results from the vagus nerve stimulation therapy patient outcome registry.

OBJECTIVE: To determine the effectiveness of vagus nerve stimulation (VNS) therapy among patients with persistent or recurrent seizures after lobar resection, callosotomy, and other cranial operations for intractable epilepsy. METHODS: Data were obtained from the VNS therapy patient outcome registry, which was established after United States Food and Drug Administration approval of the VNS device in 1997 as a means of capturing open-label clinical data outside of protocol. The integrity of the systems for collecting and processing registry data was authenticated by an independent auditing agency. The effect of potential selection bias, however, remains uncertain. RESULTS: Two nonconsecutive cohorts were compared: patients tracked in the registry who had previously undergone cranial surgery for epilepsy (CS group, n = 921) and those who had not (non-CS group, n = 3822). For the CS group, the median reduction in seizure frequency was 42.5% after 3 months of VNS therapy, 42.9% at 6 months, 45.7% at 12 months, 52.0% at 18 months, and 50.5% at 24 months. For the non-CS group, analogous rates were 47.0%, 52.9%, 60.0%, 62.7%, and 66.7%, respectively. In the CS group, seizures were reduced by at least 50% in 55.1% of patients, at least 75% in 31.4% of patients, at least 90% in 17.3% of patients, and 100% in 5.1% of patients after 24 months of VNS therapy. Response rates were more pronounced in the non-CS group: at least 50% in 62.2% of patients, at least 75% in 43.7% of patients, at least 90% in 26.8% of patients, and 100% in 8.3% of patients. Patients in both groups experienced marked improvements in quality of life parameters. CONCLUSION: The effectiveness of VNS is maintained during prolonged stimulation, and overall seizure control continues to improve with time. Patients in whom prior cranial surgery had failed did not respond as favorably as all other patients receiving VNS therapy. Nonetheless, many of the former group improved substantially. Thus, on the basis of these open-label data, VNS therapy represents a potentially palliative treatment option for patients with refractory seizures after failed cranial surgery.

Adolescent↗

An anthropomorphic phantom study of the accuracy of Cyberknife spinal radiosurgery.

OBJECTIVE: Stereotactic radiosurgery requires the highest degree of accuracy in target identification and localization. When targeting paraspinal lesions, the CyberKnife radiosurgical system (Accuray, Inc., Sunnyvale, CA) uses implanted stainless steel fiducials. The purpose of this study was to evaluate the total system for clinically relevant accuracy of this approach. METHODS: The clinically relevant accuracy of the CyberKnife depends on 1) the accuracy of beam delivery, which in turn represents a compilation of robot and camera image-tracking errors, and 2) the inherent accuracy of target localization that stems from computed tomographic imaging and treatment planning. The clinically relevant accuracy was measured at three different CyberKnife facilities using head and torso phantoms loaded with packs of radiochromic film and expressed as a displacement of the dose contours from the treatment planning. RESULTS: The mean clinically relevant error, as measured at three different CyberKnife facilities, was determined to be 0.7 +/- 0.3 mm, which did not vary with computed tomographic slice thickness in a range of 0.625 to 1.5 mm. The average treatment delivery precision was 0.3 +/- 0.1 mm. Fiducial tracking error was less than 0.3 mm for radial translations up to 14 mm and less than 0.7 mm for rotations up to 4.5 degrees. CONCLUSION: For the treatment of relatively stationary spinal lesions targeted with fiducial tracking, the CyberKnife system is capable of submillimeter accuracy.

Humans↗

Radiotherapy and stereotactic radiosurgery for pituitary tumors.

Based on a review of the literature and our medical center experience, we believe that transphenoidal surgery is the procedure of choice in most patients with pituitary adenomas. Conversely, SRS is a procedure of choice for those with cavernous sinus involvement. Patients with incomplete surgical excision should be considered either for a planned stereotactic treatment or for external beam radiotherapy. The same applies to patients with recurrent tumors. We favor stereotactic treatment in patients who have tumors that are less than 35 mm in diameter and at least 3 mm from the chiasm or optic nerves. Other patients should be considered for three-dimensional conformal radiotherapy. Radiotherapy provides a good treatment alternative in those patients who either refuse surgery or have contraindications to this therapy. Contemporary radiotherapy and SRS for pituitary adenomas is safe and effective treatment. This treatment should be undertaken in medical centers with appropriate expertise and instrumentation.

Humans↗

Artificial niches for human adult neural stem cells: possibility for autologous transplantation therapy.

Cellular transplantation therapy is thought to play a central role in the concept of restorative neurosurgery, which aims to restore function to the damaged nervous system. Stem cells represent a potentially renewable source of transplantable cells. However, control of the behavior of these cells, both in the process of clonogenic expansion and post-transplantation, represents formidable challenges. Stem cell behavior is thought to be directed by extracellular signals in their in vivo niches, many of which are protein or peptide based. As only one example, activation of Notch plays an important role in normal development and is the strongest known signal for stem cells to choose glial over neuronal fates. Therefore, artificial extracellular matrix proteins represent a potentially powerful tool to custom design artificial niches to strategically control stem cell behavior. We have developed a family of aECM proteins that incorporate the active domains of the DSL ligands to the Notch receptor into an elastin-based backbone. The development of our DSL-elastin artificial proteins demonstrates the design strategy and methodology for the production of bioactive artificial extracellular matrix proteins aimed at modulating stem cell behavior, and this method can be used to design other bioactive aECM proteins. In addition, we have developed a method for the isolation and characterization of adult human neural stem cells from periventricular tissue harvested from living patients. This paper reviews cellular transplantation therapy from the clinical perspective and summarizes ongoing work aimed at exploring the intriguing possibility of autologous transplantation, whereby neural stem cells can be harvested from adult patients, expanded or modified in vitro in artificial niches, and retransplanted into the original patient.

Adult↗

The genesis of neurosurgery and the evolution of the neurosurgical operative environment: part I-prehistory to 2003.

Despite its singular importance, little attention has been given to the neurosurgical operative environment in the scientific and medical literature. This article focuses attention on the development of neurosurgery and the parallel emergence of its operative setting. The operative environment has, to a large extent, defined the "state of the art and science" of neurosurgery, which is now undergoing rapid reinvention. During the course of its initial invention, major milestones in the development of neurosurgery have included the definition of anatomy, consolidation of a scientific basis, and incorporation of the practicalities of anesthesia and antisepsis and later operative technical adjuvants for further refinement of action and minimalism. The progress, previously long and laborious in emergence, is currently undergoing rapid evolution. Throughout its evolution, the discipline has assimilated the most effective tools of modernity into the operative environment, leading eventually to the entity known as the operating room. In the decades leading to the present, progressive minimalization of manipulation and the emergence of more refined operative definition with increasing precision are evident, with concurrent miniaturization of attendant computerized support systems, sensors, robotic interfaces, and imaging devices. These developments over time have led to the invention of neurosurgery and the establishment of the current state-of-the-art neurosurgical operating room as we understand it, and indeed, to a broader definition of the entity itself. To remain current, each neurosurgeon should periodically reconsider his or her personal operative environment and its functional design with reference to modernity of practice as currently defined.

History, 15th Century↗