Biomedical subjects
Publications and source records attributed to P L Gildenberg.
Functional neurosurgery has been involved with management of movement disorders since the first days of stereotactic surgery. Those movement disorders that can be managed surgically are reviewed, along with general criteria for patient selection. A flow sheet of surgically managed movement disorders is supplemented by descriptions of how patients are assigned to various treatment categories and the various treatments available.
A system has been devised to focus a video camera mounted on a CRW stereotactic frame onto the surgical field and to integrate the video picture with a computer-generated three-dimensional view of structures or targets deep within the brain. The surgical resection can then be done with the surgeon looking either at the composite picture on the video/computer monitor (as in almost all endoscopic surgery) or at the surgical field, to perform the resection using the conventional techniques most comfortable to the surgeon and most effective for the resection. The graphics platform on which the Exoscope program is built is the same as used for the RSA X-Knife stereotactic radiosurgery system. The X-Knife graphics program allows the reconstruction of a target mass (such as intracranial tumor) and desired objects (such as surrounding vessels) with accurate registration to stereotactic coordinates derived from the CRW localizing system. By mounting a video system through an externally mounted endoscope on the CRW arc, it is possible to orient the video image with great accuracy to this same stereotactic space. The two images are superimposed on a computer/video console in the operating room. The surgeon visualizes a real-time video image of the operating field upon which is a graphical representation of the computer-generated image of the target mass beneath the surface. In the corners are triplane orthogonal views through the center of target and a view parallel to the trajectory, so the surgeon may gauge his or her progress toward the target.(ABSTRACT TRUNCATED AT 250 WORDS)
The authors present information on the frequency of stereotactic surgical procedures for numerous clinical indications, based on the results of an international survey. Also presented is information on the interest levels of neurosurgeons in various new technologies and applications for stereotactic techniques.
The incorporation of the Omnitron device, a robotic isotope handling system, into a program of brachytherapy for glial tumors has made it possible to hyperfractionate treatment in 15-20 sessions over a 2- to 3-week period, which offers considerable theoretical advantage over conventional single dose regimens. Stereotactic catheter placement is by contrast-enhanced MR guidance, and takes advantage of the three-dimensional planning offered by voxel orientation. Initial placement is based on orientation to the three customary planes, with oblique planes added to define intercatheter placement more accurately. Catheters may be placed asymmetrically through the tumor or even at different angles of insertion to get the optimal conformation. Dosimetry is based on three-dimensional reconstruction in the Omnitron planning console, and takes advantage of the optimized localization of each catheter position. High-dose isotope insertion is performed robotically, with isotope position and dwell times controlled by computer. The phase I study demonstrates a wide safety margin and suggests better survival than would be expected with conventional management.
Cancer pain can be successfully managed with oral or parenteral narcotics in 80% of patients, if those factors that magnify pain perception are also controlled. Pain from any source can be made worse and pain tolerance impaired by depression, regression, intolerance to stress, and/or recurrent withdrawal, all of which require attention and management. Those patients whose cancer pain is still intractable may benefit from a procedure to interrupt pain pathways. Such procedures have become far less common since the introduction of chronic administration of intraspinal narcotics. The subarachnoid route is preferable to the epidural route because it is less likely to result in catheter failure and because much smaller doses can be used, with less systemic effect. In addition, tolerance can be managed more readily by readjustment of dose with the subarachnoid route, and there is no greater incidence of complications. Intraventricular narcotics can be considered in patients whose spinal canal does not allow catheter placement, at approximately 1/10th the spinal dose requirement.
Stereotactic techniques were used to transplant adrenal medullary tissue to the head of the right caudate nucleus in 12 patients with Parkinson's disease. No significant lasting complications were seen. All patients had an initial improvement. 11 of the 12 patients remain improved over their preoperative condition after 6-18 months, 3 with good results and 9 with only modest improvement. At 6 months, the mean Schwab and England score had improved from 59.2 +/- 18.8 preoperatively to 75.8 +/- 15.1 (p less than or equal to 0.01) and the mean Hoehn and Yahr scale had improved from 3.42 +/- 0.90 to 2.92 +/- 0.63 (p less than or equal to 0.01).
Until the work of Horsley and Clarke in 1908, attempts to guide electrodes to parts of the nervous system had not used a three-dimensional targeting technique. Later, from the 1930s into the 1950s, the collaboration of Spiegel and Wycis led to advances in almost every area of functional neurosurgery. Great progress occurred through the accomplishments of other neurosurgeons throughout the world. This article describes the work of many of these pioneers and the evolution of stereotactic apparatus, including the current developments that indicate even more exciting accomplishments ahead.
Review of a large data base on 76 patients who had suffered head injuries and whose metabolic changes were being studied demonstrated the variability of their neurological courses and the importance of considering confounding factors in the analysis of such a group. It was apparent that many such patients continue to change neurologically and functionally for long periods of time, and that their ultimate outcome cannot be determined for at least 1 year. The study demonstrates the inherent complexity of a group of patients with head injuries and the need to use sophisticated statistical tools and a computer to demonstrate whether apparent trends are statistically valid in light of confounding factors and variabilities. Failure to take this complexity into account seems to be a major factor in many of the ongoing controversies in research on head injuries. A possible solution to the problem of potential biases introduced by lost patients would be to develop a method to use government records to obtain current addresses for patients involved in federally funded research.
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Abnormal coagulation and fibrinolysis is a frequent complication in patients with head injury. This complication can be severe enough to lead to hemorrhage or thrombosis. A study was undertaken to determine if the hemostatic abnormalities are reliable indicators of outcome. Hemostasis in 269 patients with head injuries alone was screened using platelet count (PC), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin clotting time (TCT), fibrinogen assay (FIB), level of fibrin-fibrinogen degradation products (FDP), and disseminated intravascular coagulation (DIC) score in the first 24 hours after injury. Test results were compared with the outcome (discharged or dead) in the entire group and in subgroups divided on the basis of the severity of injury as determined by the Glasgow coma score (GCS). Increased consumptive coagulopathy at admission, as reflected in the DIC score, predicts the outcome of head-injured patients with a high degree of accuracy. The degree of increase of the initial FDP level and prolongation of TCT also correlated positively with the outcome. Prolongation of the APTT correlated strongly with unfavorable outcome in a large group of patients, and in a small group, markedly accelerated APTT also predicted death. Stepwise logistic regression analysis demonstrated that GCS, FDP level, and DIC score predicted outcome. Other tests did not provide additional predictive value. Abnormal hemostasis frequently complicates the course of patients with head injuries. This study demonstrates that hemostasis tests are predictors of outcome in these patients.
Intradural disc herniation of an intervertebral disc is a rare occurrence. The clinical presentation varies in severity and a high level of suspicion is necessary to determine the diagnosis. This is a case report of an intradural disc herniation in a young male. A review of the literature identifying the pathophysiologic mechanisms of intradural disc herniation, diagnostic imaging techniques, and treatment is presented.
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Seventy-six patients with closed head injuries alone were studied to define the relation between the severity of the head injury and secondary alterations of general metabolism. The effect of metabolic changes on neurological outcome and the importance of nutritional support on nutritional status and neurological outcome were also evaluated. Using a powerful statistical tool, convergence analysis, it was possible to take into consideration the effects of a number of confounding factors that obviously affected general metabolism. Most of the patients were hypermetabolic for prolonged periods. In addition, many did not receive even basal requirements of calories or protein for many days. Despite this, their outcomes were determined by their initial neurological status and the amounts that they were fed, admittedly relatively modest, did not influence their courses. Despite such feedings, their visceral protein levels, which often dropped initially, rose toward normal levels, indicating effective adaptation. Indeed, it could not be shown that these patients developed complications of malnutrition such as infections. However, it will require a sophisticated randomized clinical trial of vigorous intravenous hyperalimentation to determine whether this complex, dangerous, and expensive therapy is helpful for severely head-injured patients.
The field of human stereotactic surgery began when Spiegel and Wycis introduced their stereoencephalotome in 1947, reached its epitome in the early 1960s, and declined sharply after the introduction of L-dopa in 1968. When the development of implantable stimulators provided an abrupt expansion of techniques in nonstereotactic functional neurosurgery, the field became "stereotactic and functional neurosurgery." The marriage of stereotactic surgery with computed tomography has reawakened the use of stereotactic surgery and brought it closer to general neurosurgery than ever before. Stereotactic and functional neurosurgery as a subspecialty has expanded rapidly and will continue to expand at an unprecedented rate, with significant changes reflecting the continuing advances in technology begun 15 years ago. It is becoming an increasingly important part of the field of neurosurgery and has extended its influence in many new clinical areas previously outside the realm of stereotaxis.
Craniocerebral gunshot wounds are a significant cause of injury and death in the United States. However, despite reports of occasional unexpectedly favorable outcome in surgically treated patients, these injuries have been viewed pessimistically and indeed have generally been excluded from modern studies of head injuries, which have concentrated on closed head injuries. A review of 143 victims of craniocerebral gunshot wounds admitted to Hermann Hospital, Houston, Texas, during a recent 30-month period confirmed that a few apparently neurologically devastated patients can be saved. A detailed analysis of these patients, including demographic details, general and neurological condition, anatomic injuries, laboratory findings, surgical care, neurological course, and neurological and functional outcome follows. The helpfulness of early resuscitation and appropriate criteria for surgery need to be studied using historic or randomized controls.
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Spasticity is a known sequelae of spinal cord injury and head injury. We sought to examine whether there were any significant differences in the characteristics or underlying mechanisms of spasticity in these two groups in the chronic period which may be related to the level of injury of the neuraxis. The response to vibration applied to the muscle, or the tonic vibratory reflex, has been shown to be related to the degree of spasticity, and was therefore studied along with phasic reflexes and passive movements. These studies were carried out on cooperative, stabilized patients who were otherwise healthy, 5 with head injuries, and 5 with spinal cord injuries. The patients were examined in a supine position while surface EMG recordings were made of quadriceps and triceps surae muscles bilaterally. Tendon jerk responses, passive and volitional movements, and responses to a powerful vibratory stimulator were measured. In both head injury and spinal cord injury patient groups, a large EMG response was elicited by passive maneuvers, and tendon jerks were exaggerated. The tonic vibratory response, previously shown to be dependent upon brain influence, was present in both groups. These observations suggest that similar suprasegmental mechanisms may be responsible for hypertonia in both head-injured and spinal cord-injured patients.
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