The mechanisms of appetite disorders, such as refractory obesity and anorexia nervosa, have been vigorously studied over the last century, and these studies have shown that the central nervous system has significant involvement with, and responsibility for, the pathology associated with these diseases. Because deep brain stimulation has been shown to be a safe, efficacious, and adjustable treatment modality for a variety of other neurological disorders, it has also been studied as a possible treatment for appetite disorders. In studies of refractory obesity in animal models, the ventromedial hypothalamus, the lateral hypothalamus, and the nucleus accumbens have all demonstrated elements of success as deep brain stimulation targets. Multiple targets for deep brain stimulation have been proposed for anorexia nervosa, with research predominantly focusing on the subcallosal cingulate, the nucleus accumbens, and the stria terminalis and medial forebrain bundle. Human deep brain stimulation studies that focus specifically on refractory obesity and anorexia nervosa have been performed but with limited numbers of patients. In these studies, the target for refractory obesity has been the lateral hypothalamus, ventromedial hypothalamus, and nucleus accumbens, and the target for anorexia nervosa has been the subcallosal cingulate. These studies have shown promising findings, but further research is needed to elucidate the long-term efficacy of deep brain stimulation for the treatment of appetite disorders.
Alexander C. Whiting, Michael Y. Oh, and Donald M. Whiting
Derrick A. Dupré, Nestor Tomycz, Michael Y. OH, and Donald Whiting
The authors review the history of deep brain stimulation (DBS) in patients for treating obesity, describe current DBS targets in the brain, and discuss potential DBS targets and nontraditional stimulation parameters that may improve the effectiveness of DBS for ameliorating obesity. Deep brain stimulation for treating obesity has been performed both in animals and in humans with intriguing preliminary results. The brain is an attractive target for addressing obesity because modulating brain activity may permit influencing both sides of the energy equation—caloric intake and energy expenditure.
Alexander A. Khalessi, Bryan C. Oh, and Michael Y. Wang
✓ In the following literature review the authors consider the available evidence for the medical management of patients with ankylosing spondylitis (AS), and they critically assess current treatment guidelines. Medical therapy for axial disease in AS emphasizes improvement in patients' pain and overall function. First-line treatments include individualized physical therapy and nonsteroidal antiinflammatory drugs (NSAIDs) in conjunction with gastroprotective therapy. After an adequate trial of therapy with two NSAIDs exceeding 3 months or limited by medication toxicity, the patient may undergo tumor necrosis factor–α blockade therapy. Response should occur within 6–12 weeks, and patients must undergo tuberculosis screening. Evidence does not currently support the use of disease modifying antirheumatic drugs, corticosteroids, or radiotherapy in AS.
Visish M. Srinivasan, Brent R. O'Neill, Diana Jho, Donald M. Whiting, and Michael Y. Oh
External ventricular drainage (EVD) is one of the most commonly performed neurosurgical procedures. It was first performed as early as 1744 by Claude-Nicholas Le Cat. Since then, there have been numerous changes in technique, materials used, indications for the procedure, and safety. The history of EVD is best appreciated in 4 eras of progress: development of the technique (1850–1908), technological advancements (1927–1950), expansion of indications (1960–1995), and accuracy, training, and infection control (1995–present). While EVD was first attempted in the 18th century, it was not until 1890 that the first thorough report of EVD technique and outcomes was published by William Williams Keen. He was followed by H. Tillmanns, who described the technique that would be used for many years. Following this, many improvements were made to the EVD apparatus itself, including the addition of manometry by Adson and Lillie in 1927, and continued experimentation in cannulation/drainage materials. Technological advancements allowed a great expansion of indications for EVD, sparked by Nils Lundberg, who published a thorough analysis of the use of intracranial pressure (ICP) monitoring in patients with brain tumors in 1960. This led to the application of EVD and ICP monitoring in subarachnoid hemorrhage, Reye syndrome, and traumatic brain injury. Recent research in EVD has focused on improving the overall safety of the procedure, which has included the development of guidance-based systems, virtual reality simulators for trainees, and antibiotic-impregnated catheters.
Case report and review of the literature
Raymond F. Sekula Jr., Michael Y. Oh, J. Brad Bellotte, and Jack E. Wilberger
✓ Chondrolipoangioma is a mesenchymoma primarily composed of cartilage, with adipose tissue and vascular elements present in lesser proportions. Chondrolipoangiomas have been reported to occur in the extremities, chest wall, oral soft tissues, mediastinum, uterus and its round ligament, seminal vesicles, and heart. In this report, the authors present an unusual case in which a chondrolipoangioma caused a brachial plexopathy. To their knowledge, a chondrolipoangioma has never been reported in the neurosurgical literature.
Derrick A. Dupré, Daniel J. Cook, J. Brad Bellotte, Michael Y. Oh, Donald Whiting, and Boyle C. Cheng
Spinal stability is attributed in part to osteoligamentous structures, including the vertebral body, facets, intervertebral discs, and posterior elements. The materials in this study provide an opportunity to augment the degenerated nucleus without removing native disc material, a procedure introduced here as “fortification.” The objective of this study was to determine the effect of nucleus fortification on lumbar disc biomechanics.
The authors performed in vitro analysis of human cadaveric functional spinal units (FSUs), along with characterization and quantification of movement of the units using biomechanical data in intact, disc-only, and fortified specimens. The units underwent removal of all posterior elements and annulus and were fortified by injecting a biogel into the nucleus pulposus. Each specimen was subjected to load testing, range of motion (ROM) quantification, and disc bulge measurements. Optoelectric tracking was used to quantify disc bulge. These criteria were assessed in the intact, disc-only, and fortified treatments.
Disc-only FSUs resulted in increased ROM when compared with intact and fortified conditions. Fortification of the FSU resulted in partial restoration of normal ROM in the treatment groups. Analysis of hysteresis loops showed more linear response in the fortified groups when compared with the intact and disc-only groups.
Disc nucleus fortification increases linearity and decreases ROM.
John W. Gilbert, Greg R. Wheeler, John R. Spitalieri, and Gregory E. Mick
Asem Salma and Faisal Al-Otaibi
P. Pat Banerjee, Cristian J. Luciano, G. Michael Lemole Jr., Fady T. Charbel, and Michael Y. Oh
The purpose of this study was to evaluate the accuracy of ventriculostomy catheter placement on a head- and hand-tracked high-resolution and high-performance virtual reality and haptic technology workstation.
Seventy-eight fellows and residents performed simulated ventriculostomy catheter placement on an ImmersiveTouch system. The virtual catheter was placed into a virtual patient's head derived from a computed tomography data set. Participants were allowed one attempt each. The distance from the tip of the catheter to the Monro foramen was measured.
The mean distance (± standard deviation) from the final position of the catheter tip to the Monro foramen was 16.09 mm (± 7.85 mm).
The accuracy of virtual ventriculostomy catheter placement achieved by participants using the simulator is comparable to the accuracy reported in a recent retrospective evaluation of free-hand ventriculostomy placements in which the mean distance from the catheter tip to the Monro foramen was 16 mm (± 9.6 mm).