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.
Shunsuke Terasaka, Max B. Medary, Donald M. Whiting, Takanori Fukushima, Evalynne J. Espejo, and Girija Nathan
✓ Sinonasal teratocarcinosarcoma is a rare malignant neoplasm characterized by the combined histological features of carcinosarcoma and teratoma. The primary symptoms of this tumor are usually nasal obstruction and epistaxis, and a nasal cavity mass is the most common clinical finding. The authors describe an exceptionally rare case in which the patient presented with massive intracranial extension and exhibited confusion as an initial symptom. He subsequently underwent combined radical surgery and radiation therapy and has remained free of disease for 31 months. The surgical approach to the lesion, histological features, and clinical course are detailed.
Asem Salma and Faisal Al-Otaibi
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.
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.
Kai Zhang, Sanjay Bhatia, Michael Y. Oh, David Cohen, Cindy Angle, and Donald Whiting
Deep brain stimulation (DBS) of the ventral intermediate nucleus of the thalamus (VIM) has proven to be efficacious in the treatment of essential tremor (ET). The authors report on long-term follow-up of a series of patients treated at 1 institution by 1 neurosurgeon.
Thirty-four patients with ET received unilateral or bilateral VIM DBS. The tremor and handwriting components of the Fahn-Tolosa-Marin clinical tremor rating scale were assessed pre- and postoperatively. Visual analog scale scores for overall patient satisfaction and tremor control were recorded. Stimulation parameters at different intervals after surgery were also recorded.
The average follow-up period was 56.9 months. The average tremor score improved from 3.27 preoperatively to 0.64 postoperatively (on stimulation; p < 0.001) and the average handwriting score improved from 2.94 to 0.89 (p < 0.001). The average visual analog scale score for overall satisfaction was 8.12 and for tremor control was 1.43. Overall, there was an 80.4% improvement in tremor and 69.7% improvement in handwriting. In 12 patients both tremor and handwriting scores were compared between 57.3 months and 90.7 months after surgery and no significant changes were discovered. Comparison of stimulation parameters at onset and at 1–3, 3–5, 5–7, and > 7 years after surgery showed significant differences, with a gradual increase in stimulation parameters within 5 years after surgery. The overall hardware-related complication rate was 23.5%.
Deep brain stimulation of the VIM is an efficient and safe treatment for ET. Tremor and handwriting improvements in long-term follow-up are stable. The patients' perception of their outcome is quite good. However, tolerance may develop in some patients requiring changes in stimulation parameters.
Dunbar Alcindor, Michael Y. Oh, Susan Baser, Cindy Angle, Boyle C. Cheng, and Donald Whiting
The authors report the case of DYT1-positive primary generalized dystonia refractory to medical management that was successfully treated with continuous deep brain stimulation of the internal segment of the globus pallidus. Prior studies have shown that neuromusculoskeletal deficits can remain permanent if early surgical intervention is not undertaken. The authors report prolonged efficacy and safety over a 10-year period in a 28-year-old man.
Joseph M. Zabramski, Donald Whiting, Rabih O. Darouiche, Terry G. Horner, Jeffrey Olson, Claudia Robertson, and Allan J. Hamilton
Object. Catheter-related infection of the cerebrospinal fluid (CSF) pathways is a potentially life-threatening complication of external ventricular drainage. A major source of infection is bacterial contamination along the external ventricular drain (EVD) catheter track. The authors examined the efficacy of EVD catheters impregnated with minocycline and rifampin in preventing these catheter-related infections.
Methods. The authors conducted a prospective, randomized clinical trial at six academic medical centers. All hospitalized patients 18 years or older who required placement of an EVD catheter were eligible for inclusion in the study. Patients were randomly assigned to undergo placement of an EVD with a catheter impregnated with minocycline and rifampin or a standard untreated catheter (control group). To assess primary outcome, CSF samples were collected using a sterile technique at the time of catheter insertion, at least every 72 hours while the catheter remained in place, and at the time of catheter removal. At the time of removal, CSF cultures were obtained from the tip and tunneled segments of each catheter by performing semiquantitative roll-plate and quantitative sonication techniques.
Of the 306 patients enrolled in the study, data from 288 were included in the final analysis. Eighteen patients were excluded from analysis: 14 because the ventricular catheter was in place less than 24 hours, and four because CSF cultures obtained at the time of catheter insertion were positive for infection. Of these 288 patients, 139 were assigned to the control group and 149 to the treatment group. The two groups were well matched with respect to all clinical characteristics, including patient sex and mean age, indication for catheter placement, and length of time the catheter remained in place. The antibiotic-impregnated catheters were one half as likely to become colonized as the control catheters (17.9 compared with 36.7%, respectively, p < 0.0012). Positive CSF cultures were seven times less frequent in patients with antibiotic-impregnated catheters compared with those in the control group (1.3 compared with 9.4%, respectively, p = 0.002).
Conclusions. The use of EVD catheters impregnated with minocycline and rifampin can significantly reduce the risk of catheter-related infections.