Many advances have been made in the treatment of metastatic spinal disease over the last few decades. Radiotherapy offers benefit and pain relief to many patients; however, this modality provides minimal vertebral stabilization. Surgical management consists of decompression and complex fusions. Vertebroplasty offers an adjuvant therapy to both radiotherapy and surgery by providing additional stabilization and pain relief. The results of case studies suggest that including vertebroplasty in the management of these patients is beneficial. In this article the authors review the role of vertebroplasty in metastatic spinal disease.
Julie G. Pilitsis and Setti S. Rengachary
Anthony W. Lee and Julie G. Pilitsis
✓Spinal cord stimulation (SCS) is the most commonly used implantable neurostimulation modality for management of pain syndromes. In this paper the authors describe the current indications for SCS and its efficacy in the treatment of those diseases. Specifically, the literature on patient selection and outcomes after SCS for failed–back surgery syndrome (FBSS), refractory angina pectoris, peripheral vascular disease, and complex regional pain syndrome (CRPS) Type I was reviewed. Effective pain relief was obtained in 60 to 80% of patients with FBSS and CRPS Type I. Furthermore, these patients had significant improvements in quality of life (QOL) and a significantly greater chance of returning to work than patients who did not undergo SCS. The use of SCS in patients with inoperable angina (that is, refractory angina pectoris) resulted in significant decreases in chest pain and hospital admissions as well as increased exercise duration, with less morbidity than with open procedures that were performed for pain control only. Patients with inoperable PVD also demonstrated significant improvements in pain relief, QOL, and limb mobility. Reported complications were mostly related to hardware and were relatively minor. Review of randomized controlled studies supports the use of SCS as an effective treatment modality for pain associated with FBSS, refractory angina pectoris, peripheral vascular disease, and CRPS Type I.
Jeffrey A. Brown and Julie G. Pilitsis
Percutaneous balloon compression is an effective and technically simple method for treating trigeminal neuralgia (TN). Nevertheless, dysesthesias (10–20%) and masseter muscle weakness (66%) following the procedure have been noted. The purpose of this study was to evaluate the results of testing TN with percutaneousballoon compression aided by intraluminal pressure monitoring.
In this study the authors review the results and complications associated with percutaneous balloon compression by using intraluminal pressure monitoring data obtained in 65 procedures performed in 56 consecutive patients over 4 years. The mean patient age was 71 years (range 37–92 years), and the mean follow-up duration was 17 months (range 3–38 months). The mean intraluminal compression pressure was (1160 ± 62 mm Hg), and the mean duration of compression was 1.15 ± 0.27 minutes. The trigeminal depressor response was observed in 60 (92%) of 65 procedures, and initial pain relief occurred in 92% of patients. The recurrence rate in patients who had initial relief was 16% (nine of 56). The mean time until recurrence in patients who experienced pain relief after surgery was 13 months (range 3–23 months). Mild numbness immediately after surgery was observed in 83% of patients. At the most recent evaluation, 17% of patients reported persistent, nontroublesome numbness and none had moderate or severe numbness. Minor dysesthesia was present in two patients (4%). Mild masseter muscle weakness occurred in 24% of patients and resolved within a maximum period of 1 year. No patient experienced anesthesia dolorosa, corneal keratitis, or other cranial nerve deficits. These morbidity rates are lower than the incidence reported in the literature when pressure monitoring is not used.
These data show that by monitoring compression pressure and limiting the duration of compression, it is possible to reduce the incidence of dysesthesias, severe numbness, and masseter weakness after surgery without increasing the rate of recurrent pain in patients with classic TN.
Julie G. Pilitsis, David R. Lucas, and Setti R. Rengachary
Bone is a tissue that constantly undergoes deposition, resorption of stromal matrix, and remodeling. These processes may be altered by a variety of chemical, mechanical, cellular, and pathological mechanisms. Understanding the physiology of bone healing and the mechanisms affecting this process is important not only when evaluating normal skeletal development but also when initiating fracture repair. Because the ultimate success of spinal fusions involves creation of an osseous union, we focus this review on the anatomy and physiology of bone under physiological conditions, normal bone healing and mechanisms that alter it, and available adjuvant therapies that may enhance healing potential in a clinical setting.
Nir Lipsman, W. Jeffrey Elias, Ryder P. Gwinn, and Julie G. Pilitsis
Michael D. Staudt, Ilknur Telkes, and Julie G. Pilitsis
Anthony M. Burrows, Richard P. Moser, John P. Weaver, Demetrius E. Litwin, and Julie G. Pilitsis
Massachusetts' health insurance mandate and subsidized insurance program, Commonwealth Care, have been active for 2 years.
The financial impact on the neurosurgery division and demographics of the relevant patient groups were assessed. The billing records of neurosurgical patients from January 2007 to September 2008 were collected and analyzed.
Commonwealth Care comprised 2.2% of neurosurgical inpatients, and these patients did not have significantly different acuity or lengths of stay from the average. Length of stay of MassHealth patients was significantly greater, although acuity was significantly lower than the average. Increased free care reimbursement and increased MassHealth/Commonwealth Care enrollment resulted in a net gain in reimbursement of hospital charges.
The increased insurance rates have resulted in increased reimbursement for the neurosurgical division.
J. Richard Toleikis, Leo Verhagen Metman, Julie G. Pilitsis, Andrei Barborica, Sandra C. Toleikis, and Roy A. E. Bakay
Insight may be gained into the physiological mechanisms of deep brain stimulation (DBS) by analyzing local and contralateral subthalamic nucleus (STN) single-unit activity during activation of previously placed DBS electrodes. Special techniques are required to perform such analysis due to the presence of a large stimulus artifact. The purpose of this study was to determine the effects of DBS stimulation on single unit activity acquired from patients undergoing new or revised DBS placements.
Subthalamic nucleus single unit activity was acquired from awake patients during activation of a previously implanted STN DBS electrode. Stimulation was contralateral to the recording site in 4 cases and ipsilateral in 3. Data were acquired at stimulation frequencies of 30, 60, and 130 Hz and with other stimulation parameters at clinically effective settings. Cells were included if they showed kinesthetic activity before and after the stimulation paradigm and if their action potential morphology was maintained throughout the experiment. Analysis of single-unit activity acquired before, during, and after stimulation was performed employing a time-domain algorithm to overcome the stimulus artifact.
Both ipsilateral and contralateral acute stimulation resulted in reversible STN firing rate suppression. The degree of suppression became greater as stimulus frequency increased and was significant at 60 Hz (t-test, p < 0.05) and 130 Hz (p < 0.01). Suppression with ipsilateral 130-Hz stimulation ranged between 52.8% and 99.8%, whereas with similar contralateral STN stimulation, the range was lower (1.9%–50.3%). Return to baseline activity levels typically occurred within seconds after stimulation ended.
Stimulation of the STN at clinically effective frequencies has an acute suppressive rather than an excitatory effect on STN single-unit activity. The effect is bilateral, even though the degree of suppression is greater on the ipsilateral than the contralateral STN. The authors' algorithm helps reveal this effect in human patients.
Jacquelyn MacDonell, Niravkumar Patel, Sebastian Rubino, Goutam Ghoshal, Gregory Fischer, E. Clif Burdette, Roy Hwang, and Julie G. Pilitsis
Currently, treatment of brain tumors is limited to resection, chemotherapy, and radiotherapy. Thermal ablation has been recently explored. High-intensity focused ultrasound (HIFU) is being explored as an alternative. Specifically, the authors propose delivering HIFU internally to the tumor with an MRI-guided robotic assistant (MRgRA). The advantage of the authors’ interstitial device over external MRI-guided HIFU (MRgHIFU) is that it allows for conformal, precise ablation and concurrent tissue sampling. The authors describe their workflow for MRgRA HIFU delivery.
Julie G. Pilitsis, William M. Coplin, Michael H. O'Regan, Jody M. Wellwood, Fernando G. Diaz, Marilynn R. Fairfax, Daniel B. Michael, and John W. Phillis
Object. The mechanisms leading to vasospasm following subarachnoid hemorrhage (SAH) remain unclear. Accumulation in cerebrospinal fluid (CSF) of free fatty acids (FFAs) may play a role in the development of vasospasm; however, in no previous study have concentrations of FFAs in CSF been examined after SAH.
Methods. We collected samples of CSF from 20 patients with SAH (18 cases of aneurysmal SAH and two cases of spontaneous cryptogenic SAH) and used a high-performance liquid chromatography assay to determine the FFA concentrations in these samples. We then compared these findings with FFA concentrations in the CSF of control patients.
All FFA concentrations measured 24 hours after SAH were significantly greater than control concentrations (p < 0.01 for palmitic acid and < 0.001 for all other FFAs). All measured FFAs remained elevated for the first 48 hours after SAH (p < 0.05 for linoleic acid, p < 0.01 for palmitic acid, and p < 0.001 for the other FFAs). After 7 days, a second elevation in all FFAs was observed (p < 0.05 for linoleic acid, p < 0.01 for palmitic acid, and p < 0.001 for the other FFAs). Samples of CSF collected within 48 hours after SAH from patients in whom angiography and clinical examination confirmed the development of vasospasm after SAH were found to have significantly higher concentrations of arachidonic, linoleic, and palmitic acids than samples collected from patients in whom vasospasm did not develop (p < 0.05).
Conclusions. Following SAH, all FFAs are initially elevated. A secondary elevation occurs between 8 and 10 days after SAH. This study provides preliminary evidence of FFA elevation following SAH and of a potential role for FFAs in SAH-induced vasospasm. A prospective study is warranted to determine if CSF concentrations of FFAs are predictive of vasospasm.