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Biomedical subjects

Allen W Burton

Publications and source records attributed to Allen W Burton.

At least 19 recordsLinked to original sources
PubMed2006

Quantitative sensory findings in patients with bortezomib-induced pain.

UNLABELLED: Bortezomib (PS-341) is a newly developed proteosome inhibitor that shows extremely promising antineoplastic effects against a variety of neoplasias. Neuropathic pain is emerging as a major complication of bortezomib. Although clinical reports have appeared in the literature describing the general symptoms of bortezomib chemoneuropathy, specific quantitative sensory data that detail the sensory deficits that might yield insight to the primary afferent dysfunction contributing to this pain is lacking. In this report, it is shown that patients with bortezomib-induced neuropathic pain have significantly elevated touch detection threshold and slotted peg board time, impaired sharpness detection, and elevated thresholds for the detection of skin warming and heat pain. Patients also had increased reports of cold pain. These data indicate that bortezomib-induced neuropathy is associated with deficits in Abeta, Adelta, and C caliber primary afferent fibers. PERSPECTIVE: This work demonstrates that pain induced by the chemotherapy drug bortezomib is accompanied by dysfunction in all fiber types in sensory nerves. Impaired Abeta and C sensory function also extends into areas of skin that are not perceived as affected by pain.

Aged↗
PubMed2006

Percutaneous vertebroplasty of a myelomatous compression fracture in the presence of previous posterior instrumentation. Report of two cases.

The authors report the use of percutaneous transpedicular vertebroplasty performed using polymethylmethacrylate (PMMA) in two patients. These men (53 and 57 years old) had previously undergone open surgery and posterior instrumentation to treat myelomatous compression fractures. Both patients presented with acute back pain that manifested after minor activities. Kyphotic wedge fractures were diagnosed at T-1 in one case and at L-1 in the other. Both patients were treated at other hospitals with laminectomy and instrumented fusion; multiple myeloma was diagnosed after surgery. The patients experienced severe, recalcitrant, and progressive pain; on referral, they were found to have persistent kyphosis. Multiple myelomatous lesions of the spine were seen in one case and in the other the L-1 fracture represented the only site of disease. Percutaneous vertebroplasty was performed by injecting PMMA into the anterior third of the compressed vertebral body. Both patients experienced a 50% reduction in pain immediately after treatment; 3 months later both were walking and reported minimal back pain while undergoing treatment for multiple myeloma. Three years after surgery one patient reported no back pain and no progressive instability of the spine. Four years after surgery the other patient remains pain free, ambulatory, and with overall disease remission. Percutaneous vertebroplasty provided effective analgesia in these two patients with progressive back pain despite posterior stabilization. In both cases, the anterior column was effectively stabilized. A much larger operative intervention with its attendant risks of morbidity was avoided. In addition, subsequent aggressive medical treatment was well tolerated.

Adult↗
PubMed2005

Structure and synthesis of SSZ-63: toward an ordered form of zeolite beta.

The synthesis, characterization, and structure elucidation of the borosilicate zeolite SSZ-63 are described. SSZ-63 is synthesized using the 1-cyclodecyl-1-methylpyrrolidinium cation as a structure-directing agent. The structural model for SSZ-63 was determined by comparison of its powder X-ray diffraction pattern with those of zeolite beta and its polytype structures. Whereas conventional zeolite beta may be described as a random intergrowth of polytypes A and B, SSZ-63 is more accurately described as a random intergrowth of polytypes B and C(H) (the hypothetical polytype C proposed by Higgins). Polytype C(H) is essentially an ordered intergrowth (of polytypes A and B) in which one of the crystallographic projections is equivalent to those in polytype A and another projection is equivalent to those in polytype B. Unlike zeolite beta, which possesses significant disorder related to layer shifts along both the a- and b-crystallographic axes, the structure of SSZ-63 has little disorder associated with the translations of layers in the a-direction. DIFFaX simulations of the powder diffraction patterns, electron diffraction, and high-resolution transmission electron microsocopy data all support the proposed model.

Journal Article↗
PubMed2005

Vertebroplasty and kyphoplasty: a comprehensive review.

Vertebroplasty and kyphoplasty are relatively new techniques used to treat painful vertebral compression fractures (VCFs). Vertebroplasty is the injection of bone cement, generally polymethyl methacrylate (PMMA), into a vertebral body (VB). Kyphoplasty is the placement of balloons (called "tamps") into the VB, followed by an inflation/deflation sequence to create a cavity prior to the cement injection. These procedures are most often performed in a percutaneous fashion on an outpatient (or short stay) basis. The mechanism of action is unknown, but it is postulated that stabilization of the fracture leads to analgesia. The procedures are indicated for painful VCFs due to osteoporosis or malignancy, and for painful hemangiomas. These procedures may be efficacious in treating painful vertebral metastasis and traumatic VCFs. Much evidence favors the use of these procedures for pain associated with the aforementioned disorders. The risks associated with the procedures are low but serious complications can occur. These risks include spinal cord compression, nerve root compression, venous embolism, and pulmonary embolism including cardiovascular collapse. The risk/benefit ratio appears to be favorable in carefully selected patients. The technical aspects of the procedures are presented in detail along with guidelines for patient selection. A comprehensive review of the evidence for the procedures and the reported complications is presented.

Humans↗
PubMed2005

Percutaneous vertebroplasty--a technique to treat refractory spinal pain in the setting of advanced metastatic cancer: a case series.

We present three cases of severe movement-related spinal pain in patients with advanced metastatic carcinomas successfully treated with percutaneous vertebroplasty (PV). These patients had multi-symptom burden and progressive metastasis. Their movement-related pain was incapacitating and refractory to a variety of more conservative interventions. PV is a minimally invasive technique to stabilize vertebral compression fractures, thereby decreasing spinal pain in this setting. Its use in the setting of advanced cancer with severe movement-related pain has not been previously clarified in the palliative care literature. In summary, PV is a technique with a favorable risk: benefit ratio even in the setting of advanced metastatic cancer. The keys to successful utilization of PV in this patient population are careful patient assessment and selection as outlined in the report, in addition to an experienced care team approach.

Aged↗
PubMed2005

The role of opioids in cancer pain management.

Opioids remain an important cornerstone in the treatment of cancer pain. Effective analgesia is obtained in the majority of cancer pain patients with the application of fairly straightforward algorithms using opioids as the main therapy. Many rational treatment algorithms exist. In this tutorial we will describe the role of opioids in the treatment of cancer pain, including a brief overview of cancer pain syndromes, essential aspects of opioid therapy, opioid pharmacology, opioid rotation, properties of the individual opioids, and management of common side effects of opioids.

Journal Article↗
PubMed2005

Current diagnosis and therapy of complex regional pain syndrome: refining diagnostic criteria and therapeutic options.

Complex regional pain syndrome is a clinically challenging entity both in terms of accurate diagnosis and effective treatment. Complex regional pain syndrome is a post-traumatic painful neurologic syndrome involving the somatosensory, sympathetic and often the somatomotor systems. This complex condition consists of local neurogenic inflammation out of proportion to injury; severe pain in the skin, subcutaneous tissues and joints; and a central hyperexcitability that is often compounded with a sympathetic component. The syndrome is multifaceted manifesting both central and peripheral neurologic pathophysiology, frequently including a prominent psychosocial component. The wide array of possible patient presentations and antecedent pathologies also complicate successful treatment. To further add to the clinical challenges of complex regional pain syndrome, the epidemiology and natural history of complex regional pain syndrome are only partially known; evidence concerning complex regional pain syndrome treatment has grown slowly, due in large part to the vagaries of diagnosis; and research data--when they are available--are difficult to interpret. Thus, in spite of our evolving understanding of this neurologic disorder, in many cases complex regional pain syndrome remains difficult to diagnose and treat successfully.

Causalgia↗
PubMed2005

Percutaneous vertebroplasty and kyphoplasty performed at a cancer center: refuting proposed contraindications.

OBJECT: The purpose of this study was to examine a group of patients with cancer who underwent a vertebroplasty or a kyphoplasty for a vertebral body (VB) fracture, even though the procedure may have been considered contraindicated based on previous reports in the literature. METHODS: The electronic database maintained by the Departments of Neurosurgery and Anesthesiology-Pain Management at the University of Texas M. D. Anderson Cancer Center was searched for patients who underwent vertebroplasty or kyphoplasty between January 2001 and July 2003. The criteria defining a contraindicated procedure were based on a review of the literature. Group I consisted of patients who did not undergo a contraindicated vertebroplasty or kyphoplasty, whereas Group II consisted of patients who underwent one of these procedures even though it may have been considered contraindicated. There were 53 patients with fractures at 132 levels who met the criteria for the study. Of these, 17 patients with fractures at 18 levels (14% of total) were considered to have undergone a contraindicated vertebroplasty or kyphoplasty (Group II). There were 12 complications (11%) in the 114 levels in Group I and seven complications (39%) in the 18 levels in Group II (p = 0.03). The most common complication was cement extrusion from the anterior VB that did not involve the venous system. No patient required an open surgical procedure to remove extruded cement. CONCLUSIONS: Vertebroplasty and kyphoplasty appear to be safe and effective in the setting of severe back pain caused by VB fracture that is unresponsive to other therapies, even in the presence of relative contraindications to the procedures.

Adult↗
PubMed2005

Interventional techniques in the management of chronic spinal pain: evidence-based practice guidelines.

BACKGROUND: The lifetime prevalence of spinal pain has been reported as 54% to 80%, with as many as 60% of patients continuing to have chronic pain five years or longer after the initial episode. Spinal pain is associated with significant economic, societal, and health impact. Available evidence documents a wide degree of variance in the definition and the practice of interventional pain management. OBJECTIVE: To develop evidence-based clinical practice guidelines for interventional techniques in the management of chronic spinal pain, with utilization of all types of evidence, applying an evidence-based approach, with broad representation of specialists from academic and clinical practices. DESIGN: A systematic review of diagnostic and therapeutic interventions applied in managing chronic spinal pain by a policy committee. Design consisted of formulation of essentials of guidelines and a series of potential evidence linkages representing conclusions, and statements about relationships between clinical interventions and outcomes. METHODS: The elements of the guideline preparation process included literature searches, literature synthesis, systematic review, consensus evaluation, open forum presentation, formal endorsement by the Board of Directors of the American Society of Interventional Pain Physicians (ASIPP), and blinded peer review. Methodologic quality evaluation criteria utilized included AHRQ criteria, QUADAS criteria, and Cochrane review criteria. The designation of levels of evidence was from Level I (conclusive), Level II (strong), Level III (moderate), Level IV (limited), to Level V (indeterminate). RESULTS: The accuracy of facet joint nerve blocks was strong in the diagnosis of lumbar and cervical facet joint pain, whereas, it was moderate in the diagnosis of thoracic facet joint pain. The evidence was strong for lumbar discography, whereas, the evidence was limited for cervical and thoracic discography. The evidence was moderate for transforaminal epidural injections or selective nerve root blocks in the preoperative evaluation of patients with negative or inconclusive imaging studies. The evidence was moderate for sacroiliac joint injections in the diagnosis of sacroiliac joint pain. The evidence for therapeutic lumbar intraarticular facet injections of local anesthetics and steroids was moderate for short-term improvement and limited for long-term improvement, whereas, it was negative for cervical facet joint injections. The evidence for lumbar and cervical medial branch blocks was moderate. The evidence for medial branch neurotomy was moderate to strong for relief of chronic low back and neck pain. The evidence for caudal epidural steroid injections was strong for short-term relief and moderate for long-term relief in managing chronic low back and radicular pain, and limited in managing pain of postlumbar laminectomy syndrome. The evidence for interlaminar epidural steroid injections was strong for short-term relief and limited for long-term relief in managing lumbar radiculopathy, whereas, for cervical radiculopathy the evidence was moderate. The evidence for transforaminal epidural steroid injections was strong for short-term and moderate for long-term improvement in managing lumbar nerve root pain, whereas, it was moderate for cervical nerve root pain and limited for lumbar post laminectomy syndrome and spinal stenosis. The evidence for percutaneous epidural adhesiolysis was strong. For spinal endoscopic adhesiolysis, the evidence was strong for short-term relief and moderate for long-term relief. For sacroiliac intraarticular injections, the evidence was moderate for short-term relief and limited for long-term relief. The evidence for radiofrequency neurotomy for sacroiliac joint pain was indeterminate. The evidence for intradiscal electrothermal therapy was strong for short-term relief and moderate for long-term relief in managing chronic discogenic low back pain, whereas, for nucleoplasty, the evidence was limited. The evidence for spinal cord stimulation in failed back surgery syndrome and complex regional pain syndrome was strong for short-term relief and moderate for long-term relief. The evidence for implantable intrathecal infusion systems was moderate to strong. CONCLUSION: These guidelines included the evaluation of evidence for diagnostic and therapeutic procedures in managing chronic spinal pain and recommendations for managing spinal pain. However, these guidelines do not constitute inflexible treatment recommendations. These guidelines do not represent "a standard of care".

Journal Article↗
PubMed2004

Spinal cord stimulation relieves chemotherapy-induced pain: a clinical case report.

We present two patients with chemotherapy-induced painful neuropathy that had been poorly controlled with medications but successfully treated with spinal cord stimulation (SCS). A trial period of SCS provided effective pain relief in both patients who subsequently underwent permanent stimulator implantation. Psychophysical tests were performed before and after the implantation of trial and permanent stimulators. SCS improved pain scores and facilitated a reduction of medications. Both patients reported improved gait and one of them also reported an increase in leg flexibility. Psychophysical tests demonstrated an improvement in touch and sharpness detection thresholds. In summary, SCS offers a therapeutic option for patients with chemotherapy-induced peripheral neuropathy who have poor pain relief with standard medical treatment.

Aged↗
PubMed2004

Percutaneous vertebroplasty in vertebra plana secondary to metastasis.

Severe vertebral body collapse secondary to metastatic disease is considered a contraindication to vertebroplasty by most authors. Resolution of radicular pain after vertebroplasty is also not well reported. A case of successful vertebroplasty of a severe T7 collapse secondary to metastatic thymic carcinoma with an associated posterior cortical fracture of the body that resulted in resolution of axial and radicular pain is described. The patient had near-complete relief of severe axial and radicular pain. Postoperative imaging revealed anterior placement of the cement without leak into the spinal canal or the intervertebral foramen. The objectives are to describe the clinical and radiographic features of the case to support the idea that vertebra plana secondary to metastatic disease may not be a contraindication to vertebroplasty in selected patients. Simple techniques to avoid leak of cement into the spinal canal are also described. Severe vertebral collapse secondary to metastatic fractures may not be a contraindication to vertebroplasty, provided that appropriate measures are taken to place the trocars and to avoid extrusion of cement into the spinal canal.

Carcinoma, Renal Cell↗
PubMed2004

Epidural and intrathecal analgesia is effective in treating refractory cancer pain.

The use of neuraxial (intrathecal and epidural) analgesia has been suggested in treatment guidelines put forth for the treatment of refractory cancer pain. We review the literature and present our algorithm for using neuraxial analgesia. We also present our outcomes using this algorithm over a 28-month period. We used neuraxial analgesia in 87 of 4,107 patients, approximately 2% of those seen for pain consultation. Evaluation of those patients at an 8-week follow-up revealed improved pain control. After institution of neuraxial analgesia, there was a significant reduction in the proportion of patients with severe pain (defined as a "pain worst" score in the severe range of 7-10), from 86% to 17%, noted to be highly statistically significant. At follow-up, numerical pain scores decreased significantly from 7.9 +/- 1.6 to 4.1 +/- 2.3. No difference was noted between the intrathecal and epidural groups. Oral opioid intake after instituting neuraxial analgesia revealed a significant decrease from 588 mg/day oral morphine equivalents to 294 mg/day. At follow-up, self-reported drowsiness and mental clouding (0-10) also significantly decreased from 6.2 +/- 3.0 and 5.4 +/- 3.4 to 3.2 +/- 3.0 and 3.1 +/- 3.0, respectively. This retrospective review shows promising efficacy of neuraxial analgesia in the context of failing medical management.

Algorithms↗
PubMed2004

Complex regional pain syndrome (CRPS): survey of current practices.

BACKGROUND AND OBJECTIVES: There are numerous treatments for complex regional pain syndrome (CRPS). These treatments are varied in scope and include pain management therapies, psychological therapies, and physiotherapy. Treatment guidelines have been published in the past, but little information exists as to how clinicians utilize these guidelines. Moreover, there has been a paradigm shift from the older "reflex sympathetic dystrophy" (RSD) nomenclature, with largely sympathetic block driven diagnosis and therapy to more recent trends towards more inclusive "CRPS" diagnostic criteria and multidisciplinary treatment. There remains controversy regarding the selection of various techniques, and the timing of advancement through the treatment algorithm to the more aggressive, interventional techniques. We set out to determine current CRPS treatment practices of interventional pain specialists. METHODS: The authors developed a 36-item, 15-20-minute questionnaire. This questionnaire was sent to 453 interventional pain specialists. RESULTS: One-hundred-five surveys were returned, with 100 being complete. Eighty-three percent of our respondents were practicing anesthesiology pain specialists who on average treat 14.9 (SD = 16.8) CRPS patients per month. CONCLUSIONS: Our survey results revealed the use of a treatment algorithm for CRPS that consists of treatment using medical therapies (pharmacologic, blocks, catheters, and implantable devices), psychological therapies, and physiotherapy in a coordinated fashion. The trend among our survey respondents is to utilize increasingly interventional techniques after a failed 2- to 4-week trial of any one particular therapy.

Journal Article↗
PubMed2003

The effect of donepezil on sedation and other symptoms in patients receiving opioids for cancer pain: a pilot study.

Opioid-induced sedation is a major complication in patients with cancer pain. This study assessed the effectiveness of donepezil in opioid-induced sedation and related symptoms in patients with cancer pain. Twenty-seven patients who were receiving strong opioids for pain and reported sedation were enrolled. Donepezil 5 mg was given every morning for 7 days. Changes between baseline and Day 7 in sedation, pain, fatigue and other symptoms were evaluated using the Edmonton Symptom Assessment Scale. Fatigue was also measured using the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue). Overall usefulness of donepezil was measured by the patient at the end of the study. In 20 evaluable patients, sedation, fatigue, anxiety, well-being, depression, anorexia and problems with sleep were significantly improved. Side effects included nausea, vomiting, diarrhea, muscle and abdominal cramps, and anorexia. Overall, however, the treatment was well tolerated. Donepezil appears to improve sedation and fatigue in patients receiving opioids for cancer pain. Randomized controlled trials of this agent are justified.

Adult↗