Magnetic resonance imaging in patients with spinal neurostimulation systems
ABSTRACT The safety of performing magnetic resonance imaging (MRI) in patients with spinal cord stimulation (SCS) systems needs to be documented. A prospective in vivo study in patients with SCS, exploring the changes produced by MRI and the associated side effects, was performed.
After ethics committee approval and patient consent, 31 consecutive patients with SCS at different spinal levels requiring a scheduled MRI evaluation were studied during an 18-month period. All MRIs were performed with a 1.5-T clinical use magnet and a specific absorption rate of no more than 0.9 W/kg. Frequency tables were used for the descriptive study, whereas comparative evaluations were made with the chi-square test for qualitative variables and single-factor analysis of variance for quantitative variables.
The mean patient age was 49 +/- 9.5 yr; 67.7% were women (n = 21), and 32.3% were men (n = 10). None of the patients experienced hemodynamic, respiratory, or neurologic alterations. Reported changes were as follows: increased temperature in the generator's area (n = 2, 6.5%); increased in the intensity of the stimulation (n = 1, 3.2%); impedance greater than 4,000 Omega on several of the electrodes in the leads (n = 1, 3.2%); telemetry not possible (n = 2, 6.5%). Radiologic evaluation after MRI revealed no spatial displacements of the SCS leads in any case.
Under the conditions of the described protocol, MRI in patients with SCS systems resulted in few complications. None of the recorded problems were serious, and in no case were patients harmed or the systems reprogrammed. Maximum patient satisfaction was reported in all cases.
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ABSTRACT: Spinal cord stimulation (SCS) is used in the treatment of chronic pain, ischemia because of obstructive arterial disease, and anginal pain. Recently, a number of studies have described the effects of the high cervical SCS, including increased cerebral blood flow, although the underlying mechanisms are unknown. This case report describes a patient with a severe complex ischemic condition affecting both cerebral and upper limb blood flow with an associated complex regional pain syndrome in upper limb. While all previous clinical treatments proved ineffective, cervical SCS afforded satisfactory results. Possible mechanisms underlying the cervical SCS effect are discussed.Pain Practice 07/2007; 7(2):135-42. DOI:10.1111/j.1533-2500.2007.00121.x · 2.18 Impact Factor
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ABSTRACT: Introduction. Physicians, policy makers, and other interested parties require a synthesized, critical, and clear compilation of the following information to optimize spinal cord stimulation (SCS) for neuropathic pain: 1) indications and potential beneficial outcomes; 2) answers to key clinical questions; 3) cost/resource use implications; and 4) the quality and source of the evidence. This information must be nonjudgmental and noncoercive and have the sole objective of increasing the reader's expertise.Study Design. Evidence-based literature review and consensus statement.Methods. We consulted with experts to identify clinical-practice questions. Then, we conducted a critical literature review (MEDLINE, EMBASE, 1967 through March 2007) to grade treatment practices from “options” to “recommended.” We created a bibliographical database of all citations pertinent to each practice question. Several experts not otherwise involved reviewed the draft document.Results. We answered 64 questions covering 1) indications; 2) potential beneficial outcomes; 3) prognostic factors; 4) patient selection for screening trial; 5) procedural risk management; 6) screening trial; 7) device options; 8) patient management; 9) factors affecting the delivery and quality of SCS treatment; and 10) cost-effectiveness. Most of our more than 300 references are cited multiple times (in each pertinent category). This is the first overview that seeks to categorize and place the entire SCS clinical literature at the disposal of the reader. It presents the first grading system that incorporates, among other evidence sources, an assessment of the likelihood of a favorable outcome based on the evidence provided by expert consensus combined with consideration of the risk and potential benefit of an action.Conclusions. The Practice Parameters for Spinal Cord Stimulation in the Treatment of Neuropathic Pain answers important questions. It assesses supporting evidence and provides specific citations to enable the reader to conduct further study. The document will be updated regularly in a Web-based version.Pain Medicine 01/2008; 8 Suppl 4:S200-75. DOI:10.1111/j.1526-4637.2007.00388.x · 2.24 Impact Factor
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ABSTRACT: A Report by the American Society of Anesthesiologists Task Force on Anesthetic Care for Magnetic Resonance Imaging* PRACTICE advisories are systematically developed re-ports that are intended to assist decision making in areas of patient care. Advisories are based on a syn-thesis of scientific literature and analysis of expert and practitioner opinion, clinical feasibility data, open fo-rum commentary, and consensus surveys. Advisories developed by the American Society of Anesthesiolo-gists (ASA) are not intended as standards, guidelines, or absolute requirements. They may be adopted, mod-ified, or rejected according to clinical needs and con-straints. The use of practice advisories cannot guarantee any specific outcome. Practice advisories summarize the state of the literature, and report opinions obtained from expert consultants and ASA members. Practice adviso-ries are not supported by scientific literature to the same degree as standards or guidelines because of the lack of sufficient numbers of adequately controlled studies. Practice advisories are subject to periodic revision as warranted by the evolution of medical knowledge, tech-nology, and practice. The magnetic resonance imaging (MRI) suite is a haz-ardous location because of the presence of a strong static magnetic field, high-frequency electromagnetic (radiofrequency) waves, and a time-varied (pulsed) mag-netic field. Secondary dangers of these energy sources include high-level acoustic noise, systemic and localized heating, and accidental projectiles. There may be signif-icant challenges to anesthetic administration and moni-toring capabilities due to static and dynamic magnetic fields as well as radiofrequency energy emissions. Direct patient observation may be compromised by noise, dark-ened environment, obstructed line of sight, and other characteristics unique to this environment (e.g., distrac-tions). Unlike a conventional operating room, the MRI environment frequently requires the anesthesiologist to assume broader responsibility for immediate patient care decisions.Anesthesiology 03/2009; 110(3):2009. · 6.17 Impact Factor