Pain physician
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Case Reports Historical Article
Magnetic resonance imaging of the lumbar spine in a patient with a spinal cord stimulator.
The use of magnetic resonance imaging (MRI) is continuously escalating for the evaluation of patients with persistent pain following lumbar spine surgery (LSS). Spinal cord stimulation (SCS) therapy is being clinically applied much more commonly for the management of chronic pain following LSS. There is an increased probability that these 2 incompatible modalities may be accidentally used in the same patient. ⋯ This case demonstrates the lack of compatibility of lumbar MRI and the Precision SCS system as well as one of the possible patient adverse events that can occur when patients are exposed to MRI outside of the approved device labeling.
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Postoperative pain management remains a challenge for clinicians due to unpredictable patient responses to opioid therapy. Some of this variability may result from single nucleotide polymorphisms (SNPs) of the human opioid mu-1 receptor (OPRM1) that modify receptor binding or signal transduction. The OPRM1 variant with the highest frequency is the A118G SNP. However, previous studies have produced inconsistent results regarding the clinical effects of A118G on opioid response. We hypothesized that measurement of serum opioid concentrations, in addition to determining total opioid consumption, may provide a more precise method of assessing the effects of A118G on analgesic response. The current study evaluated the relationship of analgesia, side effects, total hydrocodone consumption, quantitative serum hydrocodone and hydromorphone concentrations, and A118G SNP in postoperative patients following Cesarean section. ⋯ This study found a correlation between pain relief and total hydrocodone dose in patients homozygous for the 118A allele (AA) of the OPRM1 gene, but not in patients with the 118G allele (AG/GG). However, pain relief in 118A patients did not correlate with serum hydrocodone concentrations, but rather with serum hydromorphone levels, the active metabolite of hydrocodone. This suggests that pain relief with hydrocodone may be due primarily to hydromorphone. Although pain relief did not correlate with opioid dose in AG/GG patients, they had a higher incidence of opioid side effects. The correlations identified in this study may reflect the fact that serum opioid concentrations were measured directly, avoiding the inherent imprecision associated with relying solely on total opioid consumption as a determinant of opioid effectiveness. Thus, measurement of serum opioid concentrations is recommended when assessing the role of OPRM1 variants in pain relief. This study supports pharmacogenetic analysis of OPRM1 in conjunction with serum opioid concentrations when evaluating patient responses to opioid therapy.
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Randomized Controlled Trial
Effects of transforaminal balloon treatment in patients with lumbar foraminal stenosis: a randomized, controlled, double-blind trial.
Lumbar spinal stenosis is a common condition in the elderly. Although balloon treatment is a well-known therapeutic method in specific pain conditions, applying the balloon treatment in patients with lumbar spinal stenosis is not yet well established. ⋯ Transforaminal balloon treatment leads to both significant pain relief and functional improvement in a subset of patients with refractory spinal stenosis. INSTITUTIONAL REVIEW: This study was approved by the Institutional Review Board of the Asan Medical Center.
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Randomized Controlled Trial
Stimulation of the greater occipital nerve: anatomical considerations and clinical implications.
Stimulation of the greater occipital nerve has been employed for various intractable headache conditions for more than a decade. Still, prospective studies that correlate stimulation of the greater occipital nerve with outcome of patients with respect to alleviation of headache are sparsely found in literature. ⋯ From our study we conclude that a reproducible stimulation of the greater occipital nerve can be achieved by placing the electrodes parallel to the atlas, at about 30 mm distance to the external occipital protuberance. The response to the stimulation is not correlated to the field width of the paraesthesia. We, therefore, consider stimulation of the main trunk of the greater occipital nerve to be more important than a large field of stimulation on the occiput. Still, an individual response to the occipital nerve stimulation cannot be predicted even by optimal electrode placement.
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Randomized Controlled Trial
Anatomical basis of ulnar approach in carpal tunnel injection.
Local steroid injection may be an effective conservative treatment for carpal tunnel syndrome; however, the use of a blind injection technique can increase the chance of median nerve or ulnar artery injury due to median nerve swelling or the close proximity of the median nerve and ulnar artery around the distal wrist crease. ⋯ It is important to recognize the risk of blind local steroid injection for carpal tunnel syndrome, which is most likely a result of swelling and/or flattening of the median nerve around the distal wrist crease. A real time, ultrasound-guided local steroid injection is preferred as a safe and accurate technique in carpal tunnel syndrome treatment.