Pain physician
-
Constriction of the sciatic nerve by loose ligation produces an inflammatory neuropathic injury. This represents an animal model for peripheral mononeuropathy. Oxygen-derived free radicals are suspected to play an important role in the pathogenesis of ischemia/reperfusion injury, leading to neurogenic inflammation. Hyperbaric oxygen (HBO) has been used anecdotally to treat clinically similar conditions in humans, but specific effects on the animal model have not been well studied. ⋯ This study evaluated tissue changes after nerve injury caused by loose ligation of the sciatic nerve in rats. Hyperbaric oxygen treatment following sciatic nerve injury reduced tissue edema, improved skin blood flow, and preserved muscle and neuronal ultrastructural integrity.
-
The intervertebral disc has been implicated as an etiology of chronic spine pain based on clinical, basic science, and epidemiological research. Unfortunately, there is no way to determine with absolute certainty whether or not the disc is a spinal pain generator. Recent advances in the neurobiology of pain processing further underscore the possibility that we may never know the source of a patient's pain. At our current level of understanding, from an empirical standpoint, discography is thought of as the best tool to evaluate disc-related pain. ⋯ Discography is a useful imaging and pain evaluation tool in identifying a subset of patients with chronic spinal pain secondary to intervertebral disc disorders.
-
Transforaminal epidural injections, or selective nerve root blocks, are used for a myriad of different spinal disorders. A clear consensus on the use of selective nerve root injections as a diagnostic tool does not currently exist. Additionally, the effectiveness of this procedure as a diagnostic tool is not clear. ⋯ Selective nerve root injections may be helpful as a diagnostic addition in evaluating spinal disorders with radicular features, but the role of this diagnostic test needs to be further clarified by additional research and consensus on technique.
-
Complex regional pain syndrome (CRPS) is characterized by pain that is out of proportion to the injury and is regional in distribution. A large body of literature supports a dynamic change in the physiology and structure of central pain projecting neurons mediated through the N-methyl-D-aspartate (NMDA) receptor. A critical factor in central sensitization seems to be the release of the magnesium block on the NMDA receptor with influx of calcium and initiation of intracellular cascades. Current literature supports the effectiveness of ketamine in blocking central sensitization through its effects on the NMDA receptor. Recent treatment with anesthetic doses of ketamine in severely ill patients with generalized CRPS prompted our interest in a lower dose therapy. ⋯ A four-hour ketamine infusion escalated from 40-80 mg over a 10-day period can result in a significant reduction of pain with increased mobility and a tendency to decreased autonomic dysregulation.
-
Discography has been widely used in the lumbar and cervical spine as a diagnostic tool to identify sources of discogenic pain that may be amenable to surgical treatment. Discography in the cervical spine is currently performed without the benefit of pressure monitoring, and corresponding pressure parameters have not been determined. ⋯ In the cervical spine, iatrogenic disc injury may be caused at significantly lower pressures and volumes infused than in the lumbar spine. There was no measurable pressure change in any of the adjacent disc levels evaluated at maximum intradiscal pressurization. Further cadaveric testing will be necessary to develop parameters for intradiscal pressure monitoring in the cervical spine.