Reduction in average fluoroscopic exposure times for interventional spinal procedures through the use of pulsed and low-dose image settings.

OBJECTIVE: A practice improvement project was completed with the goal of reducing radiation exposure times in a busy spinal intervention practice through the use of "pulsed" and "low-dose fluoroscopy." The goal was to quantify the reduction in fluoroscopy exposure times with these modes. DESIGN: Exposure times were recorded for 316 patients undergoing spinal interventional procedures before and after the implementation of this project. Before implementation, 158 consecutive patients received spinal interventions with nonpulsed fluoroscopy on an Orthopedic Equipment Company 9800 and exposure times were recorded. After implementation of the practice improvement project, 158 consecutive patients received spinal interventions with pulsed and low-dose modes. Exposure times were then compared between these groups. RESULTS: Pulsed and low-dose fluoroscopy modes reduced overall exposure times by 56.7% after implementation of the practice improvement project. CONCLUSIONS: The use of pulsed and low-dose fluoroscopy in addition to lead shielding; increasing distance from the radiation source; collimation; limited use of magnification, boost, or digital subtraction; and proficiency with interventional techniques should be used to reduce radiation exposure in concordance with the principle of "as low as reasonably achievable."

Outcome measures for gait and ambulation in the spinal cord injury population.

BACKGROUND: At the 2006 National Institute on Disability and Rehabilitation Research (NIDRR) sponsored pre-conference on spinal cord injury (SCI) outcomes, several gait and ambulation measures were evaluated for utility in clinical practice, validity, and reliability as research measurement tools. The Conference Subcommittee on Gait and Ambulation chose to review the Walking Index for Spinal Cord Injury II (WISCI II), 50-Foot Walk Test (50FTWT), 6-Minute Walk Test (6MWT), 10-Meter Walk Test (10MWT), and Functional Independence Measure-Locomotor (FIM-L). METHODS: A subcommittee of international experts evaluated each instrument for test construct, administration, population applicability, reliability, sensitivity to change, and validity. Evaluations for each outcome measure were compiled, distributed to the whole committee, and then further reviewed with addition of comments and recommendations for consensus. An audience of experts voted on the validity and usefulness of each measure. RESULTS: WISCI II and 10MWT were found to be the most valid and clinically useful tests to measure improvement in gait for patients with SCI. FIM-L had little utility and validity for research in SCI. 6MWT and 50FTWT were found to be useful but in need of further validation or changes for the SCI population. CONCLUSION: A combination of the 10MWT and WISCI II would provide the most valid measure of improvement in gait and ambulation in as much as objective changes of speed, and functional capacity allow for interval measurement. To provide the most comprehensive battery, however, it will be important to include a measure of endurance such as the 6MWT. Further validation and study should be devoted to WISCI II, 10MWT, and 6MWT as primary outcome measures for gait in SCI.

c-Fos expression in rat brain stem and spinal cord in response to activation of cardiac ischemia-sensitive afferent neurons and electrostimulatory modulation.

The purpose of this study was to identify central neuronal sites activated by stimulation of cardiac ischemia-sensitive afferent neurons and determine whether electrical stimulation of left vagal afferent fibers modified the pattern of neuronal activation. Fos-like immunoreactivity (Fos-LI) was used as an index of neuronal activation in selected levels of cervical and thoracic spinal cord and brain stem. Adult Sprague-Dawley rats were anesthetized with urethane and underwent intrapericardial infusion of an "inflammatory exudate solution" (IES) containing algogenic substances that are released during ischemia (10 mM adenosine, bradykinin, prostaglandin E2, and 5-hydroxytryptamine) or occlusion of the left anterior descending coronary artery (CoAO) to activate cardiac ischemia-sensitive (nociceptive) afferent fibers. IES and CoAO increased Fos-LI above resting levels in dorsal horns in laminae I-V at C2 and T4 and in the caudal nucleus tractus solitarius. Dorsal rhizotomy virtually eliminated Fos-LI in the spinal cord as well as the brain stem. Neuromodulation of the ischemic signal by electrical stimulation of the central end of the left thoracic vagus excited neurons at the cervical and brain stem level but inhibited neurons at the thoracic spinal cord during IES or CoAO. These results suggest that stimulation of the left thoracic vagus excites descending inhibitory pathways. Inhibition at the thoracic spinal level that suppresses the ischemic (nociceptive) input signal may occur by a short-loop descending pathway via signals from cervical propriospinal circuits and/or a longer-loop descending pathway via signals from the nucleus tractus solitarius.