K.John Klose

Intraoperative evoked EMG monitoring in an animal model. A new technique for evaluating pedicle screw placement.

An electric drill was used to introduce holes in the L4 through L7 pedicles in pigs. Constant-voltage stimulating pulses (5.5 V, stimulus rate = 3/sec) were delivered through a ball-tipped probe used to palpate the walls of each pedicle, and observation was made of electromyogram (EMG) evoked from hind limb muscles. Screws were placed in each pedicle hole, and evaluated for absolute voltage necessary to evoke EMG (threshold). At the conclusion of each experiment, screw positions were ascertained by removal and dissection of the lumbosacral spine. Approximately 50% of screw placements resulted in defects of the pedicle. In each of these cases, 5.5 V stimuli delivered through the probe evoked EMG from muscles innervated by adjacent motor axons. Conversely, for those cases where the pedicle was intact, significantly higher voltages were needed to evoke EMG. The authors believe that this is a promising intraoperative technique to simply and reliably identify mispositioned screws, thereby minimizing neurologic complications.

Evaluation of a training program for persons with SCI paraplegia using the Parastep 1 ambulation system: part 3. Lack of effect on bone mineral density.

OBJECTIVE To determine if the bone mineral density loss seen after spinal cord injury (SCI) is reversed by a walking program using the Parastep 1 system. DESIGN Before-after trial. SETTING Human SCI applied research laboratory. PARTICIPANTS Thirteen men and 3 women with thoracic motor- and sensory-complete SCI, mean age 28.8yrs, mean duration postinjury 3.8yrs. INTERVENTION Thirty-two functional neuromuscular stimulation (FNS) ambulation training sessions using a commercially available system (Parastep 1). This system consists of a microprocessor-controlled stimulator and a modified walking frame with finger-operated switches that permit the user to control the stimulation parameters and activate the stepping. OUTCOME MEASURE Bone mineral density at the femoral head, neck, and Wards triangle measured using a Lunar DP3 dual-photon densitometer. RESULTS No significant change in bone mineral density was found using repeated measures analyses of variance. CONCLUSIONS Axial loading combined with muscle stimulation and resistive exercise does not result in significant changes in bone mineral density in persons with complete paraplegia.

Reversal of adaptive left ventricular atrophy following electrically-stimulated exercise training in human tetraplegics

Left ventricular (LV) myocardial atrophy and diminished cardiac function have been shown to accompany chronic human tetraplegia. These changes are attributable both to physical immobilisation and abnormal autonomic circulatory regulation imposed by a spinal cord injury (SCI). To test whether exercise training increases LV mass following chronic SCI, 8 neurologically complete quadriplegic males at 2 SCI rehabilitation and research centres underwent one month of electrically-stimulated quadriceps strengthening followed by 6 months of electrically-stimulated cycling exercise. Resting M-mode and 2-D echocardiograms were measured before and after exercise training to quantify the interventricular septal and posterior wall thicknesses at end-diastole (IVSTED and PWTED, respectively), and the LV internal dimension at end-diastole (LVIDED). LV mass was computed from these measurements using standard cube function geometry. Results showed a 6.5% increase in LV IDED following exercise training (p<0.02), with increases in IVSTED and PWTED of 17.8 (p<0.002) and 20.3% (p<0.01), rspectively. Computed LV mass increased by 35% following exercise training (p=0.002). These data indicate that myocardial atrophy is reversed in tetraplegics following electrically-stimulated exercise training, and that the changes in cardiac architecture are likely to be the result of both pressure and volume challenge to the heart imposed by exercise.

Evaluation of a training program for persons with SCI paraplegia using the Parastep 1 ambulation system: part 1. Ambulation performance and anthropometric measures.

OBJECTIVE To describe performance parameters and effects on anthropometric measures in spinal cord injured subjects training with the Parastep 1 system. DESIGN Before-after trial. SETTING Human spinal cord injury applied research laboratory. PARTICIPANTS Thirteen men and 3 women with thoracic (T4-T11) motor-complete spinal cord injury: mean age, 28.8yrs; mean duration postinjury, 3.8yrs. INTERVENTION Thirty-two functional neuromuscular stimulation ambulation training sessions using a commercially available system (Parastep-1). The hybrid system consists of a microprocessor-controlled stimulator and a modified walking frame with finger-operated switches that permit the user to control the stimulation parameters and activate the stepping. OUTCOME MEASURES Distance walked, time spent standing and walking, pace, circumferential (shoulders, chest, abdomen, waist, hips, upper arm, thigh, and calf) and skinfold (chest, triceps, axilla, subscapular, supraillium, abdomen, and thigh) measurements, body weight, thigh cross-sectional area, and calculated lean tissue. RESULTS Statistically significant changes in distance, time standing and walking, and pace were found. Increases in thigh and calf girth, thigh cross-sectional area, and calculated lean tissue, as well as a decrease in thigh skinfold measure, were all statistically significant. CONCLUSIONS The Parastep 1 system enables persons with thoracic-level spinal cord injuries to stand and ambulate short distances but with a high degree of performance variability across individuals. The factors that influence this variability have not been completely identified.

Evaluation of a training program for persons with SCI paraplegia using the Parastep®1 ambulation system: Part 5. Lower extremity blood flow and hyperemic responses to occlusion are augmented by ambulation training

OBJECTIVE To test whether 12 weeks of exercise conditioning using functional neuromuscular stimulation (FNS) ambulation alters the resting lower extremity blood flow and hyperemic responses to vascular occlusion in subjects with paraplegia, and to determine whether an association exists between limb flow and lower extremity fat-free mass. DESIGN Pretest, posttest. SETTING Academic medical center. PARTICIPANTS Subjects with chronic neurologically complete paraplegia. INTERVENTION Thirty-two sessions of microprocessor-controlled ambulation using electrically stimulated contractions of lower extremity muscles and a rolling walker. OUTCOME MEASURES Subjects underwent quantitative Doppler ultrasound examination of the common femoral artery (CFA) before and after training. End-diastolic arterial images and arterial flow-velocity profiles obtained at rest and after 5 minutes of suprasystolic thigh occlusion were computer-digitized for analysis of heart rate (HR), CFA peak systolic velocity (PSV), CFA cross-sectional area (CSA), flow velocity integral (FVI), pulse volume (PV), and CFA (arterial) inflow volume (AIV). RESULTS Significant effects of training on CSA (p < .0001), FVI (p < .05), computed PV (p < .001), and computed AIV (p < .01) were observed. Resting HR was lower following training (p < .05). The change for resting PSV approached but did not reach significance (p = .083). Analysis of postocclusion PV and AIV showed significant effects for conditioning status (p values < .01), postcompression time (p values < .0001), and their interaction (p values < .01). At 1 minute after occlusion, the posttraining AIV response was 78.2% greater in absolute magnitude and 17.4% more robust when expressed as a percentage change from its resting value than before training. Significant correlations were found between thigh fat free mass and both AIV and PV (p values < .05). CONCLUSION Exercise training using FNS ambulation increases the resting lower extremity AIV in individuals with paraplegia and augments the hyperemic response to vascular occlusion. Improved posttraining blood flow is attributable both to vascular structural changes and upregulation of vascular flow control mechanisms. Limb mass is associated with the volume of arterial blood flow.

Evaluation of a training program for persons with SCI paraplegia using the Parastep®1 ambulation system: Part 2. Effects on physiological responses to peak arm ergometry

OBJECTIVE To examine the task-nonspecific effects of functional neuromuscular stimulation (FNS)-assisted ambulation training on the physiological responses of persons with paraplegia to upper extremity exercise challenge. DESIGN Before-after trial. SETTING Human spinal cord injury (SCI) applied research laboratory. PARTICIPANTS Twelve men and three women with motor- and sensory-complete thoracic-level SCI (T4-T11), mean age 28.2 +/- 6.8yrs (range, 21.1 to 45.2yrs), mean injury duration 3.7 +/- 3.0yrs (range, 7 to 8.8yrs). INTERVENTION Thirty-two sessions of FNS ambulation training using a commercial six-channel system (Parastep 1). This system is composed of a microprocessor-controlled electrical stimulation unit and a walking frame outfitted with finger switches that allow the user to independently control the system and stimulation parameters. OUTCOME MEASURES Peak and subpeak physiological responses to arm ergometry testing and upper extremity strength measures, obtained before and after the FNS ambulation training. RESULTS Statistically significant increases in peak values for time to fatigue, peak power output, and peak VO2 (all p < .001). Heart rate was significantly lower throughout subpeak levels of arm ergometry after the ambulation training (p < .05). Values of upper extremity strength were not significantly altered after training. CONCLUSIONS FNS ambulation by persons with SCI paraplegia results in task-nonspecific training adaptations. Central cardiovascular adaptations were indicated as the primary source of these beneficial alterations in exercise responses.

Relationships of oxygen uptake, heart rate, and ratings of perceived exertion in persons with paraplegia during functional neuromuscular stimulation assisted ambulation

Previous reports have described significant limitations in the daily use of functional neuromuscular stimulation (FNS) ambulation systems by persons with spinal cord injuries (SCI). The potential application of these devices to provide physiological benefits as an exercise modality has prompted a reconsideration of the technology. However, the acute physiological effects related to the use of FNS systems have not been thoroughly examined. The purpose of this study was to investigate the relationships of oxygen consumption (VO2), heart rate (HR), and ratings of perceived exertion (RPE) during FNS ambulation by persons with SCI paraplegia. Eleven persons with thoracic level paraplegia, aged 21.5 to 38.0 years, participated in an incremental FNS ambulation test. Metabolic measures were collected continuously via open circuit spirometry as the subjects performed a series of ambulation passes of progressively increasing pace. At the end of each ambulation pass, HR and RPE measures were collected. The test was terminated when either the subjects judged the effort to be maximal or when the investigators deemed the effort to be maximal based on HR. A strong linear relationship was documented between the VO2 and HR measures of all subjects throughout subpeak levels of FNS ambulation. RPE did not vary proportionally with VO2 until relatively high levels of exercise intensity were reached. This study indicates that HR, but not RPE, is an appropriate indicator of exercise intensity for persons with SCI paraplegia using a FNS ambulation system.

An assessment of the contribution of electromyographic biofeedback as an adjunct therapy in the physical training of spinal cord injured persons

This study tested the efficacy of biofeedback when administered in conjunction with physical rehabilitation therapy to chronic C5-7 quadriplegics. Triceps brachii, biceps brachii, wrist extensors, and wrist flexors were tested. The studied muscles were compromised by the injury to varying degrees, but were often still useful to these subjects. An exercise regimen was given to all subjects. In addition, subjects were separated into two groups: those who received biofeedback training and those who did not. Two measures of performance were tested: manual muscle scores and functional activities scores. Both groups scored significantly higher on both measures after 12 weeks of rehabilitation therapy. We found no evidence that biofeedback generally increased the amount of improvement seen. These results do not support the routine use of biofeedback in the treatment of chronic spinal cord injury, but rather further stress the importance of exercise therapy for such injuries.

An upper body exercise system incorporating resistive exercise and neuromuscular electrical stimulation (NMS).

A device is described which combines arm crank ergometry and neuromuscular electrical stimulation (NMS) delivered at different phases of the crank cycle. Details of the device including circuit schematics are shown. The device was evaluated by non-paralyzed subjects for its operational safety and by tetraplegic subjects for its effectiveness as a muscle-strengthening tool. All subjects showed improvement in one or more of their manual muscle scores. The most dramatic increased motor score occurred in the triceps muscle group. There was an average increase in the manual muscle score of 1.1 +/- 0.2 for the left triceps and 0.7 +/- 0.1 for the right triceps after eight weeks of NMS assisted exercise. No adverse effects were experienced and it appears to meet safety considerations necessary for this group of individuals. Preliminary observations indicate that an eight-week exercise protocol that utilizes this device can be beneficial for this population.

Acute Spinal Cord Injury: Emergency Room Care and Diagnosis, Medical and Surgical Management

Publisher Summary This chapter provides an overview of a rational approach and protocols for the multidisciplinary team triage and care of acute spinal cord injury victims from their arrival at the emergency room (ER) through the various diagnostic and therapeutic components of the acute care program. It discusses the following points: emergency room triage, neurological as well as orthopedic and general assessments, neuroradiological assessment battery, medical and surgical protocols, and intensive care management. When a patient suspected of having a spinal or spinal cord injury arrives at the ER, the same priorities as established for the accident scene must be initiated, that is, (1) respiratory stabilization; (2) cardiovascular stabilization; and (3) splinting the patient, that is, immobilizing the entire spine in a neutral supine position. The key to ER care is the multidisciplinary team triage. While the nurse takes the basic vital signs, the physician should obtain a careful detailed history and perform a complete physical and neurological examination.