Krzysztof E Kowalski

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Lower thoracic spinal cord stimulation (SCS) may be a useful method to restore an effective cough mechanism. In dogs, two groups of studies were performed to evaluate the mechanism of the expiratory muscle activation during stimulation at the T(9)-T(10) level, which results in the greatest changes in airway pressure. In one group, expiratory muscle(More)
Despite clinically available methods of diaphragm pacing, most patients with ventilator-dependent tetraplegia are still dependent on mechanical ventilation. Given the significant disadvantages of these devices, additional pacing options are needed. The objective of this study was to evaluate a novel and potentially more physiological method of inspiratory(More)
As demonstrated in a canine model, high frequency spinal cord stimulation (HF-SCS) is a novel and more physiologic method of electrical activation of the inspiratory muscles compared to current techniques. The dog model, however, has significant limitations due to cost and societal concerns. Since the rodent respiratory system is also a relevant model for(More)
Following spinal cord injury, the expiratory muscles develop significant disuse atrophy characterized by reductions in their weight, fiber cross-sectional area, and force-generating capacity. We determined the extent to which these physiological alterations can be prevented with electrical stimulation. Because a critical function of the expiratory muscles(More)
Lower thoracic spinal cord stimulation (SCS) results in the generation of large positive airway pressures (Paw) and may be a useful method of restoring cough in patients with spinal cord injury. The purpose of the present study was to assess the mechanical contribution of individual respiratory muscles to pressure generation during SCS. In anesthetized(More)
Large positive airway pressures (Paws) can be generated by lower thoracic spinal cord stimulation (SCS), which may be a useful method of restoring cough in spinal cord-injured patients. Optimal electrode placement, however, requires an assessment of the pattern of current spread during SCS. Studies were performed in anesthetized dogs to assess the pattern(More)
Projections from the nucleus reticularis tegmenti (NRTP) pontis to the cerebellar paramedian lobule were studied using a horseradish peroxidase retrograde transport technique. The rabbit's NRTP consists of a medial principal part (the nucleus papillioformis: PLF) and smaller lateral part (the processus tegmentosus lateralis: PTL). The PLF can be subdivided(More)
The spatial analysis of the potentials of single motor units of the rat medial gastrocnemius muscle evoked by stimulation of the fibres of split ventral roots was carried out with a bipolar electrode moving in the direction perpendicular to the longitudinal axis of the muscle fibres. During this movement of the electrode a variability was observed in the(More)
Following spinal cord injury, muscles below the level of injury develop variable degrees of disuse atrophy. The present study assessed the physiological changes of the expiratory muscles in a cat model of spinal cord injury. Muscle fiber typing, cross-sectional area, muscle weight, and changes in pressure-generating capacity were assessed in five cats(More)
Although pentobarbital (PB) is a commonly used anesthetic in animal studies examining respiratory motor control, there are virtually no studies that have examined the differential effects of deepening anesthesia on the activation of the various intercostal muscles. In dogs, anesthetized initially with 25 mg/kg of PB, the effects of additional doses of PB(More)