Search

Background: Spinal cord stimulation (SCS) has demonstrated multiple benefits in treating chronic pain and other clinical disorders related to sensorimotor dysfunctions. However, the underlying mechanisms are still not fully understood, including how electrode placement in relation to the spinal cord neuroanatomy influences epidural spinal recordings (ESRs). To characterize this relationship, this study utilized stimulation applied at various anatomical sections of the spinal column, including at levels of the intervertebral disc and regions correlating to the dorsal root entry zone. Method: Two electrode arrays were surgically implanted into the dorsal epidural space of the swine. The stimulation leads were positioned such that the caudal-most electrode contact was at the level of a thoracic intervertebral segment. Intraoperative cone beam computed tomography (CBCT) images were utilized to precisely determine the location of the epidural leads relative to the spinal column. High-resolution microCT imaging and 3D-model reconstructions of the explanted spinal cord illustrated precise positioning and dimensions of the epidural leads in relation to the surrounding neuroanatomy, including the spinal rootlets of the dorsal and ventral columns of the spinal cord. In a separate swine cohort, implanted epidural leads were used for SCS and recording evoked ESRs. Results: Reconstructed 3D-models of the swine spinal cord with epidural lead implants demonstrated considerable distinctions in the dimensions of a single electrode contact on a standard industry epidural stimulation lead compared to dorsal rootlets at the dorsal root entry zone (DREZ). At the intervertebral segment, it was observed that a single electrode contact may cover 20-25% of the DREZ if positioned laterally. Electrode contacts were estimated to be ~0.75 mm from the margins of the DREZ when placed at the midline. Furthermore, ventral rootlets were observed to travel in proximity and parallel to dorsal rootlets at this level prior to separation into their respective sides of the spinal cord. Cathodic stimulation at the level of the intervertebral disc, compared to an 'off-disc' stimulation (7 mm rostral), demonstrated considerable variations in the features of recorded ESRs, such as amplitude and shape, and evoked unintended motor activation at lower stimulation thresholds. This substantial change may be due to the influence of nearby ventral roots. To further illustrate the influence of rootlet activation vs. dorsal column activation, the stimulation lead was displaced laterally at ~2.88 mm from the midline, resulting in variances in both evoked compound action potential (ECAP) components and electromyography (EMG) components in ESRs at lower stimulation thresholds. Conclusion: The results of this study suggest that the ECAP and EMG components of recorded ESRs can vary depending on small differences in the location of the stimulating electrodes within the spinal anatomy, such as at the level of the intervertebral segment. Furthermore, the effects of sub-centimeter lateral displacement of the stimulation lead from the midline, leading to significant changes in electrophysiological metrics. The results of this pilot study reveal the importance of the small displacement of the electrodes that can cause significant changes to evoked responses SCS. These results may provide further valuable insights into the underlying mechanisms and assist in optimizing future SCS-related applications. [ABSTRACT FROM AUTHOR]

This study with 213 South Korean college students (113 men) examined the cross-cultural generalizability of (a) the factor structure of the Frost Multidimensional Perfectionism Scale (F-MPS) and (b) the existence of adaptive perfectionists, maladaptive perfectionists, and nonperfectionists. A confirmatory factor analysis did not support the original six-factor model of the F-MPS with 35 items. Subsequently, an exploratory factor analysis along with parallel analysis suggests five factors in Korea: Concern Over Mistakes, Organization, Parental High Standards, Personal Standards, and Doubts About Actions. Notably, Parental Expectations and Parental Criticism in the original F-MPS were subsumed under one factor, Parental High Standards. A cluster analysis results provides additional support for the existence of the three groups. Cultural implications are discussed. (Contains 3 tables.)

This research consisted of 3 studies, with a sample of over 3,000 Taiwanese college students, aimed at developing and validating a situation-specific Collectivist Coping Styles (CCS) inventory from an Asian perspective. The results from the exploratory and confirmatory factor analyses supported a stable 5-factor structure of the CCS: (a) Acceptance, Reframing, and Striving; (b) Family Support; (c) Religion-Spirituality; (d) Avoidance and Detachment; and (e) Private Emotional Outlets. These factors reflected Asians' use of a combination of primary and secondary control efforts and represented different constellations of items than typically found on coping-problem solving inventories in Western countries. Estimates of concurrent and construct validity suggest the CCS is related to a problem solving inventory, an overall problem resolution index, 2 psychological distress measures, and an index of how much the trauma interfered with the lives of participants in conceptually expected directions but is not strongly related to social desirability. Overall, the CCS was found to be a useful and psychometrically sound measure of collectivistic coping. Limitations and future directions are also discussed.