Ventricular cryosurgery: short-term effects on intramural electrophysiology

The acute effects of cryothermia on regional electrophysiology were examined in order to devise a means of localizing and monitoring the intramural progression of ventricular cryolesions during a two-minute period of cryothermia application. Intramural unipolar electrograms were recorded from multipoint plunge electrodes placed in the left ventricle in 15 dogs. Epicardial, intramural, and endocardial applications of cryothermia were then employed, and changes in the unipolar peak-to-peak amplitude (UPPA) of electrograms were recorded. The location and depth of the ultimate permanent cryolesion could be predicted by noting locations of those electrograms demonstrating a decrease in the UPPA to less than 30% of the control values. Such electrophysiological monitoring of the region of myocardium undergoing cryothermic ablation provides a means of limiting the ultimate cryolesion to the desired location and depth within the ventricular wall. This allows precise placement of cryolesions in specific areas of the left ventricle for the treatment of ventricular tachyarrhythmias by selectively ablating arrhythmogenic ventricular myocardium without inducing injury in surrounding nonarrhythmogenic myocardium.     

The relationship between self-efficacy and disability in chronic low back pain patients

This study examined the reliability of an adapted version of the Arthritis Self-Efficacy Scale in a sample of 59 chronic low back pain patients. The present study also investigated the relationship between self-efficacy and measures of disability. Regression analyses indicated a significant negative relationship between self-efficacy and low back pain disability. That is, patients who report higher levels of self-efficacy have higher activity levels (R ²=0.34,P<0.01), work more hours (R ²=0.25,P<0.01), and have lower levels of psychological distress (R ²=0.29,P<0.01), pain severity (R ²=0.46,P<0.01), and pain behavior (R ²=0.27,P<0.01) after controlling for the demographic variables of gender, duration of back pain, and having a lawyer on retainer. The results support the use of the Back Pain Self-Efficacy Scale (BPSES) as a general measure of self-efficacy in the chronic low back pain population.     

Predictors of Outcome Following Multidisciplinary Treatment of Chronic Pain: Effects of Changes in Perceived Disability and Depression

The goal of this study was to evaluate the validity of the cognitive-behavioral approach for treating chronic pain. We examined whether changes in a specific cognitive process factor (i.e., perceived disability) accounted for variance in pre- to posttreatment improvements in outcome variables even after controlling for changes in a general factor (i.e., depression). Subjects were 82 patients who completed a multidisciplinary chronic pain program. Results showed that perceived (pain) disability, depression, and pain severity decreased while general activity level and functional level increased from pre-to post-treatment (all p's < .05). Regressions revealed that perceived disability change scores predicted unique variance in pain severity and functional level changes after controlling for variance accounted for by depression changes. Results support the cognitive-behavioral approach: Decreases in perceived disability may act as a distinct therapeutic mechanism through which treatment produces improvements in outcome variables.     

To err is human, to monitor divine: environmental adaptations reduce everyday errors but do not improve monitoring

The current study aimed to address error monitoring impairments in dementia using an intervention for execution deficits. Thirty-eight participants completed the Naturalistic Action Test (NAT) under two conditions: Standard and User-Centered. The Standard NAT followed the manual procedures; in the User-Centered NAT, objects were arranged sequentially, and distractor items were separated from target objects. While participants committed fewer errors in the User-Centered condition, there was no difference in the proportion of errors detected. However, the neuropsychological processes associated with monitoring differed across conditions. The results have implications for a neuropsychological model of error monitoring in dementia.     

Dysexecutive functioning in mild cognitive impairment: derailment in temporal gradients

Libon et al. (2010) provided evidence for three statistically determined clusters of patients with mild cognitive impairment (MCI): amnesic (aMCI), dysexecutive (dMCI), and mixed (mxMCI). The current study further examined dysexecutive impairment in MCI using the framework of Fuster's (1997) derailed temporal gradients, that is, declining performance on executive tests over time or test epoch. Temporal gradients were operationally defined by calculating the slope of aggregate letter fluency output across 15-s epochs and accuracy indices for initial, middle, and latter triads from the Wechsler Memory Scale-Mental Control subtest (Boston Revision). For letter fluency, slope was steeper for dMCI compared to aMCI and NC groups. Between-group Mental Control analyses for triad 1 revealed worse dMCI performance than NC participants. On triad 2, dMCI scored lower than aMCI and NCs; on triad 3, mxMCI performed worse versus NCs. Within-group Mental Control analyses yielded equal performance across all triads for aMCI and NC participants. mxMCI scored lower on triad 1 compared to triads 2 and 3. dMCI participants also performed worse on triad 1 compared to triads 2 and 3, but scored higher on triad 3 versus triad 2. These data suggest impaired temporal gradients may provide a useful heuristic for understanding dysexecutive impairment in MCI.