Comorbidity is associated with pain-related activity limitations in multiple sclerosis.

BACKGROUND: Comorbidities are common in multiple sclerosis (MS). The high prevalence of pain in MS is well-established but the influence of comorbidities on pain, specifically, pain-related interference in activity is not. OBJECTIVE: To examine the relationship between comorbidity and pain in MS. METHODS: We recruited 949 consecutive patients with definite MS from four Canadian centres. Participants completed the Health Utilities Index (HUI-Mark III) and a validated comorbidity questionnaire at 3 visits over 2 years. The HUI's pain scale was dichotomized into two groups: those with/without pain that disrupts normal activities. We used logistic regression to assess the association of pain with each comorbidity individually at baseline and over time. RESULTS: The incidence of disruptive pain over two years was 31.1 per 100 persons. Fibromyalgia, rheumatoid arthritis, irritable bowel syndrome, migraine, chronic lung disease, depression, anxiety, hypertension, and hypercholesterolemia were associated with disruptive pain (p<0.006). Individual-level effects on the presence of worsening pain were seen for chronic obstructive pulmonary disease (odds ratio [OR]: 1.50 95% CI: 1.08-2.09), anxiety (OR: 1.49 95% CI: 1.07-2.08), and autoimmune thyroid disease (OR: 1.40 95% CI: 1.00-1.97). CONCLUSION: Comorbidity is associated with pain in persons with MS. Closer examination of these associations may provide guidance for better management of this disabling symptom in MS.

Detecting cognitive fatigue in multiple sclerosis: method matters.

BACKGROUND: Fatigue is a frequently reported and debilitating symptom in multiple sclerosis (MS). Cognitive fatigue (CF) can be defined as decreased performance with sustained cognitive effort. The effectiveness of the Paced Auditory Serial Addition Task (PASAT) and the Computerized Test of Information Processing (CTIP) at detecting CF was examined, as was the impact of methodology. Subjective fatigue was measured using the Fatigue Impact Scale (FIS). The relationship between objective and subjective fatigue was examined. METHODS: 70 MS and 72 healthy controls (HC) completed the PASAT (3″ and 2″), CTIP, and FIS as part of a larger battery. RESULTS: The MS and HCs performed worse on cognitively demanding tasks. Depending on methodology, PASAT performance varied between groups at the 3″ inter-stimulus interval (ISI) and the MS group showed greater susceptibility to CF as their ability to meet task demands declined as the task progressed. CTIP performance for both groups varied differently over time depending on task. The relationship between subjective and objective measures of fatigue varied depending on methodology, with PASAT generally correlating well with the Cognitive Dimension of the FIS. CONCLUSIONS: The PASAT is a sensitive measure of CF in MS. Additional information is obtained with different scoring methods, with percent dyad scoring method being most sensitive to CF. The ability to detect a relationship between objective and subjective measures varied with methodology.

Activation patterns in multiple sclerosis on the Computerized Tests of Information Processing.

RATIONALE: Multiple sclerosis (MS) patients exhibit cognitive deficits that negatively impact quality of life. The Relative Consequence Model suggests that problems with information processing speed (IPS) may be the basis for many of these cognitive difficulties. OBJECTIVE: To investigate, with functional magnetic resonance imaging (fMRI), if an IPS task (the Computerized Test of Information Processing (CTIP)) would reveal neurophysiological differences between MS patients and matched controls. METHODS: Performance and neural activation were investigated in twelve cognitively impaired MS patients and 12 matched controls as each performed the CTIP. The CTIP measures reaction time (RT) and errors on three tasks (simple RT, choice RT and semantic search RT) with increasing cognitive demands. RESULTS: Participants demonstrated increased RT with increased task complexity. Patients showed longer RTs for the choice RT condition than controls but the pattern of performance across tasks did not vary between groups. Errors were not significantly different between groups. Imaging results for both the choice and the semantic search conditions revealed significant differences between groups involving a compensatory increase in activation in MS participants compared to controls in prefrontal cortex and right temporal gyri. However, there were also areas of decreased activity in MS participants when compared with controls in left temporal gyri. CONCLUSIONS: Significantly different neural activation patterns between MS patients and controls were associated with IPS, as measured by the CTIP.

Factor structure of the Private Self-Consciousness Scale.

Several issues concerning the factors of the Private Self-Consciousness Scale (PRSC) of Fenigstein et al. (1975) are examined, including possible artifactuality and appropriate conceptualization. Findings confirm the existence of the 2 factors reported in previous research (Burnkrant & Page, 1984; Lennox, Welch, Wolfe, Zimmerman, & Dixon, 1987; Mittal & Balasubramanian, 1987; Piliavin & Charng, 1988) and suggest that these factors are substantive, not artifactual, in nature. One factor was found to be associated with mild levels of psychopathology, whereas the other was not. In addition to providing a clearer conception of the nature of these factors, our results may help to resolve apparently contradictory findings in the PRSC literature. Implications for research on self-focused attention are also discussed.

Durability of "posthypnotic suggestions" as a function of type of suggestion and trance depth.

3 types of "posthypnotic suggestion," based upon factor analytic studies, were administered to high hypnotizable Ss (reals) and to low hypnotizable Ss instructed to simulate hypnosis (simulators) (N = 12 high and 6 low hypnotizable Ss per suggestion). The "posthypnotic suggestions" consisted of instructions given to Ss following a hypnotic induction that, when the posthypnotic cue was later given, they would re-enter the hypnotic state and perform a certain task at that time. Ss were then tested 6 times for durability of "posthypnotic response" during an 8-week period. Responses to the "suggestions" were rated by research assistants (objective scores) and by Ss themselves (subjective scores). There was a significant Trials x Type of "Suggestion" interaction for both types of scores for the reals but not for the simulators, indicating different rates of decline with time for the different "suggestions" for the hypnotic Ss. Depth of reported hypnotic trance during the assessment sessions was found to be strongly related to performance of the "posthypnotic suggestion" for both real and simulating Ss.

Relationship of missed psychotherapy appointments to premature termination and social class.

The problem of missed appointments in psychotherapy has received little empirical study. Consequently, this problem was studied in relation to several demographic and actuarial variables. Lower socio-economic status was found to be related to missed appointments and to premature termination. Missing appointments was also found to be related to dropping out of treatment. Possible reasons for these findings are discussed and suggestions offered for reducing premature termination.