Sungkun Cho

Pain acceptance-based coping in complex regional pain syndrome Type I: daily relations with pain intensity, activity, and mood

This study aimed to examine the temporal patterning of pain acceptance-based coping, activity, and mood in patients with complex regional pain syndrome Type I (CRPS-I), by using a daily diary method. A total of 30 patients with CRPS-I seeking treatment in a tertiary pain management center located in Seoul, Korea participated in the study. Multilevel random effects analyses indicated that (a) engagement in pain acceptance-based coping was significantly associated with lower same-day pain and negative mood and greater same-day activity and positive mood; (b) pain acceptance-based coping predicted increases in activity on the following day; (c) greater pain intensity was significantly associated with lower same-day pain acceptance-based coping and activity and greater same-day negative mood; and (d) pain intensity did not predict pain acceptance-based coping, activity, or mood on the following day. These findings suggest that patients with CRPS-I may benefit from responding to pain with acceptance. Further study and eventual application of this process in CRPS-I may improve upon the success of current approaches to this problem.

Psychometric evaluation of the sleep hygiene index: a sample of patients with chronic pain

BackgroundSleep Hygiene Index (SHI) was designed to assess sleep hygiene. Although the SHI has shown adequate psychometric properties in a nonclinical sample, it has not been validated in a sample with chronic pain. Also, its factor structure, measurement error, and incremental validity over and above other factors affecting sleep quality have not been investigated in a nonclinical sample. Thus, this present study aimed to extend prior psychometric investigation of the SHI. Specifically, we evaluated the factor structure, measurement error, and incremental validity as well as the reliabilities and concurrent validity of the SHI in a sample with chronic pain.MethodsA total of 161 patients seeking treatment in a tertiary pain center located in Seoul, Korea participated. To explore the factor structure of the SHI, we performed an exploratory factor analysis using principal component with varimax. Cronbach’s alphas and intraclass correlation coefficients were computed to investigate internal consistency and 2-week test-retest stability of the SHI, respectively. Measurement error was estimated using standard error of measurement and minimum detectable change (MDC) of the SHI. For concurrent validity, Pearson correlations were calculated to examine the relations between the SHI and outcome measures including background variables. Also for incremental validity, a hierarchical multiple regression was performed in relation to sleep quality.ResultsResults indicated that two-factor solution is most appropriate; sleep disturbing behavior and environment (B/E) and irregular sleep-wake schedule. Results also showed that the internal consistencies and test–retest stability estimates of the SHI were deemed acceptable. At the 95% confidence level, the MDCs were 5.75 for ‘sleep disturbing B/E,’ 3.65 for ‘irregular sleep-wake schedule,’ and 7.49 points for total. The SHI was significantly correlated with age, depression, pain-related anxiety, and sleep quality. Also, sleep quality was significantly predicted by the irregular sleep-wake schedule subscale of the SHI, over and above background variables, pain intensity, depression, pain-related anxiety.ConclusionsThe SHI has the reliability, measurement error, and concurrent and incremental validity support for assessing sleep hygiene in a sample with chronic pain.

Effects of Pain Controllability and Discrepancy in Social Support on Depressed Mood Among Patients with Chronic Pain

BackgroundPreference of types of social support may vary across recipients, and social support that is less than the amount preferred may be associated with depressed mood.PurposeThis study aimed to investigate the interaction effects between pain controllability and discrepancy in social support and the additive utility of discrepancy in social support over perceived social support in predicting depressed mood among patients with chronic pain.MethodA total of 173 patients seeking treatment at two outpatient pain management clinics in Hawaii participated.ResultsThe results indicated that (1) patients with low pain controllability preferred significantly more social support than those with high pain controllability, for all types of social support; (2) patients preferred significantly more informational and emotional support than instrumental support for both pain controllability levels; (3) discrepancy in informational or instrumental support was not associated with depressed mood, whereas discrepancy in emotional support was significantly associated with more depressed mood for low pain controllability, but not for high pain controllability; and (4) discrepancy in emotional support added a significant increment of variance in predicting depressed mood over and above perceived emotional support, whereas discrepancy in informational or instrumental support did not.ConclusionFindings suggest the relative importance of discrepancy in emotional support from a significant other, especially for patients with low pain controllability.

Application of Virtual Body Swapping to Patients with Complex Regional Pain Syndrome: A Pilot Study

This study aimed to apply virtual body swapping through mental rehearsal for patients with complex regional pain syndrome (CRPS) and to investigate whether it is applicable to them. Ten patients who met the diagnostic criterion for CRPS type 1 were randomly assigned to either the treatment or control group. All participants were asked to watch the virtual body swapping training video clip with a head mounted display. The treatment group was additionally asked to assume a posture similar to the body on the screen and rehearse the movements mentally, as if the body presented on the screen was their body. No difference between the groups was found for pain intensity, however, the treatment group showed significantly more improvement in body perception disturbance (BPD) after the treatment than the control group. Even if the presented study is a preliminary one, the above results suggest that virtual body swapping through mental rehearsal is applicable for patients with CRPS and may be useful for improving BPD. The limitations of the study and the future investigations needed to provide clearer clinical suggestions are presented and discussed.

Confirmatory factor analysis of the Korean version of the short-form McGill pain questionnaire with chronic pain patients: a comparison of alternative models

BackgroundThe Short Form of the McGill Pain Questionnaire (SF-MPQ) is the most widely used assessment of the quality and intensity of pain. In previous validation studies, the factor structure of the SF-MPQ varied widely from various two-factor structures to a five-factor structure, although research on the SF-MPQ quite consistently supports its two-factor structure (i.e., sensory and affective) across different countries and languages. In Korea, the results of exploratory factor analysis of a Korea version of SF-MPQ (KSF-MPQ) showed 2-factor structure consisting of ‘sensory’ and ‘affective’ excluding two items such as splitting and heavy. As an attempt to further validate the KSF-MPQ, the purpose of this study was to confirm whether the KSF-MPQ model is an appropriate model for chronic pain patients in Korea by comparing several alternative models of the SF-MPQ.FindingsA total of 150 chronic pain patients seeking treatment in Seoul, Korea, participated and completed the KSF-MPQ. Confirmatory factor analysis was conducted to evaluate the adequacy of the KSF-MPQ model and several alternative models. The results indicated that the adjusted KSF-MPQ model showed the best fit to the data among the models in chronic pain patients in Korea.ConclusionsThe results showed the KSF-MPQ is cross-culturally equivalent to the original questionnaire. Thus, the KSF-MPQ is valid measurement for assessing the quality and intensity of pain to chronic pain patients and may be helpful in clinical and research settings in Korea.

The Effects of Long-Term Ketamine Treatment on Cognitive Function in Complex Regional Pain Syndrome: A Preliminary Study

OBJECTIVE This preliminary study aimed to investigate the effects of long-term frequent ketamine treatment on cognitive function in [AQ-A] CRPS patients. DESIGN A total of 30 CRPS patients were divided into two groups based on both the duration and frequency of ketamine treatment; the long-term frequent ketamine treatment (LF) group (N = 14) and the Non-LF group (N = 16). Participants were asked to complete a questionnaire packet including demographic and clinical characteristics and potential variables affecting cognitive function. Then, they performed the neuropsychological test. RESULTS Results indicated that the LF group performed significantly poorer than the Non-LF group on the digit span, digit symbol, Controlled Oral Word Association Test, and Trail Making Test, but not the Stroop task. CONCLUSIONS Patients with CRPS receiving long-term frequent ketamine treatment showed impairment in cognitive function (specifically executive function) compared with those who do not. These findings may have implications for clinical assessment and rehabilitation of cognitive function in CRPS patients.

assessment of factors affecting the difficulty of caudal epidural injections in adults using ultrasound

Caudal epidural block is used to treat pain in the lower back and lower extremities. The procedure can be difficult to perform, particularly when a blind technique is being used. The authors of this study aimed to identify variables affecting the difficulty of caudal epidural blocks performed using a blind technique by measuring relevant anatomical variables using ultrasonography.

The effect of virtual body swapping with mental rehearsal on pain intensity and body perception disturbance in complex regional pain syndrome.

The present study investigated the effects of virtual body swapping with mental rehearsal on pain intensity and body perception disturbance (BPD) in patients with complex regional pain syndrome. Patients with complex regional pain syndrome were assigned randomly to three experimental groups: the ‘virtual body swapping with mental rehearsal’ (VBS) group (n=13), the ‘watching movement only’ group (n=13), and the ‘mental rehearsal only’ (n=13) group. Then, pretreatment pain intensity and BPD were compared with post-treatment perceptions. The results showed that pain intensity did not decrease significantly after treatment in all of the groups. However, BPD improved significantly after treatment in the VBS group, but not in the other groups. Therefore, this study is the first to show the effects of a single session of VBS on BPD. Further studies should apply an elevated degree of immersion and create a more realistic virtual body.

Depressive symptoms following natural disaster in Korea: psychometric properties of the Center for Epidemiologic Studies Depression Scale

BackgroundDepressive symptoms have been recognized as one of the most frequent complaints among natural disaster survivors. One of the most frequently used self-report measures of depressive symptoms is the Center for Epidemiologic Studies Depression Scale (CES-D). To our knowledge, no study has yet examined the factor structure, reliability, and validity of the CES-D in a sample of natural disaster survivors. Thus, the present study investigated the factor structure, reliability, and validity of a Korean language version of the CES-D (KCES-D) for natural disaster survivors.MethodsWe utilized two archived datasets collected independently for two different periods in 2008 in the same region of Korea (n = 192 for sample 1; n = 148 for sample 2). Participants were survivors of torrential rains in the mid-eastern region of the Korean peninsula. For analysis, Samples 1 and 2 were merged (N = 340). Confirmatory factor analysis was performed to evaluate the one-factor model, the four-factor model, and the bi-factor models, as well as the second-order factor model. Composite reliability was computed to examine the internal consistency of the KCES-D total and subscale scores. Finally, Pearson’s r was computed to examine the relationship between the KCES-D and the trauma-related measures.ResultsThe four-factor model provided the best fit to the data among the alternatives. The KCES-D showed adequate internal consistency, except for the ‘interpersonal difficulties’ subscale. Also regarding concurrent validity, weak to moderate positive correlations were observed between the KCES-D and the trauma-related measures.ConclusionsThe results support the four-factor model and indicate that the KCES-D has adequate psychometric properties for natural disaster survivors. If these findings are further confirmed, the KCES-D can be used as a useful, rapid, and inexpensive screening tool for assessing depressive symptoms in natural disaster survivors.

The effect of negative emotions on response inhibition in smoking relapsers

The present study aimed to examine whether negative emotions have an effect on response inhibition in smoking relapsers compared to smoking abstainers. Participants were 71 young adults (42 smoking relapsers and 29 abstainers). In order to induce emotions, participants were instructed to view negative or neutral pictures of the International Affective Pictures System (IAPS). They performed a Go/No-Go task, consisting of smoking pictures (No-Go stimuli) and nonsmoking pictures (Go stimuli), to assess response inhibition toward smoking pictures before and after inducing emotions. As a result of Go/No-Go task, relapsers showed significantly fast error reaction times to smoking pictures than did abstainers, regardless of any emotion induction. However, both groups did not show significant differences in commission error to smoking pictures. These results suggest that relapsers may be vulnerable to emotion and thus have impaired response inhibition. Thus, interventions for emotion regulation may be required to prevent smoking relapse.