Kang B, et al. Ann Rehabil Med. 2015 Dec;39(6):957-963. http://dx.doi.org/10.5535/arm.2015.39.6.957

Objective: To identify ankylosing spondylitis (AS)–associated copy number variations (CNVs) in Korean subjects and their synergistic roles in the development of AS.Methods: A genome‐wide association study (GWAS) was performed in 309 patients with AS and 309 control subjects, using a copy number variant (CNV) microarray. AS‐associated CNV regions were replicated in 2 independent sets (625 patients and 891 control subjects) by quantitative polymerase chain reaction (PCR) and deletion‐typing PCR.Results: In the CNV GWAS, 227 CNV regions were shown to be significantly associated with the risk of AS. Of the candidate CNV regions, 9 were successfully replicated in the first replication analysis: 1q32.2 (HHAT), 1p34.2 (BMP8A), 2q31.2 (PRKRA), 6p21.32 (HLA–DPB1), 11q22.1 (CNTN5), 13q13.1 (EEF1DP3), 14q24.2 (RGS6), 16p13.3, and 22q11.1 (IL17RA). The 5 deletion‐type CNV regions, in 1q32.2, 2q31.2, 6p21.32, 13q13.1, and 16p13.3, were associated with an increased risk of AS, and the other 4 CNV regions were protective. In the second replication analysis, 4 CNV regions in 1q32.2, 2q31.2, 6p21.32, and 16p13.3 were replicated. Among patients with CNV regions in ≥4 risk‐increasing loci, the risk was 18.0 times higher than that in patients without any deletions (odds ratio [OR] 17.98, P = 2.3 × 10⁻⁷). Among patients with CNV regions in ≥2 protective loci, the risk was 5.2 times lower than that in those without any deletions (OR 0.19, P = 4.0 × 10⁻¹⁰). The additive effects of simultaneous events were shown to be dependent on the frequency of CNV regions. Through deletion‐typing PCR and sequencing, the exact sizes and breakpoint sequences were defined in 4 CNV regions. The mechanism of all 3 deletions was shown to be microhomology‐based nonhomologous end joining.Conclusion: The results of this study can help to identify pathogenic mechanisms of AS and can easily be applied in the development of algorithms estimating the risk of AS.

Cho H, et al. Ann Rehabil Med. 2013 Oct;37(5):675-682. http://dx.doi.org/10.5535/arm.2013.37.5.675

Objective: To evaluate the effect of an arm sling on gait speed and energy efficiency of patients with hemiplegia. Design: A randomized crossover design. Setting: A rehabilitation department of a university hospital. Subjects: Thirty-seven outpatients with hemiplegia were included in this study. Interventions: All patients walked on a 20-m walkway twice on the same day, randomly with and without an arm sling, at a self selected speed. Main measures: The heart rate, gait speed, oxygen cost and oxygen rate were measured on all patients. We analysed all values with and without an arm sling and also compared them after all patients being stratified according to demographic and clinical characteristics. Results: When we compared the heart rate between walking with (90.7 ± 17.2 beats/min) and without (91.2 ± 18.6 beats/min) the arm sling, it was significantly decreased while walking with the arm sling. When we compared the gait speed between walking with (32.8 m/min) and without (30.1 m/min), it was significantly increased with the arm sling walking. The O₂ rate in hemiplegic patients walking with the arm sling was significantly decreased by 7%, compared to walking without arm sling (5.8 mL/kg min and 6.2 mL/kg min, respectively). The O₂ cost in hemiplegic patients walking without arm sling was significantly 1.4 times greater than walking with it (0.2 mL/kg m and 0.3 mL/kg m, respectively). Conclusion: An arm sling can be used to improve the gait efficiency.

Botulinum toxin type A (BTX-A) injections improve muscle tone and range of motion (ROM) among stroke patients with upper limb spasticity. However, the efficacy of BTX-A injections for improving active function is unclear. We aimed to determine whether BTX-A injections with electrical stimulation (ES) of hand muscles could improve active hand function (AHF) among chronic stroke patients. Our open-label, pilot study included 15 chronic stroke patients. Two weeks after BTX-A injections into the finger and/or wrist flexors, ES of finger extensors was performed while wearing a wrist brace for 4 weeks (5 days per week; 30-min sessions). Various outcomes were assessed at baseline, immediately before BTX-A injections, and 2 and 6 weeks after BTX-A injections. After the intervention, we noted significant improvements in Box and Block test results, Action Research Arm Test results, the number of repeated finger flexions/extensions, which reflect AHF, and flexor spasticity. Moreover, significant improvements in active ROM of wrist extension values were accompanied by marginally significant changes in Medical Research Council wrist extensor and active ROM of wrist flexion values. In conclusion, BTX-A injections into the finger and/or wrist flexors followed by ES of finger extensors improve AHF among chronic stroke patients.

Objective To evaluate the clinical utility of the electrically calculated quantitative pain degree (QPD) and to correlate it with subjective assessments of pain degree including a visual analogue scale (VAS) and the McGill Pain Questionnaire (MPQ). Methods We recruited 25 patients with low back pain. Of them, 21 patients suffered from low back pain for more than 3 months. The QPD was calculated using the PainVision (PV, PS-2100; Nipro Co., Osaka, Japan). We applied electrodes to the medial forearm of the subjects and the electrical stimulus was amplified sequentially. Minimum perceived current (MPC) and pain equivalent current (PEC) were defined as minimum electrical stimulation that could be sensed by the subject and electrical stimulation that could trigger actual pain itself. To eliminate individual differences, we defined QPD as the following: QPD=PEC-MPC/MPC. We scored pre-treatment QPD three times at admission and post-treatment QPD once at discharge. The VAS, MPQ, and QPD were evaluated and correlations between the scales were analyzed. Results Result showed significant test-retest reliability (ICC=0.967, p<0.001) and the correlation between QDP and MPQ was significant (at admission SRCC=0.619 and p=0.001; at discharge SRCC=0.628, p=0.001). However, the correlation between QPD and VAS was not significant (at admission SRCC=0.240, p=0.248; at discharge SRCC=0.289, p=0.161). Conclusion Numerical values measured with PV showed consistent results with repeated calculations. Electrically measured QPD showed an excellent correlation with MPQ but not with VAS. These results demonstrate that PV is a significantly reliable device for quantifying the intensity of low back pain.