Immobilization-induced hypersensitivity associated with spinal cord sensitization during cast immobilization and after cast removal in rats

This study examined mechanical and thermal hypersensitivity in the rat hind paw during cast immobilization of the hind limbs for 4 or 8 weeks and following cast removal. Blood flow, skin temperature, and volume of the rat hind paw were assessed in order to determine peripheral circulation of the hind limbs. Sensitization was analyzed by measuring the expression of the calcitonin gene-related peptide (CGRP) in the spinal dorsal horn following cast immobilization. Two weeks post immobilization, mechanical and thermal sensitivities increased significantly in all rats; however, peripheral circulation was not affected by immobilization. Cast immobilization for 8 weeks induced more serious hypersensitivity compared to cast immobilization for 4 weeks. Moreover, CGRP expression in the deeper lamina layer of the spinal dorsal horn increased in the rats immobilized for 8 weeks but not in those immobilized for 4 weeks. These findings suggest that immobilization-induced hypersensitivity develops during the immobilization period without affecting peripheral circulation. Our results also highlight the possibility that prolonged immobilization induces central sensitization in the spinal cord.The final publication is available at link.springer.co

Hyperalgesia in an immobilized rat hindlimb: Effect of treadmill exercise using non-immobilized limbs

Cast immobilization of limbs causes hyperalgesia, which is a decline of the threshold of mechanical and thermal mechanical stimuli. The immobilization-induced hyperalgesia (IIH) can disturb rehabilitation and activities of daily living in patients with orthopedic disorders. However, it is unclear what therapeutic and preventive approaches can be used to alleviate IIH. Exercise that activates the descending pain modulatory system may be effective for IIH. The purpose of this study was to investigate the effects of treadmill exercise during the immobilization period, using the non-immobilized limbs, on IIH. Thirty-six 8-week-old Wistar rats were randomly divided into (1) control, (2) immobilization (Im), and (3) immobilization and treadmill exercise (Im. +. Ex) groups. In the Im and Im. +. Ex groups, the right ankle joints of each rat were immobilized in full plantar flexion with a plaster cast for an 8-week period. In the Im. +. Ex group, treadmill exercise (15. m/min, 30. min/day, 5 days/week) was administered during the immobilization period while the right hindlimb was kept immobilized. Mechanical hyperalgesia was measured using von Frey filaments every week. To investigate possible activation of the descending pain modulatory system, beta-endorphin expression levels in hypothalamus and midbrain periaqueductal gray were analyzed. Although IIH clearly occurred in the Im group, the hyperalgesia was partially but significantly reduced in the Im. +. Ex group. Beta-endorphin, which is one of the endogenous opioids, was selectively increased in the hypothalamus and midbrain periaqueductal gray of the Im. +. Ex group. Our data suggest that treadmill running using the non-immobilized limbs reduces the amount of hyperalgesia induced in the immobilized limb even if it is not freed. This ameliorating effect might be due to the descending pain modulatory system being activated by upregulation of beta-endorphin in the brain

拡散テンソル画像を用いた脳卒中後の運動麻痺の予後予測

Purpose: Diffusion tensor imaging (DTI) has garnered attention regarding the prediction of patient outcomes following stroke and its application in clinical practice is expected. Here, we evaluated the usefulness of combination analysis with fractional anisotropy (FA) and tractography parameters in order to build an optimal DTI protocol to predict motor recovery after stroke. Subjects and Methods: We recruited 35 consecutive patients with supratentorial hemorrhagic or ischemic stroke. DTI examination took place 14－16 days after stroke onset and the bilateral cerebral peduncles were regions of interest for the FA and tractography analyses. Three months after stroke, Brunnstrom recovery stage (BRS) scoring of the upper limb and fingers was performed. We tested correlations between the FA ratio (rFA) of the bilateral cerebral peduncles, tractography findings, and BRS scores. Results: A significant correlation was identified between rFA and 3-month BRS score (r ＝ 0.465, p = 0.008). The pattern of tractography was divided into 2 groups (complete-disrupted type and incomplete-disrupted type). The patients with the incomplete-disrupted type had significantly higher rFA (p = 0.008) and BRS scores (p < 0.001). After excluding patients with the complete-disrupted type who had high rFA, we observed statistically significant strong positive correlations between rFA and the BRS scores (r = 0.728, p < 0.001). Conclusions: Combination analysis with FA and tractography may be a useful predictor of motor recovery in the acute phase of stroke.目的：脳卒中後の運動麻痺の予後を予測する方法として拡散テンソル画像（DTI）が注目されており，その臨床応用が期待されている．そこで本研究では，脳卒中後の運動麻痺の予後予測における最適なDTIプロトコールを構築するために拡散異方性（FA）と tractography の組み合わせによる解析の有用性を検証した．方法：本研究では脳出血，脳梗塞を呈した35名を対象とした．DTI は脳卒中発症14 ～ 16病日目に撮像し，大脳脚を関心領域としFA及び tractography を抽出した．また身体機能は脳卒中発症 3 か月後に上肢と手指の Brunnstrom stage （BRS）を用いて評価した．解析は，tractography による皮質脊髄路の評価とrFA（両側大脳脚の FA 比）を組み合わせ，BRSとの相関関係を調査した．結果：rFAと 3 ヶ月後の BRS スコアとの間には，有意な正の相関を認めた（r = 0.465, p = 0.008）．Tractographyは 2 群（complete-disrupted type and incomplete-disrupted type） に分けられ，completedisrupted type に比べ incomplete-disrupted type は，rFA（p = 0.008）および BRS スコア（p < 0.001）が有意に高かった．高い rFA を有する complete-disrupted type の患者を除外した後の rFA と BRS スコアとの間には，より強い正の相関を認めた（r = 0.728, p < 0.001）．結論：FAと tractography を組み合わせて解析することは，急性期脳卒中患者における運動麻痺の有用な予測因子である可能性が示唆された

拡散テンソル画像を用いた脳卒中後の運動麻痺の予後予測

Purpose: Diffusion tensor imaging (DTI) has garnered attention regarding the prediction of patient outcomes following stroke and its application in clinical practice is expected. Here, we evaluated the usefulness of combination analysis with fractional anisotropy (FA) and tractography parameters in order to build an optimal DTI protocol to predict motor recovery after stroke. Subjects and Methods: We recruited 35 consecutive patients with supratentorial hemorrhagic or ischemic stroke. DTI examination took place 14－16 days after stroke onset and the bilateral cerebral peduncles were regions of interest for the FA and tractography analyses. Three months after stroke, Brunnstrom recovery stage (BRS) scoring of the upper limb and fingers was performed. We tested correlations between the FA ratio (rFA) of the bilateral cerebral peduncles, tractography findings, and BRS scores. Results: A significant correlation was identified between rFA and 3-month BRS score (r ＝ 0.465, p = 0.008). The pattern of tractography was divided into 2 groups (complete-disrupted type and incomplete-disrupted type). The patients with the incomplete-disrupted type had significantly higher rFA (p = 0.008) and BRS scores (p < 0.001). After excluding patients with the complete-disrupted type who had high rFA, we observed statistically significant strong positive correlations between rFA and the BRS scores (r = 0.728, p < 0.001). Conclusions: Combination analysis with FA and tractography may be a useful predictor of motor recovery in the acute phase of stroke.目的：脳卒中後の運動麻痺の予後を予測する方法として拡散テンソル画像（DTI）が注目されており，その臨床応用が期待されている．そこで本研究では，脳卒中後の運動麻痺の予後予測における最適なDTIプロトコールを構築するために拡散異方性（FA）と tractography の組み合わせによる解析の有用性を検証した．方法：本研究では脳出血，脳梗塞を呈した35名を対象とした．DTI は脳卒中発症14 ～ 16病日目に撮像し，大脳脚を関心領域としFA及び tractography を抽出した．また身体機能は脳卒中発症 3 か月後に上肢と手指の Brunnstrom stage （BRS）を用いて評価した．解析は，tractography による皮質脊髄路の評価とrFA（両側大脳脚の FA 比）を組み合わせ，BRSとの相関関係を調査した．結果：rFAと 3 ヶ月後の BRS スコアとの間には，有意な正の相関を認めた（r = 0.465, p = 0.008）．Tractographyは 2 群（complete-disrupted type and incomplete-disrupted type） に分けられ，completedisrupted type に比べ incomplete-disrupted type は，rFA（p = 0.008）および BRS スコア（p < 0.001）が有意に高かった．高い rFA を有する complete-disrupted type の患者を除外した後の rFA と BRS スコアとの間には，より強い正の相関を認めた（r = 0.728, p < 0.001）．結論：FAと tractography を組み合わせて解析することは，急性期脳卒中患者における運動麻痺の有用な予測因子である可能性が示唆された

Effects of Physical-Agent Pain Relief Modalities for Fibromyalgia Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Purpose. We conducted a systematic review and meta-analysis to investigate the effects of the following physical-agent modalities for pain relief in fibromyalgia (FM) patients. Methods. We identified randomized controlled studies of adults with FM in the MEDLINE, CINAHL, and PEDro databases. The primary outcome measure was pain relief measured by a visual analogue scale (VAS), and the secondary outcome measures of interest were subjective improvements in the number of tender points, Fibromyalgia Impact Questionnaire (FIQ), and quality of life (QOL) scores. Results. Eleven studies were included in our review. The studies\u27 physical-agent modalities were low-level laser therapy (LLLT), thermal therapy, electromagnetic field therapy, and transcutaneous electrical nerve stimulation (TENS). LLLT did not reduce VAS scores, but it significantly reduced both the number of tender points and FIQ score. Thermal therapy was associated with significantly reduced VAS scores, tender points, and FIQ scores. Electromagnetic field therapy was associated with significantly reduced VAS score and FIQ score. TENS significantly reduced VAS scores. Conclusion. Our analyses revealed that thermal therapy and LLLT had a partial effect on pain relief in FM patients, and this beneficial effect may have a positive influence on FM patients\u27 health status