Marcos Antônio de Resende

Blockade of Opioid Receptors in the Medullary Reticularis Nucleus Dorsalis, but not the Rostral Ventromedial Medulla, Prevents Analgesia Produced by Diffuse Noxious Inhibitory Control in Rats With Muscle Inflammation

UNLABELLED Diffuse Noxious Inhibitory Controls (DNIC) involves application of a noxious stimulus outside the testing site to produce analgesia. In human subjects with a variety of chronic pain conditions, DNIC is less effective; however, in animal studies, DNIC is more effective after tissue injury. While opioids are involved in DNIC analgesia, the pathways involved in this opioid-induced analgesia are not clear. The aim of the present study was to test the effectiveness of DNIC in inflammatory muscle pain, and to study which brainstem sites mediate DNIC- analgesia. Rats were injected with 3% carrageenan into their gastrocnemius muscle and responses to cutaneous and muscle stimuli were assessed before and after inflammation, and before and after DNIC induced by noxious heat applied to the tail (45 °C and 47 °C). Naloxone was administered systemically, into rostral ventromedial medulla (RVM), or bilaterally into the medullary reticularis nucleus dorsalis (MdD) prior to the DNIC-conditioning stimuli. DNIC produced a similar analgesic effect in both acute and the chronic phases of inflammation reducing both cutaneous and muscle sensitivity in a dose-dependent manner. Naloxone systemically or microinjected into the MdD prevented DNIC-analgesia, while naloxone into the RVM had no effect on DNIC analgesia. Thus, DNIC analgesia involves activation of opioid receptors in the MdD. PERSPECTIVE The current study shows that DNIC activates opioid receptors in the MdD, but not the RVM, to produce analgesia. These data are important for understanding clinical studies on DNIC as well as for potential treatment of chronic pain patients.

Force-displacement relationship during anteroposterior mobilization of the ankle joint.

OBJECTIVE The purpose of this study was to determinate the correlation between force and displacement during passive anteroposterior mobilization of the talus and the effect of this treatment technique on ankle dorsiflexion range of motion (ROM). METHODS This is an exploratory, methodological study. Maitland grades III and IV mobilization were applied on the right ankle of 25 healthy subjects (mean age +/- standard deviation, 25.08 +/- 3.01 years) by 2 randomized raters (A and B). Applied forces were measured using a small force plate and displayed for the rater on a computer monitor. Linear displacement of the ankle joint was quantified by a motion analysis system. Synchronization of these 2 systems was obtained by software. Dorsiflexion active ROM, before and after mobilization, was assessed using a biplane goniometer. Statistical analysis was performed using the Pearson correlation coefficient for force and displacement variables and the paired t test to compare dorsiflexion ROM mean values. RESULTS A fair positive correlation was found between force range and displacement (r = 0.370; P = .049, 1-tailed), and a fair negative correlation was found between minimum forces and displacement (r = 0.404; P = .035, 1-tailed), only for rater A data. Significant increase in dorsiflexion was found in the right ankle (P = .035), comparing ROM before and after mobilization, which did not occur in the left ankle. CONCLUSIONS These data do not support a linear force-displacement relationship during Maitland grades III and IV passive joint mobilization, although they confirmed an increase in ankle dorsiflexion ROM immediately after joint mobilization. The use of visual feedback may increase interrater reliability of forces applied during ankle joint mobilization.

Aplicação da versão brasileira do questionário de dor Mcgill em idosos com dor crônica

Chronic pain is a multidimensional experience that involves sensory-perceptual affective-motivational and cognitive-evaluation aspects, which interact and contribute to the ultimate painful response. The characteristic changes of the aging process on each of these aspects can interfere with the experience of pain, thus making appropriate assessment more difficult. The use of multidimensional scales, such as the McGill Pain Questionnaire (MPQ) makes more appropriate evaluations possible. The aims of this study were to assess the intra- and inter-examiner reliability of the Brazilian Version of the MPQ (Br-MPQ) and characterize the perceptions of chronic pain in elderly individuals with orthopedic and neurological diseases. The sample consisted of 19 elderly individuals (71.21  7.51 yrs) with orthopedic (G1) and 19 (69.79  5.30 yrs) with neurological diseases (G2), all with a clinical diagnosis of chronic pain but no cognitive alterations. The general intra- and inter- examiner reliability was 0.86 and 0.89 for G1, and 0.71 and 0.68 for G2, respectively (p<0.05). The results showed that the Br-MPQ was easily applied to a group of elderly individuals with chronic pain (8.54  2.35 minutes). The present study demonstrated that the Br-MPQ can be more effective to assess pain in the elderly, as the perception of this symptom is more associated to sensorial, affective, and subjective aspects than to pain intensity.Chronic pain is a multidimensional experience that involves sensory-perceptual affective-motivational and cognitive-evaluation aspects, which interact and contribute to the ultimate painful response. The characteristic changes of the aging process on each of these aspects can interfere with the experience of pain, thus making appropriate assessment more difficult. The use of multidimensional scales, such as the McGill Pain Questionnaire (MPQ) makes more appropriate evaluations possible. The aims of this study were to assess the intraand inter-examiner reliability of the Brazilian Version of the MPQ (Br-MPQ) and characterize the perceptions of chronic pain in elderly individuals with orthopedic and neurological diseases. The sample consisted of 19 elderly individuals (71.21  7.51 yrs) with orthopedic (G1) and 19 (69.79  5.30 yrs) with neurological diseases (G2), all with a clinical diagnosis of chronic pain but no cognitive alterations. The general intraand interexaminer reliability was 0.86 and 0.89 for G1, and 0.71 and 0.68 for G2, respectively (p<0.05). The results showed that the Br-MPQ was easily applied to a group of elderly individuals with chronic pain (8.54  2.35 minutes). The present study demonstrated that the Br-MPQ can be more effective to assess pain in the elderly, as the perception of this symptom is more associated to sensorial, affective, and subjective aspects than to pain intensity. Key-woRds chronic pain, McGill Pain Questionnaire, elderly ____ Received on February 21, 2006 and accepted on June 14, 2006 1Departament of Physical Therapy of Universidade Federal de Minas Gerais 2Physical Therapists Address correspondence to: Dra. Leani Souza Máximo Pereira, Dep. de Fisioterapia da Escola de Ed. Física , Fisioterapia e Ter. Ocupacional da Univ. Federal de MG Av. Antonio Carlos, 6627, Campus da Pampulha, Belo Horizonte, Minas Gerais, Brazil CEP:31270-901, phone/fax n.:55-31-3499-4783 e-mail: leanismp.bh@zaz.com.br

Redução do efeito analgésico da estimulação elétrica nervosa transcutânea de baixa freqüência em ratos tolerantes à morfina

OBJECTIVE: To investigate the effects of low (10 Hz) and high-frequency (130 Hz) transcutaneous electrical nerve stimulation (TENS) applied to inflamed paws of rats following chronic treatment with morphine. METHOD: 140 female Holtzman rats were utilized. Carrageenan (250 µg/0.1 ml) was administered to the right hind paws to induce inflammation. Two and a half hours after carrageenan injection, low and high frequency TENS was applied to the inflamed paw for 20 min, and its effect was measured via the Randall-Selitto method. The opioid antagonist naltrexone (3.0 mg/kg, subcutaneously) was administered 30 min before TENS, to verify the release of endogenous opioids. Morphine tolerance (10 mg/kg, subcutaneously) was induced by twice-daily injection over seven days. Low and high frequency TENS treatment was carried out on the eighth day, 2.5 hours after carrageenan injection. Statistical analysis was performed using one-way analysis of variance (ANOVA), followed by the post hoc Bonferroni test, with a significance level of p < 0.05. RESULTS: Both low and high frequency produced 100% inhibition of carrageenan-induced hyperalgesia. Naltrexone-treated animals showed complete reversion of analgesia induced by low but not high-frequency TENS. After attaining morphine tolerance, the low-frequency TENS values indicated complete absence of analgesia, whereas high-frequency TENS induced anti-hyperalgesia. CONCLUSION: The analgesic activity of low-frequency TENS is reduced following the development of morphine tolerance.

Hyperalgesia and Edema Responses Induced by Rat Peripheral Blood Mononuclear Cells Incubated with Carrageenin

The aim of this study was to verify the role played by mononuclear cells in an acute (nonimmune) inflammatory reaction. Mononuclear cells purified from rat peripheral blood were incubated for 1, 2, or 24 h with 100 or 250 μg/ml carrageenin (Cg). The resultant donor supernatant was injected into recipient rats to test its ability to induce hyperalgesia (reduction in threshold for paw pressure) and edema (increase in paw volume). Mononuclear cell supernatants (MnS) induced a significant time- and dose-dependent hyperalgesia and edema in rat paws, which reached a maximal effect at 3 h, lasted for 6 h, and returned to basal levels at 24 h of injection. Prostaglandins and cytokines (interleukin 1, 2, 6, 8, and tumor necrosis factor alpha) accounted for the hyperalgesia induced by MnS, as it was reduced (40 to 90%) by synthesis inhibitors such as indomethacin, dexamethasone, rolipram, and cyclosporin added to the cultures at a microgram dose-range. Edema was dependent on serotonin release in rat paws. These results indicate that mononuclear cells may be important contributors to acute inflammatory reactions, especially under those conditions where pain is an important component.

Immediate Effect of a Single Anteroposterior Talus Mobilization on Dorsiflexion Range of Motion in Participants With Orthopedic Dysfunction of the Ankle and Foot

OBJECTIVE The purpose of this study was to determine the immediate effects of a single anteroposterior mobilization of the talus on the active dorsiflexion range of motion (ROM) in participants with different orthopedic foot and ankle injuries. METHODS This study included 30 male and female participants aged 18 to 50 years with unilateral orthopedic foot and ankle dysfunction. All participants underwent 3 sets of active dorsiflexion ROM measurement in both ankles. Measurements included baseline, post-first treatment, and post-second treatment values. Participants received either joint mobilization or manual contact (control) on the affected ankle. Active dorsiflexion ROM was assessed using a biplanar goniometer with participants in the prone position and 90° of knee flexion. RESULTS Both groups (joint mobilization and manual contact) showed increased active dorsiflexion ROM. However, the mean difference of dorsiflexion measurements before and after mobilization was greater than before and after control treatment. CONCLUSION A single session of articular mobilization of the talus did not significantly increase dorsiflexion ROM in participants with orthopedic dysfunctions of the ankle and foot compared with a manual contact procedure.

Instrumentos clínicos de avaliação funcional do tornozelo: revisão sistemática

Lateral ankle sprain is the most common injury among athletes and physically active adults. The adoption of valid and reliable clinical assessment instruments is basic for determining the most adequate therapeutic intervention, hence to achieve better rehabilitation. This is a systematic literature review to search for available and reliable outcome measures (questionnaires and functional scales) in the assessment of individuals who suffered lateral ankle sprain. After a search in Medline and Scielo databases a total of 11 instruments were selected and critically analysed. The Lower Extremity Functional Scale and the Foot and Ankle Ability Measure showed the best methodological properties and provided more information concerning measurement features and clinical application (but have not been translated into Portuguese). Two instruments were found that were translated and culturally adapted for the Brazilian people, the CAIT (Cumberland Ankle Instability Tool) and the AOFAS (American Orthopaedic Foot and Ankle Society - ankle-hindfoot scale). The AOFAS was found to present a more thorough analysis of its properties and applicability, being thus suggested to be used for functional assessment of ankle and hindfoot in Brazil.

Estudo da confiabilidade da força aplicada durante a mobilização articular ântero-posterior do tornozelo

Reliability Study on the Force Applied During Anteroposterior Mobilization of the Ankle Joint Background: Factors that contribute towards the efficiency of joint mobilization maneuvers is the intensity and reproducibility of the force applied during mobilization, by one or more examiners. Objective: To evaluate the intra and inter-examiner reliability of Maitland grade III and IV anteroposterior mobilization force on the ankle joint. Method: Two experienced examiners mobilized both ankles of thirty-five healthy subjects. A force platform was positioned under the calves of these subjects to detect the forces applied during the maneuvers. The signals were converted and recorded using the DasyLab 4.0 software. The maximum and minimum peak forces from the curves obtained were then analyzed. The intraclass correlation coefficient (ICC) was used to assess the intra and inter-examiner reliability. To evaluate any systematic error in the measurements, the paired t-test was utilized on the intra-examiner data and the t-test for independent samples for the inter-examiner data. The Bland & Altman method was used to assess the concordance limits for the measurements from the two examiners. Results: The data showed high intraexaminer reliability. The inter-examiner reliability was low and moderate for the maximum and minimum forces respectively, during anteroposterior mobilization of the ankle joint. Conclusions: These data suggest that the force applied during Maitland grade III and IV mobilization of the ankle joint presents high intra-examiner reliability and low inter-examiner reliability.

Translation, cross-cultural adaptation and validity of the Brazilian version of the Foot and Ankle Ability Measure questionnaire

Abstract Purpose: To translate and cross-culturally adapt the Foot and Ankle Ability Measure (FAAM) questionnaire and verify the psychometric properties of the Brazilian–Portuguese version of this instrument. Methods: Analysis of validity was carried out by applying the Rasch model and evaluating correlations with the Short Form-36 (SF-36) Physical Function (PF) subscale. Test–retest reliability and internal consistency were analyzed with the intraclass correlation coefficient (ICC2,1) and Cronbach’s alpha tests, respectively. Results: Ninety subjects with various foot and ankle musculoskeletal disorders (age 37.05 SD 10.49 years) were included. The ICC2,1 was 0.88 and 0.82 with Cronbach’s alphas of 0.93 and 0.90 for the “Activities of Daily Living” (ADL) and “Sports” subscales, respectively. Correlations with the SF-36 PF were 0.78 (p < 0.01, CI95: 0.62–0.87) and 0.65 (p < 0.01, CI95: 0.45–0.79) for the ADL and Sports subscales, respectively. Item reliability indices in Rasch analysis were 0.91 (ADL) and 0.84 (Sports). Three items from the ADL subscale (14.2%) did not match the expectations of the model. All items from the Sports subscale fit the model. Conclusions: There is evidence of validity and reliability of the FAAM-Brazil. Rasch analysis indicated that three items of the ADL subscale did not fit the model in the sample studied. Implications for Rehabilitation Self-report questionnaires are commonly used in both clinical practice and research because of their ability to efficiently collect information. If the instrument is created properly, the information collected can be used to interpret the effect of clinical conditions on physical function. The Foot and Ankle Ability Measure (FAAM) is an evaluative instrument that assesses functional limitations for those with foot- and ankle-related disorders. It was translated into four languages and has evidence of validity, reliability, and responsiveness. Evidence of validity and reliability is provided for the FAAM-Brazil when applied to subjects with a wide range of foot and ankle musculoskeletal disorders.

Effects of Anteroposterior Talus Mobilization on Range of Motion, Pain, and Functional Capacity in Participants With Subacute and Chronic Ankle Injuries: A Controlled Trial

Objective: The purpose of this study was to measure the acute (1 session) and chronic effects (6 sessions) and the follow‐up (2 weeks) of anteroposterior articular mobilization of the talus, grade III of Maitland, on the dorsiflexion range of motion (ROM), pain, and functional capacity of individuals with subacute and chronic traumatic injuries of the ankle. Methods: Thirty‐eight volunteers, men and women, with a mean age of 40.8 years, with subacute and chronic ankle injuries participated. The volunteers were blinded to the study purpose and were allocated into the experimental group (EG) or sham group (SG). Dorsiflexion ROM, pain, and functional capacity were measured using the universal goniometer, visual analog scale, and Foot and Ankle Ability Measure, respectively. Measurements were taken on 4 different occasions: (1) baseline, (2) after the first session, (3) after the sixth session, and (4) at follow‐up. Articular anteroposterior mobilization of the talus grade III of Maitland was applied to the EG, whereas manual contact was applied to the SG. Three series of 30 seconds each with a 30‐second rest interval between the series were conducted. Results: Significant increases in ankle dorsiflexion ROM were observed only for the EG after the first (EG: 9.5 ± 1.1; SG: 7.6 ± 1.1) and sixth (EG: 12.8 ± 1.2; SG: 8.4 ± 1.2) sessions and were maintained at follow‐up (EG: 13.2 ± 1.1; SG: 9.3 ± 1.3). Decreases in pain and improvements in functional capacity (FC) were identified for both groups after the first and sixth sessions (Pain, EG: 1.3 ± 0.5; SG: 1.8 ± 0.6 and EG: 0.7 ± 0.3; SG: 0.7 ± 0.3; FC, EG: 64.6 ± 3.5; SG: 67.4 ± 4.4 and EG: 79.9 ± 3.3; SG: 86.2 ± 3.3) and remained at follow‐up (Pain, EG: 0.3 ± 0.2; SG: 0.5 ± 0.3; FC, EG: 86.8 ± 2.7; SG: 89.8 ± 3.7). Conclusion: Articular grade III mobilization improved ankle dorsiflexion ROM, when compared with the SG. Changes in pain and functional capacity were similar in both groups.