Serum activity of matrix metalloproteinase-2 and -9 is increased in chronic post-stroke individuals: a cross-sectional exploratory study.

BACKGROUND: High concentrations of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) are associated with inflammation early after stroke. In chronic stages, the elevation of some cytokines is related to the presence of co-morbid conditions in these individuals. In addition to this, some characteristics such as sensorimotor impairment, atrophy, and sedentary lifestyle predispose the system to an inflammatory response. OBJECTIVE: To quantify MMP-2 and -9 serum activity in chronic post-stroke individuals and correlate it with variables of physical activity level, body composition, functional and walking capacity, and with inflammatory biomarkers. Additionally, gelatinase activity was characterized according to motor impairment. METHODS: Fourteen patients with stroke onset >6 months and seven healthy individuals were enrolled in this study. The clinical assessment included: body composition, measure by bioelectrical impedance analyzer; Fugl-Meyer Motor Assessment Scale; six-minute and ten-meter walk tests, and physical activity level assessed by the StepWatch® Activity Monitor. Blood samples were collected from antecubital vein and serum MMP-2 and -9 activity was analyzed using gelatin Zymography, and the TNFα, IL-6, IL-1ß, IL-10 biomarkers using ELISA kits. RESULTS: Chronic post-stroke individuals presented an increased activity of MMP-2 and -9 compared to healthy individuals. Positive correlations with time and steps in low cadence and negative ones with medium cadence and peak activity index were observed. According to the motor impairment, the MMP-2 activity was increased in the mild-moderate group compared to the control group. CONCLUSION: Increased gelatinases in chronic post-stroke individuals could describe an inflammation process related to the limited capacity of walking in high intensities.

Adiponectin Concentration and Chronic Stroke Individuals, Associations with Body Composition, Physical Activity Levels and Lipid Profile: A Cross-Sectional Explorative Study.

OBJECTIVE: Higher adiponectin concentration has been associated with the presence of sarcopenia in individuals with cardiovascular diseases. Post-stroke individuals presented higher adiponectin concentrations than non-stroke ones. However, no previous study has investigated the association between the adiponectin concentration and skeletal muscle mass in post-stroke individuals. On the other hand, higher adiponectin concentration has been associated with a more favorable lipid profile and the physical activity level might regulate adiponectin concentration. These associations have not been studied in this population. Thus, the main objective of this study was to determine whether the adiponectin concentration is associated with: (1) body composition; (2) lipid profile; and (3) physical activity level in chronic post-stroke individuals. MATERIALS AND METHODS: This study was a correlational, cross-sectional exploratory study. Data on body composition and lipid profile were collected using a bioelectrical impedance analyzer (InBody® 720) and an automated method analyzer (CELL-DYN Ruby), respectively. The physical activity level was measured by the StepWatch® Activity Monitor and the serum adiponectin concentration was analyzed using an enzyme-linked immunosorbent assay kit. Correlation analyses were made using Spearman's rank correlation coefficient (rs). RESULTS: Twenty-one post-stroke participants took part in the study. The adiponectin concentration was associated with the following: skeletal muscle mass (rs = -0.78), skeletal muscle mass index (rs = -0.75) and high-density lipoprotein (rs = 0.43). CONCLUSIONS: A greater adiponectin concentration is associated with a lower skeletal muscle mass and a higher high-density lipoprotein level in chronic post-stroke individuals, but not with physical activity levels.

Decreased Brain-Derived Neurotrophic Factor Serum Concentrations in Chronic Post-Stroke Subjects.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) plays a critical role in sensorimotor recovery after a stroke. However, few studies have assessed the circulating BDNF levels in post-stroke humans to understand its changes. This study was conducted to measure BDNF serum concentrations in subjects with chronic hemiparesis, as well as to correlate serum concentrations with age, post-stroke time, total score of Stroke Specific Quality of Life Scale (SS-QOL), mobility subscale score, and motor function of SS-QOL. METHODS: Seventeen chronic post-stroke subjects matched by age and gender with healthy controls took part in the study. Personal data (age, hemiparesis side, and post-stroke time) were collected, and a physical examination (weight, height, body mass index) and SS-QOL assessment were carried out. On the same day, after the initial evaluation, venous blood samples were collected from the chronic post-stroke subjects and the healthy subjects. The BDNF serum concentrations were measured blindly by enzyme-linked immunosorbent assay. RESULTS: Subjects with chronic hemiparesis presented a decrease in BDNF serum compared with healthy subjects (P < .01). There was no correlation between BDNF serum levels with post-stroke time, age or quality of life, mobility, and the upper extremity motor function (P > .05). BDNF concentrations are related to structural and functional recovery after stroke; thus, this reduction is important to understand the rehabilitation process more clearly. However, more studies are needed considering the genetic variations and other tools to assess motor impairment and functional independence. CONCLUSION: Chronic post-stroke subjects presented a decrease in BDNF serum concentrations, without a correlation with post-stroke time, age, and quality of life.

Torque steadiness and muscle activation are bilaterally impaired during shoulder abduction and flexion in chronic post-stroke subjects.

OBJECTIVE: To characterize sensorimotor control and muscle activation in the shoulder of chronic hemiparetic during abduction and flexion in maximal and submaximal isometric contractions. Furthermore, to correlate submaximal sensorimotor control with motor impairment and degree of shoulder subluxation. METHODS: Thirteen chronic hemiparetic post-stroke age-gender matched with healthy were included. Isometric torques were assessed using a dynamometer. Electromyographic activity of the anterior and middle deltoid, upper trapezius, pectoralis major and serratus anterior muscles were collected. Variables were calculated for torque: peak, time to target, standard deviation (SD), coefficient of variation (CV), and standard error (RMSE); for muscle activity: maximum and minimum values, range and coefficient of activation. Motor impairment was determined by Fugl-Meyer and shoulder subluxation was measured with a caliper. RESULTS: Paretic and non-paretic limbs reduced peak and muscle activation during maximal isometric contraction. Paretic limb generated lower force when compared with non-paretic and control. Paretic and non-paretic presented higher values of SD, CV, RMSE, and CV for prime mover muscles and minimum values for all muscles during steadiness. No correlation was found between sensorimotor control, motor impairment and shoulder subluxation. CONCLUSION: Chronic hemiparetic presented bilateral deficits in sensorimotor and muscle control during maximal and submaximal shoulder abduction and flexion.

Intrinsic properties and functional changes in spastic muscle after application of BTX-A in children with cerebral palsy: systematic review.

OBJECTIVE: This article aimed to review the literature to verify the effect of botulinum toxin type A (BTX-A) on the intrinsic properties of spastic muscles and functionality in children with cerebral palsy (CP). METHODS: A literature search was conducted in the following databases: CINAHL, SCOPUS, Web of Science and PubMed. Database searches were limited to the period from January 1993 to March 2014. RESULTS: A total of 2182 papers were identified, and 17 met the inclusion criteria. Only one study analyzed the effect of the toxin on muscle intrinsic properties and others analyzed the effect on functionality. CONCLUSION: BTX-A application demonstrated no changes in the passive stiffness of spastic muscle. In relation to functional level, the evidence of BTX-A effect was controversial. These studies showed methodological quality limitations that restrict the interpretation of the results for the entire CP population, which justifies the need for further randomized controlled trials.