Abstract WP317: High Metabolic Cost of Mobility and Balance Activities in Individuals Post-Stroke

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Michal Kafri ◽  
Mary Jane Myslinski ◽  
Venkata Gade ◽  
Judith E Deutsch

Purpose: Metabolic cost of walking at a comfortable speed for individuals post-stroke is higher than for healthy individuals. However, metabolic cost of other activities, relevant for community activity, such as transfer from sitting to standing and walking over obstacles, has not been reported. Hence, the aim of this study was to measure metabolic cost of mobility and balance activities for individuals post-stroke, and to assess the hypothesis that it will be higher than for healthy individuals. Methods: Eleven post-stroke (7 men, age 49.5±12.2), and 8 healthy (3 men, age 46.8±6.7) individuals of comparable height and weight participated in the study. Gait speed was measured and motor impairment was evaluated using the Fugl-Meyer test. Four activities were tested for their metabolic cost; walking at a comfortable speed, walking over an obstacle course, sit to walk and standing on balance foam while reaching forward. Each activity was performed repeatedly for 8 minutes, while metabolic measures were recorded. In addition, distance covered, or number of repetitions completed, during the activity were recorded. Metabolic cost of each activity was calculated by dividing the mean oxygen consumption of the last four minutes of the activity by the number of repetitions or walking speed. Results: The Fugl-Meyer scores for post-stroke individuals for lower and upper extremities were 23.6±6.5 and 43.6±19.3 respectively. Comfortable gait speed was 0.8±0.3 m/sec. for post-stroke and 1.4±0.1 m/sec. for healthy individuals. Groups were not significantly different in weight and height. Metabolic cost and between-group comparisons are shown in the table. Conclusion: The metabolic cost of the activities was significantly higher for individuals post stroke than for healthy, suggesting that rehabilitation programs should aim to improve economy of movement.

2021 ◽  
Author(s):  
Russell T Johnson ◽  
Nicholas August Bianco ◽  
James Finley

Several neuromuscular impairments, such as weakness (hemiparesis), occur after an individual has a stroke, and these impairments primarily affect one side of the body more than the other. Predictive musculoskeletal modeling presents an opportunity to investigate how a specific impairment affects gait performance post-stroke. Therefore, our aim was to use to predictive simulation to quantify the spatiotemporal asymmetries and changes to metabolic cost that emerge when muscle strength is unilaterally reduced. We also determined how forced spatiotemporal symmetry affects metabolic cost. We modified a 2-D musculoskeletal model by uniformly reducing the peak isometric muscle force in all muscles unilaterally. We then solved optimal control simulations of walking across a range of speeds by minimizing the sum of the cubed muscle excitations across all muscles. Lastly, we ran additional optimizations to test if reducing spatiotemporal asymmetry would result in an increase in metabolic cost. Our results showed that the magnitude and direction of effort-optimal spatiotemporal asymmetries depends on both the gait speed and level of weakness. Also, the optimal metabolic cost of transport was 1.25 m/s for the symmetrical and 20% weakness models but slower (1.00 m/s) for the 40% and 60% weakness models, suggesting that hemiparesis can account for a portion of the slower gait speed seen in people post-stroke. Adding spatiotemporal asymmetry to the cost function resulted in small increases (~4%) in metabolic cost. Overall, our results indicate that spatiotemporal asymmetry may be optimal for people post-stroke, who have asymmetrical neuromuscular impairments. Additionally, the effect of speed and level of weakness on spatiotemporal asymmetry may explain the well-known heterogenous distribution of spatiotemporal asymmetries observed in the clinic. Future work could extend our results by testing the effects of other impairments on optimal gait strategies, and therefore build a more comprehensive understanding of the gait patterns in people post-stroke.


2008 ◽  
Vol 64 (2) ◽  
Author(s):  
M.R. Modisane ◽  
A. Stewart ◽  
M. Riley

The aim of this study was to investigate the effects of the useof a knee brace on 15 subjects with hypertonic hemiparesis. The middlecerebral artery was involved in all subjects. The Ashworth scale was usedto screen for the presence of spasticity in the quadriceps muscles.Measurements of gait speed, step and stride length were taken in the middle 10 metres of a 15 metre paper walkway. A comparison of these gait parameters without and with the use of a knee brace was made. A ques-tionnaire was also used to evaluate how subjects responded to the use of aknee brace.The results showed that the mean speed for all 15 subjects increased withthe use of a brace, (p = 0.05). Step and stride length without and with the use of a brace showed no statistical differences.It was therefore concluded that the FECK brace appears to have an effect on the walking speed of subjects withhypertonic  hemiparesis


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ronit Feingold-Polak ◽  
Anna Yelkin ◽  
Shmil Edelman ◽  
Amir Shapiro ◽  
Shelly Levy-Tzedek

AbstractImpairment in force regulation and motor control impedes the independence of individuals with stroke by limiting their ability to perform daily activities. There is, at present, incomplete information about how individuals with stroke regulate the application of force and control their movement when reaching, grasping, and lifting objects of different weights, located at different heights. In this study, we assess force regulation and kinematics when reaching, grasping, and lifting a cup of two different weights (empty and full), located at three different heights, in a total of 46 participants: 30 sub-acute stroke participants, and 16 healthy individuals. We found that the height of the reached target affects both force calibration and kinematics, while its weight affects only the force calibration when post-stroke and healthy individuals perform a reach-to-grasp task. There was no difference between the two groups in the mean and peak force values. The individuals with stroke had slower, jerkier, less efficient, and more variable movements compared to the control group. This difference was more pronounced with increasing stroke severity. With increasing stroke severity, post-stroke individuals demonstrated altered anticipation and preparation for lifting, which was evident for either cortical lesion side.


1993 ◽  
Vol 70 (05) ◽  
pp. 730-735 ◽  
Author(s):  
P Toulon ◽  
M Lamine ◽  
I Ledjev ◽  
T Guez ◽  
M E Holleman ◽  
...  

SummaryIn human plasma, heparin cofactor II (HCII) is a thrombin inhibitor, whose deficiency has been reported to be associated with recurrent thrombosis. The finding of two cases of low plasma HCII activity in two patients infected with the human immunodeficiency virus (HIV) led us to investigate this coagulation inhibitor in the plasma of a larger population of HIV-infected patients. The mean plasma HCII activity was significantly lower in 96 HIV-infected patients than in 96 age- and sex-matched healthy individuals (0.75 ± 0.24 vs 0.99 ± 0.17 U/ml, p <0.0001). HCII antigen concentration was decreased to the same extent as the activity. The proportion of subjects with HCII deficiency was significantly higher in the HIV-infected group than in healthy individuals (38.5% vs 2.1%). In addition, HCII was significantly lower in AIDS patients than in other HIV-infected patients, classified according to the Centers for Disease Control (CDC) on the basis of an absolute number of circulating CD4+ lymphocytes below 200 x 106/1. The link between HCII and immunodeficiency is further suggested by significant correlations between HCII activity and both the absolute number of CD4+ lymphocytes and the CD4+ to CD8+ lymphocyte ratio. Nevertheless, the mean HCII level was not different in the various groups of patients classified according to clinical criteria, except in CDC IVD patients in whom HCII levels were significantly lower. In addition, no correlation could be demonstrated between HCII and protein S activities, another coagulation inhibitor whose plasma level was also found to be decreased in HIV-infected patients. A similar prevalence of HCII deficiency was also found in a small series of 7 HIV-infected patients who developed thrombotic episodes, an unusual complication of the infection. This suggests that, in HIV-infected patients, HCII deficiency is not in itself the causative factor for the development of thrombosis.


2019 ◽  
Vol 16 (2) ◽  
pp. 184-197 ◽  
Author(s):  
Hossein Bakhtou ◽  
Asiie Olfatbakhsh ◽  
Abdolkhaegh Deezagi ◽  
Ghasem Ahangari

Background:Breast cancer is one of the common causes of mortality for women in Iran and other parts of the world. The substantial increasing rate of breast cancer in both developed and developing countries warns the scientists to provide more preventive steps and therapeutic measures. This study is conducted to investigate the impact of neurotransmitters (e.g., Dopamine) through their receptors and the importance of cancers via damaging immune system. It also evaluates dopamine receptors gene expression in the women with breast cancer at stages II or III and dopamine receptor D2 (DRD2) related agonist and antagonist drug effects on human breast cancer cells, including MCF-7 and SKBR-3.Methods:The patients were categorized into two groups: 30 native patients who were diagnosed with breast cancer at stages II and III, with the mean age of 44.6 years and they were reported to have the experience of a chronic stress or unpleasant life event. The second group included 30 individuals with the mean age of 39 years as the control group. In order to determine the RNA concentration in all samples, the RNA samples were extracted and cDNA was synthesized. The MCF-7 cells and SKBR-3 cells were treated with dopamine receptors agonists and antagonists. The MTT test was conducted to identify oxidative and reductive enzymes and to specify appropriate dosage at four concentrations of dopamine and Cabergoline on MCF-7 and SKBR-3 cells. Immunofluorescence staining was done by the use of a mixed dye containing acridine orange and ethidiume bromide on account of differentiating between apoptotic and necrotic cells. Flow cytometry assay was an applied method to differentiate necrotic from apoptotic cells.Results:Sixty seven and thirty three percent of the patients were related to stages II and III, respectively. About sixty three percent of the patients expressed ER, while fifty seven percent expressed PR. Thirty seven percent of the patients were identified as HER-2 positive. All types of D2-receptors were expressed in PBMC of patients with breast cancer and healthy individuals. The expression of the whole dopamine receptor subtypes (DRD2-DRD4) was carried out on MCF-7 cell line. The results of RT-PCR confirmed the expression of DRD2 on SKBR-3 cells, whereas the other types of D2- receptors did not have an expression. The remarkable differences in gene expression rates between patients and healthy individuals were revealed in the result of the Real-time PCR analysis. The over expression in DRD2 and DRD4 genes of PBMCs was observed in the patients with breast cancer at stages II and III. The great amount of apoptosis and necrosis occurred after the treatment of MCF-7 cells by Cabergoline from 25 to 100 µmolL-1 concentrations.Conclusion:This study revealed the features of dopamine receptors associated with apoptosis induction in breast cancer cells. Moreover, the use of D2-agonist based on dopamine receptors expression in various breast tumoral cells could be promising as a new insight of complementary therapy in breast cancer.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1358.1-1359
Author(s):  
C. Romero-Sánchez ◽  
W. Bautista-Molano ◽  
Y. M. Chamorro-Melo ◽  
A. Beltrán-Ostos ◽  
J. De Avila ◽  
...  

Background:HLA-B*27 has been identify as a susceptibility and prognostic factor associated to axial spondyloarthritis. HLA-B*27 allele has been described to be present in about 90% of patients with ankylosing spondylitis, and with a different frequency in patients with other subtypes of SpA. In contrast, this allele has been observed to be present only in 7–8% in general population. A remarkable heterogeneity in HLA-B*27 alleles has been reported. They have been determined at DNA sequence and some subtypes have been associated increasing the risk to develop the diseaseObjectives:To establish the frequencies of HLA-B27 subtypes in a group of Colombian patients with SpA and healthy populationMethods:In total, 61 Blood samples from Colombian mestizo individuals with SpA according to ASAS classification-criteria were evaluated by Sequencing Technology: Illumina Sequencing/PacBio Sequencing with analysis of the second and third exon. Results reported with six digits (including null alleles). In total, 294 results of peripheral blood from healthy individuals without joint symptoms were analyzed. Frequencies were obtained for demographic and genetic variables. Ethic Committee approval code 2018-020/2017-023Results:The SpA group had a mean age of 45,88 ± 11,67, 62.3% of them were male, 6.6% reported current smoking and 37.7% reported smoking sometime in life. In total, 67.2% had inflammatory back pain, 14.8% had dactylitis, 63.9% enthesitis and 57.4% arthritis. Thirty patients were HLA-B*27 positive with a genotypic frequency of 50.8% and an allelic frequency of 24.6%. In this group of patients, the mean age was 43,5 ± 11,8, 76.6% were male, 86.7% of them were subtype B*27:05:02g and 13.3% presented the B27:02:01g. None of the SpA patients had both B*27 alleles.On the other hand, the healthy individuals were men in 51.0% and the mean age was 37±15.4 years. Ten subjects were positive for the HLA-B*27 allele with a genotypic frequency of 3.4% and an allelic frequency of 1.7%. In this group of individuals 50.0% were male gender with a mean age of 38.4±17.9. No individuals were found to have the two alleles or homozygous for the B*27 allele. In all of them the subtype B*27:05:02g was observed in high-resolution sequencingConclusion:The SpA group had a mean age of 45,88 ± 11,67, 62.3% of them were male, 6.6% reported current smoking and 37.7% reported smoking sometime in life. In total, 67.2% had inflammatory back pain, 14.8% had dactylitis, 63.9% enthesitis and 57.4% arthritis. Thirty patients were HLA-B*27 positive with a genotypic frequency of 50.8% and an allelic frequency of 24.6%. In this group of patients, the mean age was 43,5 ± 11,8, 76.6% were male, 86.7% of them were subtype B*27:05:02g and 13.3% presented the B27:02:01g. None of the SpA patients had both B*27 alleles.On the other hand, the healthy individuals were men in 51.0% and the mean age was 37±15.4 years. Ten subjects were positive for the HLA-B*27 allele with a genotypic frequency of 3.4% and an allelic frequency of 1.7%. In this group of individuals 50.0% were male gender with a mean age of 38.4±17.9. No individuals were found to have the two alleles or homozygous for the B*27 allele. In all of them the subtype B*27:05:02g was observed in high-resolution sequencingAcknowledgments:Hospital Militar Central (Grant 2017-023/2018-020), the Government Institute of Science, Technology, and Innovation, Francisco Jose de Caldas—COLCIENCIAS (Grant No. 130877757442) and Colombian Rheumatology Association (Grant-Conv-2019)Disclosure of Interests:None declared


Author(s):  
Hadar Lackritz ◽  
Yisrael Parmet ◽  
Silvi Frenkel-Toledo ◽  
Melanie C. Baniña ◽  
Nachum Soroker ◽  
...  

Abstract Background Hemiparesis following stroke is often accompanied by spasticity. Spasticity is one factor among the multiple components of the upper motor neuron syndrome that contributes to movement impairment. However, the specific contribution of spasticity is difficult to isolate and quantify. We propose a new method of quantification and evaluation of the impact of spasticity on the quality of movement following stroke. Methods Spasticity was assessed using the Tonic Stretch Reflex Threshold (TSRT). TSRT was analyzed in relation to stochastic models of motion to quantify the deviation of the hemiparetic upper limb motion from the normal motion patterns during a reaching task. Specifically, we assessed the impact of spasticity in the elbow flexors on reaching motion patterns using two distinct measures of the ‘distance’ between pathological and normal movement, (a) the bidirectional Kullback–Liebler divergence (BKLD) and (b) Hellinger’s distance (HD). These measures differ in their sensitivity to different confounding variables. Motor impairment was assessed clinically by the Fugl-Meyer assessment scale for the upper extremity (FMA-UE). Forty-two first-event stroke patients in the subacute phase and 13 healthy controls of similar age participated in the study. Elbow motion was analyzed in the context of repeated reach-to-grasp movements towards four differently located targets. Log-BKLD and HD along with movement time, final elbow extension angle, mean elbow velocity, peak elbow velocity, and the number of velocity peaks of the elbow motion were computed. Results Upper limb kinematics in patients with lower FMA-UE scores (greater impairment) showed greater deviation from normality when the distance between impaired and normal elbow motion was analyzed either with the BKLD or HD measures. The severity of spasticity, reflected by the TSRT, was related to the distance between impaired and normal elbow motion analyzed with either distance measure. Mean elbow velocity differed between targets, however HD was not sensitive to target location. This may point at effects of spasticity on motion quality that go beyond effects on velocity. Conclusions The two methods for analyzing pathological movement post-stroke provide new options for studying the relationship between spasticity and movement quality under different spatiotemporal constraints.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manjot Kaur Grewal ◽  
Shruti Chandra ◽  
Alan Bird ◽  
Glen Jeffery ◽  
Sobha Sivaprasad

AbstractTo evaluate the effect of aging, intra- and intersession repeatability and regional scotopic sensitivities in healthy and age-related macular degeneration (AMD) eyes. Intra- and intersession agreement and effect of age was measured in healthy individuals. The mean sensitivity (MS) and pointwise retinal sensitivities (PWS) within the central 24° with 505 nm (cyan) and 625 nm (red) stimuli were evaluated in 50 individuals (11 healthy and 39 AMD eyes). The overall intra- and intersession had excellent reliability (intraclass correlation coefficient, ICC > 0.90) and tests were highly correlated (Spearman rs = 0.75–0.86). Eyes with subretinal drusenoid deposit (SDD) had reduced PWS centrally, particularly at inferior and nasal retinal locations compared with controls and intermediate AMD (iAMD) without SDD. There was no difference in MS or PWS at any retinal location between iAMD without SDD and healthy individuals nor between iAMD with SDD and non-foveal atrophic AMD groups. Eyes with SDD have reduced rod function compared to iAMD without SDD and healthy eyes, but similar to eyes with non-foveal atrophy. Our results highlight rod dysfunction is not directly correlated with drusen load and SDD location.


2017 ◽  
Vol 33 (12) ◽  
pp. 932-942 ◽  
Author(s):  
Mona Kristin Aaslund ◽  
Rolf Moe-Nilssen ◽  
Bente Bassøe Gjelsvik ◽  
Bård Bogen ◽  
Halvor Næss ◽  
...  

2016 ◽  
Vol 31 (2) ◽  
pp. 168-177 ◽  
Author(s):  
James M. Finley ◽  
Amy J. Bastian

Stroke survivors often have a slow, asymmetric walking pattern. They also walk with a higher metabolic cost than healthy, age-matched controls. It is often assumed that spatial-temporal asymmetries contribute to the increased metabolic cost of walking poststroke. However, elucidating this relationship is made challenging because of the interdependence between spatial-temporal asymmetries, walking speed, and metabolic cost. Here, we address these potential confounds by measuring speed-dependent changes in metabolic cost and implementing a recently developed approach to dissociate spatial versus temporal contributions to asymmetry in a sample of stroke survivors. We used expired gas analysis to compute the metabolic cost of transport (CoT) for each participant at 4 different walking speeds: self-selected speed, 80% and 120% of their self-selected speed, and their fastest comfortable speed. We also computed CoT for a sample of age- and gender-matched control participants who walked at the same speeds as their matched stroke survivor. Kinematic data were used to compute the magnitude of a number of variables characterizing spatial-temporal asymmetries. Across all speeds, stroke survivors had a higher CoT than controls. We also found that our sample of stroke survivors did not choose a self-selected speed that minimized CoT, contrary to typical observations in healthy controls. Multiple regression analyses revealed negative associations between speed and CoT and a positive association between asymmetries in foot placement relative to the trunk and CoT. These findings suggest that interventions designed to increase self-selected walking speed and reduce foot-placement asymmetries may be ideal for improving walking economy poststroke.


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