scholarly journals A Method to Experimentally Estimate the Conductivity of Chronic Stroke Lesions: A Tool to Individualize Transcranial Electric Stimulation

2021 ◽  
Vol 15 ◽  
Author(s):  
Joris van der Cruijsen ◽  
Maria Carla Piastra ◽  
Ruud W. Selles ◽  
Thom F. Oostendorp
Keyword(s):  
Electric Stimulation ◽  
Estimation Error ◽  
Chronic Stroke ◽  
Stroke Patients ◽  
Estimation Errors ◽  
Experimental Conditions ◽  
Stroke Population ◽  
Cortical Stroke ◽  
Transcranial Electric Stimulation ◽  
Stroke Lesion

The inconsistent response to transcranial electric stimulation in the stroke population is attributed to, among other factors, unknown effects of stroke lesion conductivity on stimulation strength at the targeted brain areas. Volume conduction models are promising tools to determine optimal stimulation settings. However, stroke lesion conductivity is often not considered in these models as a source of inter-subject variability. The goal of this study is to propose a method that combines MRI, EEG, and transcranial stimulation to estimate the conductivity of cortical stroke lesions experimentally. In this simulation study, lesion conductivity was estimated from scalp potentials during transcranial electric stimulation in 12 chronic stroke patients. To do so, first, we determined the stimulation configuration where scalp potentials are maximally affected by the lesion. Then, we calculated scalp potentials in a model with a fixed lesion conductivity and a model with a randomly assigned conductivity. To estimate the lesion conductivity, we minimized the error between the two models by varying the conductivity in the second model. Finally, to reflect realistic experimental conditions, we test the effect rotation of measurement electrode orientation and the effect of the number of electrodes used. We found that the algorithm converged to the correct lesion conductivity value when noise on the electrode positions was absent for all lesions. Conductivity estimation error was below 5% with realistic electrode coregistration errors of 0.1° for lesions larger than 50 ml. Higher lesion conductivities and lesion volumes were associated with smaller estimation errors. In conclusion, this method can experimentally estimate stroke lesion conductivity, improving the accuracy of volume conductor models of stroke patients and potentially leading to more effective transcranial electric stimulation configurations for this population.

scholarly journals Pendulum test in chronic hemiplegic stroke population: additional ambulatory information beyond spasticity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yin-Kai Dean Huang ◽  
Wei Li ◽  
Yi-Lin Chou ◽  
Erica Shih-Wei Hung ◽  
Jiunn-Horng Kang
Keyword(s):  
Knee Extensor ◽  
Chronic Stroke ◽  
Stroke Patients ◽  
Timed Up And Go ◽  
Recovery Stage ◽  
Mobility Function ◽  
Stroke Population ◽  
Pendulum Test ◽  
Modified Ashworth Scale ◽  
Positive Correlations

AbstractSpasticity measured by manual tests, such as modified Ashworth scale (MAS), may not sufficiently reflect mobility function in stroke survivors. This study aims to identify additional ambulatory information provided by the pendulum test. Clinical assessments including Brünnstrom recovery stage, manual muscle test, MAS, Tinetti test (TT), Timed up and go test, 10-m walk test (10-MWT), and Barthel index were applied to 40 ambulant chronic stroke patients. The pendular parameters, first swing excursion (FSE) and relaxation index (RI), were extracted by an electrogoniometer. The correlations among these variables were analyzed by the Spearman and Pearson partial correlation tests. After controlling the factor of motor recovery (Brünnstrom recovery stage), the MAS of paretic knee extensor was negatively correlated with the gait score of TT (r =  − 0.355, p = 0.027), while the FSE revealed positive correlations to the balance score of TT (r = 0.378, p = 0.018). RI were associated with the comfortable speed of 10-MWT (r = 0.367, p = 0.022). These results suggest a decrease of knee extensor spasticity links to a better gait and balance in chronic stroke patients. The pendular parameters can provide additional ambulatory information, as complementary to the MAS. The pendulum test can be a potential tool for patient selection and outcome assessment after spasticity treatments in chronic stroke population.

Abstract P195: Assessing the Validity of Predicting Resting Metabolic Rate in Chronic Stroke Patients

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Maria Novitskaya ◽  
Alice Ryan
Keyword(s):  
Metabolic Rate ◽  
Lean Mass ◽  
Resting Metabolic Rate ◽  
Chronic Stroke ◽  
Healthy Adults ◽  
Stroke Patients ◽  
Estimation Equations ◽  
Stroke Population ◽  
History Of ◽  
Total Body

Chronic stroke patients may have lower resting metabolic rate (RMR) due to disability and ensuing loss of skeletal muscle. Established equations used to estimate RMR based on weight, height, age, or lean body mass in healthy non-stroke individuals may not be accurate for a hemiparetic patient population. The purpose of this study is to determine resting metabolic rate in chronic stroke survivors and compare to RMR calculated with established equations in healthy adults. Adults (n=71; 56 males, 15 females; 40 African American, 27 Caucasian, 4 other / not reported) aged 44-76 years (61 ± 7.5 yrs) who had a history of chronic stroke (> 3 months prior) underwent a 30 minute test after a 12-hour fast to measure RMR by indirect calorimetry, total body DXA scan, and treadmill test (VO2 peak). Estimated RMR was calculated using nine established equations. RMR measured in the total group (1552 ± 319 kcal/day) was significantly different from all nine estimated RMR values (Katch-McArdle 1664 ± 242 kcal/day, P=0.05; Livingston 1671 ± 239 kcal/day, P<0.001; Mifflin 1703 ± 254 kcal/day, P<0.001; Owen 1761 ± 269 kcal/day, P<0.001; Harris Benedict 1782 ± 308 kcal/day, P<0.001; revised Harris-Benedict 1795 ± 306 kcal/day, P<0.001; Cunningham 1818 ± 247 kcal/day, P<0.001; Schofield 2147 ± 301 kcal/day, P<0.001; IMNA 2428 ± 405 kcal/day, P<0.001). Calculated RMR was between 9% and 60% greater than measured RMR, regardless of race. Appendicular lean mass (r=0.65, P<0.001), total lean mass (r=0.65, P<0.001), and VO2 peak (r=0.50, P<0.001) were associated with measured RMR. RMR estimation equations established in healthy adults are not reliable for the chronic stroke population, indicating the need for a more accurate predictive equation to better assist nutritional status in patients with conditions of muscle atrophy.

scholarly journals Functional outcome of joint mobilization added to task-oriented training on hand function in chronic stroke patients

2020 ◽  
Vol 56 (1) ◽  
Author(s):  
Asmaa Sabbah ◽  
Sherine El Mously ◽  
Hanan Helmy Mohamed Elgendy ◽  
Mona Adel Abd Eltawab Farag ◽  
Abeer Abo Bakr Elwishy
Keyword(s):  
Functional Outcome ◽  
Hand Function ◽  
Chronic Stroke ◽  
Stroke Patients ◽  
Joint Mobilization ◽  
Task Oriented

scholarly journals Impact of Somatosensory Training on Neural and Functional Recovery of Lower Extremity in Patients with Chronic Stroke: A Single Blind Controlled Randomized Trial

2021 ◽  
Vol 18 (2) ◽  
pp. 583
Author(s):  
Reem M. Alwhaibi ◽  
Noha F. Mahmoud ◽  
Mye A. Basheer ◽  
Hoda M. Zakaria ◽  
Mahmoud Y. Elzanaty ◽  
...  
Keyword(s):  
Physical Therapy ◽  
Lower Extremity ◽  
Functional Recovery ◽  
Intervention Group ◽  
Chronic Stroke ◽  
Post Treatment ◽  
Control Group ◽  
Stroke Patients ◽  
Significant Difference ◽  
Group Post

Recovery of lower extremity (LE) function in chronic stroke patients is considered a barrier to community reintegration. An adequate training program is required to improve neural and functional performance of the affected LE in chronic stroke patients. The current study aimed to evaluate the effect of somatosensory rehabilitation on neural and functional recovery of LE in stroke patients. Thirty male and female patients were recruited and randomized to equal groups: control group (GI) and intervention group (GII). All patients were matched for age, duration of stroke, and degree of motor impairment of the affected LE. Both groups received standard program of physical therapy in addition to somatosensory rehabilitation for GII. The duration of treatment for both groups was eight consecutive weeks. Outcome measures used were Functional Independent Measure (FIM) and Quantitative Electroencephalography (QEEG), obtained pre- and post-treatment. A significant improvement was found in the FIM scores of the intervention group (GII), as compared to the control group (GI) (p < 0.001). Additionally, QEEG scores improved within the intervention group post-treatment. QEEG scores did not improve within the control group post-treatment, except for “Cz-AR”, compared to pretreatment, with no significant difference between groups. Adding somatosensory training to standard physical therapy program results in better improvement of neuromuscular control of LE function in chronic stroke patients.

Sign in / Sign up

Export Citation Format

Share Document