Gait Disorders, Neurologic, Muscle Spasticity, Spasticity as Sequela of Stroke, Stroke Sequelae
Conditions
Keywords
Post-Stroke, Gait analysis, Botulinum toxin, High-density electromyography
Brief summary
According to our hypothesis, the use of HD-EMG shall allow an accurate localization of the innervations zones of the muscles, offering a better complement to the methodology applied so far to define the botulinum neurotoxin (BoNT) injection site. To achieve that goal, a randomized clinical trial comparing the effectiveness of two guiding methods to define the BoNT injection site in the gastrocnemius muscles will be conducted. One arm will be guided with ultrasonography + localized IZ using anatomical references; while the second arm with ultrasonography + in vivo location of the IZ through HD-EMG. The effectiveness will be evaluated by changes in functional tests and in biomechanical parameters of the gait assessed with a three-dimensional motion analysis system. These outcomes will be measured at baseline (T0), at three (T3w) and six weeks (T6w), post BoNT injection. The differences between sessions will be evaluated as measurements of effectiveness. We expect that greater effectiveness will be found in the group that receives the injection of BoNT, guided by the in vivo location of the IZ.
Detailed description
This research proposal seeks to improve the current procedures to determinate the botulinum neurotoxin (BoNT) injection site. More precisely, we propose to complement the ultrasonography with an in vivo location of the IZ, using a non-invasive technique based on surface multielectrode electromyography grid, which is called high density-surface EMG (HD-EMG). According to our hypothesis, the use of HD-EMG shall allow an accurate localization of the IZs of the muscles, offering a better complement to the methodology applied so far to define the BoNT injection site. To achieve that goal, a randomized clinical trial comparing the effectiveness of two guiding methods to define the BoNT injection site in the gastrocnemius muscles (main ankle extensors or plantar flexors) will be conducted. One arm will be treated with the best available option, which includes ultrasonography + localized IZ using anatomical references. The second arm will be managed using ultrasonography + in vivo location of the IZ through. The last will be measured using HD-EMG by recording the motor unit action potentials along the muscle fibers. This technique can identify the location of the IZ by the change of phase of those potentials. The effectiveness will be evaluated by changes in biomechanical parameters of the gait, assessed using a three-dimensional motion analysis system. The outcomes will be biomechanical gait variables associated with the ankle joint (ankle joint moment, dorsiflexion range, among others) and functional tests (spasticity using Ashworth scale, 6-minute walk test and the Timed Up and Go Test). These outcomes will be evaluated at baseline (T0), at three (T3w) and six weeks (T6w), post BoNT injection. The differences between sessions will be evaluated as measurements of effectiveness (Delta1 = T3w-T0; Delta2 = T6w - T0). To compare the effectiveness between groups, these delta values will be compared using a student's t-test or a Mann-Whitney U test, as appropriate. Also, a Cohen's d will be calculated to determine the magnitude of these differences. In addition, the post-hoc power (1-β) will be measured. All statistical analyses will be performed in the STATA software (version 14.0 Stata-Corp LP, USA), considering a one tailed analysis, and a confidence level of 95%. Statistically significant differences will be considered those associated with a p-value lower than 0.05. We expect to find greater effectiveness in the group that receives the injection of BoNT, guided by the in vivo location of the IZ using HD-EMG.
Interventions
COMBINATION_PRODUCTBotulinum toxin guided by ultrasonography and anatomical references
The botulinum neurotoxin (BoNT) will be calculated according to the weight of each patient. It will be injected in four places: two of them into the medial gastrocnemius and the other two into the lateral gastrocnemius. For medial gastrocnemius muscle, ¼ of the dose will be injected into the muscle belly at the 25% of the distance between the popliteal fossa and the intermalleolar line. Another ¼ will be injected into the muscle belly at the 35% of the previously mentioned distance. For lateral gastrocnemius, ¼ of the dose will be injected into the muscle belly at the 20% of the distance between the popliteal fossa and the intermalleolar line. The remaining ¼ of the dose will be injected into the muscle belly at the 30% of the previously described distance. All patients will conduct the same physical therapy program and under the direction of the same team of physical therapists. This program will begin two weeks after receiving the BoNT injection.
COMBINATION_PRODUCTBotulinum neurotoxin guided by ultrasonography and in vivo location of innervation zones guided by high-density electromyography
The botulinum neurotoxin (BoNT) will be calculated according to the weight of each patient. It will be injected in eight places: four will be located in vivo for gastrocnemius medialis and four for gastrocnemius lateralis. These places will correspond to innervation zones located by high-density electromyography in different zones of each muscle. Thus, each of the eight located innervation zones will receive 1/8 of the calculated dose for the gastrocnemius muscle. All patients will conduct the same physical therapy program and under the direction of the same team of physical therapists. This program will begin two weeks after receiving the BoNT injection.
Sponsors
Fondo Nacional de Desarrollo Científico y Tecnológico, Chile
Instituto Nacional de Rehabilitación Pedro Aguirre Cerda
Universidad de los Andes, Chile
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
The nature of the interventions makes blinding almost impossible. However, it will be possible to blind the support staff when they conduct the gait and functional evaluations. In the same way, the allocation of groups will be blinded at the time of performing the statistical analysis, which shall be performed by a third party.
Intervention model description
The design is a randomized controlled trial. One arm will be treated with a botulinum neurotoxin (BoTN) injection guided by the best available option, including ultrasonography + localized innervation zone (IZ) using anatomical references. The second arm will be treated with BoTN but guided with ultrasonography + in vivo location of the IZ using high-density electromyography.
Eligibility
Sex/Gender
ALL
Healthy volunteers
No
Inclusion criteria
* Hemiplegia secondary to an ischemic of hemorrhagic stroke. * Focal spasticity of gastrocnemius muscles status 1-3 according to the modified Ashworth scale. * Independent gait ability with or without the use of technical assistance.
Exclusion criteria
* Spasticity status 4 according to the modified Ashworth scale. * Focal spasticity of the tibialis posterior and/or soleus. * Fracture and/or contracture in the lower extremities. * Other medical treatment for spasticity. * Allergy to the botulinum neurotoxin. * Suffering from some infectious disease * Pregnancy or breastfeeding
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Maximum ankle dorsiflexion during the stance phase in the paretic limb. | Before intervention (T0), three weeks (T3w) and six weeks (T6w) post botulinum neurotoxin injection | Peak dorsiflexion angle during the stance phase in the paretic limb. This value will be calculated from Vicon Nexus 2.12 software, using the conventional gait model + functional calibration, and will be considered as the average value within 8 to 10 gait cycles. |
| Maximum ankle plantarflexion moment during the stance phase in the paretic limb | Before intervention (T0), three weeks (T3w) and six weeks (T6w) post botulinum neurotoxin injection. | Peak internal ankle dorsiflexion moment during the stance phase in the paretic limb. This value will be calculated from Vicon Nexus 2.12 software, using the conventional gait model + functional calibration, and will be considered as the average value within 8 to 10 gait cycles. |
| Foot clearance in the paretic limb. | Before intervention (T0), three weeks (T3w) and six weeks (T6w) post botulinum neurotoxin injection. | Minimum distance between the lowest point on the shoe and the ground during the swing phase in the paretic limb. This value will be calculated from a custom-made biomechanical model, and will be considered as the average value within 8 to 10 gait cycles. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Spasticity of plantar flexor muscles using the Ashworth modified scale. | Before intervention (T0), three weeks (T3w) and six weeks (T6w) post botulinum neurotoxin injection. | Qualitative evaluation of the increase in ankle plantar flexors tone during a muscle stretch movement (dorsiflexion). This will be scaled from 0 (no increase in muscle tone) to 4 (ankle rigid during dorsiflexion movement). |
| 6-minute walk distance. | Before intervention (T0), three weeks (T3w) and six weeks (T6w) post botulinum neurotoxin injection. | Measurement of distance walked over a span of 6 minutes. |
| Timed up and go time. | Before intervention (T0), three weeks (T3w) and six weeks (T6w) post botulinum neurotoxin injection. | Time to complete a standing from a chair with no arms, walking 5 meters and returning to sit down. |
Countries
Chile
Outcome results
None listed