The Use of Photobiomodulation in the Treatment of Spasticity After Stroke.
Trial statusRecruiting
Trial phasePhase 1, Phase 2
Trial typeInterventional
Biological sexAll
Age18+
SponsorUniversity of Nove de Julho
About this trial
Stroke is a non-progressive and permanent syndrome in adults, with approximately 60% of patients presenting with spastic hemiparesis. Spasticity leads to changes in the physiological pattern of muscle tissue contraction and hemodynamics, and, when left untreated, negatively impacts functionality. Photobiomodulation (PBM) has demonstrated positive effects on tissue regeneration, muscle relaxation, reduction of inflammation, fatigue, and pain relief in various muscular and neurological disorders. Methods: This blinded, randomized, controlled clinical trial aims to evaluate the effects of PBM on triceps surae muscle spasticity in adults with stroke. Forty-two participants with spastic hemiparesis post-stroke will be randomized into two groups: active PBM (850 nm, 200 mW, 4 J/point in the gastrocnemius, 12 points, weekly for 8 weeks) or placebo PBM (same protocol, device switched off). Both groups will receive the institute's standard rehabilitation treatment. Outcomes will be assessed using the Modified Ashworth Scale (MAS), ankle range of motion, presence of pain, amount of antispastic medication in use, contraction strength (by manual examination) muscle oxygenation (by transcutaneous near-infrared spectroscopy), functionality, and the occurrence of adverse events before and after the intervention. At the end of recruitment, comparisons between groups and between time points will be performed and statistically analyzed using a two-way repeated means ANOVA test and the Generalized Estimating Equations (GEE) test. We also foresee a pilot interim analysis when recruitment reaches a size of 10 participants per group. This interim analysis will be performed using a two-way/means ANOVA to assess effect size and recalculate sample size, making adjustments to the design if necessary.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Adults who have sustained a unilateral ischemic or hemorrhagic cortical motor stroke, with the diagnosis documented in the acute phase by computed tomography (CT) or magnetic resonance imaging (MRI);
Patients currently undergoing multidisciplinary rehabilitation at the Rehabilitation Center where the study will be conducted;
Patients presenting with a motor pattern of spastic hemiparesis secondary to stroke;
Patients demonstrating the ability to perform orthostatism (standing posture) or therapeutic or functional gait activity.
Disqualifiers
Presence of uncontrolled systemic diseases, including but not limited to cancer, active infections, or uncontrolled diabetes mellitus;
History of photosensitivity or known hypersensitivity to light exposure;
Triceps surae spasticity graded as 4 on the Modified Ashworth Scale (MAS) at the initial pre-screening assessment;Acute clinical instability or any acute medical condition requiring immediate intervention;
Fixed anatomical deformities of the ankle joint that preclude a minimum passive or active range of motion of at least 60 degrees;
Trial design
Design model
Parallel
Treatments tested in this trial
Photobiomodulation Therapy
RadiationPhotobiomodulation (PBM)-formerly referred to as low-level laser therapy (LLLT) or cold laser therapy-is a non-invasive, non-thermal therapeutic modality that employs light in the red to near-infrared spectrum (typically spanning wavelengths from approximately 600 nm to 1,100 nm) to elicit beneficial biological responses in target tissues. The underlying mechanism of action is primarily photochemical rather than photothermal: photons delivered to the tissue are absorbed by endogenous chromophores, most notably cytochrome \*c\* oxidase (CCO), a key enzyme in the mitochondrial electron transport chain. This absorption transiently increases mitochondrial membrane potential, augments adenosine triphosphate (ATP) synthesis, and modulates the generation of reactive oxygen species (ROS). These primary mitochondrial events subsequently trigger a cascade of secondary intracellular signaling pathways-including the activation of transcription factors such as nuclear factor kappa-B (NF-κB) and hypox
Placebo PBM
RadiationApplication of transcutaneous PBM therapy - device switched off- to the gastrocnemius muscles
Standard Multidisciplinary Rehabilitation Program for Spasticity
Other interventionA comprehensive, multidisciplinary intervention delivered by a specialized team-including physical therapists and rehabilitation physicians-who collaboratively develop an individualized treatment plan tailored to each patient's functional deficits, baseline mobility, and specific spasticity profile. The physical therapy component emphasizes a combination of passive and active stretching protocols, therapeutic exercise to strengthen agonist muscles and improve motor control, gait and balance training, and adjunctive modalities such as neuromuscular electrical stimulation or therapeutic ultrasound, all administered at a frequency and intensity commensurate with the patient's tolerance and clinical progression. Concurrently, the multidisciplinary team addresses associated impairments through therapy focused on activities of daily living and limb function, pharmacological management with oral or antispastics injections as indicated
Treatment groups
42 Participants
are divided into 2 treatment groupsGroup A: PBM groupExperimental treatment 2 interventions
Group B: PlaceboPlacebo comparator 2 interventions
Trial outcomes
Primary outcomes
1
Spasticity Grade
The change in triceps surae spasticity severity, assessed using the Modified Ashworth Scale (MAS). The MAS is a widely validated, clinician-rated ordinal scale that quantifies muscle hypertonia by measuring the resistance encountered during passive joint mobilization; it grades spasticity from 0 (no increase in muscle tone) through 4 (affected part rigid in flexion or extension), with intermediate scores of 1, 1+, 2, and 3 denoting progressively greater degrees of resistance and catch phenomena throughout the range of motion.
Time frame
Baseline" or "Day 1" and * through study completion, an average of 8 weeks. It will also be assessed immediately before and after each PBM session.2
Spasticity Grade
Quantity of antispastic medications used. Information regarding the medications (class, quantity, dose, and route of administration) used by participants for the treatment of spasticity before and after the end of the 8-week therapeutic period will be collected from medical records.
Time frame
Baseline" or "Day 1" and * through study completion, an average of 8 weeks.Secondary outcomes
1
Pain Intensity
The presence of pain in the cutaneous reference region of the triceps surae will be assessed using a Numerical Pain Scale (NPS) / The NPS is an aid in measuring the intensity of pain felt by the patient, an important instrument to verify progress and analyze the treatment instituted. The participant should be asked about their level of pain, where 0 means total absence of pain and 10 the maximum pain level.
Time frame
Baseline" or "Day 1" , and immediately before and after each weekly PBM session and through study completion, an average of 8 weeks2
Active and Passive Ankle Range of Motion
Active and passive range of motion (ROM) of the ankle joint on the affected hemibody will be assessed using standard goniometry. Goniometric measurement is a reliable and widely accepted clinical method for quantifying joint mobility, performed with a universal goniometer aligned to the anatomical landmarks of the ankle joint complex. Active ROM will be measured with the participant performing the ankle movement independently through the available range, whereas passive ROM will be measured with the examiner passively mobilizing the joint through its full available range of motion, ensuring that no excessive force is applied (McRae, 2011). This outcome provides an objective indicator of joint mobility impairment and allows for the evaluation of treatment-related changes in musculoskeletal restriction secondary to spasticity.
Time frame
Baseline" or "Day 1" and * through study completion, an average of 8 weeks3
Functional Independence
Functional status will be assessed using the Functional Independence Measure (FIM) is an 18-item, 7-point ordinal scale that evaluates the level of assistance required for activities of daily living across motor and cognitive domains, with higher scores indicating greater independence .
Time frame
Baseline" or "Day 1" and * through study completion, an average of 8 weeks4
Motor recovery
the lower-extremity motor subscale of the Fugl-Meyer Assessment (FMA-LE) will be employed to evaluate sensorimotor recovery, focusing on volitional movement, coordination, and reflex activity of the affected lower limb; this scale is scored on a 3-point ordinal system (0 = no performance, 1 = partial performance, 2 = full performance), with higher scores reflecting better motor function (Shim, 2025).
Time frame
Baseline" or "Day 1" and * through study completion, an average of 8 weeksOther outcomes
1
Adverse effects
Any adverse effect related to PBM founded after study will be report
Time frame
Baseline" or "Day 1" and weekly after each PBM session and through study completion, an average of 8 weeks2
Epidemiological Data
Epidemiological data will be collected from medical records: Age, Gender, Etiology of stroke, medications used, motor dominance, injury time, stroke type, lesion location, affected side, comorbidities, and use of orthoses will be collected from medical records.
Time frame
Baseline" or "Day 1" and weekly after each PBM session and through study completion, an average of 8 weeksSponsors and contacts
Click on the lead sponsor to view all of their trials.
Source ClinicalTrials.gov