The Use of Photobiomodulation in the Treatment of Spasticity After Stroke.

NCT07784231 | Not Yet Recruiting Phase 1 DMC

• 1 other identifier: DarbarIllora
• Study Type: interventional
• Target: 42
• Locations: 0 countries
• Sites: N/A

Brief Summary

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.

Conditions

Stroke; Spasticity; Photobiomodulation; NIRS

Keywords

stroke; photobiomodulation; spasticity; NIRS

Outcome Measures

Primary Outcomes (2)

• 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.

  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.

• 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.

  Baseline" or "Day 1" and * through study completion, an average of 8 weeks.

Secondary Outcomes (6)

• Pain Intensity

  Baseline" or "Day 1" , and immediately before and after each weekly PBM session and through study completion, an average of 8 weeks

• Active and Passive Ankle Range of Motion

  Baseline" or "Day 1" and * through study completion, an average of 8 weeks

• Functional Independence

  Baseline" or "Day 1" and * through study completion, an average of 8 weeks

• Motor recovery

  Baseline" or "Day 1" and * through study completion, an average of 8 weeks

• Oxygenation of the Gastrocnemius Muscles

  Baseline" or "Day 1" , on fifth PBM session, and * through study completion, an average of 8 weeks

Other Outcomes (2)

• Adverse effects

  Baseline" or "Day 1" and weekly after each PBM session and through study completion, an average of 8 weeks

• Epidemiological Data

  Baseline" or "Day 1" and weekly after each PBM session and through study completion, an average of 8 weeks

Study Arms (2)

PBM group

EXPERIMENTAL

Application of transcutaneous PBM therapy to the gastrocnemius muscles of the hemiparetic limb associated with standardized rehabilitation therapies according to the institution's protocol

Radiation: Photobiomodulation Therapy; Other: Standard Multidisciplinary Rehabilitation Program for Spasticity

Placebo

PLACEBO COMPARATOR

Application of transcutaneous PBM therapy - device switched off- to the gastrocnemius muscles of the hemiparetic limb associated with standardized rehabilitation therapies according to the institution's protocol

Radiation: Placebo PBM; Other: Standard Multidisciplinary Rehabilitation Program for Spasticity

Interventions

Photobiomodulation Therapy RADIATION

Photobiomodulation (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

Also known as: Low level Laser Therapy

PBM group

Placebo PBM RADIATION

Application of transcutaneous PBM therapy - device switched off- to the gastrocnemius muscles

Placebo

Standard Multidisciplinary Rehabilitation Program for Spasticity OTHER

A 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

PBM group; Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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;
• Malnutrition or significant nutritional deficiencies;Acute clinical conditions with the potential to exacerbate spasticity, such as acute fractures, cutaneous ulcers, or acute infections;Presence of any other movement or tone disorder (e.g., dystonia, chorea, or parkinsonism) that could confound spasticity assessments;
• Exposed tumors or undiagnosed lesions in the area to be irradiated;
• Change in the pharmacological class of antispastic medications during the therapeutic period of the study. Dose adjustments within the same medication class will be permitted and documented;
• Administration of botulinum toxin type A injections into the triceps surae muscle during the study period or within six months prior to study enrollment;
• Discontinuation of the concomitant physical therapy rehabilitation program, even if the participant continues to receive photobiomodulation per the study protocol;
• Occurrence of any adverse event attributable to photobiomodulation;
• Death;
• Withdrawal of informed consent.

Sponsors & Collaborators

• University of Nove de Julho: lead

MeSH Terms

Conditions

Stroke; Muscle Spasticity

Interventions

Low-Level Light Therapy

Condition Hierarchy (Ancestors)

Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Muscular Diseases; Musculoskeletal Diseases; Muscle Hypertonia; Neuromuscular Manifestations; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Laser Therapy; Therapeutics; Phototherapy

Central Study Contacts

Rebeca B Cecatto, MD, Ph.D.

CONTACT

+55 11970842496; rebeca.boltes@gmail.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor M.D. Ph.D. Rebeca Boltes Cecatto

Study Record Dates

• First Submitted: August 18, 2026
• First Posted: August 25, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): April 30, 2027
• Study Completion (Estimated): June 30, 2027
• Last Updated: August 28, 2026

Record last verified: 2026-08