# Transcranial Photobiomodulation for Spasticity in Pediatric Cerebral Palsy: A Scoping Review of Neurodevelopmental Considerations, Treatment Protocols, Functional Outcomes, and Methodological Gaps

## TL;DR

This review finds that transcranial photobiomodulation for spasticity in children with cerebral palsy has limited and unreliable evidence, requiring more rigorous research.

## Contribution

The paper identifies critical gaps in the methodological quality and standardization of tPBM studies in pediatric cerebral palsy spasticity.

## Key findings

- Only five studies exist, with low methodological quality and inconsistent dosimetry reporting.
- Spasticity reductions reported are not conclusively linked to tPBM due to lack of sham-controlled trials.
- The field needs foundational, double-blind trials with pediatric-specific safety protocols.

## Abstract

What are the main findings?
The current evidence base for transcranial photobiomodulation (tPBM) in pediatric cerebral palsy spasticity is critically small (only five studies), methodologically weak, and characterized by profound heterogeneity and inconsistent dosimetry reporting.Despite reported reductions in spasticity, the absence of sham-controlled, blinded trials and pediatric-specific safety protocols prevents any attribution of these effects to tPBM rather than placebo or other factors.

The current evidence base for transcranial photobiomodulation (tPBM) in pediatric cerebral palsy spasticity is critically small (only five studies), methodologically weak, and characterized by profound heterogeneity and inconsistent dosimetry reporting.

Despite reported reductions in spasticity, the absence of sham-controlled, blinded trials and pediatric-specific safety protocols prevents any attribution of these effects to tPBM rather than placebo or other factors.

What are the implications of the main findings?
tPBM must be considered an unproven experimental intervention and should not be used clinically for pediatric CP spasticity outside of rigorously controlled research trials.Future research must prioritize foundational, sham-controlled, dose-ranging trials based on pediatric-specific computational head models and standardized safety and dosimetry reporting.

tPBM must be considered an unproven experimental intervention and should not be used clinically for pediatric CP spasticity outside of rigorously controlled research trials.

Future research must prioritize foundational, sham-controlled, dose-ranging trials based on pediatric-specific computational head models and standardized safety and dosimetry reporting.

Background: Spasticity, affecting over 80% of children with cerebral palsy (CP), is a major source of disability. Transcranial photobiomodulation (tPBM) is a promising non-invasive neuromodulatory intervention, but evidence for its use in pediatric CP spasticity is fragmented and limited. Objective: This scoping review aimed to systematically map the literature to characterize neurodevelopmental considerations, treatment protocols, functional outcomes, and methodological gaps related to tPBM for spasticity in pediatric CP. Methods: The review followed the PRISMA extension for Scoping Reviews (PRISMA-ScR). A systematic search was performed across eight databases from January 2000 to September 2025. The PCC framework guided inclusion of studies involving children/adolescents (0–18 years) with CP and spasticity, investigating PBM with a primary focus on transcranial application. Results: From 345 records, only five primary studies (total n = 45 children) met the inclusion criteria. The evidence base is severely limited and heterogeneous, with only two of the five studies applying tPBM. A profound lack of protocol standardization was identified, with frequent reports that are internally inconsistent or contain physically implausible dosimetry reporting. Methodological quality was pre-preliminary, with no sham-controlled or adequately blinded trials. Although all studies reported reductions in spasticity and/or motor improvements, the high risk of bias prevents attribution of the effects to tPBM. Conclusions: The evidence supporting tPBM for spasticity in pediatric CP is in a pre-preliminary stage, defined by a critically small number of studies, a pervasive lack of methodological rigor, and an absence of pediatric-specific safety protocols. The field requires an immediate pivot to foundational, sham-controlled, double-blind trials with standardized dosimetry before tPBM can be considered anything other than an unproven experimental intervention.