Cerebellar ataxias cause progressive impairments in balance, gait coordination, motor timing, and cognitive functions such as attention and executive control (Buckner, 2013; Salmi et al., 2010; Timmann \& Daum, 2007). These symptoms substantially reduce independence and quality of life, and current treatments remain limited. There is an urgent need for safe, low-burden interventions that can support everyday functioning and potentially enhance compensatory neural processes.
Transcranial photobiomodulation (tPBM) uses red and near-infrared light (600-1100 nm) to modulate mitochondrial cytochrome-c oxidase, increasing ATP production, reducing oxidative stress, and improving cerebral blood flow (Hamblin, 2016; Salehpour et al., 2019). Several studies show that tPBM can acutely improve cognitive performance and motor control in both healthy adults and clinical groups (Barrett \& Gonzalez-Lima, 2013; Chan et al., 2019; Henderson \& Morries, 2017). A growing neurobiological literature suggests that light can penetrate posterior cortical areas sufficiently to modulate networks involving cerebellar-cortical loops (Jagdeo et al., 2012).
Importantly for ataxia, preliminary work shows that tPBM may acutely improve balance stability and gait metrics in older adults and patients with neurological conditions (Moro et al., 2022; Shin et al., 2021). In our own laboratory, we have observed immediate improvements in sway range and cognitive control in older adults after a 24-minute tPBM session applied over midline and posterior scalp regions. These medium to large size effects are consistent with enhanced sensorimotor integration and improved control of attention in distracting environments.
Given that individuals with cerebellar ataxia experience both motor incoordination and difficulties in maintaining cognitive stability under distracting conditions, tPBM is a promising non-pharmacological intervention worth preliminary investigation.