Repetitive Transcranial Magnetic Stimulation as a Therapeutic Strategy in Spinocerebellar Ataxia: Current status and proposed Clinical Intervention Protocol

Abstract

Introduction: Repetitive transcranial magnetic stimulation (rTMS) has emerged as a noninvasive neuromodulation strategy with therapeutic potential in disorders characterized by cerebellar dysfunction, including spinocerebellar ataxias (SCAs), for which no curative or effective pharmacological treatments currently exist. By modulating neuronal excitability and promoting activity-dependent synaptic plasticity, rTMS may optimize cortico-cerebellar circuits involved in motor coordination and balance.
Methods: We present a literature review of rTMS application in SCAs and report preliminary clinical experience in a pilot cohort of four patients with different SCA subtypes treated with an adapted cerebellar intermittent theta-burst stimulation (iTBS) protocol. Stimulation was delivered over the cerebellar vermis and bilateral hemispheres during 15 consecutive daily sessions. Clinical response was assessed using the Scale for the Assessment and Rating of Ataxia (SARA) at baseline and immediately after treatment. Pre–post differences were analyzed using a paired Student’s t-test (α = 0.05).
Results: The cohort included four female patients (39–77 years) with SCA17, SCA3, AE2, and ATP2B3. A mean reduction of 6 points in total SARA score was observed following treatment (p = 0.016). Improvements were more pronounced in upper-limb coordination subdomains, with a trend toward gait improvement. No moderate or severe adverse events occurred; transient fatigue and mild headache were reported in some patients.
Discussion: These findings support the feasibility and safety of a standardized cerebellar iTBS protocol in SCAs and suggest clinically meaningful improvements, particularly in appendicular coordination. Variability across stimulation protocols in the literature underscores the need for standardization, identification of response predictors, and integration with structured neurorehabilitation strategies.
Conclusions: Cerebellar rTMS delivered through an adapted iTBS protocol was associated with clinically relevant SARA improvements and a favorable safety profile in this pilot series. Larger controlled studies with longer follow-up are required to establish efficacy, durability of effects, and optimal patient selection criteria.