Objective:

To evaluate the short-term effects of 50 Hz cerebellar intermittent theta burst stimulation (iTBS) on static balance and prefrontal cortical activation in patients with cerebellar ataxia (CA).

Approach:

• Participants: Ten patients with CA (4 males; mean age, 57.6 ± 9.1 years) underwent iTBS over the bilateral cerebellum for five consecutive days.
• Intervention: iTBS was applied for 8 minutes per session at 80% active motor threshold.
• Assessment: Static balance was assessed using a Balance Trainer 4 (BT4) under eyes-open (EO) and eyes-closed (EC) conditions at baseline, immediately post-intervention, and 6 weeks post-treatment.
• Additional Measures: Clinical scales and functional near-infrared spectroscopy (fNIRS) were used to evaluate motor and cognitive responses.

Key Findings:

• Significant improvements in postural balance were observed immediately post-intervention (V1) compared to baseline (V0) under both EO and EC conditions, as assessed by clinical scales.
• Improvements included decreased anterior–posterior sway and total displacement under EO, and improved medial–lateral sway under EC (p < 0.05).
• These effects were not sustained at 6 weeks post-treatment (V2).
• Dizziness was reported as a mild–moderate adverse event in 50% of participants, resolving without treatment discontinuation.

Interpretation:

50 Hz cerebellar iTBS was well tolerated and transiently enhanced postural stability in CA patients, with fNIRS monitoring indicating cortical engagement during cognitive-motor integration.

Limitations:

• Small sample size of ten patients limits generalizability.
• Short follow-up period may not capture long-term effects.

Conclusion:

The study provides evidence for the effects of 50 Hz cerebellar iTBS on postural stability in CA patients, with fNIRS serving as a candidate biomarker for monitoring neuromodulation effects.