NCT06420271

Effects of Cerebellar tACS-iTBS in Ataxia

Effects of Combined Transcranial Electrical and Magnetic Stimulation of Cerebellum on Balance Function in Ataxia Patients

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 30 (estimated)
• Sponsor: I.R.C.C.S. Fondazione Santa Lucia · Academic / Other
• Sex: All
• Age: 8 Years – 80 Years
• Healthy volunteers: Not accepted

Summary

Ataxia refers to a group of neurological disorders characterized by impaired coordination and balance due to dysfunction in the cerebellum or its connections. Traditional therapeutic approaches for ataxia have shown limited efficacy, prompting researchers to explore alternative interventions. Non-invasive brain stimulation (NIBS) techniques, such as transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and intermittent theta burst stimulation (iTBS), have emerged as potential therapeutic options. The aim of this study is to investigate the combined effect of tACS-iTBS on balance functions in ataxia disorders.

Detailed description

Ataxia comprises a heterogeneous group of acquired or inherited disorders primarily involving cerebellar dysfunction, leading to impaired coordination and motor learning. Traditional treatments, including medication and physical therapy, often provide limited symptomatic improvement. Non-invasive brain stimulation (NIBS) techniques have emerged as promising tools for modulating cerebellar activity and enhancing motor function. Transcranial magnetic stimulation (TMS) can influence cortical excitability and plasticity, and studies have shown that high-frequency cerebellar rTMS can improve motor performance in spinocerebellar ataxia. Intermittent theta burst stimulation (iTBS), a patterned form of TMS, has demonstrated benefits in other movement disorders, suggesting potential applicability to ataxia. Transcranial direct current stimulation (tDCS), which modulates neuronal excitability via weak electrical currents, has shown improvements in static and dynamic balance in degenerative cerebellar ataxia. Transcranial alternating current stimulation (tACS) modulates neural oscillations and early studies indicate possible benefits for ataxia symptoms. Recent work has explored combining NIBS modalities to enhance neuromodulatory effects. In preliminary experiments, combined cerebellar tACS and iTBS increased MEP amplitudes more than iTBS alone, with effects lasting up to 30 minutes. These synergistic effects may translate into improved motor performance, coordination, and balance. The present study aims to investigate whether combining real or sham tACS with iTBS produces greater benefits than exergaming biofeedback alone in individuals with ataxia. A cross-over design will be used so that each participant serves as their own control. The primary outcomes will include motor coordination, balance, and cerebello-cortical plasticity. The rationale is that tACS may optimize oscillatory activity while iTBS enhances excitability, thereby jointly promoting neuroplasticity in cerebellar networks. The study will recruit individuals diagnosed with ataxia and assess the therapeutic potential of combined NIBS interventions.

Conditions

• Ataxia

Interventions

Type	Name	Description
DEVICE	Real (real iTBS/tACS + exergaming)	Stimulation will be applied to the cerebellum. The tACS session duration will be 190 seconds with a frequency of 5 Hz coupled with iTBS (coil positioned tangentially with respect to the scalp)(600 pulses consisting of bursts of 3 stimuli at 50 Hz, repeated at intervals of 200ms, with an intensity of 80% of active motor threshold -AMT-) (Huang et al., 2005) for a total duration of 190 seconds (repeated over both cerebellar hemispheres after a 15-minute rest period). The exergaming will be performed with an adaptive system, comprising a force platform connected to a computer. The system is designed to enhance standard balance rehabilitation programs by guiding the user's performance of prescribed physical exercises through a video interface. Patients will perform 3 different exercises (10 minutes of training for a total of 30 minutes): latero-lateral and antero posterior load shift, omnidirectional displacement (combined latero-lateral and antero-posterior loading).
DEVICE	Sham (sham iTBS/tACS + exergaming)	Stimulation will be applied to the cerebellum. The tACS session duration will be 10 seconds with a frequency of 5 Hz coupled with sham iTBS (coil positioned perpendicularly with respect to the scalp)(600 pulses consisting of bursts of 3 stimuli at 50 Hz, repeated at intervals of 200ms, with an intensity of 80% of active motor threshold -AMT-) (Huang et al., 2005) for a total duration of 190 seconds (repeated over both cerebellar hemispheres after a 15-minute rest period). The exergaming will be performed with an adaptive system, comprising a force platform connected to a computer. The system is designed to enhance standard balance rehabilitation programs by guiding the user's performance of prescribed physical exercises through a video interface. Patients will perform 3 different exercises (10 minutes of training for a total of 30 minutes): latero-lateral and antero posterior load shift, omnidirectional displacement (combined latero-lateral and antero-posterior loading).

Timeline

• Start date: 2025-05-01
• Primary completion: 2026-09-30
• Completion: 2026-12-31
• First posted: 2024-05-20
• Last updated: 2026-02-17

Locations

1 site across 1 country: Italy