The Effects of Deep Transcranial Magnetic Stimulation Targeting the Insular Cortex in Patients with Infratentorial Stroke and Aspiration: A Randomized Controlled Trial.

Abstract

This study aims to investigate the effects of deep transcranial magnetic stimulation (dTMS) on the treatment of dysphagia to reduce aspiration episodes in patients with infratentorial stroke (IS). A prospective, double-blinded, sham-controlled, single-center clinical trial. A tertiary hospital rehabilitation center. Forty-eight patients were enrolled and allocated to three groups: high-frequency (HF) group, low-frequency (LF) group, or sham stimulation group. DTMS targeting the bilateral insular cortex was performed using the H-coil. LF (1 Hz) was delivered in 20 trains (50 pulses/train, 50s duration) with 15s inter-train intervals, and HF (10 Hz) consisted of 34 trains (30 pulses/train, 3s duration) . The primary outcomes of the study included the respiratory-swallow coordination (RSC) parameters and Penetration Aspiration Scale (PAS) scores. Secondary outcomes comprised Functional Oral Intake Scale (FOIS) scores, with assessments performed at baseline, immediately post-intervention (day 0), and at 1- and 2-month follow-ups. The swallow apnea duration (SAD) in the treatment group was significantly prolonged compared to the sham group (p<0.05), and the change in SAD in both the HF and LF groups was significantly greater than that in the sham group (p<0.05). Although a reduction in the swallow-inhale RSC pattern was observed only in the HF group following the intervention, this change did not achieve statistical significance (p>0.05). The FOIS scores in the HF and LF groups demonstrated significant effects of time and intervention (F=2.48, p<0.001). At 0 day post-intervention, the improvement in FOIS scores was significantly greater in the HF group compared to the sham group (p<0.05); additionally, the PAS scores in the HF group showed a notable reduction. The study demonstrated that both HF dTMS and LF dTMS influenced the SAD values, RSC patterns did not change significantly. Notably, the HF group showed more pronounced improvements in both aspiration reduction and overall swallowing function. These findings support the clinical application of dTMS in this patient population.