The effects of intermittent theta burst stimulation at different side of the cerebellar hemisphere on swallowing in healthy subjects / 中华物理医学与康复杂志

ABSTRACT

Objective:To observe any stimulatory effect of intermittent theta burst stimulation (iTBS) on the cerebral swallowing cortex and the cerebellar swallowing motor area and to explore the related mechanisms.Methods:Forty-four healthy right-handed subjects were divided at random into a dominant cerebellum group ( n=15), a non-dominant cerebellum group ( n=15) and a control group ( n=14). In the dominant cerebellum group, iTBS was administered to the cerebellum of the dominant hemisphere, and the other hemisphere was given sham stimulation. In the non-dominant cerebellum group, it was the opposite. The dominant cerebellum received the sham stimulation. In the control group both hemispheres received sham stimulation. Before and after the stimulation, single-pulse transcranial magnetic stimulation (TMS) was applied to the representative regions of suprahyoid muscles in bilateral brain and cerebellum to observe changes of the latency and amplitude of motor evoked potentials (MEPs). Results:After the intervention the MEP amplitude of the bilateral swallowing cortex and the stimulated cerebellum had increased in the non-dominant cerebellum group, with increased MEP amplitude only from the stimulated cerebellum of the dominant cerebellum group. Compared with the control group, the non-dominant cerebellum group showed the greatest improvement in MEP amplitude of the stimulated bilateral cerebral cortex and cerebellum. Improvement in the dominant cerebellum group was significantly smaller. However, there were no significant differences in MEP latency or the percentage change in MEP latency from baseline among the three groups.Conclusions:Applying iTBS to either the non-dominant or the dominant cerebellum excites the brain areas related to swallowing, but in different ways.