Activation of cerebellum and basal ganglia on volitional swallowing detected by functional magnetic resonance imaging

Although regions of the sensorimotor cortex, insula, and anterior cingulate gyrus are reported to be activated during swallowing, findings concerning contributions of the cerebellum and basal ganglia have been contradictory. We investigated cerebellar and basal ganglionic activation using functional magnetic resonance imaging (fMRI). In 11 subjects, single-shot gradient-echo echoplanar image volumes sensitive to BOLD contrast were acquired in block design fashion using an oblique orientation covering both cerebrum and cerebellum. Using statistical parametric mapping, regional activation upon swallowing was observed in the sensorimotor cortex, insula, cerebellum, putamen, globus pallidus, thalamus, anterior cingulate gyrus, supplementary motor area, superior temporal gyrus, and substancia nigra. The cerebellum was activated bilaterally, especially on the left; activation of the putamen and globus pallidus was also found bilaterally. Thus, volitional swallowing involves the cerebellum and basal ganglia as well as cortical structures. The method used was well tolerated by normal subjects and should also be applicable to patients with dysphagia.