On the activation mechanism of swallowing-related brain functional areas via blood oxygenation level dependent-functional magnetic resonance imaging between normal adults and acute cerebral infarction patients with dysphagia

Abstract:

Objective To study the activation characteristics of swallowing-related brain functional areas of acute cerebral infarction（ACI）patients with dysphagia and normal adults using blood oxygenation level dependent-functional magnetic resonance imaging（BOLD-fMRI），and to explore the regulation way of relevant brain functional areas during dysphagia recovery of ACI patients.Methods One hundred and fifty ACI patients with dysphagia，who were hospitalized in Yan’an Hospital Affiliated to Kunming Medical University from July 2018 to July 2021，and 100 normal adults were selected in the study and received BOLD-fMRI. The activation volume and intensity of relevant brain functional areas during swallowing activities were recorded and the differences between them were compared.Results Among the 150 ACI patients with dysphagia collected during the study，50 cases［29 males and 21 females，averaged at （56.22±7.33） years］ old）were classified into the right ACI group，and 100 cases［61 males and 39 females，averaged at （58.07±6.84） years old］ were classified into the left ACI group. There were 100 normal adults［57 males and 43 females，averaged at （53.56±11.41） years old］ in the control group. Characteristics of relevant brain functional areas activated during swallowing activities in the control group showed that increased activation volume and intensity were observed for brain functional areas including bilateral primary motor cortex center（BA4），premotor area/supplementary motor area（BA6/8），supramarginal gyrus（BA40），insular lobe insular（BA13），superior temporal gyrus（BA22），cingulate cortex（BA24），frontal medial surface（BA32），medulla oblongata，pons，basal ganglia，thalamus and cerebellum as well as left temporal pole（BA38） and right Heschl’s gyrus（BA41），etc.，and the activation volumes of BA4，BA40 and cerebellum were significantly larger in the left than in the right（P<0.05）； there was no significant difference in activation intensity between the left and right brain areas（P>0.05）. The activation volume of each brain area of the right ACI group suggested by BOLD-fMRI showed that the activation volumes of the right BA4 and BA6/8 were smaller than those of the control group，the activation volumes of the left BA6/8 and BA4 were larger than those of the control group，and the activation volumes of the bilateral posterior cingulate cortex（BA23），the parietal medial surface（BA31） were larger than those of the control group，and in the BA18/19 of the left visual center and BA41 of the primary auditory center，the cortical activation volumes were larger than those of the control group，with statistically significant differences. The activation intensities of the right BA4，BA6/8，BA40 and BA13 were significantly lower than those of the control group. The activation volume of each brain area of the left ACI group suggested by BOLD-fMRI showed that the activation volumes of the left BA4 and BA6/8 were smaller than those of the control group，the activation volumes of the right BA4 and BA6/8 were larger than those of the control group，and the activation volumes of bilateral BA23/31，left BA41，bilateral BA7，bilateral BA18/19 and bilateral cerebellums increased compared with the control group，with statistically significant differences. The activation intensities of the left BA4，BA6/8，BA40 and BA13 were significantly lower than those of the control group.Conclusion Brain functional areas involved in regulating swallowing activities of normal people include bilateral motor，pre-motor，sensory，olfactory，auditory，brain stem，cerebellum，and basal ganglia，etc.，and the regulation is hemilateral to some extent. Decreased activation volume of the ipsilateral motor area and premotor area and increased activation volume of the contralateral motor area and premotor area are the main compensatory features of swallowing-related brain functional areas in ACI patients with dysphagia.