Mechanism of recovery of dysphagic patients caused by stroke:A fMRI study / 中华物理医学与康复杂志

ABSTRACT

Objective To study the recovery mechanism of dysphagic patients after stroke using functional magnetic resonanee imaging(fMRI). Methods Thirteen patients with dysphagia caused by unilateral cortical or subcortical lesions were recruited into a dysphagia group,and eight age-matched healthy volunteers were recruited as controls.Both grouDs performed experimental volitional swallowing tasks during fMRI studies.All patients of the dys-phagia group received rehabilitation treatment targeting dysphagia.Of the 13 dysphagia patients,7 reached almost complete recovery and were identified as recovered in follow-up fMRI studies.A 3.0 T MR scanner and echo planar imaging(EPI)T_2 WI sequence were employed to obtain the fMRI data.SPM2 software was used for post-processing of the fMRI data and displaying activated brain maps.Lateral index(LI)was calculated as LI(C-1)/(C+I).Paired t tests were used to compare activated brain volume before and after complete recovery. Results Consistent activation of the bilateral primary sensorimotor cortex,anterior cingulated gyrus and the bilateral insular cortex were observed in the control group. Activation of the pons,medulla,left cerebellum,left prefrontal area,right occipital area and the left insular cortex were observed in the dysphagia group.Activation was observed in the bilateral primary sensorimotor cortex.bilateral prefrontal area,bilateral superior temporal gyrus,left insular cortex,bilateral frontal o-pereulum and anterior cingulated gyrus in the recovered patients.The total activated volume before recovery in the ip-silesional hemisDhere was significantly less compared with the contralesional hemisphere in the dysphagia group.In the recovered patients,both the activated brain volume of the ipsilesional hemisphere and value of LI were significant-ly larger than those at the initial examination.Conclusions Decreased activation in the sensorimotor cortex,the in-sular lobe and the cingulate gyms might be causes.of dysphagia.Compensation by the contralesional hemisphere in the early stages and then the restoration of the ipsilesional hemisphere after recovery may be mechanisms of dysphagia recovery in stroke patients.