Introduction
Post-stroke dysphagia is a prevalent impairment with devastating complications such as aspiration pneumonia, malnutrition, and increased mortality.Most of patients recover from dysphagia and proceed to oral feeding, whereas some of the patients do not recover and need tube feeding.Previous studies tried to define the lesions contributing to post-stroke dysphagia using voxel-based lesion symptom mapping(VLSM).These studies used delayed oral and pharyngeal transit time or aspiration as symptoms of dysphagia. However, swallowing is a complex process and lesions related with recovery of each swallowing process are yet to be defined.This study aims to investigate the lesions related with the recovery of dysphagia in supratentorial stroke patients through the findings of VideofluoroscopicSwallowingStudy(VFSS).
Methods
42 supratentorial stroke patients with post-stroke dysphagia, who were evaluated with VFSS during admission from September2018 to August2019 were included(mean age,75.17±10.9years;left:right 19:23).We divided the patients into two groups according to tube feeding or oral feeding at the time of discharge; Group1(G1) with tube feeding and Group2(G2) with oral feeding.Demographic data of two groups were compared using Student’s t-test.VFSS findings were assessed using Videofluoroscopic Dysphagia Scale(VDS)score.Lesions were traced on brain diffusion magnetic resonance images acquired at the time of onset.Lesions of two groups were analyzed by overlapping, subtraction, and VLSM.Non-parametric Brunner?Munzel tests were used for continuous data of VDS score.
Results
There were no significant differences between the two groups in age, sex, lesion side, NIHSS score at the time of onset.There were significant differences of total VDS score(G1 vs. G2;32.61±15.02 vs 20.88±12.04), Penetration-Aspiration Scale score(G1 vs. G2;4.33±2.65 vs 2.45±1.80), bolus formation(G1 vs. G2;2.33±2.0 vs 0.82±1.36),and triggering of pharyngeal swallowing(G1 vs. G2;3.50±1.98 vs 1.63±2.20).Lesions associated with delayed recovery of dysphagia were left insula and claustrum, right putamen, posterior cingulate, cuneus, and precuneus(Fig1). VLSM with NPM analysis showed that bolus formation was associated with lesions in right superior temporal gyrus,superior,middle,inferior frontal gyrus,subcallosal gyrus,caudate,lentiform nucleus,left claustrum,and lentiform nucleus. Triggering of pharyngeal swallowing was associated with right thalamus,inferior frontal gyrus,superior temporal gyrus, insula,left caudate,claustrum,lentiform nucleus,and insula(Fig2).
Conclusions
This study showed that bolus formation is related with frontal gyrus and basal ganglia, while triggering of pharyngeal swallowing is related with thalamus,inferior frontal gyrus,insula,and basal ganglia.This suggests that sensory input to the thalamus is crucial in delayed dysphagia recovery.Lesion location could help potential therapy planning for patients with delayed dysphagia recovery |
