Effect of Sour Taste on Swallowing Function of Patients With Dysphagia After Acute Ischemic Stroke: A Randomized Controlled Trial.

BACKGROUND

Untreated swallowing disorders lead to increased morbidity and mortality in acute stroke patients due to inadequate nutrition, dehydration, and aspiration pneumonia, resulting in prolonged hospital stays. Therefore, we aimed to evaluate the effect of early administration of a sour taste on the swallowing function of patients with post-stroke dysphagia.

MATERIALS AND

METHODS

This study was a randomized controlled trial, which was conducted with 95 patients with a confirmed diagnosis of ischemic stroke and dysphagia, admitted to the neurology department of a university hospital. The primary outcome of the study was swallowing function assessed using the Gugging Swallowing Screen (GUSS), while stroke severity assessed using the National Institutes of Health Stroke Scale (NIHSS) was evaluated as a secondary outcome. The intervention group (n = 47) received 4 mL of room temperature lemon juice, while the control group (n = 48) received 4 mL of room temperature water before breakfast, lunch, and dinner for a duration of 7 days. The Standard Swallowing Test, Gugging Swallowing Screen, and National Institutes of Health Stroke Scale were applied. Swallowing function and stroke severity were assessed at the initial assessment, at the end of the seventh and 30th days. A p-value <0.05 was found as statistically significant.

RESULTS

Patients in the intervention group demonstrated significantly greater improvement in swallowing function compared with the control group on day 7 and day 30 assessments. The between-group difference in total GUSS scores at day 30 demonstrated a large effect size (r = 0.54, p < 0.001). No statistically significant difference between groups was observed in NIHSS scores during follow-up (all p > 0.05). In both groups, swallowing function improved as stroke severity decreased.

CONCLUSIONS

Administration of a sour taste during the early period of acute ischemic stroke had a beneficial effect on swallowing function in patients with dysphagia. Sour taste stimulation may be considered a practical, feasible, and complementary sensory intervention in post-stroke dysphagia management.

TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (NCT07400822).