Analysis of Cough in Post-stroke Individuals with Dysphagia

Introduction: Stroke is considered to be one of the major causes of morbidity and mortality globally, associated with numerous medical complications leading to an extended hospital stay and significant health care expenses. Dysphagia is one of the most common and life-threatening conditions seen in nearly 65% of stroke survivors. Stroke is reported to have an adverse effect on cough function. Aim: To analyse the cough in individuals with dysphagia. Materials and Methods: The study was conducted in the Department of Neurology, Kasturba Hospital, Manipal, Karnataka, India. A cross sectional research design with the convenient sampling was adopted. A total of 30 participants were recruited in the age range of 40-70 years. All the participants were tube dependent with a functional oral intake scale score of >= Level 2. The clinical swallowing examination was initiated using Manipal Manual for Swallowing Assessment. The participants were asked to cough pre and post-swallow and the cough was analysed perceptually and acoustically. Perceptually it was rated by two experienced raters using 3-point rating scale and acoustically using Mel's Frequency Cepstral Coefficients. Results: It was observed that the majority of the participants were rated as having weak cough both pre and post-swallow which is suggestive of overall effectiveness of cough being weak among the stroke individuals. The results showed a moderate agreement between the two raters for perceptual analysis of cough pre and post-swallow. The acoustic analysis using the Mel Frequency Cepstral Coefficients plots indicated that for majority of the participants, the cough pre-swallow had a higher likelihood value when compared to cough post-swallow. Conclusion: It can be concluded that the cough can also serve as a screening indicator, in identifying the signs of dysphagia. Cough is easier to elicit as compared to phonation task or speech, especially from post-stroke individuals. Since the results of the present study followed a similar trend as that of change of speech or voice post-swallow, cough also can be effectively used in probing the signs of possible aspiration.