**5. Discussion**

According to various recommendations the diagnostic process of chronic cough usually begins with the exclusion of the pulmonary ailments (asthma, eosinophilic bronchitis, lung cancer, Chronic Obstructive Pulmonary Disease (COPD), inflammatory lung diseases, etc.), iatrogenic causes (drug-induced cough), and next gastrointestinal (gastroesophageal reflux), and laryngological or phoniatric problems [9–11, 22, 23]. There is also as a new disease called Chronic Cough Hypersensitivity Syndrome (CCHS), characterized by cough attacks lasting more than 8 weeks, aggravated upon exposure to specific factors i.e. cold fluids, poorly responsive to treatment, and with no links to the general health status of the patient [22]. In their study, Sandhu et al. [23] mentioned about the possible relation between chronic cough and dysphagia, in particular between presbyphagia and increased stiffness of the pharyngeal walls. Langmore et al. [18] described endoscopic examination of swallowing disorders in 1988, however, it was not until now routinely used to assess dysphagia as the cause of chronic cough.

The results of our study revealed dysphagia in little more than a half of the patients with chronic cough (56.67%). The patients presented episodes of spillage, double swallows, penetration, aspiration and residue of food at the hypopharynx, which are an indirect evidence of oral stage of swallowing disturbances, and direct evidence of pharyngeal phase of swallowing problems. The results of functional assessment correlated with the WST results, which seems logical – the external laryngeal muscles take part in the laryngeal elevation and their increased tension

makes it difficult for the upper pharyngeal sphincter to open thus promoting retention (residue) at the level of the hypopharynx. Decrease in the elevation of the larynx was correlated with the 5 ml WST results.

The correlation between FEES and WST results was found for aspiration risk, spillage, and retention of saliva. It is known that pharyngeal retention of saliva is associated with impaired sensation in the critical region of the hypopharynx and larynx. The retention is slightly higher in patients with laryngopharyngeal reflux, which was found in all patients in the study group. It may be associated with an increased risk of serious swallowing disorders such as penetration or aspiration. In case of reduced sensation in the pharynx a chance of liquid or food penetration/ aspiration to upper airways increases, especially when it resides in the hypopharynx and leads to multiswallows. However, more studies in larger group of patients should be conducted.

In their retrospective study, Drozd et al. [24] investigated the group of 15 patients with upper airways problems and found chronic cough in 40% of them. They used videofluoroscopy to assess dysphagia and showed correlation between degree of dysphagia and penetration, aspiration (the more severe dysphagia the higher score in PAS scale), and multiswallows. The authors believe that the dysphagia in this group of patients may be caused by incoordination between breathing and swallowing. In our study, the lower elevation of the larynx and increased muscle tension in the neck may confirm this hypothesis. Most authors involved in the problem of chronic chough highlights the difficulty not only with its diagnostics, but also with treatment [9, 11, 25–28]. There are a few reports in the literature about decrease of symptoms after speech therapy [4, 25]. It seems that the severity of dysphagia should be decreased after a treatment, which relaxes the external muscles of the larynx, however, it requires further study.

Taking into consideration that chronic cough can be harmful for larynx, the functions of the larynx will be more disturbed. The vocal folds oedema, hemorrhage, granuloma or other organic lesions can have an impact on vocal folds contraction (decreased defense reflex) [29]. Shorter maximal phonation time associated with dysphonia and chronic cough have an impact on swallowing and breathing function discoordination [30]. In that case non-pharmacological therapy can be applied, mainly forced/dry swallow, sipping water, chewing gum, sucking non-medical sweets, abdominal breathing pattern technique, cough control breathing technique exercise and physiotherapy which reduce upper body shoulder and neck tension, nasal breathing. Avoiding of irritants is also recommended. In case of risk of aspiration Mendelshon maneuver, suprahyoid muscle exercise (Shaker technique) [31] and lax vox technique is recommended [32].

The small group of patients and the lack of control group are the weak points of our study. However, to our best knowledge, this is the first study to assess the problem of dysphagia as a risk factor of chronic cough and we have been still working and collecting more data from patients and controls to analyze the results in much bigger group.

#### **6. Conclusions**

The results of the study showed prevalence of dysphagia in most patients with chronic cough. It seems that phoniatric assessment in those cases should be expanded and the following tests should be performed: assessment of the laryngeal elevation, WST, and FEES. It seems important to also investigate how rehabilitation techniques used by phoniatric specialists and speech therapists improve functional outcome and quality of life in patients with chronic cough.

*Assessment of Dysphagia as a Risk Factor of Chronic Cough DOI: http://dx.doi.org/10.5772/intechopen.97038*
