This was a prospective long-term study of 24 dysphagic patients with idiopathic PD, followed-up for a five-year period (2006–2011) in a large Brazilian university hospital. This was an open case series and, during the five years of study, some patients dropped out. The patients were in use of medicines with Levodopa.

Only the patients who had at least three evaluations, complaints of swallowing, exclusive oral feeding, and regular check-ups with an outpatient neurologist were included in the study. Patients with non-oral feeding and concomitant diseases or disorders that could cause dysphagia were excluded.

Patients underwent swallowing evaluation, assessment through the Functional Oral Intake Scale (FOIS),13 and therapeutic intervention every three months.

The swallowing evaluation was obtained through a fiberoptic endoscopic evaluation of swallowing (FEES) and clinically. In both evaluations, three types of food were offered: (1) lemon juice colored with green food coloring; (2) Nectar, honey, and pudding consistencies, all colored with green food coloring (these fluids were obtained with the addition of two, three, and four teaspoons of a thickener [Thicken-easy®] to 100mL of water, respectively, and were offered in two different quantities, 3mL and 7mL); (3) solid consistency, represented by a cornstarch biscuit.

The food was given to patients in the following sequence: liquid and nectar (3mL and 3mL, respectively, followed by 7mL and 7mL, respectively); honey (3mL and 3mL, respectively, followed by 7mL and 7mL, respectively); pudding (two tablespoons); solid (½ cornstarch biscuit). The liquid food was administered in 20mL syringes, and the sample was introduced into the patient's oral cavity. As difficulties in swallowing were observed, airway protective maneuvers and/or changes in head posture were performed in order to assist oral feeding in a safe way.

FEES was conducted by an otolaryngologist, while the food was offered by a speech-language therapist.

In the clinical evaluation, as the patients swallowed, cervical auscultation was performed to identify abnormal signs at the pharyngeal swallowing phase. Oral bolus transit time, anterior or posterior escape, positive cervical auscultation (with signs that indicate a presence of stasis or penetration with aspiration risk), coughing (before, during, or after swallowing), and wet voice were also observed by a speech-language therapist.

Based on the clinical evaluation and FEES, the FOIS13 was applied. The FOIS ranks patients into levels, adapted to the present study as follows: level 1, No oral feeding; Level 2, tube-dependent with minimal attempts of food or liquid; Level 3, Tube-dependent with consistent oral intake of food or liquid; Level 4, Complete oral diet of one or two consistencies (nectar and honey, honey and pudding); Level 5a, Complete oral diet with multiple consistencies but with restrictions in two consistencies (for example, solid and liquid), with or without compensation; Level 5b, Complete oral diet with multiple consistencies but with restriction of one consistency (for example, solid or liquid), with or without compensation; Level 5c, Complete oral diet with multiple consistencies, but requiring compensation; Level 6, Complete oral diet with multiple consistencies without special preparation but with specific food limitations (for example: fibers, grains, and some vegetables) and speed and volume modification if necessary; and Level 7, Complete oral diet with no restriction.

At the initial evaluation, every patient received a corresponding FOIS classification. Every time the patients returned to the hospital they were reevaluated and reclassified under FOIS. To analyze the swallowing functionality by Kaplan–Meier survival analyses, patients were observed until occurrence of the event improvement or the event worsening, i.e., they were observed until the point of the time at which a fall or rise in FOIS was noted. Patients whose swallowing functionality stayed the same were observed during the follow-up period and no event was registered.

Following these swallowing evaluations, patients received therapeutic intervention every three months regarding adequate food consistency and volume, in addition to maneuvers or exercises to improve swallowing functionality. They were oriented to perform the maneuvers daily and received written instructions for each one.

The compensatory maneuvers used were (1) chin-tuck, to improve airway protection during swallowing; (2) bolus consistency, to facilitate the feeding of patients with decreased coordination of tongue, reduced contraction of pharynges, delay in triggering swallowing reflex, reduced airway protection and chewing difficulty; (3) effortful swallow, to increase strength to eject the bolus and to approximate the larynx structures, improving airway protection; (4) frequency of swallowing (multiple swallows), to clear stasis; and (5) bolus effects, i.e. changes in volume, viscosity, temperature, or taste, were introduced in order to improve oral and pharyngeal sensibility and control bolus management.

The following rehabilitation maneuvers were used (1) tongue strengthening, to increase strength to eject the bolus; (2) tongue control, to improve tongue mobility and facilitate the bolus management in the oral cavity; (3) Shaker maneuver, to increase strength in supra hyoid muscles reducing the penetration and aspiration risk due to stasis in pyriform sinus; (4) vocal exercises, to improve airway protection though the improvement in the glottis adduction; (5) tongue holding (Masako maneuver), to increase movements of pharyngeal muscles against the basis of the tongue during the act of swallowing.

The patients were classified according to changes in swallowing functionality measured by FOIS, grouped as: improved, no change, and worsened.

In order to investigate factors related to swallowing functionality, the Chi-square, Kruskal–Wallis, and Fisher's tests were used. The gender and age at first evaluation, age at onset of symptoms, and disease duration (disease duration=time between the onset of PD symptoms and the first evaluation) were considered as independent variables.

The swallowing functionality over time was described by Kaplan–Meier Survival Analysis. It is important to mention that the results of a survival analysis express the probability of the patient not suffering from a given event over time.

The statistical analysis was performed using Statistical Package for the Social Sciences (SPSS), version 13.0 for Windows, and p-values lower than 0.05 were considered significant.

This study was approved by the Ethic Board Committee of the University of Campinas (Protocol number 796/2005).

The swallowing management of patients with neurodegenerative diseases is relatively recent; for many years, it was believed that degenerative disease would have a consequent progressive dysphagia; swallowing could not be rehabilitated, and thus any attempt to therapeutic intervention would be doomed to failure.

The swallowing management aims to improve the swallowing act as much as possible and to compensate for what cannot be solved, in order to save deglutition.

As a result of this study, it was observed that one of the most recommended interventions were compensatory. The greater use of compensatory maneuvers in PD can be explained by the instantaneous result of these in swallowing, what can be verified empirically in clinical and instrumental evaluation.

Compensatory maneuvers are designed to redirect the bolus away from the airway, without changing airway physiology. The literature elucidates that thickening liquids to a nectar or honey consistency should be used because it exhibits an immediate effect.27 Chin-tuck maneuver is frequently recommended for swallowing thin liquids.28 In PD, there are evidences that the chin-tuck maneuver combined with thick liquid can be important in preventing pneumonia.20

In this swallowing management program, bolus consistency was indicated when other maneuvers were inefficient to maintain oral feeding and it was necessary to avoid the consistencies that were hazardous.

For the patient of this study, the bolus effect maneuver was indicated when the lack of oral control made it difficult to swallow quickly and in greater volumes. The bolus effect, and changes in the consistency, taste, or temperature of the bolus, improve oral intake and prevent aspiration.

Other frequently indicated maneuvers in this swallowing management were frequency or multiple swallowing. They were indicated to be performed during the daily feeding, aiming to clear stasis and reduce the chance of larynx penetration or aspiration.

In rehabilitation maneuvers, the exercises of tongue strengthening and tongue control were frequently indicated because tongue movements of PD patients, especially those responsible for propulsion and chewing, are considered hypokinetic in the oral phase. In these patients the swallowing oral phase is usually longer and even slower than the pharyngeal phase.29

For half of the patients, vocal exercises were indicated, as there are evidences that this type of exercises works to improve the cough function and tongue's mobility during swallowing,27 which leads to a better swallowing functionality and less bronchoaspiration.

Future studies about the efficacy of intervention methods in swallowing of PD patients are necessary. The improvement and maintenance, not expected in neurodegenerative diseases, found in the present study, suggest that swallowing management might positively affect swallowing functionality of PD patients, but it cannot be affirmed due to the design of this study.

In conclusion, the swallowing functionality was characterized by maintenance or improvement, especially in the first ten months of follow-up, comprising compensatory and rehabilitation maneuvers, reoriented each three months. There was no associated factor with changes in swallowing functionality in these cases.