This is an interventional therapy study designed to evaluate the efficacy of a two-week
intervention, i.e. training with a specialized exhalation training device (called expiratory
muscle strength training; EMST150 or EMST75; Aspire Products, Gainsville, FL) on swallowing
function in patients with neurodegenerative Parkinsonian disorders. This study involves a
routine endoscopic evaluation of swallowing (FEES) to diagnose dysphagia before and after the
intervention. Between the two FEES, a two-week exhalation training program takes place, which
the patients perform independently following instructions from a speech and lanuage
pathologist. In addition demographic and disease-specific data and two questionnaires
(Swallowing Disturbance Questionnaire for Parkinson's disease patients, SDQ-PD, and
Swallowing specific Quality Of Life Questionnaire SWAL-QoL) are recorded.
Main hypothesis: Two weeks of EMST will lead to a significant improvement of the endoscopic
dysphagia score in patients with neurodegenerative Parkinsonian disorders with endoscopically
proven oropharyngeal dysphagia. Patients with idiopathic Parkinson's syndrome as well as its
differential diagnoses, multiple system atrophy (MSA) and diseases from the group of 4repeat
tauopathies, will be examined.
Idiopathic Parkinson's disease (PD):
More than 80% of all patients with PD develop clinically relevant dysphagia during the course
of the disease. This can lead to a significant reduction in quality of life, decreased
medication efficacy, malnutrition, dehydration, and ultimately aspiration pneumonia in
affected patients, which is the most common cause of death in advanced PD patients. The cause
of PD-associated dysphagia is a multifactorial genesis with impairment of dopaminergic and
non-dopaminergic pathways of the central swallowing network and additional peripheral
neuromuscular influences.
Multiple System Atrophy (MSA):
MSA is clinically associated with autonomic dysregulation manifested by neurogenic urinary
bladder emptying dysfunction, orthostatic hypotension, sleep-related respiratory
dysregulation, etc. in addition to Parkinsonian and/or cerebellar symptoms. Median survival
after diagnosis is approximately 7 years. At disease onset, differentiation from idiopathic
PD is difficult. However, relatively early in the course of the disease, symptoms such as a
brittle voice or stridor may appear during normal breathing, which may be clues to the
diagnosis of MSA. Since laryngeal abnormalities are associated with a significantly reduced
life expectancy, they require special attention and diagnosis. In this regard, we have
recently shown that a high prevalence of laryngeal movement abnormalities is present in MSA
patients and can even be used to differentiate them from idiopathic Parkinson's disease.
Swallowing function, the regulation of which is associated with autonomic centers of
laryngeal function, is also often impaired early in patients with MSA. Because dysphagia can
further limit quality of life and life expectancy, this symptom also requires early diagnosis
and treatment. We could recently show that the dysphagia pattern also differs between PD and
MSA.
4repeat tauopathies (4RT): The form of 4RT, also named progressive supranuclear gaze palsy
(PSP) with all clinical subtypes, is a rapidly progressive neurodegenerative disease that
leads to progressive functional impairment of cortical and subcortical function in affected
individuals due to accumulation of tau protein in the brain. Due to the clinical variability
of presentation, early diagnostic certainty is desirable, especially since human IgG4-
antibodies directed against extracellular tau protein are currently in clinical trials to
modify the course of the disease (see NCT03068468, NCT02985879). 4RT are also associated with
swallowing and speech problems, and aspiration pneumonia is among the leading causes of death
in this disease group. In addition, characteristic abnormalities may also occur due to
dystonic dysinnervation of laryngeal muscles.
For dysphagia in atypical Parkinsonian syndromes, there are no proven interventional or drug
therapy options. Previous studies in patients with PD had shown efficacy of a four-week
training with a special expiratory muscle strength training (EMST) device. Both swallowing
reliability and swallowing efficiency were improved. Studies on the efficacy of EMST on
dysphagia of atypical Parkinsonian syndromes do not yet exist. Having demonstrated the
efficacy of EMST in a 4-week intervention regime, the first aim is to test whether a
shortened intervention duration of two weeks is also effective in patient with PD. In
addition, this protocol will be performed in patients with MSA and 4RT to investigate
effects, particularly on swallowing safety (reduction of penetration/aspiration events) and
swallowing efficiency (reduction of pharyngeal residuals). Currently, all patients with PD,
MSA, or 4RT at participating study sites receive a speech and language pathology examination
and endoscopic diagnostics according to a defined protocol. In addition to phoniatric and
swallowing-specific examinations, an endoscopic evaluation of swallowing (FEES) is routinely
performed. Regarding the efficacy of EMST training on pharyngeal dysphagia in patients with
PD, two randomized, placebo-controlled studies from recent years with n=60 and n=50 patients,
respectively, have already shown an efficacy of training on both swallowing reliability and
swallowing efficiency in PD patients. Relevant side effects or risks from training for the
patients were not reported in the studies.
Studies using an EMST device have been conducted in recent years not only in patients with
IPS, but also in patients with dysphagia due to other primary pathologies (e.g., amyotrophic
lateral sclerosis, multiple sclerosis, stroke, etc.). In summary, a positive effect was
shown, particularly on laryngeal muscle strengthening, which was reflected in an improvement
in dysphagia.
The affected patients receive an initial endoscopic evaluation of the swallowing act in the
clinical setting as part of routine diagnostics. In addition, oral and written patient
education is provided. After written consent on the informed consent form, the following data
are then collected anonymously prior to the start of the intervention:
sociographic data
disease milestones
MDS-UPDRS I-IV
UMSARS / PSP-RS
SDQ-PD
SWAL-QOL
Hoehn and Yahr stage
Current drug therapy
MSA-FEES examination protocol
Pulmonary function test
This is followed by the individual adjustment of the EMST device for the respective patient.
For this purpose, the maximum expiratory pressure (MEP) is first determined for the
respective patient in the pulmonary function examination using a pressure manometer. 75% of
the MEP is set for the subsequent training on the EMST device. This is then followed by the
actual intervention. For this, the patient receives logopedic instruction on the correct use
of the EMST device. The intervention regime then consists of 5x5 breaths per day for 14
consecutive days. Immediately following, items 3-10 will be collected again.
The collection of data regarding the effectiveness of EMST in a shortened protocol (two
weeks) on swallowing function in patients with PD can help to integrate this form of
therapy firmly in the therapy regime of speech and language therapy also in the context
of inpatient stays.
The evaluation of the efficacy of EMST in atypical Parkinsonian syndromes is the first
interventional study with the attempt to improve dysphagia in these disease spectra. If
this study demonstrates improvement in dysphagia in MSA and 4RT, appropriate patients
would be offered a specific EMST in the future, which may then delay or prevent the
development of higher-grade dysphagia. Since consecutive aspiration pneumonia on the
floor of neurogenic dysphagia is the leading cause of death in these patients, this
could at least delay serious medical complications in the future, improve quality of
life, and prolong survival. In addition, new evidence would be gained for the use of
activating therapies in the treatment of Parkinson's-associated dysphagia.