Innovative Treatments for Neurogenic Dysphagia

Neurogenic dysphagia, commonly seen in post-stroke and Parkinson's disease patients, significantly impacts quality of life. Despite emerging treatments, there remains a lack of consensus on the best approaches for these conditions. This study evaluates three different innovative therapeutic interventions and their efficacy in improving swallowing function:

Sub-study 1: Evaluates the effects of unilateral, bihemispheric, or sham tDCS applied to the swallowing motor cortex in post-stroke patients with dysphagia.

Sub-study 2: Evaluates the effects of bihemispheric or sham tDCS in Parkinson's disease patients with dysphagia.

Sub-study 3: Examines the effects of neuromuscular electrical stimulation (NMES) therapy on swallowing function in both post-stroke and Parkinson's disease patients.

Each intervention was administered over a 6-week period with outcome measures assessed at baseline and post-treatment. All treatments were applied in conjunction with a personalized and intensive speech therapy program.

This study aims to provide valuable insights into the effectiveness of tDCS and NMES as adjuncts to traditional swallowing therapy. By targeting mechanisms of brain plasticity and neuromuscular function, the study could improve treatment strategies for neurogenic dysphagia in stroke and Parkinson's disease patients. Ultimately, the findings could contribute to evidence-based guidelines for managing dysphagia in these populations.

This interventional study recruited a total of 110 participants: 70 patients with post-stroke dysphagia and 40 patients with Parkinson's disease-related dysphagia. Participants were consecutively enrolled from collaborating institutions.

Following informed consent, participants underwent a standardized evaluation protocol consisting of clinical and neurophysiological assessments. Swallowing function was assessed using the Dysphagia Outcome and Severity Scale (DOSS) as the primary outcome measure. Secondary outcomes include the Penetration-Aspiration Scale (PAS), Mann Assessment of Swallowing Ability (MASA), Swallowing Quality of Life Questionnaire (SWAL-QOL), and Motor Evoked Potentials (MEPs) of tongue musculature in a subgroup of participants.

All stimulation interventions (tDCS or NMES) were delivered by trained clinicians according to standardized protocols. Each session was accompanied by a personalized intensive speech and swallowing therapy session, administered by certified speech-language pathologists.

Inclusion criteria

• Adults aged 18-85 years
• Diagnosis of post-stroke or Parkinson's disease-related dysphagia
• Dysphagia duration ≥ 2 weeks for post-stroke patients and ≥ 6 months for Parkinson's disease patients
• Ability to undergo rehabilitation therapy
• Written informed consent obtained

Exclusion criteria

• Severe dysphagia requiring Percutaneous Endoscopic Gastrostomy (PEG) feeding for more than 1 year
• Non-neurogenic causes of dysphagia
• Contraindications to tDCS or NMES
• Cognitive impairment affecting compliance with treatment