At what stage does Parkinson's disease typically affect swallowing?

When Parkinson's Disease Affects Swallowing

Swallowing problems typically begin at Hoehn & Yahr stage III of Parkinson's disease, although they can occur earlier in the disease course and should be screened for regardless of stage if warning signs are present. 1

Prevalence and Timeline of Dysphagia in Parkinson's Disease

• More than 80% of patients with Parkinson's disease develop dysphagia during the course of their disease 1, 2
• Dysphagia can occur at different stages:
  • Stage I (early disease): 58% of patients show abnormal swallowing test results 3
  • Stage II: 93% of patients show abnormal swallowing test results 3
  • Stage III: 91% of patients show abnormal swallowing test results 3
  • Stage IV (advanced disease): 94% of patients show abnormal swallowing test results 3

Silent Dysphagia: A Critical Concern

• Only 20-40% of PD patients are aware of their swallowing dysfunction 1
• Less than 10% of PD patients spontaneously report dysphagia 1
• Silent aspiration is very common in PD patients 1
• In early stages (I-III), abnormal swallowing test results are seldom related to symptoms noticed by patients 3
• In advanced disease (stage IV), swallowing difficulties become more obvious to patients 3

Risk Factors for Dysphagia in Parkinson's Disease

Statistical risk factors for dysphagia in Parkinson's disease include:

• Hoehn and Yahr stage above III 1
• Weight loss 1
• BMI below 20 kg/m² 1
• Drooling or sialorrhea 1
• Dementia 1

Screening and Assessment

Regular screening is recommended for:

• All patients with Hoehn & Yahr stage above II 1, 4
• Any patient with warning signs (weight loss, low BMI, drooling, dementia) 1, 4
• Any patient with signs of dysphagia (coughing during meals/drinking, pneumonia) 1

Screening methods:

• PD-specific questionnaires:
  • Swallowing Disturbance Questionnaire (SDQ) - simpler to apply 1, 4
  • Munich Dysphagia Test-Parkinson's Disease (MDT-PD) - detects milder forms 1, 4
• Water swallow test with measurement of average volume per swallow 1, 4
• Volume-viscosity swallow test 1, 4

Clinical Implications and Complications

Dysphagia in PD is associated with:

• Increased risk of aspiration pneumonia 1
• Pneumonia as the most frequent cause of death in PD 1, 4
• Decreased intake of food and fluids 1
• Malnutrition 1
• Complications with medication intake 2
• Reduced quality of life 1, 2

Management Approach

For patients who screen positive for dysphagia:

• Instrumental assessment with FEES (preferred) or VFSS 1, 4
• Optimization of dopaminergic medication for fluctuating dysphagia 4, 2
• Swallowing therapy with:
  • Expiratory Muscle Strength Training (EMST) 4
  • Shaker Head Lift Exercise 4
  • Oral Motor Exercise Program 4
  • Lee Silverman Voice Treatment 4
• Dietary modifications:
  • Thickened liquids (honey-thick more effective than nectar-thick) 4
  • Chin-down posture for specific swallowing problems 4

Key Clinical Pitfalls to Avoid

• Relying on patient self-reporting of dysphagia (most cases are silent) 1
• Waiting until advanced stages to screen (dysphagia can occur early) 1, 3
• Using standard water swallowing tests without volume measurement (not predictive in PD) 1
• Failing to perform assessments during medication ON-phase 4
• Not monitoring for aspiration pneumonia, which is a leading cause of mortality 1, 4

Regular reassessment of swallowing function is necessary as the disease progresses to prevent complications and maintain quality of life 4.