Why do individuals with Parkinson's disease (PD) experience difficulty walking and can it cause dysphagia (difficulty swallowing)?

Walking Difficulties and Dysphagia in Parkinson's Disease

Individuals with Parkinson's disease experience walking difficulties and dysphagia due to the progressive neurodegeneration affecting both motor and non-motor functions of the brain. 1

Walking Difficulties in Parkinson's Disease

Pathophysiology of Walking Difficulties

• PD is characterized by dopamine depletion in the brain leading to cardinal motor symptoms including:
  • Bradykinesia (slowness of movement)
  • Muscular rigidity
  • Postural instability
  • Tremor 1

Primary Factors Contributing to Walking Difficulties

1. Freezing of gait (FOG) - the strongest contributing factor to walking difficulties 2
2. Bradykinesia - slowness in initiating and executing movements 1, 2
3. Postural instability - impaired balance and coordination 1, 2
4. Rigidity - stiffness in muscles affecting fluid movement 1
5. Disease duration - longer duration correlates with worse walking ability 2

Additional Contributing Factors

• Lower extremity function impairment
• Fatigue
• Orthostatic hypotension
• Reduced self-efficacy 2

Dysphagia in Parkinson's Disease

Prevalence and Timing

• Dysphagia typically occurs in advanced phases of PD, affecting 60-80% of patients during the course of their disease 1, 3
• In some cases, swallowing difficulties may be present at disease onset 1

Characteristics of PD-Related Dysphagia

• Functional alterations in oropharyngeal and esophageal motility 1
• Often asymptomatic in early stages despite functional impairment 1
• Can significantly impact medication intake, nutrition status, and quality of life 3
• Increases risk of aspiration pneumonia, a major cause of death in PD 3

Response to Medication

• Dysphagia may fluctuate with medication status, often worsening during "off" periods 3, 4
• Approximately half of advanced PD patients with motor fluctuations show clinically relevant improvement in swallowing function after levodopa administration 4

Management Approaches

For Walking Difficulties

• Optimization of dopaminergic medication to improve motor symptoms 1
• Physical therapy focusing on:
  • Task-specific training for walking and balance 5
  • Resistance exercises to improve walking speed 1
  • Rhythmic auditory cueing for gait training 6

For Dysphagia

• Rehabilitation treatment is recommended after multidimensional assessment of swallowing function 1
• Approaches include:
  • Adapting bolus characteristics (food consistency and volume) 1
  • Postural maneuvers during swallowing 1
  • Exercise programs targeting swallowing muscles 1
  • Expiratory muscle strength training 3
• Optimizing dopaminergic medication for patients with fluctuating dysphagia 3, 4

Monitoring and Assessment

• Regular monitoring of nutritional and vitamin status is recommended throughout disease progression 1
• Standardized assessment of swallowing function before oral feeding is initiated 1
• Fiberoptic endoscopic evaluation of swallowing (FEES) or videofluoroscopic swallowing study for reliable detection of aspiration 3

Clinical Implications

• Both walking difficulties and dysphagia significantly impact quality of life and increase morbidity and mortality risk 1, 3
• Early identification and management of these symptoms is crucial to prevent complications
• Treatment approaches should be adjusted as the disease progresses and symptoms evolve 5