What are the most common causes of death in patients with Parkinson's disease (PD)?

Common Causes of Death in Parkinson's Disease

Pneumonia is the most common cause of death in patients with Parkinson's disease, accounting for approximately 70% of deaths, primarily due to aspiration resulting from dysphagia and impaired airway protection.

Primary Causes of Death in Parkinson's Disease

Respiratory Complications

• Pneumonia: The leading cause of death in Parkinson's disease (PD) patients 1
  • Occurs in late stages of disease when dysphagia becomes prominent
  • Often aspiration pneumonia due to impaired swallowing mechanisms
  • Accounts for approximately 70-75% of deaths in PD 2, 3

Cardiovascular Causes

• Second most frequent cause of mortality 1
• Includes:
  • Myocardial infarction
  • Heart failure
  • Sudden cardiac death (SUDPAR - Sudden Unexpected Death in Parkinson's Disease) 4
• Cardiovascular mortality is higher in PD patients compared to the general population 5
  • Hazard ratio of 2.3 for ischemic heart disease
  • Hazard ratio of 3.6 for cerebrovascular disease

Disease Progression Leading to Mortality

Dysphagia and Aspiration Risk

• Dysphagia develops in >80% of PD patients during disease progression 1
• Key risk factors for aspiration and pneumonia:
  • Hoehn & Yahr stage above III
  • Weight loss
  • BMI below 20 kg/m²
  • Drooling/sialorrhea
  • Cognitive impairment/dementia 1
• Silent aspiration is common in PD, with only 20-40% of patients aware of their swallowing dysfunction 1

Nutritional Decline

• Weight loss is a key feature of PD progression 1
• Malnutrition is often underreported, affecting approximately 15% of community-dwelling PD patients 1
• Regular monitoring of nutritional status and vitamin levels is recommended throughout disease course 6

Late-Stage Complications

• In advanced disease stages, patients commonly experience:
  • Choking episodes requiring nasal feeding 2
  • Repeated pulmonary infections (average 2.9 episodes) 2
  • Immobility leading to pressure sores and further complications
  • Cognitive decline and dementia (63% of patients who died had dementia) 3

Predictors of Mortality

Clinical Markers

• Advanced age
• Male gender
• Higher disease severity (Hoehn & Yahr stages 4-5)
• Longer disease duration (average 12.5 years at time of death) 3
• Presence of dementia (found in 63% of deceased patients) 3
• Autonomic dysfunction 4

Motor Symptoms

• Akinetic-dominant phenotype has worse prognosis than tremor-dominant 2
• Postural instability and gait difficulty
• Severe dyskinesias

Non-Motor Symptoms

• Cognitive impairment/dementia
• Orthostatic hypotension
• Sleep disorders
• Weight loss

Prevention Strategies

Dysphagia Management

• Regular screening for dysphagia in patients with:
  • Hoehn & Yahr stage above II
  • Weight loss
  • Low BMI
  • Drooling
  • Dementia
  • Signs of aspiration 1
• Early intervention with swallowing therapy
• Consider nasal feeding when appropriate to prevent aspiration 2

Respiratory Care

• Prompt treatment of respiratory infections
• Pneumococcal and influenza vaccinations
• Airway clearance techniques

Nutritional Support

• Regular monitoring of nutritional status and body weight
• Supplementation of vitamin D, folic acid, and vitamin B12 when needed 1, 6

Cardiovascular Management

• Regular cardiac evaluation
• Management of orthostatic hypotension
• Monitoring for cardiac arrhythmias

Conclusion

Understanding the common causes of death in Parkinson's disease helps guide preventive strategies and end-of-life care. Pneumonia remains the leading cause of mortality, followed by cardiovascular complications. Regular screening for dysphagia, nutritional monitoring, and management of both motor and non-motor symptoms can potentially reduce premature mortality and improve quality of life for patients with Parkinson's disease.