What is the most likely cause of progressive dysphagia with esophageal retention in a 59‑year‑old man with Parkinson disease treated with dopamine agonists (pramipexole, ropinirole, rotigotine), no weight loss, and a recent unexplained chest infection, and what immediate diagnostic and therapeutic steps are recommended?

Progressive Dysphagia with Esophageal Retention in Parkinson's Disease

This patient most likely has Parkinson's disease-related esophageal dysphagia, and the recent chest infection strongly suggests aspiration pneumonia from silent aspiration—a common and dangerous complication in PD that requires immediate instrumental swallowing assessment and optimization of antiparkinsonian therapy.

Most Likely Diagnosis

Parkinson's disease-related dysphagia with esophageal involvement and silent aspiration. The constellation of esophageal retention on prior VFSS, progressive dysphagia requiring self-induced emesis, and recent unexplained chest infection in a PD patient on dopamine agonists points directly to PD-related swallowing dysfunction with aspiration pneumonia. 1

Key Clinical Features Supporting This Diagnosis:

• Silent aspiration is extremely common in PD and cannot be detected by clinical assessment alone—this patient's recent "chest infection of uncertain etiology" is almost certainly aspiration pneumonia. 1
• Esophageal dysphagia occurs in 60-80% of PD patients, often asymptomatically, due to esophageal dysmotility from autonomic nervous system involvement. 1
• The sensation of bolus obstruction requiring emesis and incomplete transit are classic features of PD-related esophageal retention. 1
• Presyncopal symptoms with choking suggest severe episodes potentially related to vagal stimulation during esophageal distention or aspiration events. 1

Immediate Diagnostic Steps

Perform fiberoptic endoscopic evaluation of swallowing (FEES) immediately—this is the preferred instrumental assessment over repeat VFSS. 1

Why FEES Over VFSS:

• FEES is superior to VFSS in PD patients because it can be performed at bedside, requires minimal patient cooperation, involves no radiation exposure, and can detect silent aspiration more reliably. 1
• FEES can simultaneously serve as therapeutic intervention through video-assisted swallowing therapy (VAST). 1
• The reliability of VFSS in PD has been questioned, whereas FEES provides direct visualization of pharyngeal and laryngeal structures. 1

Additional Diagnostic Considerations:

• High-resolution esophageal manometry with impedance should be considered to fully characterize the esophageal dysmotility pattern and detect clinically silent impairment. 1
• Evaluate for aspiration pneumonia with chest imaging if not already done—the recent chest infection warrants confirmation. 1

Immediate Therapeutic Steps

1. Optimize Antiparkinsonian Medication

Adjust dopamine agonist therapy immediately, as dopaminergic mechanisms directly contribute to dysphagia in PD. 1

• The effect of dopaminergic treatment on dysphagia is unpredictable in individual patients and must be tested—some patients improve, others do not. 1
• Consider whether the patient is in an "off" state during swallowing difficulties, as timing medication before meals may help. 2
• Administer dopamine agonists at least 30 minutes before meals to optimize motor function during eating. 2

2. Nutritional and Safety Interventions

Monitor for medication side effects that worsen dysphagia, particularly nausea, vomiting, dry mouth, and anorexia—all common with dopamine agonists (ropinirole, pramipexole, rotigotine). 3

• Ropinirole specifically lists dysphagia as an adverse effect occurring in 2% of advanced PD patients. 3
• The FDA label for ropinirole reports nausea in 30% and vomiting in 7% of advanced PD patients, which can exacerbate dysphagia. 3

Implement dietary modifications immediately:

• Avoid thin liquids if aspiration is confirmed—thickened liquids may be safer pending FEES results. 1
• Do NOT implement strict protein restriction, as this lacks evidence and can worsen nutritional status. 2
• Monitor weight closely, as the absence of weight loss currently does not exclude future malnutrition risk. 1, 2

3. Address Aspiration Risk

Treat the recent chest infection as aspiration pneumonia until proven otherwise and implement aspiration precautions. 1

• Educate the patient to stop inducing emesis, as this significantly increases aspiration risk. 1
• Consider empiric antibiotic therapy if not already initiated for the chest infection. 1

Critical Pitfalls to Avoid

Common Errors in PD Dysphagia Management:

• Never rely on clinical swallowing examination alone in PD—silent aspiration occurs in the majority of patients and cannot be detected without instrumental assessment. 1
• Do not assume the patient is aware of swallowing problems—only 20-40% of PD patients recognize their dysphagia. 1
• Avoid delaying instrumental assessment in patients with pneumonia or rapid deterioration—this patient meets criteria for urgent FEES. 1
• Do not ignore esophageal involvement—the prior VFSS showing esophageal retention indicates both oropharyngeal AND esophageal phases are affected. 1

Medication-Specific Considerations:

• Monitor for dopamine agonist withdrawal syndrome if medication adjustments are made—abrupt cessation can cause severe apathy and worsening motor symptoms. 4
• Dopamine agonists can cause impulse control disorders and sleep attacks that require routine monitoring, though these are not directly related to dysphagia. 4

Algorithmic Approach to This Patient

1. Immediate (within 1 week): Perform FEES to assess aspiration risk and guide dietary modifications 1
2. Concurrent: Optimize dopaminergic therapy timing and dosing 1, 2
3. If FEES confirms aspiration: Implement diet texture modifications and consider swallowing therapy 1
4. If esophageal dysmotility is severe: Obtain high-resolution manometry to guide further management 1
5. Monitor closely: Weekly weight checks, nutritional status assessment, and vitamin supplementation (B12, folate, vitamin D) 1, 2

Long-term Monitoring:

• Regular reassessment of swallowing function as PD progresses 1
• Surveillance for recurrent aspiration pneumonia 1
• Consideration of enteral feeding if oral intake becomes unsafe, though this is not currently indicated given no weight loss 1