What are the treatment options for a patient with Parkinson's disease (PD) experiencing dysphagia (swallowing difficulties)?

Treatment of Swallowing Issues in Parkinson's Disease

All Parkinson's disease patients with positive dysphagia screening should undergo instrumental assessment with fiberoptic endoscopic evaluation of swallowing (FEES) as the preferred method, followed by individualized rehabilitation treatment including expiratory muscle strength training, thickened liquids (honey-thick being most effective), and optimization of antiparkinsonian medications. 1

Initial Assessment and Screening

Mandatory Screening Protocol

• Perform instrumental dysphagia assessment in all PD patients who screen positive for dysphagia, show rapid disease deterioration, have pneumonia, or demonstrate any signs of swallowing difficulty 1
• Use FEES preferentially over videofluoroscopic swallowing study (VFSS) when available, as FEES avoids radiation exposure, requires minimal patient cooperation, and can be performed at bedside 1
• Clinical assessment alone is unreliable in PD—silent aspiration occurs frequently and cannot be detected by bedside examination 1, 2
• Modified water swallow test measuring maximum swallowing volume is recommended, with values <13-15 ml suggesting significant dysphagia 2, 3

Critical Pitfall to Avoid

Never assume absence of aspiration based on lack of coughing—silent aspiration is extremely common in PD and can occur in up to 80% of cases 1, 2. Three patients in one study demonstrated silent aspiration despite no subjective complaints 4.

Pharmacological Optimization

Dopaminergic Medication Management

• Optimize antiparkinsonian treatment first to ameliorate motor symptoms contributing to dysphagia 1
• Test whether dopaminergic treatment improves dysphagia, as both dopaminergic and non-dopaminergic mechanisms are involved—response is unpredictable 1
• Perform dysphagia assessments during the medication "ON" phase for accurate evaluation 2
• Approximately 50% of PD patients with dysphagia show objective improvement after levodopa treatment, while 50% show no change 4

Medication Side Effects Monitoring

• Monitor for medication side effects that influence nutritional status: nausea, vomiting, abdominal pain, dyspepsia, constipation, weight loss, dry mouth, diarrhea, and anorexia 1
• Check homocysteine levels and vitamin B status (folate, B12, B6) in patients on levodopa, as long-term use causes hyperhomocysteinemia 1
• Consider vitamin B supplementation to maintain normal homocysteine levels and reduce cardiovascular disease risk 1

Rehabilitation Treatment Strategies

Evidence-Based Interventions with Strongest Support

Expiratory Muscle Strength Training (EMST)

• EMST for 4 weeks improves penetration/aspiration scores and hypolaryngeal complex function (excursion time and displacement) 1
• This intervention has demonstrated improvement in both cough and swallow function in controlled studies 1
• Grade A recommendation for motor-neuron disorders and Parkinson's disease 1

Thickened Liquids for Aspiration Prevention

• Honey-thick liquids are most effective at preventing aspiration, followed by nectar-thick liquids 1
• Pudding-thick liquids result in significantly lower penetration-aspiration scores compared to thin liquids 1
• Chin-down posture with thin liquids is the least effective intervention 1
• Critical limitation: 39% of PD patients and 50% of PD patients with dementia aspirated on all three interventions (chin-down, nectar-thick, honey-thick) 1

Additional Therapeutic Options

Structured Exercise Programs

• Oral motor exercise programs supervised by speech-language therapists for 5 weeks increase strength and range of motion of mouth, larynx, and pharynx 1
• Lee Silverman Voice Treatment (LSVT) improves neuromuscular control of oral phase and tongue function 1
• Shaker head lift exercise (Grade A recommendation for upper esophageal sphincter dysfunction) improves suprahyoid muscle strength and UES opening 1

Bolus Modification

• Adapt consistency and volume based on individual swallowing patterns identified on instrumental assessment 1
• Training with different amounts of thin/thick liquids, puree, and soft solid foods improves bolus control and airway protection 1

Interventions with Insufficient Evidence

Surface electrical stimulation, repetitive transcranial magnetic stimulation, and video-assisted swallowing therapy do not yet have sufficient evidence for recommendation 1. Studies show no statistically significant differences between electrical stimulation combined with traditional therapy versus traditional therapy alone 1.

Treatment Algorithm

1. Screen all PD patients for dysphagia using modified water swallow test
2. If positive screening → Perform FEES (or VFSS if unavailable) during medication "ON" phase
3. Optimize dopaminergic medications and assess response
4. Implement individualized rehabilitation based on instrumental findings:
   • Start EMST training (4-week protocol)
   • Prescribe honey-thick liquids for aspiration risk
   • Add structured swallowing exercises (oral motor program or LSVT)
   • Modify bolus characteristics based on specific deficits
5. Monitor medication side effects and vitamin B status
6. Reassess regularly with instrumental testing to evaluate treatment effects 1

Prognostic Considerations

• Over 80% of PD patients develop dysphagia during disease course 1, 2, 3
• Aspiration pneumonia is a major cause of death in PD 5, 3
• Dysphagia reduces quality of life, complicates medication intake, and leads to malnutrition 5, 3
• Rehabilitative approaches have greater potential for long-term improvement in swallowing safety and quality of life compared to compensatory strategies alone 1

Key Clinical Caveat

The evidence base for dysphagia interventions in PD remains limited—no RCTs or controlled trials were found in the 2001 Cochrane review, and subsequent systematic reviews identify only modest evidence for specific interventions 1. Despite this, the high mortality risk from aspiration pneumonia necessitates aggressive multidimensional assessment and treatment using the best available evidence, particularly EMST and thickened liquids.