What is the relationship between Parkinson's disease and syncope (fainting)?

From the Guidelines

Parkinson's disease patients with syncope should be managed with a multi-faceted approach, including increasing fluid intake, adding salt to the diet, using compression stockings, and rising slowly from sitting or lying positions, as well as considering medications like midodrine, fludrocortisone, or droxidopa for persistent orthostatic hypotension, as recommended by the 2017 ACC/AHA/HRS guideline 1. To manage syncope in Parkinson's patients, the following strategies can be employed:

• Increase fluid intake to 2-3 liters daily, as acute water ingestion can temporarily restore orthostatic tolerance in patients with neurogenic orthostatic hypotension (OH) 1
• Add salt to the diet (unless contraindicated), as salt supplementation can increase plasma volume and improve blood pressure in patients with OH 1
• Use compression stockings, as compression garments can improve orthostatic symptoms and blunt associated decreases in blood pressure in patients with OH, including those with neurogenic etiologies 1
• Rise slowly from sitting or lying positions, as physical counter-pressure maneuvers, such as leg crossing or squatting, can increase blood pressure and improve orthostatic tolerance in patients with neurogenic OH 1 Medications like midodrine (2.5-10mg three times daily) or fludrocortisone (0.1-0.2mg daily) may be prescribed for persistent orthostatic hypotension, as they can improve symptoms of OH in patients with neurogenic OH 1. For severe cases, droxidopa (100-600mg three times daily) might be considered, as it can improve symptoms of neurogenic OH due to Parkinson's disease, pure autonomic failure, and multiple system atrophy 1. Regular blood pressure monitoring in both sitting and standing positions is essential to track orthostatic changes, and patients should keep a symptom diary to identify triggers and patterns of syncope episodes, which helps tailor treatment strategies more effectively. It is also important to adjust Parkinson's medications by reducing doses or changing timing to help minimize syncope risk, as certain medications, such as levodopa and dopamine agonists, can worsen orthostatic hypotension 1.

From the FDA Drug Label

1. 2 Syncope Syncope, sometimes associated with bradycardia, was observed in association with treatment with ropinirole in both patients with Parkinson’s disease and patients with RLS In controlled clinical trials in patients with Parkinson’s disease, syncope was observed more frequently in patients receiving ropinirole than in patients receiving placebo (early Parkinson’s disease without levodopa [L-dopa]: ropinirole 12%, placebo 1%; advanced Parkinson’s disease: ropinirole 3%, placebo 2%)

• Syncope is a potential side effect of ropinirole, particularly in patients with Parkinson’s disease.
• The incidence of syncope in patients with Parkinson’s disease was higher in those receiving ropinirole (12% in early Parkinson’s disease and 3% in advanced Parkinson’s disease) compared to those receiving placebo (1% and 2%, respectively) 2.
• Patients with Parkinson’s disease should be monitored for signs and symptoms of orthostatic hypotension, especially during dose escalation, and should be informed of the risk for syncope and hypotension.

From the Research

Parkinson's Disease and Syncope

• Syncope is a common symptom in patients with Parkinson's disease, often caused by orthostatic hypotension (OH) 3, 4
• OH is a sustained pathological reduction in blood pressure within 3 minutes after orthostatic stress, such as standing or tilt-table testing 5
• Neurogenic OH is a type of OH that results from inadequate release of norepinephrine in the vasomotor sympathetic system, commonly seen in parkinsonian diseases 5

Pathophysiology and Treatment

• The pathophysiology of neurogenic OH in parkinsonian diseases includes sympathetic neurocirculatory failure and impaired cardiovagal activity 5
• Non-pharmacologic therapies, such as lifestyle changes and behavioral measures, are the cornerstone of OH treatment 3, 4
• Pharmacological interventions, such as sympathomimetic agents and fludrocortisone, may be introduced stepwise depending on the severity of symptoms 3, 5

Diagnosis and Management

• Ambulatory blood pressure monitoring is a cost-effective method for diagnosing OH and supine hypertension 4, 6
• A mean standing blood pressure below 75 mmHg appears to be a useful benchmark for detecting symptomatic OH 7
• Treatment of OH should aim to improve quality of life and prevent short- and long-term complications, such as syncope and falls 3, 4

Associated Conditions

• Supine hypertension is a common comorbidity with OH, which can limit effective treatment and increase the risk of hypertensive emergencies 3, 4
• Postprandial hypotension is another comorbidity that can exacerbate OH and cause syncope 6