What is Neurogenic Orthostatic Hypotension?
Neurogenic Orthostatic Hypotension (nOH) is a form of orthostatic hypotension caused by the brain. This type of orthostatic hypotension can be caused by conditions such as Parkinson’s disease, Multiple sclerosis, and stroke.
The brain controls the body’s autonomic nervous system, which controls the body’s blood pressure. When this system malfunctions, it can cause one to experience symptoms like dizziness, fainting, and heart palpitations when standing up quickly or prolonged standing.
What are the Symptoms of Neurogenic Orthostatic Hypotension?
Symptoms of neurogenic orthostatic hypotension include:
- Dizziness
- Headache
- Nausea
- Faintness
- Blurred vision
How is nOH Treated?
Doctors treat orthostatic hypotension in patients with Parkinson’s by prescribing medications like dopamine agonists to help control their Parkinson’s symptoms, including tremors, stiffness, slowness of movement, and difficulty walking. They will also prescribe drugs to increase blood flow to the brain, which will help prevent the drop in blood pressure when standing.
The goal of nOH treatment is not to normalize standing BP but to reduce symptom burden. Treatment priorities include correcting aggravating factors and implementing both nonpharmacological and pharmacological therapies if necessary.
Nonpharmacological therapies are the first line of treatment in nOH. They include:
- Small and frequent meals with a low carbohydrate load.
- Avoiding increased core body temperature (e.g., from excessive high-intensity exercise, use of hot tubs or saunas).
- Elevating head of bed up to 30° during sleep to mitigate supine hypertension.
- Moderate but nonstrenuous activities with lower body strength training.
- Proper hydration (at least 64 oz of water intake daily).
- Use of compression garments (e.g., abdominal binders) when supine.
- Treatment of anemia if present.
When nonpharmacological treatments of nOH fail to improve symptoms, the most common medications used are droxidopa, midodrine, and fludrocortisone.
Droxidopa (100-600 mg/d) is the only US Food and Drug Administration–approved drug for nOH in PD. It is a prodrug of norepinephrine that increases peripheral vascular resistance and, subsequently, BP. Midodrine (2.5-10 mg orally every 8 hours) also increases vascular resistance by an unknown mechanism.
Both drugs can cause potentially dangerous supine hypertension; therefore, supine and orthostatic BP should be monitored when initiating and titrating these medications.
Fludrocortisone (0.1 or 0.2 mg orally per day) is a mineralocorticoid that raises intravascular volume and, subsequently, orthostatic BP by retaining sodium in exchange for potassium; therefore, electrolytes should be routinely monitored when prescribing this medication. The goal of pharmacological treatment is to minimize bothersome symptoms of nOH while being vigilant about drug-specific potential adverse effects.
For more information on living with Parkinson’s, including details on how to manage other non-motor symptoms of PD, please check out our book, The Complete Guide For People With Parkinson’s And Their Loved Ones.
Pravin Khemani, MD
Swedish Neuroscientist Specialists
Movement Disorders
Medical Disclaimer: Dr. Khemani’s comments are not prescriptive advice and do not supplant the directions of your treating physician. His views are his alone, based on years of practice and experience in treating Parkinson’s disease, and do not represent the views of his employer or any other organization. Always make medical decisions only under the guidance of your treating doctor.