Abdominal Compression in Orthostatic Hypotension

Inclusion Criteria

• •SUBJECTS We will study 15 patients of both genders with neurogenic orthostatic hypotension (OH). Subjects will be recruited from the existing list of patients available in the database of the Autonomic Disorders Center.
• •1. Men and nonpregnant women aged 18-80 years.
• •2. Chronic neurologic conditions known to cause OH: multiple system atrophy (MSA), Parkinson's disease, autoimmune autonomic ganglionopathy or progressive autonomic neuropathy (e.g., diabetic, amyloid).
• •3. Orthostatic hypotension defined as a drop of systolic BP\>30 mmHg or diastolic BP\>15 mmHg.
• •4. Adrenergic failure of at least moderate severity defined as CASS-adrenergic ≥3.
• •5. Ambulatory and able to stand more than 3 minutes without pre-syncope.
• •6. BMI \<29.
• •7. Ability to comply with study procedures and appointments.
• •8. Normal cognition (able to understand the study, learn the maneuvers, and follow complex commands).
• •9. Concomitant therapy with anticholinergic, alpha and beta agonists will be withdrawn 48 hours prior to autonomic evaluations. Midodrine will be withdrawn the night before evaluation. Fludrocortisone doses up to 0.2 mg per day will be permitted.
• •The diagnosis of probable MSA requires 1) the presence of orthostatic hypotension or urinary incontinence, and 2) poorly levodopa responsive parkinsonism or cerebellar ataxia.
• •The diagnosis of clinically definite Parkinson's disease requires 1) the presence of resting tremor, bradykinesia and rigidity, 2) clinical asymmetry, and 3) response to levodopa.
• •The diagnosis of autoimmune autonomic ganglionopathy requires 1) a sub-cute onset, 2) the presence of generalized and severe autonomic failure (CASS\>6), 3) selective involvement of autonomic nerve fibers and 4) positive alpha-3 nicotinic acetylcholine receptor auto-antibodies.