Abdominal Compression in Orthostatic Hypotension

In 3 protocols, patients will undergo standing maneuvers, measured abdominal compressions,
continuous BP monitoring and symptoms, ease-of-use and compliance scoring. In protocol 1,
patients will exert abdominal compression to maximal tolerable and comfortable levels and
values will be recorded. In protocol 2, patients will perform 3 standing maneuvers following
a preceding rest period with and without abdominal compression at 20 mmHg (binders used in
random order). In protocol 3, the standing maneuvers will be extended and the investigator
will adjust binders to levels of abdominal compression corresponding to what patient gauged
as maximal tolerable and comfortable levels. Comparison of outcome measures will establish
which binder achieves higher abdominal compression, is easier to adjust, likely will be used
in the future, if elastic and adjustable binders are equally effective in attenuating OH and
its associated symptoms at comparable pressures and which binder is more effective in
recovering standing BP and improving orthostatic symptoms.

SUBJECTS We will study 15 patients of both genders with neurogenic OH. Subjects will be
recruited from the existing list of patients available in the database of the Autonomic
Disorders Center.

Inclusion Criteria

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 Concomitant therapy with anticholinergic, alpha and beta agonists will be withdrawn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 Midodrine will be withdrawn the night before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.

Exclusion Criteria

1. Pregnant or lactating females.

2. Non-neurogenic OH, such as that due to medication or hypovolemia.

3. Chronic illnesses or other CNS conditions that affect autonomic function.

4. Established dementia.

5. Debilitating ataxia.

6. Moderate to severe lower extremity weakness.

7. Severe systemic illness, such as end-stage pulmonary, cardiac or renal disease.