This document provides information on neurogenic orthostatic hypotension (nOH) and autonomic dysfunction. It defines nOH as a drop in blood pressure of at least 20 mmHg systolic or 10 mmHg diastolic within 3 minutes of standing. The most common causes of autonomic dysfunction are Parkinson's disease, aging, and peripheral neuropathies. Norepinephrine transport is often impaired, leading to symptoms like fainting, dizziness, and incontinence. Patients with neurodegenerative disorders, unexplained falls, syncope, peripheral neuropathies, older age/frailty, or orthostatic symptoms should be screened. Treatment aims to reduce episodes and includes increasing salt/

1. When Compensatory
Mechanisms Fail
Margaret Rene Williams
RN, MSN, NP-BC
2017

2. LEARNING OBJECTIVES
üDefine the criteria for neurogenic orthostatic hypotension.
üRecognize the 3 most common causes of the condition.
üIdentify patients who need to be routinely screened for orthostatic
hypotension.
üTarget the point in the spinal column that separates upper from lower
dysautonomic problems.
üUnderstand the various treatment options for decreasing episodes of
syncope.

3. Autonomic dysfunction
is a highly complex and
Poorly understood condition for which there is no cure.
Most patients who have autonomic dysfunction in the absence
of a known causative condition have been everywhere
and have had every diagnostic test imaginable.
There are as many potential causes as there are symptoms.
Tachycardia, hypotension, visual disturbances, fainting,
headache, nausea, vomiting, diaphoresis, tremors, weakness,
pallor, sweating and incontinence are only a few of the
common presentations in Primary Care.

4. Postural Hypotension or Abnormal Heart Rate Regulation
are the most troublesome or disabling symptoms
(Iodice & Sandroni, 2014) and may be seen in Primary
Care as fainting spells or black-outs with no apparent cause.
It is important to note that neurogenic postural hypotension
occurs when the autonomic system is affected at the T-6 level
of the spinal cord and that other symptoms such as
incontinence and sexual dysfunction occur below this level.
The most current evidence points to impaired norephinephrine
transport at the neuron level (Shannon, Flattem & Jordan, 2000).

5. Impaired Norepinephrine Transport
Vanderbilt Autonomic Dysfunction Center (2000)

6. The Definition and Diagnostic Standard
Recognizing that “The literature on neurogenic orthostatic hypotension (nOH) is
fraught with inconsistencies in the definition and methods of diagnosis, and
suffers from a lack of evidence-based guidelines to direct clinicians towards
‘best practice’, The American Autonomic Society and the National Parkinson
Foundation convened in 2017 and defined orthostatic hypotension as: “…a
sustained reduction of systolic blood pressure of at least 20 mmHg or diastolic
blood pressure of 10 mmHg, or both, within 3 min of standing or head-up tilt to
at least 60° on a tilt table.”
2017 Consensus statement on the definition of orthostatic hypotension, neurally mediated
syncope and the postural tachycardia syndrome. J Neurol. 2017 Jan 3. doi:
10.1007/s00415-016-8375-x. [Epub ahead of print].

7. Patients in 5 Categories Need to be Screened for nOH
üPatients suspected of, or diagnosed with any neurodegenerative disorder associated
with autonomic dysfunction, including Parkinson’s Disease, Multiple System Atrophy,
Pure Autonomic Failure, or Dementia with Lewy Bodies.
üPatients who have reported an unexplained fall or have had an episode of syncope
üPatients with peripheral neuropathies known to be associated with autonomic
dysfunction (e.g., diabetes, amyloidosis, HIV).
üPatients who are elderly (≥70 years of age) and frail or on multiple medications.
üPatients with postural (orthostatic) dizziness or non-specific symptoms that only occur
when standing.

8. SUGGESTED SCREENING QUESTIONS
• Have you fainted/blacked out recently? Do you feel dizzy or lightheaded upon
standing?
• Do you have vision disturbances when standing?
• Do you have difficulty breathing when standing?
• Do you have leg buckling or leg weakness when standing?
• Do you ever experience neck pain or aching when standing?
• Do the above symptoms improve or disappear when you sit or lay down?
• Are the above symptoms worse in the morning or after meals?
• Have you experienced a fall recently?
• Are there any other symptoms you commonly experience when you stand up or
within 3–5 min of standing and get better when you sit or lay down?
• Any positive response should prompt further investigation with orthostatic blood
pressure measurement.

9. CASE PRESENTATION
A 45-year-old white female presents to the clinic with a history of
“fast heart beat and passing out.” She has been to numerous
doctors for this problem and has even been committed to a mental
hospital without any definitive diagnosis. She has a surgical history
that is significant for: hysterectomy, breast implants, gastric bypass
surgery, cholecystectomy and cervical neck fusion. She does not
smoke, drink alcohol or use any kind of opiate or other drug. She
has asthma attacks occasionally but is maintained on ProAir and an
albuterol inhaler. She is here today for a checkup and refills.
Her vital signs are: Wt. 165 lb. Ht. 66.5 in. Temp. 98.0 Pulse 82
Resp 18 B/P 118/68 and O2 sat 98% on room air.

10. Question #1
What is the FIRST priority in this situation?
a. Check the pulse oximetry reading
b. Begin CPR.
c. Lower her head and assure that she is safely positioned
on the table.
d. Check the blood pressure.
She is sitting erect on the table as you begin your
examination.
Suddenly she states: “I am going to pass out!”.

11. Before you can yell for help, she wakes up just as suddenly
as she passed out and says “I do this and sometimes I will
get a feeling that it is going to happen.”
After sitting up for a few minutes and describing an occasional visual
disturbance before she passes out, she does it AGAIN!
This time you watch and note that she begins with tachycardia as the
B/P drops, becomes unconscious and has apnea for 15-20 seconds as
you watch her 02 sat. drop to the high 80’s with the heart rate at 35-
40 (apical) before becoming alert and awake again.
Your preceptor explains that this patient was evaluated in the
Dysautonomic Research Dept. at Mayo Clinic and determined to have
an idiopathic form of neurogenic orthostatic hypotension.
She is one of the fortunate few who usually has an ‘aura’ before an
attack occurs.

12. Question # 2
What are the most common causes of autonomic insufficiency?
a. Parkinson’s Disease, Aging, Peripheral Neuropathies
b. Multiple sclerosis, Hypertension, Medication
c. Spinal cord trauma, AIDS, constipation
d. Guillain Barre’ Syndrome, MMR vaccine, Diabetes

13. Question # 3
Which neurotransmitter is most often impaired in
autonomic insufficiency?
a. Dopamine
b. Norepinephrine
c. Acetylcholine
d. Serotonin

14. What Are The Goals and Types of Treatment?
• The goal for patients with autonomic dysfunction is to reduce the number and
frequency of episodes and to prevent injury from falling.
• The type of treatment depends upon the most likely causative factor.
• In neurogenic OH some patients have had improvement by doing things that
are the opposite of Hypertension guidelines: increasing SALT intake,
increasing Caffeine intake, exercise and using the Valsalva Maneuver (to
increase blood pressure when they feel faint).
• Some have had improvement with drug therapy that primarily induces an
increase in peripheral and central vasoconstriction.
• In facilities with the equipment, some success in ‘retraining’ the autonomic
response with tilt-table therapy has been achieved in younger patients.

15. An Algorithm for Treating Orthostatic Hypotension
Gibbons, C., Schmidt, P. & Biaggioni, I. et al. (2017). J Neurol doi:10.1007/s00415-016-8375-x

16. Question # 4
What is the Standard Definition of Orthostatic
Hypotension?

17. FINAL QUESTION
Which patients should be screened for orthostatic
hypotension?

18. References
Gibbons, C., Schmidt, P., Biaggioni, I., Frazier-Mills, C., Freeman, R., Isaacson,S., Karabin,
B., Kuritzky, L., Lew, M., Low, P., Mehdirad, A., Raj, S., Vernino, S. and Kaufmann, H.
(2017). The recommendations of a consensus panel for the screening, diagnosis, and
treatment of neurogenic orthostatic hypotension and associated supine hypertension. J
Neurol. 2017 Jan 3. doi: 10.1007/s00415-016-8375-x. [Epub ahead of print].
Iodice, V. And Sandroni, P. (2014). Autonomic Neuropathies. CONTINUUM: Lifelong Learning in
Neurology. October 2014 – Volume 20 – Issue 5, Peripheral Nervous System Disorders
- p. 1373-1397. doi:10.1212/01.CON0000455875.76179.b1
Lambert, E. And Lambert, G. (2014). Sympathetic dysfunction in vasovagal syncope
and the postural orthostatic tachycardia syndrome. Frontiers in Physiology.
2014; 5: 280. Published online 2014 Jul 28.
Shannon, J., Flattem, N., Jordan, J., Jacob, G., Black, BK., Biaggioni, I., Blakely, R. and Robertson
D. (2000). Orthostatic intolerance and tachycardia associated with norepinephrine-
transporter deficiency. N Engl J Med. 2000 Feb 24;342(8):541-9.

19. PHOTO CREDITS
Vanderbilt Autonomic Dysfunction Center (2000). Published online
2000 Feb 24 as Open Access article.
Yale J Biol Med. 2016 Mar; 89(1): 59–71. (2016). Published online 2016
Mar 24 as Open Access article.