Description

• Degenerative disorder of the peripheral autonomic nervous system and considered to be one of the Lewy body diseases (1,2)
• Blood pressure (BP) drops with inadequate compensatory rise in heart rate while standing, such as symptomatic orthostatic hypotension, attributed to autonomic system impairment (1,3).
• Maintaining upright posture is difficult for patients with this disorder. They are at increased risk for fall and syncope.

Epidemiology

Incidence
Unconfirmed, area of ongoing research (4)

Prevalence

• Male > female (1,4)
• Starts at middle age and progresses through life (1)
• True prevalence currently unknown

Etiology and Pathophysiology

• Actual cause not known; however, it impairs responses to homeostatic mechanism that regulate BP, causing loss of cerebral perfusion from poor arterial resistance, loss of increase in heart rate as compensation, and venous pooling in positional change (1).
• Neurodegenerative disease classified as an α-synucleinopathy, with Lewy bodies seen on histopathologic samples (1,2)
• No stimulation of sympathetic nervous system, and postganglionic sympathetic neurons do not release norepinephrine properly (1).

Genetics
No specific genetic component identified

Risk Factors

• Male gender
• Environmental: morning time, hot weather (1)
• Medications: diuretics, α-adrenergic antagonists, calcium channel blockers, nitrates, levodopa and dopaminergic drugs for Parkinson, antipsychotics and antidepressants (4)

General Prevention

• Avoid abrupt change in posture and standing motionless for extended periods.
• Avoid lying completely supine if resting during day and elevate head of bed 6 to 9 inches at night (1).
• Remove any compressive stockings or abdominal bindings during supine positioning (1).
• Perform isometric or dynamic muscle contractions to squeeze venous blood upward to heart (1).
• Avoid large meals, hot environments (2).
• Drink adequate water (at least 2 to 2.5 L/day) and take salt at least 5 to 10 g/day (2).

Commonly Associated Conditions

Not applicable