Pure autonomic failure, or Bradbury-Eggleston syndrome, is a degenerative disorder of the autonomic nervous system presenting in middle to late life, affecting men more than women. The orthostatic hypotension may be described as unsteadiness, dizziness, or faintness upon standing. It is worse in the morning, after meals or exercise, or in hot weather.
Patients also complain of pain in the neck or back of the head, relieved by lying down.
Urological manifestations include nocturia, or urination during the night, hesitancy, urgency, dribbling, and occasional incontinence. Patients also often complain of a change in the pattern of sweating. The definitive diagnosis of hypotension as the cause of orthostatic symptoms is usually made by the demonstration of a decline in systolic blood pressure of 20 mm Hg and diastolic blood pressure of 10 mm Hg after at least one minute of standing. However, a decrease in systolic blood pressure by 50 mm Hg or greater is not unusual in these patients. The orthostatic hypotension is usually accompanied by supine hypertension, or increased blood pressure while lying, even when the patient is on no medications to raise blood pressure.