[show abstract][hide abstract] ABSTRACT: To undertake a prospective study of the clinical characteristics of orthostatic intolerant patients referred to the Mayo Autonomic Reflex Laboratory with suspected orthostatic hypotension (OH).
Autonomic function tests were performed to quantify the severity of sudomotor, adrenergic, and cardiovagal failure and generate a composite autonomic symptom score (CASS). CASS was related to a symptom score, which was derived from the frequency of orthostatic intolerance and syncope and the standing time until occurrence of symptoms.
Three groups were defined by their response to a tilt study: group I, 90 patients with symptomatic OH, mean age, 63.6 years; group II, 60 patients who had symptoms without OH, mean age, 48.9 years; and group III, 5 patients with asymptomatic OH, mean age, 68.0 years. Group I had a significantly higher CASS (P < 0.001) than did those without OH. Further analysis was done on the 90 patients in group I. The most common symptoms were lightheadedness, weakness, impaired cognition, visual blurring, tremulousness, and vertigo. The most common aggravating factors were prolonged standing, exercise, warming, and eating. Most patients (75%) could stand for less than 5 minutes before symptoms occurred. Symptoms regressed significantly with CASS but not with the tilt grade.
Patients with generalized autonomic failure have a recognizable pattern of symptoms and aggravating factors that relate, albeit imperfectly, to the severity of autonomic failure.
Mayo Clinic Proceedings 07/1995; 70(7):617-22. · 5.79 Impact Factor
[show abstract][hide abstract] ABSTRACT: We performed infrared telethermography in 55 patients with the clinical diagnosis of lumbosacral radiculopathy and in 37 normal controls. Five readers interpreted the thermograms in a blinded fashion. A moderate degree of agreement was noted in tests of intraobserver and interobserver variability. The sensitivity of thermography ranged from 78% to 94% compared with 81% to 92% for imaging studies and 77% for EMG. The specificity of thermography ranged from 20% to 44%. Thermography predicted the level of the radiculopathy correctly in less than 50% of cases. Thermography has little or no utility in the diagnosis of lumbosacral radiculopathy.
[show abstract][hide abstract] ABSTRACT: Little quantitative information is available on the effects of age on peripheral autonomic function. We studied the effect of age on the heart rate (HR) responses to deep breathing and the Valsalva maneuver in 122 and 155 subjects, respectively, aged 10 to 83 years. The quantitative sudomotor axon reflex test (QSART) was determined in 114 subjects in the same age group. The HR responses were not different between the sexes, but a consistently significant regression with age was demonstrated in response to deep breathing and the Valsalva ratio. The QSART responses were significantly larger in male subjects and were generally lower in older subjects of both sexes but a significant negative regression with age was found only in female subjects. Cardiac vagal function is impaired with age, but postganglionic sympathetic function is little affected by age, suggesting selectivity of effects of aging on autonomic function.
[show abstract][hide abstract] ABSTRACT: Limb dependency activates the venoarteriolar reflex (VAR), resulting in reflex vasoconstriction (RV). Since others have reported the VAR to fail in diabetic neuropathy, we examined the reliability of this test in detecting sympathetic failure in diabetic and other neuropathies. We studied 40 controls, 49 diabetic subjects, and 29 patients with other neuropathies. The mean RV was greater in controls than in diabetics or other neuropathies, but there were marked overlaps among groups. We conclude that the VAR, while impaired in the neuropathies, is of little value as a clinical test and is a poorer test of autonomic function than the quantitative sudomotor axon reflex test or heart rate responses to deep breathing or the Valsalva maneuver.