An autonomic reflex screen, which consisted of a quantitative sudomotor axon reflex
test, orthostatic blood pressure and heart rate response to tilt, heart rate response
to deep breathing, the Valsalva ratio, and beat-to-beat blood pressure measurements
during phases II and IV of the Valsalva maneuver, tilt, and deep breathing, was used
to develop a 10-point composite autonomic scoring scale of autonomic function. The
scheme allots 4 points for adrenergic and 3 points each for sudomotor and cardiovagal
failure. Each score is normalized for the compounding effects of age and sex. Patients
with a score of 3 or less on the composite autonomic scoring scale have only mild
autonomic failure, those with scores of 7 to 10 have severe failure, and those with
scores between these two ranges have moderate autonomic failure. The sensitivity and
specificity of the method were assessed by evaluating the composite autonomic scoring
scale in four groups of patients with known degrees of autonomic failure: 18 with
multisystem atrophy, 20 with autonomic neuropathy, 20 with Parkinson's disease, and
20 with peripheral neuropathy but no autonomic symptoms. The composite scores (means
+/- SD) for these four groups, respectively, were as follows: 8.5 +/- 1.3, 8.6 +/-
1.2, 1.5 +/- 1.1, and 1.7 +/- 1.3. Patients with symptomatic autonomic failure had
scores of 5 or more, those without symptomatic autonomic failure had scores of 4 or
less, and no overlap existed in these groups. Thus, autonomic laboratory tests should
be useful in grading the degree of autonomic failure.