TY - JOUR
T1 - Electrophysiological tests of autonomic function in patients with idiopathic autonomic failure syndromes
AU - Ravits, John
AU - Hallett, Mark
AU - Nilsson, Jan
AU - Polinsky, Ronald
AU - Dambrosia, James
PY - 1996/6
Y1 - 1996/6
N2 - Three electrophysiological tests of autonomic function were performed in patients with autonomic nervous system dysfunction to define test sensitivities and specificities. The skin sympathetic response, Valsalva ratio, and heart rate variation with deep breathing were studied in 10 patients with multiple system atrophy (MSA) and in 7 patients with pure (also called progressive or primary) autonomic failure (PAF); control subjects were 17 normal individuals of similar age. Thirteen patients had abnormal skin sympathetic responses, and 16 had abnormal Valsalva ratios. Fourteen patients had an abnormal variation of the heart rate with deep breathing. Taking the three tests together, binary logistic regression for distinguishing between patients and normal subjects correctly classified 91% of the 33 individuals for whom there were complete data with sensitivity of 88% and specificity of 94%. However, only 69% of the patients could be correctly classified by a logistic regression for discriminating between MSA and PAF. Electromyography (EMG) studies showed that 7 of 8 patients with MSA but only 2 of 7 patients with PAF (both multiparous women) had denervation of the rectal sphincter muscle. The EMG study is, therefore, valuable in men, but has a high false positive rate in women, probably because of pudendal nerve injury from parturition.
AB - Three electrophysiological tests of autonomic function were performed in patients with autonomic nervous system dysfunction to define test sensitivities and specificities. The skin sympathetic response, Valsalva ratio, and heart rate variation with deep breathing were studied in 10 patients with multiple system atrophy (MSA) and in 7 patients with pure (also called progressive or primary) autonomic failure (PAF); control subjects were 17 normal individuals of similar age. Thirteen patients had abnormal skin sympathetic responses, and 16 had abnormal Valsalva ratios. Fourteen patients had an abnormal variation of the heart rate with deep breathing. Taking the three tests together, binary logistic regression for distinguishing between patients and normal subjects correctly classified 91% of the 33 individuals for whom there were complete data with sensitivity of 88% and specificity of 94%. However, only 69% of the patients could be correctly classified by a logistic regression for discriminating between MSA and PAF. Electromyography (EMG) studies showed that 7 of 8 patients with MSA but only 2 of 7 patients with PAF (both multiparous women) had denervation of the rectal sphincter muscle. The EMG study is, therefore, valuable in men, but has a high false positive rate in women, probably because of pudendal nerve injury from parturition.
KW - autonomic function
KW - multisystem atrophy
KW - pure autonomic failure
KW - sinus arrhythmia
KW - sympathetic skin response
KW - Valsalva ratio
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U2 - 10.1002/(SICI)1097-4598(199606)19:6<758::AID-MUS11>3.0.CO;2-H
DO - 10.1002/(SICI)1097-4598(199606)19:6<758::AID-MUS11>3.0.CO;2-H
M3 - Article
C2 - 8609927
AN - SCOPUS:0029866442
VL - 19
SP - 758
EP - 763
JO - Muscle and Nerve
JF - Muscle and Nerve
SN - 0148-639X
IS - 6
ER -