Measures of small-fiber neuropathy in HIV infection

Abstract

Introduction: Noninvasive methods are needed to detect distal sensory polyneuropathy in HIV-infected persons on antiretroviral therapy (ART).

Methods: Quantitative sudomotor axon reflex test (QSART) and Utah Early Neuropathy Scale (UENS), small-fiber sensitive measures, were assessed in subjects with and without clinical neuropathy. Pain was assessed by visual analog scale (VAS).

Results: Twenty-two subjects had symptoms and signs of neuropathy, 19 had neither, and all were receiving ART. Median sweat volume (μL) was lower at all testing sites in those with neuropathy compared to those without (p<0.01 for all). UENS and VAS (mm) were higher in neuropathy subjects (p<0.05 for each). Lower sweat volume at all sites correlated with higher pin UENS subscore, total UENS, and VAS (p<0.05 for all). In multivariable analyses adjusting for age, CD4⁺ T cells, sex, and use of "d-drug" ART, QSART and UENS remained associated (p=0.003).

Conclusion: QSART and UENS have not been previously studied in this patient population and may identify small-fiber neuropathy in HIV-infected, ART-treated persons.

Copyright © 2012 Elsevier B.V. All rights reserved.

Figures

Figure 1

Neuropathy assessments according to the presence (neuropathy subjects) or absence (non-neuropathy subjects) of clinical neuropathy. (A) Sweat volume (μL) by quantitative sudomotor axon reflex test (QSART). Testing sites are as follows: white bar=forearm, light gray bar=proximal leg, dark gray bar=distal leg, dot filled bar=proximal foot, and vertical filled bar=total sweat volume. +p=0.006 for difference between study groups and *p<0.001 for difference between study groups. (B) Utah Early Neuropathy Scale (UENS). Elements of the UENS are as follows: white bar=motor subscore, light gray bar=deep tendon reflex (DTR) subscore, dark gray bar=large fiber subscore, dot filled bar=allodynia subscore, vertical filled bar=pin sensation subscore, and diagonal filled bar=total UENS score. +p=0.02 for difference between study groups, *p=0.009 for difference between study groups, #p=0.001 for difference between study groups, and ^p<0.001 for difference between study groups. (C) Visual analog scale (VAS, mm). Elements of the VAS are as follows: white bar=worst pain over the last day, light gray bar=worst pain during the prior week, and dark gray bar=least pain over the prior week. +p=0.001 for difference between study groups and *p<0.001 for difference between study groups.

Figure 1

Neuropathy assessments according to the presence (neuropathy subjects) or absence (non-neuropathy subjects) of clinical neuropathy. (A) Sweat volume (μL) by quantitative sudomotor axon reflex test (QSART). Testing sites are as follows: white bar=forearm, light gray bar=proximal leg, dark gray bar=distal leg, dot filled bar=proximal foot, and vertical filled bar=total sweat volume. +p=0.006 for difference between study groups and *p<0.001 for difference between study groups. (B) Utah Early Neuropathy Scale (UENS). Elements of the UENS are as follows: white bar=motor subscore, light gray bar=deep tendon reflex (DTR) subscore, dark gray bar=large fiber subscore, dot filled bar=allodynia subscore, vertical filled bar=pin sensation subscore, and diagonal filled bar=total UENS score. +p=0.02 for difference between study groups, *p=0.009 for difference between study groups, #p=0.001 for difference between study groups, and ^p<0.001 for difference between study groups. (C) Visual analog scale (VAS, mm). Elements of the VAS are as follows: white bar=worst pain over the last day, light gray bar=worst pain during the prior week, and dark gray bar=least pain over the prior week. +p=0.001 for difference between study groups and *p<0.001 for difference between study groups.

Figure 1

Neuropathy assessments according to the presence (neuropathy subjects) or absence (non-neuropathy subjects) of clinical neuropathy. (A) Sweat volume (μL) by quantitative sudomotor axon reflex test (QSART). Testing sites are as follows: white bar=forearm, light gray bar=proximal leg, dark gray bar=distal leg, dot filled bar=proximal foot, and vertical filled bar=total sweat volume. +p=0.006 for difference between study groups and *p<0.001 for difference between study groups. (B) Utah Early Neuropathy Scale (UENS). Elements of the UENS are as follows: white bar=motor subscore, light gray bar=deep tendon reflex (DTR) subscore, dark gray bar=large fiber subscore, dot filled bar=allodynia subscore, vertical filled bar=pin sensation subscore, and diagonal filled bar=total UENS score. +p=0.02 for difference between study groups, *p=0.009 for difference between study groups, #p=0.001 for difference between study groups, and ^p<0.001 for difference between study groups. (C) Visual analog scale (VAS, mm). Elements of the VAS are as follows: white bar=worst pain over the last day, light gray bar=worst pain during the prior week, and dark gray bar=least pain over the prior week. +p=0.001 for difference between study groups and *p<0.001 for difference between study groups.