Title: Symptomatic and electrodiagnostic features of
peripheral neuropathy in scleroderma

Background/Purpose: Peripheral
neuropathy in scleroderma has been poorly characterized and the prevalence is
unknown. The purpose of this study was to determine the prevalence of
peripheral neuropathy in scleroderma.

Methods: The prevalence of length
dependent peripheral neuropathy was rigorously assessed using signs and symptoms
of neuropathy derived from a previously validated Total Neuropathy Score (TNS),
and standardized nerve conduction study (NCS). Criteria for enrollment was an
established diagnosis of scleroderma based upon the 1980 American
College of Rheumatology (ACR) criteria for scleroderma, possessing at least 3
of 5 features of the CREST syndrome, or having all 3 of the following features:
Raynaud’s phenomenon, nail fold capillary changes and a scleroderma-specific
antibody.  Enrolled
subjects underwent a uniform evaluation
(TNS) that
consisted of neuropathy symptom assessment by questionnaire, physical
examination using objective measurement tools (graduated Rydel-Seiffer 64 Hz tuning fork and NeuroPen), and a
standardized nerve conduction protocol.  Those who were symptomatic or had NCS
evidence of peripheral neuropathy underwent laboratory evaluation for secondary
causes of neuropathy. We
defined the presence of neuropathy to be those who either were screen positive
on the TNS and/or electrophysiologic evidence of neuropathy. Statistical
analyses were performed using the statistical software (STATA, release 12.1;
StateCorp, College Station, Texas). Fischer’s exact test was used to analyze
differences in dichotomous variables. Differences between means were examined
using the Student’s t test for continuous variables.

Results: 130 subjects were approached
for participation and 60 enrolled. Of the 60 subjects, 50 (83.3%) were
female, 37(61.7%) were of the limited cutaneous subtype and 23 (38.3%) were the
diffuse subtype of scleroderma. The mean age was 55 ± 11.1 years and
mean disease duration was 15.3 ± 10.1 years. 17/60 (28%) had evidence of
a peripheral neuropathy as defined by the presence of neuropathic symptoms on
the TNS and/or electrophysiologic evidence of neuropathy. Subjects with
neuropathy were more likely to be male (60% vs. 40%, p=0.02), African-American
(41% vs. 4.6%, p=0.001), have diabetes (17.7% vs 0%, p=0.02), have limited
cutaneous scleroderma (82.3% vs. 53.5%, p=0.04), and have RNP antibodies (23.5%
vs 0%, p=0.009) than those without neuropathy.  A potential non-scleroderma
etiology for the peripheral neuropathy was defined in 82.3% (14/17) of subjects
with neuropathy.  

Conclusion: While symptoms or objective
evidence of peripheral neuropathy is common among patients with scleroderma,
the cause is usually explained by co-morbid non-scleroderma related causes.