Peripheral Nerve Dysfunction in Scleroderma

Peripheral neuropathy in patients with scleroderma is thoughtto be rare. We have undertaken a quantitative assessment ofperipheral nerve function in 29 patients with either limitedcutaneous scleroderma or progressive systematic sclerosis. Tactilethresholds were raised in the fingers in 28 per cent of patientsand in the foot in 50 per cent. Two-point discrimination wasabnormal in 10 patients, thermal thresholds were abnormal infive and vibration thresholds were abnormal in one. Nerve conductionstudies showed abnormalities in six patients, five of whom hadclinical signs of a mild peripheral neuropathy: the mean durationof disease in these six patients was 10 years longer than thatin the remainder of the patients. There was electrophysiologicalevidence of a subclinical carpal tunnel syndrome in two patients.The sympathetic skin response was recorded in 16 patients whohad not been subjected to sympathectomy for Raynaud's phenomenon,and was abnormal in four. These results indicate that peripheralnerve dysfunction in scleroderma, though mild, is not as uncommonas previously thought. The abnormal cutaneous sensory thresholdsmay be partly due to altered viscoelastic properties of theskin, but abnormal responses in the lower limbs to tests oftactile sensitivity, the clinical findings and the disturbancesof nerve conduction argue in favour of an additional neuropathicprocess in some patients. Low grade distal nerve trunk ischaemiamay be responsible.