Sympathetic skin response in scleroderma

Area of Science:

• Neurology
• Dermatology
• Autonomic Neuroscience

Background:

• Scleroderma encompasses systemic and localized forms, often presenting with skin hardening.
• Autonomic nervous system (ANS) dysfunction can manifest in various connective tissue diseases.
• The sympathetic skin response (SSR) is a key indicator of sympathetic sudomotor function.

Purpose of the Study:

• To investigate sympathetic skin response (SSR) abnormalities in patients with systemic sclerosis, morphea, and mixed connective tissue disease.
• To determine the prevalence and characteristics of SSR disturbances in different scleroderma subtypes.
• To explore correlations between SSR findings and clinical/electrophysiological parameters.

Main Methods:

• SSR was assessed in 32 patients with scleroderma-like conditions and compared to 38 controls.
• Electrical stimulation of median and tibial nerves was performed.
• SSR was recorded from palms and soles, analyzing latency, amplitude, and symmetry.

Main Results:

• SSR abnormalities were detected in 68.8% of patients, most notably in linear scleroderma.
• Amplitude asymmetry in upper extremities was the most frequent abnormality.
• No significant correlation was found between SSR abnormalities and disease duration, skin changes, or capillaroscopy findings.
• Slowed motor and sensory conduction velocities correlated with lower SSR amplitude.
• Prolonged skin sensory chronaxy was associated with delayed SSR latency.

Conclusions:

• Autonomic nervous system dysfunction, indicated by SSR abnormalities, is prevalent in all forms of scleroderma, including localized and systemic.
• These autonomic disturbances can be present even in the absence of other clinical signs of autonomic dysfunction.
• SSR assessment provides valuable insights into subclinical autonomic neuropathy in scleroderma patients.