Autonomic dysfunction is frequent and disabling in non-paraneoplastic sensory neuronopathies

Sensory neuronopathies (SN) are characterized by asymmetric non-length dependent sensory deficits and sensory ataxia. Autonomic dysfunction in SN was not yet evaluated regarding its frequency, characteristics and relationship to sensory deficits. To address these issues, we performed a comprehensive clinical and neurophysiological evaluation of a large cohort of patients with non-paraneoplastic SN (np-SN).We enrolled 50 consecutive patients with npSN and 32 age/sex-matched healthy controls. They were clinically evaluated (SCOPA-Aut scale) and underwent neurophysiological autonomic assessment (quantitative sudomotor axon reflex test, heart rate variability and sympathetic skin response).Mean age of patients was 50.9 ± 10.3 years and there were 18 men. npSN patients had higher SCOPA-Aut scores than controls (26.63 ± 12.72 vs. 12.66 ± 9.11, p .001). QSART was abnormal in 92% of the patients - sweat volumes in all examined sites were smaller among patients (p .001). Cardiovascular autonomic neuropathy was more frequent in these patients as well (p .001).Altogether our results suggest that autonomic dysfunction in distinct domains is frequent in npSN patients. These findings suggest that the clinical picture of npSN is related to a double neuronopathy: sensory and autonomic.