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.