Autonomic dysfunction in non-paraneoplastic sensory neuronopathy: beyond sensory abnormalities

Sensory neuronopathies (SN) represent a subgroup of peripheral nervous system disorders which are becoming increasingly recognized. Despite a few reports of autonomic dysfunction, this complication has not been fully appreciated. Autonomic function was quantified through tests of sympathetic and parasympathetic function (forming the Autonomic Tests Score, ATS), and through a 40-item questionnaire assessing autonomic symptoms (constituting the Autonomic Questionnaire Score, AQS). Twenty patients were enrolled. Forty-six age- and gender-matched controls were evaluated for the AQS and 15 for the ATS. All patients reported symptoms of autonomic dysfunction. Of the patients, 60% had one or more abnormal cardiovagal test, 60% orthostatic hypotension and 20% abnormal pupillary function. Their ATS was significantly different from the controls (p < 0.0001). Neither the ATS nor AQS were different between groups of SN associated disorders. Autonomic dysfunction is a frequent and important complication in SN, and it does not seem to be related to a specific etiology, as previously thought.