Autonomic symptoms, cardiovascular and sudomotor evaluation in de novo type 1 narcolepsy

Purpose: To evaluate cardiovascular and sudomotor function during wakefulness and to assess autonomic symptoms in de novo patients with type 1 narcolepsy compared to healthy controls. Methods: De novo patients with type 1 narcolepsy (NT1) and healthy controls underwent cardiovascular function tests including head-up tilt test, Valsalva maneuver, deep breathing, hand grip, and cold face, and sudomotor function was assessed through Sudoscan. Autonomic symptoms were investigated using the Scales for Outcomes in Parkinson’s Disease–Autonomic Dysfunction (SCOPA-AUT) questionnaire. Results: Twelve de novo patients with NT1 and 14 healthy controls were included. In supine rest condition and at 3 min and 10 min head-up tilt test, the systolic blood pressure values were significantly higher in the NT1 group than in controls (p < 0.05). A lower Valsalva ratio (p < 0.01), significantly smaller inspiratory–expiratory difference in deep breathing (p < 0.05), and lower delta heart rate in the cold face test (p < 0.01) were also observed in the NT1 group. The mean hand electrochemical skin conductance values were significantly lower (p < 0.05) and the mean SCOPA-AUT total scores were significantly higher in patients with NT1 than in healthy subjects (p < 0.001), with greater involvement of cardiovascular and thermoregulatory items. Conclusion: De novo patients with NT1 exhibit blunted parasympathetic activity during wakefulness, mild sudomotor dysfunction, and a large variety of autonomic symptoms.