Vol.:(0123456789) 1 3 Clinical Autonomic Research https://doi.org/10.1007/s10286-020-00718-w RESEARCH ARTICLE Autonomic symptoms, cardiovascular and sudomotor evaluation in de novo type 1 narcolepsy Camilla Rocchi 1  · Fabio Placidi 2  · Chiara Del Bianco 2  · Claudio Liguori 2  · Antonio Pisani 2  · Nicola B Mercuri 1  · Francesca Izzi 2 Received: 10 June 2020 / Accepted: 6 August 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract 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 con- trols (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 dys- function, and a large variety of autonomic symptoms. Keywords Narcolepsy type 1 (NT1) · Autonomic nervous system (ANS) · Cardiovascular reflexes · Sudomotor function · Scales for Outcomes in Parkinson’s Disease–Autonomic Dysfunction questionnaire (SCOPA-AUT) Introduction The link between narcolepsy and the autonomic nervous sys- tem (ANS) has been observed since the early descriptions of the disease and includes cardiovascular, pupillomotor, sexual, gastrointestinal, respiratory dysfunction, and meta- bolic and body temperature abnormalities during sleep and wakefulness [1–4]. First studies on the matter reported attenuation of auto- nomic reactivity to cardiovascular reflexes, which were par- tially modified by amphetamines [5], and a central origin of the sympatho-vagal imbalance was hypothesized [6]. Confirmation of such a hypothesis stems from the discov- ery of orexins, whose projections modulate both vagal and sympathetic outflows [4]. Lack of orexin in type 1 narco- lepsy (NT1) may influence a wide variety of autonomic functions, but mechanisms and pathways are not yet com- pletely known. As to cardiovascular autonomic impairment, previous authors have reported conflicting results, possibly deriving from different methodological approaches and conditions concerning the sleep–wake cycle [3]. Regarding core body and skin temperature regulation, a few authors have described abnormalities in narcoleptic patients [1, 7], although, to date, sudomotor function has not been inves- tigated. On the basis of these assumptions, we studied * Francesca Izzi fraizzi@tin.it 1 Neurology Unit, Department of Systems Medicine, Policlinico Tor Vergata, University of Rome “Tor Vergata”, Rome, Italy 2 Sleep Medicine Center, Department of Systems Medicine, Policlinico Tor Vergata, University of Rome “Tor Vergata”, Viale Oxford 81, 00133 Rome, Italy