Beschreibung:
<jats:title>Abstract</jats:title><jats:sec><jats:title>Objectives</jats:title><jats:p>Tick‐borne encephalitis (<jats:styled-content style="fixed-case">TBE</jats:styled-content>) is an emerging flaviviral zoonosis in Central and Eastern Europe. <jats:styled-content style="fixed-case">TBE</jats:styled-content> can present as meningitis, meningoencephalitis, or meningoencephalomyelitis. Dysfunction of the autonomic (<jats:styled-content style="fixed-case">ANS</jats:styled-content>) and peripheral motoric and sensory nervous system (<jats:styled-content style="fixed-case">PNS</jats:styled-content>) might contribute to acute and long‐term complications. We aimed to examine, whether the <jats:styled-content style="fixed-case">ANS</jats:styled-content> and <jats:styled-content style="fixed-case">PNS</jats:styled-content> are affected in acute <jats:styled-content style="fixed-case">TBE</jats:styled-content>.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Fourteen patients with acute <jats:styled-content style="fixed-case">TBE</jats:styled-content>, 17 with diabetic polyneuropathy (d‐PNP), and 30 healthy controls (<jats:styled-content style="fixed-case">HC</jats:styled-content>) were examined in our single‐center, prospective study. <jats:styled-content style="fixed-case">ANS</jats:styled-content> and <jats:styled-content style="fixed-case">PNS</jats:styled-content> function was assessed by time‐ and frequency‐domain parameters of the heart rate (HR) variability at rest and deep respiration, and by sural and tibial nerve neurography. Primary endpoint was the HR variability at rest measured by root mean square of the successive differences (<jats:styled-content style="fixed-case">RMSSD</jats:styled-content>). Autonomic symptoms and quality of life (QoL) were assessed by questionnaires.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Tick‐borne encephalitis patients had a lower <jats:styled-content style="fixed-case">RMSSD</jats:styled-content> at rest (<jats:styled-content style="fixed-case">TBE</jats:styled-content> 13.1 ± 7.0, <jats:styled-content style="fixed-case">HC</jats:styled-content> 72.7 ± 48.3; <jats:italic>P</jats:italic> < 0.001) and deep respiration (<jats:styled-content style="fixed-case">TBE</jats:styled-content> 42.8 ± 27.0, <jats:styled-content style="fixed-case">HC</jats:styled-content> 109.7 ± 68.8; <jats:italic>P</jats:italic> < 0.01), an increased low‐frequency to high‐frequency power component ratio at rest (<jats:styled-content style="fixed-case">TBE</jats:styled-content> 4.0 ± 4.0, <jats:styled-content style="fixed-case">HC</jats:styled-content> 0.8 ± 0.5; <jats:italic>P</jats:italic> < 0.001), and a higher minimal heart rate at rest (<jats:styled-content style="fixed-case">TBE</jats:styled-content> 85.4 ± 7.0, <jats:styled-content style="fixed-case">HC</jats:styled-content> 69.5 ± 8.5; <jats:italic>P</jats:italic> < 0.001), all similar to patients with d‐PNP, indicating sympathovagal imbalance with increased sympathetic activation. Compared to <jats:styled-content style="fixed-case">HC</jats:styled-content>, sural and tibial nerve conduction velocities and action potential amplitudes were reduced, <jats:styled-content style="fixed-case">ANS</jats:styled-content> symptoms were more frequent, and QoL was lower in patients with <jats:styled-content style="fixed-case">TBE</jats:styled-content>.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>The <jats:styled-content style="fixed-case">ANS</jats:styled-content> and to a lesser degree the <jats:styled-content style="fixed-case">PNS</jats:styled-content> are affected by acute <jats:styled-content style="fixed-case">TBE</jats:styled-content>, which could potentially contribute to short‐ and long‐term morbidity.</jats:p></jats:sec>