Sleep architecture, obstructive sleep apnea and functional outcomes in adults with a history of Tick-borne encephalitis

Abstract

Tick-borne encephalitis (TBE) is a widespread viral infection of the central nervous system with increasing incidence in Europe and northern Asia. Post-infectious sequelae are frequent, and patients with TBE commonly experience long-term fatigue and subjective sleep disturbances. Obstructive sleep apnea (OSA) may be a contributing factor, and objective sleep studies with polysomnography (PSG) are lacking. Forty-two adults, 22 TBE patients (cases), diagnosed in Region Västra Götaland, Sweden, between 2012 and 2015, and 20 controls without a known TBE history, underwent an overnight PSG, respectively. All participants responded to questionnaires. The cases and controls were similar regarding age, sex, obesity, concomitant diseases, smoking, and alcohol habits. Despite similar PSG characteristics such as total sleep time and OSA severity indices, the TBE cases reported statistically more sleep-related functional impairment on the Functional Outcome of Sleep Questionnaire (FOSQ) compared with the controls (median scores 18.1 vs. 19.9; p<0.05). In a multivariate analysis, TBE correlated significantly with the lower FOSQ scores (unstandardized β −1.80 [%95 confidence interval −3.02 - −0.58]; p = 0.005) independent of age, sex, total sleep time and apnea-hypopnea-index. TBE cases with OSA reported the lowest scores on the FOSQ compared with the other subgroups with TBE or OSA alone, and the ones with neither TBE nor OSA. TBE is associated with impaired functional outcomes, in which concomitant OSA may worsen the subjective symptoms. Further studies are warranted to determine the effect of treatment of concomitant OSA on functional outcomes with regard to optimal rehabilitation of TBE.

Tick-Borne Encephalitis Affects Sleep-Wake Behavior and Locomotion in Infant Rats

“…Extensive changes in sleep macrostructure, as observed in infected animals, could not be documented in a recent case-control study assessing similar parameters in TBE patients [36]. This discrepancy could be caused by differences in the experimental setup, since the clinical study only conducted measurement during a single night, while data were collected for 24 hours in the experimental study.…”

“…After TBEV, the most consistently reported parameter related to sleep-wake disturbance is fatigue, with a signi cantly higher number of patients complaining from fatigue compared to control groups [17][18][19]28]. Fatigue is assessed throughout the day and therefore represents a sleep-wake disturbance seen during the active phase of the patients [29].…”

“…A wide variety of sleep-wake disorders has been reported during the acute phase of the TBE infection as well as during short and long-term follow-ups [17][18][19]. Unfortunately, only few studies used clear de nitions of sleep-wake disorders or assessed them using objective measurement tools or standardized questionnaires.…”

“…Furthermore, sleep-wake disorders after TBE may well be under-diagnosed or underreported [14]. However, several studies have shown, that TBE patients suffer signi cantly more frequently from daytime fatigue compared to age-matched controls [18,19]. Additionally, newly occurring narcolepsy after the TBE vaccination has been reported [20].…”

Meningitis, meningoencephalitis and encephalitis in Bern: an observational study of 258 patients

“…In particular, signs and symptoms such as fatigue, excessive daytime sleepiness (EDS) or disturbed nighttime sleep/insomnia are frequently reported in routine clinical follow-up consultations. Fatigue as a long-term sequelae, without a detailed definition, has been described in the literature [ 15 , 16 ] However, studies evaluating these important clinical issues have been published only recently [ 17 , 18 ].…”