Risk of Unsatisfactory Functional Outcome of Stroke in Patients with Clinical Manifestation of Persistent Viral Infection

Abstract

Acute cerebrovascular disorders represent up to 75–85 % of strokes inUkraine. The wide spread of herpesvirus infection in developing countries (with a prevalence of 35–40 %), as well as influenza virus, requires consideration of the viral risk factor of stroke for prognostic purposes.The objective: to study the influence of the most common types of viral infection: the family of herpesviruses and influenza virus on the neurological and one-year functional outcome of stroke and to determine the predictors of unsatisfactory recovery of patients.Materials and methods. In the period from 2016–2020, on the basis of the neurological departments ofAlexanderHospital andClinicalHospital № 4 we performed research on the presence of herpes viruses. 70 patients with ischemic stroke with moderate and severe neurological disorders were examined, in whom herpes and influenza viruses were detected in the blood (the main group) within 2 weeks before hospitalization against the background of viral manifestation. The comparison group consisted of 220 patients without clinical signs of viral manifestations were compared with the main group by stroke severity, average age and gender. The severity of neurological disorders was assessed by the NIHSS scale. Functional recovery was assessed by the Barthel index. The presence of viral infection (family of herpesviruses and influenza virus) was studied using polymerase chain reaction.Results. HSV1 DNA was detected in 43 (61.4 %) cases, HSV2 – in 30 (42.9 %), EBV4 – in 19 (27.1 %), CMV5 – in 18 (25.7 %), HNV6 – in 27 (38.6 %), Influenza RNA – in 16 (22.9 %). Only one type of virus was present in 21 (30.0 %) patients, two types of viruses were identified in 31 (44.3 %), three or more types of viruses – in 18 (25.7 %). In the presence of viral infection, the relative risk of unsatisfactory recovery of neurological functions in the main group increases 1.99 times relative to the comparison group: RR=1.99 (95 % CI: 1.60–2.48). The presence of viral infection predicted unsatisfactory recovery with a sensitivity of 74.3 %, a specificity of 62.7 % and an area under the curve ROC=0.69. There was a negative correlation between increasing the number of virus types in patients and the lack of neurological improvement: r=0.370 (p=0.002). The presence of viral infection significantly increased the risk of moderate and severe disability one year after stroke, the relative risk of disability in patients of the main group relative to patients of comparison group was: RR=1,668 (95 % CI: 1,256–2,214), and IB score according to the linear regression analysis inversely depended on the number of viruses in patients, linear R2=0.423 (correlation coefficient r=–0.660). In the presence of two types of viruses in the blood, the probability of unsatisfactory recovery increased – 1.5 times (RR=1,562; 95 % CI: 1,064–2,265), three or more viruses 2.5 times (RR=2,511; 95 % CI: 1,888–3,340). One year after stroke, there was a significant correlation between lower IB score and the presence of HSV1 in associations: r=0.323; CMV: r=0.351; EBV: r=0.430. If there are at least 2 types of viruses in the blood, in particular HSV1+CMV and HHV6+CMV, the relative risk of PI and TI increases 2.9 times.Conclusions. The presence of a viral infection significantly increases the risk of unsatisfactory regression of neurological disorders, allows to predict poor neurological recovery with a sufficiently high sensitivity and specificity. In patients with viral manifestations and detection of the virus in the blood, functional recovery one year after stroke is significantly worse than in patients without it; this applies to a lower mean score of IB and the percentage of patients with minimal limitation of function. When the number of persistent viruses increases to two or more, the relative risk of PI and TI increases one year after stroke, with the highest rate in the presence of EBV and CMV associations. If there are at least 2 types of viruses in the blood, in particular HSV1+CMV, HHV6+CMV, HSV1+EBV the relative risk of PI and TI increases 2.9 times.