Clinical significance of electroencephalographic changes in children with tick-borne meningoencephalitis

Abstract

Compared to adult population, children are less frequently affected by tick-borne encephalitis (TBE) and have a much more favorable clinical course of the disease with less permanent consequences, but more frequently exhibit electroencephalography (EEG) changes. The aim of the study was to determine the prevalence and characteristics of abnormal EEG findings in children with TBE, as well as their correlation with clinical manifestation of the disease. Patients and methods: A retrospective study over a 30- year period (1979-2009) included 103 children (77 boys and 26 girls) aged 2 to 14 years, with confirmed acute infection with tickborne encephalitis virus (TBEV). In the majority of children (70.0%), EEG was performed during the acute stage of the disease. Clinically, the disease manifested with viral meningitis in 68/103 (66.0%) and meningoencephalitis (ME) in 35/103 (34.0%) children, of biphasic course in 86 (83.4%) children. EEG finding was normal in 23/72 (32.0%), borderline with nonspecific changes in 2/72 (3.0%) and pathologic in 47/72 (65.0%) children. Abnormal finding most frequently presented as slow diffuse dysrhythmia in 31/72 (43.1%) patients, then as slow focal dysrhythmia in 14/72 (19.4%) and paroxysmal generalized slow dysrhythmia in 2/72 (2.8%) patients. Normalization of EEG finding occurred 1 to 3 months from initial evaluation in 38/47 (81.0%) patients. Follow up EEG was performed in nine (19.1%) children, but not up to normalization of the finding. Slow diffuse dysrhythmia is the most frequent type of EEG changes in children with TBE. There was no significant correlation between EEG finding and clinical manifestation of the disease.