Clinical and electroencephalographic characteristics of chronic tic disorders in children and adolescents

Abstract

Chronic tic disorders (CTDs) are one of the relevant problems of pediatric neurology, the higher prevalence of which is associated with undifferentiated therapy without considering comorbidity. Objective: to enhance the efficiency of diagnosis and therapy of tic disorders in children and adolescents in terms of video-electroencephalography (EEG) monitoring data. Patients and methods. The investigation enrolled 116 patients, including 83 (71.6%) boys and 33 (28.4%) girls at the age of 3 to 15 years (mean age, 9.0±3.0 years), diagnosed with CTD who had been examined at the Specialized Neurology Department, Voronezh Regional Children's Clinical Hospital One, in the period 2010–2014. The investigation consisted of two steps: 1) clinical, laboratory, and neurophysiologic examination; 2) differentiated therapy. The Yaele Global Tic Severity Scale (YGTSS) was used. The diagnosis was established in accordance with the draft classification of epileptic seizures and epilepsy syndromes by the Intern ational League Against Epilepsy. Video-EEG monitoring was carried out in an awake state and during daytime and/or nighttime sleep. Results and discussion. EEC epileptiform activity was recorded in 46.6% of the patients; a concurrence of CTDs and epilepsy was ascertained in 16.4% of cases. The risk factors of epilepsy in children with CTDs and EEG epileptiform activity are isolated motor tics in the facial region (p=0.0023), MRI epileptogenic changes (p = 0.01), a remitting course (p=0.02), and an early age at the full-scaled picture of tic disorder (p=0.02). CTD therapy with antiepileptic drugs (extended-release valproic acid) was effective and safe in both epileptic seizures (remission in 85.7% of cases) and tics with an improvement in 81.5% of cases with retention in therapy during 2–3 years. Therapy with dopamine transmissionlowering drugs was effective against tics; however, their intake for more than 6 months increased a risk for added epileptic seizures in patients with EEG epileptiform activity (the secondary bilateral synchronization phenomenon and epileptic seizures were recorded in 42.9 and 14.3% of the patients, respectively).