**4. Discussion**

Antiepileptic therapy in children can be optimized via the anticipation of the efficacy of AED during the early stages of therapy. Since EEG provides rich information about the brain activity, we hypothesized that the comprehensive EEG evaluation during Dep therapy in the children with epilepsy can be a sensitive indicator of the efficacy of the treatment.

Dep therapy induced decreases of APs of low-frequency waves, which is an indicator of reducing of CNS excitation. Dep reduces beta bends in the posterior lobes, which is related with the CNS dysfunction [32].

Dep reduces spike-waves (3/s), which is related to the absence of epilepsy that is triggered from the thalamocortical pathway. Dep was considered as an effective drug in such cases [31, 36, 37].

Dep does not have an effect on irregular single spike-wave complexes, sharp waves, spikes-polyspikes, and paroxysmal bursts provoked by functional trials. These cases reflect certain specificity of epileptogenesis [7, 38]. Dep differently acts on the generation of epileptiform elements with various morphologies—particularly, it suppresses SW complexes (3/s) but does not have a good effect on irregular single spike-wave complexes, sharp waves, and spikes. Such a picture allows us to suggest the differences in the morphology of epileptiform elements that may reflect different neurophysiological and neurochemical mechanisms [3, 7, 39]. Revealing of selectivity represents certain theoretical and practical interests as it can serve as an indirect evidence of assumptions in the genesis of various epileptiform EEG elements and accordingly different types of epileptic attacks [39, 40]. Other researchers like Truccolo et al. [41] apparently pay attention to the morphological pictures of background EEG [13].

VPA was shown different activity and is not effective of any type of epilepsy [38]. The possibility of Dep treatment of non-epileptic paroxysmal conditions in children and adolescents [42–45] and the investigation of children with partial epilepsy during carbamazepine (CBZ) treatment were described in our previous investigation [46].

Brain mapping revealed the essential prognostic value of morphology of the theta waves and its distribution upon the cortical surface. The EEG pattern was revealed before treatment initiation and was persistent during Dep therapy. The presence of rhythmic monomorphic mid-/high-amplitude theta waves on the EEG, especially of the temporoparietal regions, despite clinical improvements (seizurefree and no epileptiform EEG correlates) may suggest the possible recurrence of seizures after withdrawal of Dep. Not only withdrawal but even reduction of doses can lead to a recommencement of the attacks in this group of patients. Such a feature of VPA suggests that its antiepileptic effect is achieved via neurophysiological and molecular mechanisms, which partly differ from the action mechanisms of other AEDs [33, 34]. Analysis of basic characteristics of EEG during the treatment suggests that the rhythmic monomorphic mid−/high-amplitude theta waves are predicting signs of aggravation. Such an EEG pattern is revealed based on the evaluation of background EEG characteristics, spectral analysis, and EEG mapping using a quantitative EEG approach.

AED treatment should be done under a regular EEG control due to aggravation of the EEG pattern, which sometimes predicts the clinical signs of exacerbation [47, 48].

Reduction of slow wave concomitant with decreases of epileptiform pattern and clinical signs at 3 months after DEP treatment suggests that the treatment is effective in these cases [49].

*The Dynamic of EEG Characteristics in Epileptic Children during the Treatment with Valproic… DOI: http://dx.doi.org/10.5772/intechopen.93574*
