Long latency auditory evoked potentials in children with phonological disorder.

BACKGROUND Auditory evoked potentials in children with phonological disorder. AIM To characterize the long latency auditory evoked potentials (LLAEP) results N1, P2, N2 and P300 of children with phonological disorder and to verify the improvement of such potentials with speech therapy. METHOD 25 children without phonological disorder (control group) and 41 with phonological disorder (study group) underwent a basic audiological evaluation and LLAEP. The study group was divided into two subgroups: subgroup A composed by 22 children, underwent 12 sessions of speech therapy and were submitted to audiological retesting after this period, and subgroup B composed by 19 children, who were also reassessed three months after the initial testing. RESULTS Statistically significant differences between groups for the P2 and P300 latencies and P300 amplitude were observed. Comparison between the first and the second audiological assessments indicated no significant statistical differences between both subgroups regarding wave latencies. However, a significant statistical difference was verified for the P300 (study subgroup A) and P2/N2 (study subgroup B) wave amplitudes. The study group presented higher percentage of altered results in the P300; wave latency increase was the most frequent type of alteration. After speech therapy, the results of all components improved, however, there was no association between the improvement of LLAEP results with the background of otitis, as well as with the Percentage of Consonants Correct-Revised. CONCLUSION Children with phonological disorder present altered P300 suggesting involvement of the central auditory pathway, probably due to alterations in the auditory processing, presenting improvement in all components of LLAEP results after speech therapy.