Ocular findings from otoneurological examinations in children with and without dyslexia: a systematic review with meta-analysis

Abstract Objective: To investigate ocular movements measures of vectoelectro-nystagmography and video-nystagmography in dyslexic children and compare with measures of typical children. Methods: A systematic review of observational studies comparing the ocular movements differences between dyslexic and typical children with no publication date or language restriction. The literature survey included the bibliographic databases MEDLINE, ScienceDirect, Scopus, Web of Science, SciELO, Lilacs and CENTRAL. Gray literature databases were also searched, including: OpenGrey.eu, DissOnline.de, The New York Academy of Medicine and WorldCat. The meta-analysis was performed using software RevMan 5.3 (Cochran Collaboration). Results: A total of 2375 articles were found of which 113 fell within the inclusion criteria. Among these, 52 were duplicates (found in more than one research source), and 45 articles were selected for reading in full. Thirteen (13) articles were included for analysis and discussion. Meta-analysis showed statistical differences between the two groups for the total number of saccades and duration of fixation. Conclusion: The study revealed that children with dyslexia have longer duration of fixation and fewer saccades during ocular movements on vectoelectro-nystagmography and videonystagmography when compared to children without dyslexia.

Afasias e áreas cerebrais: argumentos prós e contras à perspectiva localizacionista / Aphasias and brain areas: positive and negative aspects of the localization argument

O objetivo do presente estudo foi investigar como áreas corticais comprometidas por um acidente vascular encefálico (AVE) estão relacionadas com os diferentes tipos de afasia, visto que há controvérsias com relação à localização da lesão no cérebro e as características dos quadros de alteração da linguagem. Foram avaliados 26 indivíduos destros, portadores de lesão cérebro-vascular esquerda e de sintomas afásicos, através do protocolo de Montreal-Toulose, módulo standard inicial - versão alpha, que inclui provas de nomeação, repetição, compreensão oral, compreensão escrita e leitura, e de uma entrevista, que possibilitou a avaliação da fluência do discurso. Os sujeitos foram divididos em quatro subgrupos, de acordo com o sítio de lesão: frontal, temporal, têmporo-parietal e parietal/ parieto-occipital. Os dados foram submetidos a uma análise multidimensional (Similarity Structure Analysis [SSA]) e o método das variáveis externas como pontos. Os resultados revelaram uma correlação positiva alta entre lesão na área frontal e o acometimento da fluência no discurso, assim como correlações positivas altas entre lesão no lobo temporal e prejuízos em todas as habilidades avaliadas no teste: nomeação, repetição, compreensão oral, compreensão escrita e leitura, o que, até certo ponto, corrobora as idéias de estudos localizacionistas, na medida em que estabelece o papel preponderante do lobo temporal para a linguagem e a importância do lobo frontal para as praxias da fala. No entanto, nos demais subgrupos, têmporo-parietal e parietal/ parieto-occipital, se observou correlações positivas apenas com a compreensão oral e com a repetição, essa última somente no segundo grupo e com índice baixo, e correlações negativas altas com a fluência no discurso, o que sugere que esta habilidade se manteve preservada nestes grupos e fragiliza o argumento localizacionista.

The aim of the present work was to investigate how cortex areas compromised by Cerebral Vascular Accident (CVA) are related to the classification of aphasia, since there are controversies about the location of the lesion in the brain and the characteristics related to variations in speech patterns. Through the Montreal-Toulose protocol, 26 right-handed persons who were affected by left cerebral-vascular lesion and have been showing aphasic symptoms have been evaluated. The Montreal-Toulose protocol, initial standard module - version alpha, includes nomination, repetition, oral comprehension, reading and writing comprehension tests as well as an interview, which allows an evaluation of the discourse fluency. The subjects were allocated into four sub-groups, according to the lesion sites: frontal, temporal, temporo-parietal and parieto-occipital. For the analysis of the data, a Multidimensional Similarity Structure Analysis (SSA) was carried out along with an external variable method. The results show a high positive correlation between the lesion in the brain's frontal lobe and difficulties in the discourse fluency as well as a high positive correlation between the lesion in the brain's temporal lobe and hindrances in all abilities tested: nomination, repetition, oral comprehension, reading and writing comprehension. It is in accordance with localizational studies, since it highlights the fundamental role of the temporal lobe for the language and the importance of the frontal lobe for the speech praxis. However, in the remaining sub-groups (temporo-parietal and parieto-occipital) there have been positive correlations only between oral comprehension and repetition, with the latter showing correlation only with the second group and presenting a low score. High negative correlations with the discourse fluency were observed. It suggests that this ability has remained preserved in those groups, which in turns weakens the localization argument.