Le syndrome de dysfonctions non verbales (SDNV) : actualisation des connaissances et analyse d’une cohorte de 89 patients traités dans le centre expert Resodys

The so-called Non-Verbal Learning Disabilities (NVLD) syndrome is a type of learning disorder that is frequently discussed in clinical, educational, and community contexts, particularly in Anglo-Saxon countries and Quebec. However, its nosographic identity remains undefined, which hinders the early identification of affected children and adolescents and consequently delays diagnosis and the implementation of appropriate intervention protocols. In France, the term is gradually gaining recognition among professionals involved in learning disorders, while its specific impacts on daily, academic, and social life are also becoming more acknowledged. This article has three main objectives: 1/to provide an overview of current knowledge regarding the presentation and mechanisms of the disorder through a brief literature review focused on recent publications, including two meta-analyses and a summary of the few neuroimaging studies dedicated to it; 2/to address ongoing questions regarding the clinical reality of the disorder and its classification among learning disabilities and, more broadly, neurodevelopmental disorders (NDDs) by analyzing a cohort of 89 patients recently admitted to the Résodys center which is specialized in the care of severe learning disorders in the PACA region of France; 3/finally, in light of these findings, to examine the relevance of a new set of diagnostic criteria for clinicians, adopting a dimensional rather than categorical approach to better support affected children and adolescents. We thus propose a new perspective on this syndrome—one that no longer focuses on deviation from the norm but rather on two key observations: the multiplicity of moderately or partially affected cognitive domains, and the intra-individual performance discrepancies among these domains, particularly verbal and nonverbal. From this standpoint, our clinical experience diverges from a portion of the recent literature that equates NVLD with visuospatial disorder. More than an isolated cognitive deficit, the hallmark of this syndrome seems to lie in the coexistence of subtle impairments across several domains—even at a subclinical level. Though still limited, neuroimaging data tend to support the hypothesis of impaired connectivity among neural networks that jointly contribute to several of the cognitive functions involved.