Specific disorders in the language development: neurobiological basis
Narbona-García J, Schlumberger E.
Dpto. de Pediatría, Clínica Universitaria de Navarra, Facultad de Medicina, Universidad de Navarra, Pamplona, España
Studies of twins, familial aggregates and particular phenotypic conditions have shown an inherited basis for some dysphasias or specific developmental language impairments (SLI). This predisposition is usually multifactorial but the analysis of some families allows to postulate an autosomal dominant transmission of deficits in specific modular aspects of linguistic competences.
Moreover, neuroimaging studies have shown modifications of normal volumetric interhemispheric asymmetries, and in group of SLI with receptive prominent disorder coexist epileptiform activity in wakefulness and non-REM sleep EEG; in some of these cases, antiepileptic drugs, specially steroids, can significantly ameliorate the language processing.
As many patients with SLI have a difficulty for discrimination of subtle temporal indices, a hypothesis can also be made of a dysfunction in various subcortical structures (thalamus, basal ganglia, cerebellum) modulating the cerebral cortex in phonological processing.
CITATION Rev Neurol. 1999 Feb;28 Suppl 2:S105-9