Introduction: Pragmatics refers to the social use of language; its precursors are already present during the process of maturing, during the preverbal stage, and become manifest when the child starts to point and to share his or her attention with another person. In cases of specific language impairment (SLI) and autism spectrum disorders (ASD) it can be altered to varying degrees.
Patients and methods: Due to the difficulties involved in diagnosis from a clinical point of view, we carried out a study by means of magnetoencephalography (MEG) on a series of 11 patients who had SLI and another series of 9 patients with ASD, in order to determine whether MEG is capable of distinguishing these diagnoses.
Results: Patients with SLI displayed pathological activity in the frontal and middle temporal regions of both hemispheres. Patients with ASD showed pathological activity in the perisylvian area. Expressive-receptive SLI with pragmatic language disorder showed pathological activity that was similar to that seen in autism.
Conclusion: MEG can be used to distinguish between SLI and ASD by studying the epileptiform activity that occurs in pervasive developmental disorders. MEG helps us to understand the continuum that exists between SLI or expressive-receptive SLI and autism.