Pathophysiology of language switching and mixing in an early bilingual child with subcortical aphasia

Abstract

Acquired aphasia after circumscribed vascular subcortical lesions has not been reported in bilingual children. We report clinical and neuroimaging findings in an early bilingual boy who incurred equally severe transcortical sensory aphasia in his first language (L1) and second language (L2) after a posterior left thalamic hemorrhage. Following recurrent bleeding of the lesion the aphasic symptoms substantially aggravated. Spontaneous pathological language switching and mixing were found in both languages. Remission of these phenomena was reflected on brain perfusion SPECT revealing improved perfusion in the left frontal lobe and left caudate nucleus. The parallelism between the evolution of language symptoms and the SPECT findings may demonstrate that a subcortical left frontal lobe circuity is crucially involved in language switching and mixing.

Acknowledgments

We are indebted to Mrs. H. Baillieux (Free University of Brussels) and I. Bats (Born-Bunge Foundation, University of Antwerp) for the photographic work. S.Engelborghs is a Ph. D fellow of the Fund for Scientific Research - Flanders (F.W.O. - Vlaanderen)

Notes

** not assessed since the patient had not been trained to write English.