SMALL PLANUM TEMPORALE VOLUME IN DOWNS-SYNDROME - A VOLUMETRIC MRI STUDY

Objective: Down's syndrome is associated with structural brain abnorma lities and language deficits. The aim of this study was to investigate whether the superior temporal gyrus and the planum temporale, both pa rts of the anatomic substrate for language, are abnormal in Down's syn drome. Method: The authors examined volumetric magnetic resonance imag ing (MRI) measures of the superior temporal gyrus and the planum tempo rale for 17 community-dwelling patients with Down's syndrome and 17 ma tched healthy comparison subjects. For the subjects with Down's syndro me, the correlations of the superior temporal gyrus and planum tempora le volumes with performance on tests of language function were examine d. Results: The planum temporale volume of the patients with Down's sy ndrome was smaller than that of the healthy subjects, even after diffe rences in whole brain volume were controlled for. The volume of the su perior temporal gyrus in the Down's syndrome patients was proportional ly similar to that of the comparison group. For the subjects with Down 's syndrome, neither superior temporal gyrus nor planum temporale volu me was significantly correlated with performance on language tests aft er total brain volume was controlled for. Conclusions: In Down's syndr ome, planum temporale volume may be selectively smaller than normal, a lthough the effect of this volume deficit on language is not clear.