これまでの研究から, 非嚢胞性脳室周囲白質軟化症では, 高次脳機能障害を呈することが報告されている。本研究は, 71名の早産児を対象とし, 近赤外分光法を用いて音声誘発脳反応を調べた。早産児は音韻・抑揚刺激に対するヘモグロビン(Hb)変化パターンが正期産児と異なり, また, 音韻・抑揚の処理で大脳半球の優位性を示さなかった。修正週数が進むと非典型的なHb変化パターンは減少し, 抑揚刺激に対して正期産児同様に右大脳半球優位な脳活動を示した。本研究は, 早産児の音韻・抑揚刺激に対する脳活動は正期産児と異なるが, 分娩予定日までに発達し, 正期産児と同等になることを示した。
Previous work has demonstrated higher brain dysfunction in infants with periventricular leukomalacia. The present study examined the hemodynamic response of the brain to speech stimulation, imaged using near-infrared spectroscopy in 71 preterm infants. The preterm infants showed a different time course of hemoglobin change in response to phonemic or prosodic contrasts and did not demonstrate functional hemispheric specialization during speech stimulation. At a later corrected gestational age, the proportion of atypical hemoglobin change patterns decreased, and a right-dominant functional laterality, similar to that in term infants, was demonstrated. The findings of this study indicate differences between the functional system for phonemic and prosodic processing in preterm and term infants. However, that system develops and catches up by the preterm infants' projected due dates.
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