一卵性双生児の1例で認めた特徴的な書字障害

A neuropsychological analysis of a specific writing disorder in a twin girl

　一卵性双生児の1例に認めた書字障害の特徴を中心に報告した．症例は初診時6歳10か月の右利き，女児である．神経心理学的検査の結果，以下のことがわかった．明らかな知的低下は認めず，文字の音読についても問題がなかったが，仮名1文字の写字ではバランスや歪みが目立ち，文字列の場合には文字の重なりなど空間配置に問題があった．本例の書字障害について，崎原(1998)が報告した幼児期における書字(写字)の発達分析を参考に，双生児の妹の書字と比較した．その結果，本例の書字障害は，視覚-運動(構成)能力の発達の遅れによると考えた．

　We report a case of specific writing disorder in a 6-year-10-month-old girl, the elder of identical twin sisters.　Although she did not have an obvious mental delay, her scores on the Frostig developmental test of visual perception were low.　She had no problem in reading aloud, but manifested writing disorders for kana and kanji.　Her writing style was slow and strained.　We analyzed her writing of kana using Sakihara's (1998) system which evaluated developmental changes in copying letters in preschool children.　Our case did not reach the level of proper segmentation or construction.　We concluded that she shows developmental disorders in letter formation and visual-motor (constructional) abilities.