視覚失認に対する視覚イメージを用いた介入の検討

Visual agnosia intervention using the visual images

要旨：両側後頭葉梗塞により視覚失認を呈した70歳代女性を担当した．症例は家族など熟知相貌の失認を呈していたが，家族に関する世間話をした直後，困難であった家族写真の人物同定が可能となった．このエピソードより視覚イメージ想起が顔認識向上を促したと仮説を立てた．また，視覚イメージ想起を促すことで，物品や画像に対する失認改善を促す可能性があると考え介入方法を検討し実施した．結果，持続的効果は認められなかったが，視覚イメージ想起直後であれば，物品と画像の視覚認識は向上を認めた．他感覚による視覚認識向上の可能性も考えられるが，視覚失認に対する視覚イメージ想起の効果は不明確のままであり，引き続き調査していきたい．

　We report a case of a 70-something woman with visual agnosia caused by bilateral occipital lobe infarction. The patient presented agnosia for familiar faces including her family. Although she had difficulty recognizing members of her family, after chatting about her family she became able to identify faces in family pictures. This episode suggested that visual recall improved the ability of face-recognition. Thus, we hypothesized that it could be possible to improve object- or image-recognition by stimulating visual recall and we examined clinical interventions based on this hypothesis. By evoking visual images, object- and image-recognition of the patient was temporarily improved, although the effect was not continuous. Also, visual recognition could be improved by alternative sensory stimulation. We will continue to investigate clinical intervention using visual recall.