メントール剤の前腕貼付が糖尿病視覚障害者の触覚機能および点字触読に及ぼす影響

Effect of menthol application to the forearm on tactile sensation and Braille reading accuracy in persons with diabetes-induced visual impairment

要旨：糖尿病中途視覚障害者に対するメントール剤の前腕貼付が，手指の触知覚と点字触読に及ぼす影響を調べた．対象は，糖尿病視覚障害者12名で内訳は男性10名，女性2名（平均年齢49.9±8.3歳），介入として前腕にメントール剤を40分間局所貼付し，反対側前腕にプラセボ剤を同様に貼付した．その前後で，前腕と手指の触知覚，点字識別能力を調べた．結果は，介入肢で前腕の触覚閾値の上昇，指尖の触覚閾値と2点識別の改善，点字識別の精度の向上が認められた．これによりメントールは，糖尿病視覚障害者の初期の点字学習を促すための補助的手段に成り得る可能性が示唆された．しかし具体的な適用方法については更なる研究が必要である．

　Purpose of the study: To examine the effect of menthol application to the forearm on fingertip tactile perception and Braille reading accuracy in subjects with diabetic visual impairment. Study design: A repeated measurement controlled study. Methods: Researchers applied a topical menthol patch to the forearms of twelve vision-impaired people with diabetes. The arm the subjects used for reading Braille became the experimental arm and received the menthol patch. As a control, a placebo patch was applied to the contralateral side. Examination of sensory function both before and after application of both patches took place. Accuracy of Braille identification was recorded. Results: After application of menthol patches, tactile threshold on the forearm increased significantly. Researchers observed improved tactile gnosis/discrimination of fingers. Accuracy of Braille identification also improved. Conclusion: This study suggests that application of menthol to the forearm of diabetic persons with vision and tactile sensory problems is a helpful adjunct to facilitate the ability to read Braille. Further methodological studies and studies to investigate the cortical mechanisms are needed.