レニン依存性高血圧症を合併したCharcot-Marie-Tooth症候群の1例のpattern VEP所見

Pattern VEP in a case of Charcot-Marie-Tooth syndrome with renin-dependant systemic hypertension

（26C2-5）　レニン依存性高血圧症を併発したCharcot-Marie-Tooth症候群の診断を受けた11歳女児が，左眼の突然の視力低下で当科を受診した。視力は右1.5，左0.05（n．c．），左眼swinging flashlight test陽性。頭部CT，眼底ともに著変はなかつた。Pattern VEPは，左眼刺激，右眼遮蔽下の誘導波形で，特に反応の低下とP₁₀₀頂点潜時の延長が著明であった。左眼球後視神経炎の診断下に副腎皮質ステロイドパルス療法を行い，視力は0.9（1.0）に回復したが，pattern VEP所見には改善の傾向はみられなかった。さらに後日，右片麻痺を生じ，頭部CTにて左後頭葉の脳梗塞所見を認め，右側同名半盲を生じた。これより，本症候群における球後視神経炎ならびに随伴する頭蓋内障害の予測にpattern VEPは有用と思われた。

An 11-year-old girl presented with acute visual disturbance in the left eye. She had developed nephritis during infancy. She had been diagnosed as Charcot-Marie-Tooth syndrome with renin-dependent systemic hypertension 3 years before. The corrected visual acuity was 1.5 right and 0.05 left. Swinging flashlight test was positive in the left eye. Computed tomography of the brain and funduscopy showed no abnormal findings. Patteren VEP showed markedly delayed peak latency of Pioo with remarkably reduced VEP response when only the left eye was stimulated. Under the tentative diagnosis of retrobulbar neuritis, she received intravenous corticosteroid pulse therapy. The left visual acuity gradually improved to 1.0, but there was no recovery of the abnormal pattern VEP findings. Few days later, she developed right homonymous hemianopsia and right hemiplegia due to to cerbral infarction in the left striate cortex. This case illustrates that pattern VEP is useful in predicting the onset of retrobulbar neuritis and associated intracranial disorders in this syndrome.