症例報告 Ecchordosis physaliphoraおよびanterior inferior cerebellar arteryの圧迫により発症した片側顔面痙攣の1例

 症例は61歳男性, 難治性の左顔面痙攣にて当科外来で経過観察中, 症状増悪傾向であったため加療目的に入院となった. 頭部MRIでは, 脳幹前面から左小脳橋角部にかけて不整形な腫瘍性病変を認めた. 腫瘍と前下小脳動脈が左顔面神経のroot exit zoneを圧迫していた. 症状改善目的に開頭腫瘍部分摘出術および微小血管減圧術を施行した. 病理診断はchordomaであったが, MRIの結果や臨床像から最終的にecchordosis physaliphoraと診断した. Ecchordosis physaliphoraは通常無症候性であるが, 発生母地から脳神経圧迫により症候性になり得ることもあると考えられる.

  A 61-year-old man was admitted to our hospital for the treatment of refractory left hemifacial spasm. Magnetic resonance imaging (MRI) revealed an irregular neoplastic tumor in front of the brain stem towards the left cerebellar peduncle, which was in contact with the root exit zone (REZ) of the left facial nerve, with anterior inferior cerebellar artery (AICA) running near the REZ. Partial removal of the tumor and microvascular decompression were performed. The postoperative pathological diagnosis was chordoma. However, we eventually diagnosed ecchordosis physaliphora based on MRI and clinical findings. His hemifacial spasm resolved, and he was discharged home with a modified Rankin Scale score of 1.

  Ecchordosis physaliphora is usually asymptomatic and does not require treatment. However, treatment should be considered in symptomatic cases.