角膜潰瘍を契機に発見された両側三叉神経低形成の1例

A case of congenital bilateral trigeminal nerve hypoplasia revealed by corneal ulcer

先天性三叉神経低形成は，難治性の角膜上皮障害や顔面の感覚障害をきたすまれな疾患である^1）。先天性三叉神経麻痺は3つのグループに分類され，先天性三叉神経低形成は三叉神経のみが障害されるグループ1の原因と考えられる（Rosenberg，1984年）^2）。その後も先天性三叉神経麻痺に関してはいくつかの症例報告が散見されるが，画像所見に関してのまとまった報告はみられない。

We present a case of a 10-year-old girl with bilateral trigeminal nerve hypoplasia, which is considered a very rare clinical condition. She suffered corneal epithelial disorder of the left eye around one and a half years old, and the symptoms were aggravated in spite of ophthalmic drop therapy. Though no abnormal findings of cranial nerve were found by neurological examination other than corneal lesions, normal bilateral trigeminal nerve could not be identified by MRI. Congenital trigeminal hypoplasia is one of the causative condition of neuroplegic keratopathy evoking severe corneal disorder. Those cases have been reported sporadically, but as far as we know, little with imaging findings of MRI. We will report congenital bilateral trigeminal nerve hypoplasia with MRI finding with some discussion.