小児の慢性炎症性脱髄性多発神経炎

Chronic Inflammatory Demyelinating Polyneuropathy in Childhood

　乳幼児期から小児期に発症したステロイド反応性慢性脱髄性ニューロパチー6症例において，臨床的，電気生理学的，組織学的所見をまとめた。現在用いられている成人慢性炎症性脱髄性多発神経炎（CIDP）の診断基準は，小児にもほぼあてはめられる妥当性を有する。しかし，乳幼児発症例では，凹足変形や神経肥厚など遺伝性ニューロパチー類似の徴候がみられることがあり，診断上注意が必要である。また，神経伝導では伝導ブロックにとらわれずmultifocalityを示唆する所見に注目し，経過を追って検査を繰り返すことによって，診断基準をみたす結果が得られる場合がある。腓腹神経所見では菲薄髄鞘有髄線維のほか，浮腫，細胞浸潤をみることが多い。生検神経において軸索変性が高度であっても，神経伝導が後天性慢性脱髄性ニューロパチーすなわちCIDPの所見である限り，治療努力を続けるべきである。

Clinical, electrophysiological and histopatho-logical findings in 6 children with steroid-respon-sive acquired demyelinating neuropathy are present-ed. The clinical features and nerve conduction findings are basically simillar to those of chronic inflammatory demyelinating neuropathy (CIDP) in adults, although early-onset cases had prominent pes cavus deformity and thickened nerves, which are rare findings in acquired neuropathies in adults. The diagnostic criteria of adult CIDP can be adopt-ed for most of the cases, however, repeated electro physiological tests may be required to identify multifocality of the nerve lesion, especially when conduction block is not apparent before treatment. The biopsied sural nerves showed many thinly-myelinated fibers, subperineurial and endoneurial edema, and cellular infiltrations. Varied fascicular involvements were common. Two cases with almost complete or considerable loss of myelinated fibers in the biopsied sural nerve revealed good clinical response to steroid therapy. The degree of nerve degeneration in the sural nerve thus, may not be helpful to estimate the prognosis and the responsive-ness to treatment. Therapeutic trials should be employed when the main conduction findings are those of demyelinating neuropathies, even if genetically-determined neuropathy is suggested from the clinical pictures.