両側顔面神経麻痺と嚥下障害を呈したエンテロウイルスD68脳脊髄炎の成人例

An Adult Case of Enterovirus D68 Encephalomyelitis Presenting as Bilateral Facial Nerve Palsy and Dysphagia

呼吸器感染症の原因ウイルスの1つであるエンテロウイルスD68型による，稀な成人の脳脊髄炎の1例を報告する。患者は33歳男性。発熱，咽頭痛，頭痛で，5日後に両側顔面神経麻痺，嚥下障害，頸部・傍脊柱筋の筋力低下を呈した。頭部MRIのT₂強調画像にて脳幹（橋）背側と上位頸髄腹側に高信号病変を有する特徴的な画像所見を認めた。血清PCRにより当時流行していたエンテロウイルスD68型が検出された。両側末梢性顔面神経麻痺を急性にきたす疾患の鑑別としてエンテロウイルスD68型脳脊髄炎も考慮すべきである。

Abstract

A 33-year-old man was admitted to our hospital with bilateral facial nerve paralysis, dysphagia, and muscle weakness in the neck and trunk following fever, headache and throat pain. T₂-weighted brain magnetic resonance imaging (MRI) showed hyperintense lesions in the tegmentum of the brain stem and the ventral region of the superior cervical cord. Based on the characteristic findings on the brain MRI, we diagnosed the patient with enteroviral encephalomyelitis. Steroid therapy was administered; however, his bilateral facial nerve paralysis and dysphagia were refractory to this therapy. Subsequently, enterovirus D68 was detected in the serum using polymerase chain reaction (PCR) analysis. At that time, an outbreak of enteroviral D68 infection was reported in Japan. Finally, we diagnosed encephalomyelitis caused by enteroviral D68 infection. Characteristic MRI findings were very useful in narrowing down the differential diagnosis in this patient.

(Received March 3, 2017; Accepted April 20, 2017; Published August 1, 2017)