三叉神経脊髄路核に拡散強調画像で高信号を呈した三叉神経帯状疱疹の1例

Trigeminal Herpes Zoster Presenting with High-intensity Signals for the Spinal Trigeminal Nucleus and Tract on Diffusion-weighted Image: A Case Report of Stroke Mimic

症例は50歳女性。右顔面の腫脹感と頭痛で発症，MRI拡散強調像で延髄外側の高信号を認め，延髄外側梗塞として治療開始した。3日目に右三叉神経帯状疱疹が出現し，MRI病巣は三叉神経脊髄路核と思われた。三叉神経帯状疱疹のMRI異常は延髄外側梗塞に類似することがあり，皮疹を伴わない時期には初期診断が困難な場合がある。画像上，延髄外側梗塞よりも多いスライスにわたる病巣を示すのが三叉神経帯状疱疹の特徴である。

Abstract

A 50-year-old woman was admitted to our hospital with dysesthesia on the right upper portion of her face and a headache. Diffusion-weighted brain magnetic resonance imaging (MRI) revealed high-intensity signals in the dorsolateral portion of the medulla oblongata. She was diagnosed with lateral medullary infarction and was intravenously treated with sodium ozagrel. On the second day of hospitalization, she had nausea and vomiting and showed nystagmus to all directions, suggesting damage to the vestibular nucleus. These manifestations coincided with partial symptoms of lateral medullary syndrome. On the third day of hospitalization, a rash appeared on the region of skin innervated by the first and second branches of the right trigeminal nerve. A reevaluation of the MRI findings indicated the presence of a lesion of the right spinal trigeminal nucleus and tract. She was treated with acyclovir for 14 days, and was discharged without any residual symptoms. Varicella zoster virus-DNA was detected in her cerebrospinal fluid. This disease mimics the presentation of a stroke and is important for differential diagnosis.

(Received August 1, 2017; Accepted September 14, 2017; Published February 1, 2018)