搔痒感から発症した視神経脊髄炎の再発

A Case of Neuromyelitis Optica with Relapse Symptoms from Paroxysmal Pruritus

右後頭部搔痒感を先行症状とし約1カ月後に下位延髄から上位頸髄に広がる脊髄炎を生じた抗アクアポリン4抗体陽性の視神経脊髄炎患者を報告する。多発性硬化症では搔痒感を主症状とする再発の報告は過去に散見されるが，その多くは視神経脊髄炎が多発性硬化症から分離される以前になされたものであり，血清学的に確定診断された視神経脊髄炎における搔痒症の報告は少ない。視神経脊髄炎患者において搔痒感を先行症状とした再発が生じうることを念頭に置く必要がある。

Abstract

We report the case of a 34-year-old woman who presented with neuromyelitis optica and paroxysmal pruritus. She noticed an itching sensation with no obvious rash in the right postauricular region. Seven days later, the pruritus changed to an abnormal, painful sensation. One month after the onset of the painful sensation, she was hospitalized due to abnormal sensations that extended along the right side of her body and extremities. A hyperintense area on T₂-weighted imaging was accompanied by partial enhancement that extended from the lower medulla oblongata to the upper cervical spinal cord. The anti-aquaporin (AQP)-4 antibody was detected in serum. The patient had a history of optic neuritis. Therefore, neuromyelitis optica (NMO) was diagnosed. Her symptoms improved after intravenous and oral corticosteroid treatment. Itching attacks have been occasionally reported with multiple sclerosis, but many of these cases were described before the discovery of the anti-AQP4 antibody. Information on pruritus in serologically confirmed NMO is lacking. We should be aware that patients with NMO can experience recurrence that develops as pruritus.

(Received November 27, 2014; Accepted February 23, 2015; Published August 1, 2015)