変形性頚椎症に合併した特発性脳脊髄液漏出症の1例

A Case of Spontaneous Cerebrospinal Fluid Leak Associated with Cervical Spondylosis

Ⅰ．はじめに

　脳脊髄液漏出症は，脊髄硬膜外に髄液が漏出することで，起立性頭痛を中心とする多彩な症状が生じる疾患である．症状は，起立性頭痛のほかに，めまい，嘔気，やる気がでないなど非特異的であり，交通外傷や腰椎穿刺が原因となることもあるが，その原因が特定できないことも多い^4,5)．今回われわれは，非典型的な症状で外来受診し，入院後の診療経過によって診断に至った，変形性頚椎症に合併した特発性脳脊髄液漏出症を経験したので，若干の文献的考察を加えて報告する．なお，脳脊髄液減少症，低髄液圧症候群の用語も使用されているが，低髄液圧でない症例もあり，病態の本質は脳脊髄液漏出である⁵⁾．本症例では脳脊髄液漏出を画像的に証明できていることから，脳脊髄液漏出症を用いた．

　Spontaneous cerebrospinal fluid leak and intracranial hypotension associated with cervical spondylosis have rarely been observed, and only a few cases are reported. A 69-year-old woman, previously treated for rectal and thyroid cancer, complained of a non-postural persistent headache. The patient regularly practiced aerobic exercise, but a month earlier she had started experiencing headache and neck pain while exercising. Computed tomography（CT）showed bilateral chronic subdural hematomas, and magnetic resonance imaging（MRI）revealed diffuse dural enhancement and tonsillar herniation. We drained the subdural hematomas and replaced the ventricular reservoir to safely access the cerebrospinal fluid space. After surgery, the persistent headache disappeared for several days, but a postural headache emerged. CT myelogram showed extradural accumulation of the contrast medium at the C2-5 level with cervical spondylosis. The patient was treated with conservative therapy of bed rest and intravenous fluid hydration for two weeks, and the headache improved. CT myelogram after treatment showed no extradural accumulation of the contrast medium. Spontaneous cerebrospinal fluid leak associated with cervical spondylosis could be induced by the repeated minor mechanical stress caused by physical exercise. Therefore, the possibility that non-postural persistent headache may be caused by spontaneous cerebrospinal fluid leak should not be underestimated.