特発性髄液耳漏の1例

A Case Report of Spontaneous Cerebrospinal Fluid Otorrhea

Ⅰ．はじめに

　髄液耳漏は頭部外傷・腫瘍性疾患・炎症性疾患・術後合併症を主な原因として起こるが，稀に特発性にも起こり得る．特発性髄液耳漏は，内耳奇形などを原因として幼小児期に発症する小児型と，内耳奇形を伴わない成人型に分類される．今回われわれは，細菌性髄膜炎を発症後，髄液耳漏が出現し，経中頭蓋窩法で髄液漏閉鎖術を施行した1例を報告する．

　Spontaneous cerebrospinal fluid（CSF）otorrhea is less common than CSF leakage caused by trauma, and rarely occurs in adults. We report an adult case of CSF otorrhea. A 71-year-old woman with no traumatic or otologic history was hospitalized due to bacterial meningitis. After hospitalization, CSF leakage started suddenly from the left external ear canal. A high resolution CT scan with intrathecal administration of contrast material revealed CSF leakage in the left ear canal and multiple bone erosions in both the tegmen mastoideum and the posterior fossa aspect of the petrous bone. We performed closure and surgery via the middle fossa approach. We identified a bone defect in the tegmen mastoideum but could not detect any obvious abnormality in the dura mater. We placed both a pericranial flap and a free abdominal fat on the middle base of the skull as sealing materials. There was no recurrence of CSF otorrhea following surgery. In this surgery, the use of a multilayered closure technique is very important to avoid the recurrence of CSF leakage.