成人における脳実質内症候性くも膜囊胞に対する内視鏡手術—後期高齢者を含む3症例の報告

Neuro-endoscopic Management of Intraparenchymal Arachnoid Cyst in Adults:Three Case Reports

Ⅰ．はじめに

　くも膜囊胞は全頭蓋内占拠性病変の約1%を占め⁴⁾，多くは無症候性に経過するがときに増大し神経症状を呈する．小児期に発見されることが多いと言われ，成人，特に高齢者のくも膜囊胞の自然歴や症候化のメカニズム・頻度，手術適応については不明な点が多い．われわれの施設で後期高齢者を含む3例の成人症候性脳実質内くも膜囊胞を経験し，内視鏡的開窓術を施行した．症候性くも膜囊胞は高齢でも低侵襲治療で良好な経過を得られることを示す知見と考え，報告する．

　We report 3 cases of symptomatic intraparenchymal arachnoid cysts in adults, including 2 in elderly patients. Case 1:An 81-year-old woman developed right-sided hemiparesis and hemianopsia due to the enlargement of left occipital arachnoid cyst, which had been incidentally diagnosed 3 years ago. Under the guidance of neuronavigation, we inserted a rigid endoscope into the cyst and perforated the cyst wall toward the posterior horn of the lateral ventricle, making a good communication between the cyst and the ventricle for cerebrospinal fluid. Her symptoms improved within 3 days after the surgery, and the cyst mass reduced. Case 2:A 57-year-old woman was incidentally found to have a right frontal arachnoid cyst. She had a 3-month long history of low mood and loss of interest in work. We perforated the transparent septum via the cyst wall toword the left lateral ventricle in a neuro-endoscopic procedure. After the surgery, she regained interest in work, and her symptom was considered to be indicative of depression due to arachnoid cyst. Case 3:A 94-year-old woman in a geriatric facility developed left-sided hemiparesis due to the enlargement of a right temporal arachnoid cyst, which had been detected 10 years ago. Neuro-endoscopic perforation of the cyst wall toward the lateral ventricle remarkably improved her symptoms. Arachnoid cysts can become symptomatic in the long term, not only in the young but also in the elderly. Neuro-endoscopic fenestration is an effective treatment for symptomatic intraparenchymal cysts, especially in elderly patients. The neuronavigation system was useful in the planning of the trajectory and in the detection of the target point of fenestration.