大脳鎌髄膜腫摘出約4年半後に完全対麻痺をきたした胸髄髄膜腫の1例

A case of thoracic meningioma presenting paraplegia at 4.5 years after removal of a falx meningioma

I．はじめに

　頭蓋内での多発性髄膜腫の頻度は，諸家により1—9％と報告されており，また，autopsyによれば，16％にも達するとされている^5）．これに対し，頭蓋内髄膜腫と脊髄髄膜腫の合併例は，極めて稀である．文献的にも15例の報告を見るにすぎない^{1-5,7,10,14,16,19-21,23）}．

　今回われわれは，右前頭葉大脳鎌髄膜腫摘出から4年半後に胸髄髄膜腫による完全対麻痺をきたした高齢者例を経験した．幸い，胸髄髄膜腫摘出により，独歩可能なまでに回復した．このような頭蓋内および脊髄髄膜腫の合併例の特徴および重症脊髄障害の予後判定に関して，文献的考察を含め，報告する．

A case of a thoracic meningioma presenting paraple-gia 4.5 years after removal of a falx meningioma is re-ported.

A 73-year-old woman, complaining of diplopia, was admitted to our department. Neurological examination revealed right abducens palsy. CT demonstrated a well-enhanced right frontal mass beneath the falx. The mass was totally removed under right frontal craniotomy. Its histology was transitional meningioma with rich fibro-blasts.

4.5 years after craniotomy, she complained of pro-gressing gait disturbance and nocturnal leg pain. Neuro-logical examination revealed paraplegia, complete loss of leg sensation, loss of patellar and ankle reflex, bi-lateral positive Babinski reflex and urinary disturbance.Rectal function and anal reflex were preserved. Thor-acic MRI demonstrated an intradural extramedullary mass which was well enhanced with Gd-DTPA at Th6-7. Under laminectomy, the mass was totally removed. Its histology was transitional meningioma with rich psammoma bodies and whirl formations. 4 months after removal, her palsy and sensory loss were almost com-pletely recovered.

We were able to find 15 cases of combined intracra-nial and spinal meningiomas in the literature. A young woman of neurofibromatosis suffered from tentorial, in-traventricular and C1-2 meningiomas. Of 15 cases without neurofibromatosis including our case, 4 cases were of young boys and 11 cases were of women. Their initial symptoms originated from intracranial me-ningiomas in 8 cases. Multiple intracranial meningiomas were revealed in only 4 cases. In 9 cases, one case pre-sented a combination of one intracranial meningioma and one spinal meningioma. Histology of intracranial meningioma was almost the same that of spinal meningioma in almost half of the 10 cases. These find-ings suggest the multi sentricity theory of multiple meningiomas originating in other neuroaxial compart-ments.

Severe spinal dysfunction was recovered after remov-al in our case. Rectal function and anal reflex were pre-served. These anorectal findings suggest that spinal dysfunction is either complete or incomplete. Motor evoked potentials are hopeful tools which can select re-versible spinal motor dysfunctions.