血小板増多症に伴った脳静脈洞血栓症の1例

A Case of Cerebral Venous Thrombosis Associated with Thrombocythemia

Ⅰ．はじめに

　脳静脈洞血栓症は，頭痛，痙攣，意識障害，うっ血乳頭などで発症し，上矢状静脈洞血栓症が多いとされている^6,7)．原因として，特発性のほか，感染，外傷，悪性腫瘍，血液疾患，膠原病，妊娠，経口避妊薬などが挙げられているが血小板増多症に伴うことは極めて稀である^{1,4,6,7,10,11,13)}．われわれは，再発性脳静脈洞血栓症に，抗血小板療法，抗凝固療法，機械的血栓破砕術，バルビツレート療法，および腰椎ドレナージを併用することにより良好な転帰が得られ，精査の結果，血小板増多症が原因と考えられた症例を経験したので文献的考察を加え報告する．

　A rare case of cerebral venous thrombosis associated with thrombocythemia is reported.

　A 47-year-old man presented with headache, papilledema, and diplopia. Complete blood count showed an increased number of platelets. MR images and venography showed the thrombosis from the superior sagittal sinus (SSS) to the bilateral transverse sinuses (TS). The patient was treated with thrombolysis, continuous heparin infusion, and oral warfarin. On day 2, angiography demonstrated partial recanalization of the SSS and the left TS. Since CSF pressure was 30cmH₂O at day 11, a spinal drainage catheter was installed. Nevertheless, the patient presented with left hemiparesis, seizure, and loss of consciousness on day 12. Angiography revealed thrombosis from the SSS to the left TS and the right sigmoid sinus. Mechanical thrombolysis with a balloon was performed, and partial recanalization was obtained. In order to control the intracranial pressure, barbiturate coma therapy was performed for 1 week. On day 19 aspirin therapy was initiated become of continuous thrombocythemia. On day 25, the patient recovered completely.

　This case suggests that thrombocythemia may be able to cause refractory cerebral venous thrombosis.