2025 Volume 47 Issue 3 Pages 158-164
A 70-year-old woman underwent coil embolization for SAH due to a dissecting aneurysm of the left ICA. On the seventh day, cerebral angiography was performed to examine vasospasm and coil compaction using heparin. At the end of the examination, she showed right hemiplegia and aphasia with disturbance of consciousness. A repeat left ICA angiography was performed; however, no embolism was found. MRI after the cerebral angiography showed acute infarction in the watershed region of both cerebral hemispheres and the left cerebellar hemisphere. On the ninth day, a significant decrease in platelet count was observed, and heparin-induced thrombocytopenia (HIT) was suspected. The clinical score for HIT was 8 points, and HIT antibodies were measured, which were found to be positive. This case was considered to have been acute cerebral infarction caused by HIT due to heparin sensitization caused by coil embolization. It is important to keep HIT in mind when performing endovascular treatment and/or cerebral angiography using heparin.