Delayed Deep White Matter Ischemia After Resection of Gliomas by Awake Surgery.

Background And Objectives: Deep white matter (DWM) is perfused by the medullary arteries from the cortex, and ischemia sometimes occurs after glioma resection. However, the clinical significance of postoperative medullary artery-related ischemia has not been well studied. We retrospectively reviewed cases of delayed DWM ischemia after awake craniotomy to elucidate the clinical characteristics, mechanisms, and management of delayed ischemia.

Methods: We identified 4 cases of intra-axial brain tumors, mainly gliomas, that underwent tumor resection by awake craniotomy at our hospital and developed DWM ischemic symptoms after surgery, despite no worsening of neurological symptoms at the end of surgery.

Results: Four patients (3 men and 1 woman) presented with glioblastoma, oligodendroglioma, astrocytoma, and brain metastasis. The median age at surgery was 47.5 years (41-73 years). The tumors were located in the watershed area in the frontal lobe ( = 2) and the parietal lobe ( = 2), all of which were left-sided ( = 4). DWM ischemic symptoms, such as motor dysfunction, aphasia, dysarthria, and dysgraphia, developed at an average of 24 hours (14-48 hours) after resection by awake craniotomy. All 4 patients showed symptom improvement within a week after surgery and completely recovered within a month.

Conclusion: DWM ischemia is caused by sacrifice of the medullary artery, which feeds the tumor and adjacent brain tissue during tumor resection, and should be considered when delayed aphasia or paralysis occurs postoperatively. These symptoms are often transient and recovery usually occurs. Tumors located in the frontal or parietal lobes, particularly in the watershed area, should be carefully monitored for postoperative ischemia.