Feasibility of Intraoperative Microdialysis During Neurosurgery for Central Nervous System Malignancies

This feasibility study tests whether a technique called microdialysis — which involves placing a tiny sampling tube into brain tissue during surgery — can safely collect information about the brain's chemical environment in real time while a patient is having brain tumor surgery or epilepsy surgery. This could help doctors monitor brain health during operations. **You may be eligible if...** - You are 18 or older - You have a brain tumor (glioma, brain metastasis) or epilepsy requiring surgical treatment - You are scheduled for brain tumor biopsy or resection, or surgery for epilepsy, at Mayo Clinic in Rochester, Minnesota - You are able to give written informed consent **You may NOT be eligible if...** - You are pregnant - You are a prisoner or have a mental disability that prevents giving informed consent - You are not medically fit for surgery Talk to your doctor to see if this trial is right for you.