Aloha! You're speaking with Dr. Michael SalkinMatilda presents me with a bit of a conundrum. You're correct to be concerned about brain tumor at her age. It's the most common cause of seizures in an elderly cat and a meningioma is most often found. Headache may certainly be associated with such a tumor and might well underlie her current change in behavior.The conundrum is as follows: Pain relief in cats usually involves nonsteroidal antiinflammatory drugs (NSAIDs) such as robenacoxib or meloxicam but we have to be careful with such drugs because they can affect the kidneys. I would be pleased to review her kidney blood tests/urinalysis for you to better understand if such a drug would be appropriate for her. Alternatively, a low dose of a glucocorticosteroid such as prednisolone can be prescribed. Prednisolone relieves pain by reducing the inflammation associated with brain tumor. It, too, however, has multiple adverse effects on multiple body systems. Finally, analgesic opiates such as tramadol or buprenoprhine can be prescribed but Matilda is likely to become quite sedated by these drugs.Please respond with further questions or concerns if you wish. Feel free to discuss our conversation with Matilda's vet.