Can an abcessed tooth affect my brain aneurysm?

Not likely: Tooth abscess will not resolve on its own with home care. The most common type of dental abscess is a tooth, and the second most common is a gum or combination of both tooth-gum abscess. In order to get appropriate treatment it is important to know the underlying cause for this infection. Rec.: see your dentist for evaluation, x-rays and treatment. Predictable treatment and outcome.

Yes and no: Infected tooth will not cause an aneurysm directly. The inflammatory chemicals produced will, in general, affect all body tissues. This generalized inflammation process can adversely affect both healthy and compromised tissues. Test thing to do is immediate treatment of the abscessed tooth (It won't "heal" with pills alone, nor will it get better if ignored). Requires immediate treatment.