What is a “mycotic” aneurysms?
Words like mycotic and mycosis brings to mind fungus and fungal infections. But when the term mycotic is used in reference to cerebral aneurysm or endocarditis, it actually refers to a bacterial infection. For this reason, the term “infective” is replacing “mycotic” in these situations.
Infective endocarditis typically involves the development of platelet and bacteria rich vegetations on the heart valves. One of the greatest fears (for neurologists, anyway) is that bits and pieces of these valvular vegetations will embolize to the brain and cause strokes.
But, very small emboli can also seed the distal cerebral blood vessels with bacteria. This creates areas of infection and inflammation in the wall of the blood vessel, causing outpouchings or pseudo-aneurysms, which easily rupture.
These are infective (or “mycotic”) cerebral aneurysms.
See below for an annotated version. The majority of the infective aneurysms in this case are in the anterior cerebral artery distribution.
The primary treatment for infective aneurysms is with antibiotics. As the infection is treated, most areas of cerebral pseudo-aneurysm resolve. In rare cases, surgical treatment of unruptured aneurysms is performed.