<unk>  is caused by an infection of the ventricles, causing an immune response in the lining, which in turn, leads to inflammation. The<unk> , is in truth, a complication of the initial infection or abnormality. The underlying infection can come in the form of a number of different bacteria or viruses. The data seems to point to Staphylococci as the leading bacterial cause of infection leading to<unk>  being present in about 90% of cases, but generally, what is of more concern is the way the infection entered the ventricles. The brain in its natural state is very protected from infection. The blood–brain barrier serves to keep pathogens from entering the sensitive areas of the brain. However, when those natural defenses are by-passed in the hospital setting, the brain is suddenly exposed to a host of potentially harmful bacteria and viruses. Patients that have had invasive brain surgery or procedures are considered to be the most at risk for experiencing<unk> . Two procedures, in particular have been studied extensively due to their high rate of<unk>  contractions post operation. The first group consists of patients that have had an external ventricular drain implanted to allow physicians to reduce the intracranial pressure they experience. The duration that the drain is implanted varies by necessity, however, the longer the drain is in, the more likely an infection will occur. The second group consists of patients that have an implanted intracranial stent. Both groups of patients have a much higher rate of<unk>  than the general populace, though there is very little supporting evidence due to the lack of definition of<unk>  as frequent misdiagnosis. Nearly 25% of patients with an external ventricular drain experience infection-based meningitis or<unk> .
Ventriculitis
Meningitis
Meningoencephalitis
Encephalitis
Granulomatous meningoencephalitis
Encephalomyelitis
Tuberculous meningitis
Brain abscess