Neurological infections encompass a large variety of conditions that invade and affect the nervous system. Despite advances in therapy and the development of early detection techniques, many of these conditions cause severe, chronic and even life threatening problems for those affected by neurological infections. Several viral infections of the central nervous system have emerged that are not yet amenable to available treatment. The most common forms of neurological infection include meningitis which causes inflammation of the meninges, membranes which cover the brain and spinal cord. The infection may be bacterial or viral. Ventriculitis causes infection to the ventricles of the brain. Encephalitis causes infection or inflammation of the brain caused by either bacteria or a virus. Meningoencephalitis, causes simultaneous infection of the meninges and the brain. Myelitis causes infection that involves the spinal cord.