Viral infections of the cerebrum typically involve the cortex (encephalitis), sometimes with meningeal involvement as well (meningoencephalitis). There are many viral infections that can involve the brain. Some, such as rabies virus, involve very specific areas, while others, such as West Nile virus or echovirus, have more general involvement. Seen here are characteristic lymphocytic infiltrates in the cortical parenchyma as well as around cerebral vessels. Examination of the cerebrospinal fluid may reveal increased numbers of mononuclear cells, along with somewhat elevated protein but normal glucose.