Pain is typically worse with respiration and when lying down. Some patients report that pain is better when leaning forward. EKG abnormalities are invariably present, and serum levels of cardiac enzymes are frequently elevated. Conduction abnormalities and cardiac enlargement may occur. Enteroviruses are the most common cause of aseptic meningitis syndrome.
Clinical manifestations depend on the age and immune status of the host.
Neonates less than 2 weeks of age may develop a very severe meningoencephalitis. Complications include hepatic necrosis, myocarditis, and necrotizing enterocolitis. Encephalitis with seizures and focal neurologic findings may occur. By contrast, enterovirus meningitis after 2 weeks of age rarely results in severe disease or long-term sequelae. Clinical presentation includes an initial phase with nonspecific constitutional symptoms and fever followed by development of nuchal rigidity, headache, nausea and vomiting, and photophobia.