Polioencephalitis

Polioencephalitis is a viral infection of the brain, causing inflammation within the grey matter of the brain stem. The virus has an affinity for neuronal cell bodies and has been found to affect mostly the midbrain, pons, medulla and cerebellum of most infected patients. The infection can reach up through the thalamus and hypothalamus and possibly reach the cerebral hemispheres. The infection is caused by the poliomyelitis virus which is a single-stranded RNA virus surrounded by a non-enveloped capsid. Humans are the only known natural hosts of this virus. The disease has been eliminated from the U.S. since the mid-twentieth century, but is still found in certain areas of the world such as Africa.