Polioencephalitis 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, positive sense 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.
Anatomy of the cerebellum posterior inferior portion of the cerebellum, the inferior cerebellar peduncle, the nucleus ambiguus, the vagus motor nucleus, the spinal trigeminal nucleus, the solitary nucleus, and the vestibulocochlear nuclei. There is considerable variation in the size and shape of the cerebellum in different vertebrate species. It is generally largest in cartilaginous and bony fish, birds, and mammals, but somewhat smaller in reptiles. The large paired and convoluted lobes found in humans are typical of mammals, but the cerebellum is generally a single median lobe in other groups, and is either smooth or only slightly grooved. In mammals, the neocerebellum is the