Creutzfeldt Jacob disease
A rare transmittable degenerative disorder of the brain caused by prions. Morphologically it is characterized by spongiform degeneration of the cerebral and cerebellar cortex. Signs and symptoms include sleep disturbances, personality changes, aphasia, ataxia, muscle atrophy and weakness, visual loss, and myoclonus. It usually leads to death within a year from the onset of the disease.