(Science: infectious disease) a very rare form of encephalopathy thought to be caused by a virus (slow-virus), termed a prion. There is little known about the mode of transmission. Human to human transmission has occurred through the use of contaminated brain electrodes and transplantation of infected tissues. The agent can be recovered in the csf of infected individuals. Standard disinfectants such as formalin, heat, exposure to ultraviolet light or x-rays is ineffective to inactivate the virus. Autoclaving to at least 132 degrees c. Or immersion in 4% sodium hydroxide or 10% sodium hypochlorite solution for 1 hour is recommended for sterilisation. The disease occurs primarily in adults, with peak incidence in the late 50's. Infection results in dementia, myoclonus, ataxia and other neurologic symptoms. The disease progresses rapidly to coma and death after a 3 to 12 month illness. There is no known cure.