panencephalitis /pan′ənsef′əlī″tis/ [Gk, pan + enkephale, brain, itis] , inflammation of the entire brain characterized by an insidious onset, a progressive course with deterioration of motor and mental functions, and evidence of a viral cause. One example is subacute sclerosing panencephalitis, an uncommon childhood disease thought to be caused by a “slow” latent measles virus after recovery from a previous infection. Most of the patients are younger than 11 years of age, and many more boys than girls are affected. The disease results in ataxia, myoclonus, atrophy, cortical blindness, and mental deterioration. Antiviral drugs, immunosuppressants, and interferon inducers are sometimes administered, but the disease is usually unremitting and fatal.
