Subacute sclerosing panencephalitis

SSPE is characterized by a history of primary measles infection, followed by a normal, unremarkable recovery. The very earliest symptoms are small, subtle changes in behavior, such as not paying attention or struggling with schoolwork. By the time family members have become concerned, the disease is at Stage 1. It shows nonspecific symptoms of neurological problems, such as being more irritable than usual, more affectionate than usual, lethargic, or having speech difficulties. • Stage 1: There may be personality changes, mood swings, or depression. Fever, headache, and memory loss may also be present. This stage may last up to 6 months. • Stage 2: This stage may involve jerking, muscle spasms, seizures, loss of vision, and dementia. • Stage 3: Jerking movements are replaced by writhing (twisting) movements and rigidity. At this stage, complications may result in blindness or death. • Stage 4: Progressive loss of consciousness into a persistent vegetative state, which may be preceded by or concomitant with paralysis, occurs in the final stage, during which breathing, heart rate, and blood pressure are affected. Death usually occurs as a result of fever, heart failure, or the brain's inability to control the autonomic nervous system. ==Pathogenesis==

SSPE is caused by a latent infection by mutated copies of wild type (naturally occurring) measles virus. Without the envelope protein, infectious particles are not produced, and the defective virus can survive persistently without evoking an immune response. Eventually, the infection will lead to SSPE. When SSPE begins, it demyelinates nerves, causing them to signal unreliably. Later, the brain cortex atrophies, and the ventricular system becomes dilated. Nerve cells are destroyed through phagocytosis. Tauopathies and neurofibrillary tangles develop. ==Diagnosis==

SSPE may be suspected in any child with symptoms of a progressive (keeps getting worse) neurological disease and who has never been vaccinated against measles. Typical diagnostic tests include electroencephalography (EEG) to look for evidence of epilepsy or other disturbances to brain waves and a test of the cerebrospinal fluid to look for elevated levels of antibodies against measles and to rule out multiple sclerosis. Magnetic resonance imaging (MRI) of the brain usually looks normal early in the disease. ==Treatment==

There is no cure. Most treatments are supportive measures, such as anticonvulsants to reduce seizures. If the diagnosis is made early, oral isoprinosine (Inosiplex) is standard, but it is expensive and only stabilizes or improves symptoms for about 30% of people with SSPE. Less effective medications include intraventricular interferon alfa, amantadine, ribavirin, and others. Immunoglobulin therapy (IVIG) is also used. Isoprinosine is sometimes combined with interferon alfa. Following the onset of stage 2, the disease is invariably fatal. == Prevention ==

SSPE is a disease for which prevention is the best medicine. SSPE can be prevented by vaccinating children against measles before they become infected. The strains of measles virus in the measles vaccines do not cause SSPE. ==Prognosis==

Almost everyone who develops SSPE dies as a result of SSPE or secondary complications. This faster progression may be called measles inclusion body encephalitis. If a remission is achieved, the subsequent relapse is untreatable. ==Epidemiology==

The number of people who develop SSPE depends on the number of infections. ==History==

SSPE was first described by James R. Dawson Jr. of the Vanderbilt University School of Medicine in 1933. ==See also==