Acute Disseminated Encephalomyelitis (ADEM)
Background
Acute Disseminated Encephalomyelitis: ADEM
Acute Disseminated Encephalomyelitis (ADEM) accounts for up to one third of all known cases of encephalitis. This illness was first described two hundred and fifty years ago by the distinguished English physician, Clifton who noted that it occurred occasionally in patients who had smallpox. The white matter of the brain is predominantly affected and under the microscope it can be seen that there is invasion around small veins by white blood cells from the blood. Where these cells accumulate, myelin is destroyed. The illness has been poorly understood and a variety of terminologies used to describe it, these include post infectious, parainfectious or post vaccinial.