The attack damages their myelin sheath. Myelin assists nerve fibers in conducting electrical impulses to and from a person's brain. Conditions that cause damage to a person's myelin sheath are referred to as, 'demyelinating disorders.'
The symptoms of ADEM are similar to those of multiple sclerosis. Because of this, the disorder is many times misdiagnosed as a severe attack of multiple sclerosis. There are some key differences; however, between the symptoms of ADEM and multiple sclerosis, ones that can be recognized by a skilled neurologist. The initial symptoms of ADEM happen intensely and rapidly as a single and short-lived attack, although some children do experience recurrent episodes over a period of months. The initial symptoms of ADEM can include:
A child affected by ADEM can experience changes in their consciousness, to include seizures, or in severe cases - coma. The child can also experience changes in their behavior, such as irritability. Additional symptoms, caused by myelin damage include difficulty coordinating muscle movements, weakness in a single limb or one side of the body, and visual disturbances.
Reaching an early and accurate diagnosis of Acute Disseminated Encephalomyelitis (ADEM) is crucial where management of a child's health and quality of life are concerned. A child's doctor, while reaching for a diagnosis, will conduct a complete physical examination and ask about any symptoms the child is experiencing, to include when the symptoms began and how they have eased or progressed over a period of time. The child's doctor will also make a record of their full medical history to include any information about their immediate and extended family members.
The doctor will order a series of tests, such as magnetic resonance imaging (MRI) of the child's spinal cord and brain, with the intention of looking for any lesions or areas that may have been damaged. Such areas might indicate ADEM and rule out other forms of disorders including multiple sclerosis in the process. MRI scans are non-invasive and use powerful magnets to create clear and detailed images of a person's spinal cord and brain tissues. Brain lesions that are recent are more indicative of ADEM, yet may also occur in multiple sclerosis. Older and inactive lesions commonly indicate multiple sclerosis, a disorder that many times causes brain lesions prior to development of symptoms that are obvious.
The child's doctor might also order a lumbar puncture or spinal tap with the intention of determining if there are abnormalities in the child's cerebrospinal fluid (CSF). CSF is the fluid that cushions, bathes, and protects a person's spinal cord and brain - it flows through the spine and skull in the, 'subarachnoid,' space; an area that is inside the arachnoid membrane. With ADEM, a child's CSF usually contains elevated levels of white blood cells and protein. A diagnosis of ADEM is made based upon the child's symptoms, the results of their physical examination, as well as the results of testing.
The majority of children diagnosed with ADEM respond either partially or completely to corticosteroid therapy, something that diminishes the symptoms of the disorder through suppression of inflammation in their spinal cord and brain. Should corticosteroids fail, there are additional forms of treatments available that a doctor might prescribe. These treatments include:
Plasmapheresis: Plasmapheresis involves the removal, treatment and return of blood plasma
Immunosuppressive therapy: Immunosuppressive therapy involves treatment to reduce or deactivate the immune system
Intravenous immunoglobulin therapy: Intravenous immunoglobulin therapy involves the administration of antibodies extracted from plasma
Treating a child who has been diagnosed with ADEM can include other medications to treat symptoms, as well as supportive care to help the child to recover mentally and physically - a process that can take from weeks to months. Some children with ADEM experience memory problems, particularly involving short-term memory. They might also experience emotional disturbances. Rest, alternated with physical and mental forms of exercises, is a recommended path through rehabilitation for children with ADEM.