What is Acute Disseminated Encephalomyelitis: Causes, Symptoms, Treatment, Prognosis

Acute Disseminated Encephalomyelitis is a rare pathological condition of the brain in which there is episodic and brief but widespread inflammation across the brain and spinal cord incurring significant damage to the myelin sheath which is the protective covering which protects the nerve fibers. Acute Disseminated Encephalomyelitis usually is followed by a viral or bacterial infection. It may also occur after vaccinations for diseases like rubella or mumps but this is quite rare.

The symptoms of Acute Disseminated Encephalomyelitis are rapid in onset beginning with symptoms similar to that of an Encephalomyelitis like fever, severe fatigue and lethargy, headaches, nausea and vomiting and as the disease progresses it may cause even seizures and coma. This condition normally damages the myelin which is a covering of the nerve fibers and protects the nerve fibers from any damage. This condition also damages the white matter of the brain which causes symptoms like vision loss or paralysis.

Since Acute Disseminated Encephalomyelitis is quite rare and hence this condition is often misinterpreted as an attack of multiple sclerosis which also is an inflammatory neurological disorder and damages the myelin sheath. A detailed difference between Acute Disseminated Encephalomyelitis and Multiple Sclerosis has been delineated below. Acute Disseminated Encephalomyelitis strikes children more than adults.

The exact cause of Acute Disseminated Encephalomyelitis is not known but it is believed to occur normally after a severe bacteria or a viral infection. In some rare cases it has also occurred after vaccinations for rubella or mumps. Acute Disseminated Encephalomyelitis is an autoimmune disorder in which the immune system of the body mistakenly identifies the healthy cells of the body as potentially dangerous and starts attacking them which causes inflammation.

In majority of cases, the symptoms of Acute Disseminated Encephalomyelitis can be observed after about a couple of weeks post an infection or a few months after vaccinations, although in some cases there is no preceding event that causes occurrence of Acute Disseminated Encephalomyelitis.

Due to the rarity of Acute Disseminated Encephalomyelitis, it is often misinterpreted as an attack of multiple sclerosis but both these conditions are two separate entities. The following are the differences between Acute Disseminated Encephalomyelitis and Multiple Sclerosis:

• In majority of cases, an attack of Acute Disseminated Encephalomyelitis happens only once but in case of Multiple Sclerosis there may be multiple attacks of inflammation in the brain and spinal cord.
• In majority of cases, patients with Acute Disseminated Encephalomyelitis do not have substantial changes on their MRIs of the brain but in cases of Multiple Sclerosis there is always a significant change in followup MRI studies.
• The symptoms observed in Acute Disseminated Encephalomyelitis like fever, headaches, seizures etc. are not seen in people with Multiple Sclerosis.
• Majority of patients with Multiple Sclerosis require preventive medications to ward off any attack but patients with Acute Disseminated Encephalomyelitis do not require such medications.
• Acute Disseminated Encephalomyelitis is seen mostly in males while Multiple Sclerosis is seen mostly in females
• Acute Disseminated Encephalomyelitis occurs mostly in children which is not the case with Multiple Sclerosis.

In majority of cases of Acute Disseminated Encephalomyelitis, the patient must have had a bacteria or a viral infection a couple of weeks before the onset of symptoms of this condition. The presenting symptoms of Acute Disseminated Encephalomyelitis are persistent headaches and fever. As the disease progresses, there are neurological symptoms that include:

• Altered awareness
• Confusion
• Drowsiness
• Imbalance and frequent falling
• Diplopia
• Dysphagia
• Weakness of the upper and lower extremities.

In adults with Acute Disseminated Encephalomyelitis, there may be additional symptoms of motor and sensory deficits.

Acute Disseminated Encephalomyelitis is suspected whenever there is bacterial or viral infection followed in close proximity with the development of certain neurological symptoms along with classic symptoms of headaches, fever, and altered awareness. If Acute Disseminated Encephalomyelitis is suspected, then the treating physician will order an MRI scan of the brain to look for changes within the white matter and also look for any damage to the myelin sheath. If these changes are confirmed it further pinpoints to the diagnosis of Acute Disseminated Encephalomyelitis. This will be followed by serial MRI imaging in which the changes will start to gradually disappear and will be completely gone in some time which further confirms the diagnosis of Acute Disseminated Encephalomyelitis.

Apart from this, the physician will also perform a lumbar puncture to rule out other conditions like multiple sclerosis. In a lumbar puncture, the cerebrospinal fluid is taken from the spinal cord and is sent for analysis in a laboratory. In Acute Disseminated Encephalomyelitis, the CSF will show increased white cells which will confirm the diagnosis of Acute Disseminated Encephalomyelitis.

Acute Disseminated Encephalomyelitis is a rare disease condition and hence there is no specific treatment for it. As of now, the front line treatment for Acute Disseminated Encephalomyelitis is the administration of intravenous methylprednisolone and other steroid medications. These medications are normally given usually for a week or so followed by tapering of the steroids. The function of these steroids is to reduce inflammation. Patients on steroids for Acute Disseminated Encephalomyelitis often complain of mood changes, anxiety, and sleep disturbances which need to be monitored closely.

If there is no favorable response to the steroid therapy then the next step towards treatment of Acute Disseminated Encephalomyelitis is intravenous IVIG. This form of treatment has shown a lot of promise in treating autoimmune conditions. The intravenous IVIG is given for a few hours for a time period of five to six days.

Yet another approach towards treating Acute Disseminated Encephalomyelitis is called plasmapheresis. In this form of treatment, the blood is circulated through a machine that captures components of the immune system from the blood and thus reduces immune activity. This treatment is done for a few hours for a period of a couple of weeks.

In some cases, chemotherapy has also been used for treatment of Acute Disseminated Encephalomyelitis.

In majority of the cases, Acute Disseminated Encephalomyelitis can be successfully treated with steroid therapy. The long-term prognosis for patients with Acute Disseminated Encephalomyelitis is quite good. In majority of cases, the patient starts to recover in a few days and it usually takes about six months for the patient to be fully recovered from Acute Disseminated Encephalomyelitis.