Acute Disseminated Encephalomyelitis (ADEM)

Acute disseminated encephalomyelitis (ADEM) is an inflammation of the brain and spinal cord. ADEM is a demyelinating disease of the brain and spinal cord. Demyelination is the destruction or loss of the myelin from the sheath. The inflammation is caused by an autoimmune attack, a hypersensitivity reaction of the brain. Often the attack is a response to a viral infection. Sometimes ADEM occurs after immunization or it may be a manifestation of other diseases such as multiple sclerosis. It is not a common disease. Most of the preceding infections are typically upper respiratory tract infections. It can occur at any age, but is most common in children.

Etiology (Causes)

Some of the more common causes following infection have been measles, chicken pox, rubella and influenza. Occasionally a bacterial infection causes ADEM.

Following immunization, vaccination such as the smallpox vaccine and rabies vaccine, may cause ADEM.

The development of ADEM usually occurs over several days or a week or two. And, again, the disease is most common in childhood.

Symptoms and Signs

There are various neurological symptoms and signs that include headache and fever and altered mental status. A respiratory illness or a gastrointestinal disease may precede these various neurologic symptoms and signs. The level of consciousness may be impaired and the patient may be confused and even become comatose. Seizures sometimes occur. Also, there may be meningeal irritation and weakness including of the extremities. Also, there may be loss of sensation. Ataxia with unsteadiness also occurs. The optic nerve and other cranial nerves are sometimes involved and when the intracranial pressure becomes involved, accompanying symptoms also appear, such as headache and vomiting.

Diagnosis and Investigation MRI

MRI can be very helpful and quite sensitive. CT scans may be used, but MRI is a superior study as compared to CT for ADEM. The MRI can detect the lesions that can be widespread in the brain, such as the white matter with the lesions occurring primarily in the cerebrum as well as other areas within the brain and spinal cord. Occasionally the lesions do not resolve entirely. However, usually there are no new lesions after six months.

CT is not as sensitive as MRI. However, it still can be helpful because it is usually quite available and may rule out other disease processes.


CSF testing refers to testing of the spinal fluid. The CSF often shows lymphocytes. The testing may also indicate that the protein is elevated but the blood glucose is normal. CSF may be tested for different viruses, and viral cultures may also be done.

Brain Biopsy

If a patient is not doing well, a biopsy of the brain may be performed.

Various other studies may also be performed, including laboratory work that could consist of chemistries and blood counts. Chest x-ray and urinanalysis and an electroencephalogram (EEG) could also be investigated.


Antibiotics may be used if there is a consideration of a bacterial infection and acyclovir can be used when considering herpes simplex virus causing an encephalitis.

Steroids are often used such as intravenous methylprednisolone. If methylprednisolone is not sufficient treatment, then intravenous immunoglobulins may be attempted. Therapy could also include plasma exchange.

Additionally, supportive care is utilized including medication for fever and treatment with fluids and, if necessary, medication for seizures.


Complications and mortality varies. The most frequent sequelae follow measles. The most serious neurological defects occur in infants.

  • Clinical Neurology, 9th Edition, 2015
  • Hankey’s Clinical Neurology, 2nd Edition, 2014
  • The Merck Manual, 19th Edition, 2011
Client Reviews
"Phyllis Widman and her staff are the type of people you want fighting for you. They are organized, tenacious, thorough and compassionate. They understand how to work with the government and medical communities. If you are lucky to have Phyllis and her team work for you, you will be successful with your case." Bob and Ann, Waretown, NJ
"I can sit here and write you a book about how hard she works for her clients. Long story short All around great lawyer highly recommended" Anonymous
"Phyllis Widman, and staff, after years of continuous working on my behalf, keeping in touch with me every step of the way, for years, was happy to inform me that we had won the case. It wasn't easy, but she never gave up. Always answering my emails, and on top of my case. If you are looking for someone you can trust, and have faith in her and her team, will try very hard to get the right and fair results for you." Jim S.
"I hired Phyllis Widman to assist me with the denial of my religious exemption for the COVID vaccine and employment termination by my employer. Phyllis was extremely knowledgeable and clearly explained to me about my legal rights and the legal process. I found her to be very efficient, organized, and passionate about her work and I especially liked that she really cared about me as a person and truly wanted what was best for me. I am very grateful to say, I did have a successful outcome. The religious exemption denial was overturned and I am back to work. I highly recommend Phyllis Widman." Kimberly R.
"Phyllis and her team took care of everything after my injury. When I was hurt, I was unsure who to speak to, as I'm quite young and typically "let things go." After a few recommendations and the first phone call I knew I was in good hands. I don't know where I'd be right now if I didn't make that simple first phone call. A thank you just isn't enough, but thank you so so much for what your firm does." Anonymous
"My experience with Phyllis Widman was excellent. I know that I would not have had the successful outcome that I did without the expertise and specialty training of Phyllis Widman. Phyllis worked tirelessly to make sure that my concerns were addressed, and my needs were met. Phyllis is extremely personable, friendly, comforting and very relatable. She is so well versed in the field of vaccine injury law. I am extremely fortunate to have found Phyllis for my case and would highly recommend her to anyone in search of a truly compassionate professional." Kristen M.