Subacute sclerosing panencephalitis

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at September 24, 2016
StartDiseasesSubacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (subacute sclerosing panencephalitis) is a deadly brain disease related to the measles infection. A rare disease, it is an abnormal response from the immune system that leads to inflammation of the brain.


Definitions & Facts

Subacute sclerosing panencephalitis is incapacitating and progressive. Under normal circumstances, the immune system can fight off measles. In rare cases, the immune system can have an irregular response to the infection for a variety of reasons which causes brain inflammation (encephalitis).

Subacute sclerosing panencephalitis mostly affects children and young adults. It is relatively rare in developed countries with adequate health care infrastructure where the measles vaccine is more readily available. One cannot develop subacute sclerosing panencephalitis without having had the measles infection sometime prior.

Statistics show that this infection affects males more than females, and most people who develop subacute sclerosing panencephalitis have a history of measles at an early age. Most people diagnosed with this condition die within one to three years following diagnosis. Rarely, the condition progresses rapidly and results in death in a much shorter time.

Symptoms & Complaints

After having the measles, it may take years to see any signs of subacute sclerosing panencephalitis. Over a period of six to fifteen years (on average), patients notice a variety of symptoms that do not appear all at once. Usually, these symptoms are gradual. Symptoms may include:

The progression of subacute sclerosing panencephalitis is defined by two stages. During stage one, the patient's behavior may become progressively strange. They may become irritable or suffer from dementia symptoms. Since the brain infection affects the central nervous system, the patient may lose control of movement.

During stage two, the intensity of movement loss becomes more severe and mental deterioration is more noticeable. The person may even lose the ability to walk and the ability to speak properly. They may also have difficulty swallowing (dysphagia). The final stages can involve blindness or coma. A persistent vegetative state may ensue.


The exact cause of subacute sclerosing panencephalitis is under debate, and no definitive scientific conclusions have been made. Most believe that subacute sclerosing panencephalitis is caused by an abnormal response by the immune system to the measles virus. This response to the measles virus causes swelling that affects both the brain and spine. It gradually breaks down nerve cells because of the constant swelling the condition causes. One theory is that this abnormal response is triggered by a mutated form of the measles virus.

Getting the measles infection at an age under two increases a person's risk, along with not being vaccinated. Males are more likely to have this condition.

Diagnosis & Tests

Upon presentation of symptoms during a doctor's visit, a physician may recommend physical examinations to reveal the following: damage to the optic nerve, damage to the retina, muscle twitching, or poor performance on coordination tests. In addition to basic physical exams, a doctor may also recommend:

More than likely, some of these tests may be done multiple times to see progression or changes in the brain. If the serum antibody titer shows signs of a previous measles infection, the other tests are highly recommended, as measles is the precursor to subacute sclerosing panencephalitis.

Treatment & Therapy

Currently, there is no cure for subacute sclerosing panencephalitis. However, there are treatments being tested that may slow the condition's progression although this is still being researched through clinical trials. Antiviral drugs can sometimes reduce the symptoms of subacute sclerosing panencephalitis.

Most care provided for the patient is in giving comfort. Anticonvulsants may help reduce symptoms and antispasmodics can reduce twitching and spasms associated with subacute sclerosing panencephalitis. Assistive devices, physical therapy, occupational therapy, psychotherapy, and speech therapy all may be utilized in improving a patient's quality of life. In advanced stages, nursing care may be necessary, as the patient could need feeding tubes or may have lost the ability to move or function.

Prevention & Prophylaxis

The only known prevention of subacute sclerosing panencephalitis is the prevention of measles. Since measles is the precursor of subacute sclerosing panencephalitis, getting vaccinated against the measles virus is the only definitive method of preventing subacute sclerosing panencephalitis.

The vaccine has been enormously effective in reducing the number of people affected by measles. This immunization is usually given in the form of the MMR vaccine and should be done according to the recommended immunization schedule provided by the Centers for Disease Control.

Young children, since they are especially susceptible, should get this vaccine as soon as possible. The vaccine is also available to adults who are not immunized.