8 Children Hospitalized for Possible Rare Nervous System Disorder

— -- Federal and state health officials are investigating a possible cluster of a rare nervous system disorder after multiple children reported symptoms, including weakness or loss of movement in one or more limbs.

Eight children in the Washington state were hospitalized recently for symptoms that matched a rare condition called acute flaccid myleititis (AFM). It is condition that affects the nervous system, specifically the spinal cord, and can occur due to various causes, including the polio virus.

Experts at the U.S. Centers for Disease Control and Prevention as well as the Washington State Health Department are still evaluating if these children's symptoms point to AFM as an "exact cause" and other conditions are being investigated as well, according to the Washington State Health Department.

"None of them have been confirmed or ruled out," department spokeswoman Julie Graham told ABC News.

"At this point there isn’t evidence that would point to a single source of illness among these cases," Dr. Scott Lindquist, state infectious disease epidemiologist at the Department of Health, said in the statement on Friday.

All of the children, between the ages of 3 to 14, reported a loss of strength or movement in one or more limbs. Three of the children remain hospitalized and five have been released, according to the state health department.

Since AFM can be caused by a viral infection, officials at Seattle Children's Hospital have taken steps to minimize the risk of infection among patients.

"At Seattle Children’s, patient safety is our top priority and parents should rest assured that it is safe to bring their children to the hospital," Dr. Mark Del Beccaro, chief medical officer at Seattle Children’s Hospital, said in a statement. "We are following our standard infection control protocols, including putting patients with symptoms of active respiratory infections in isolation so they do not have contact with any other patients."

The CDC was already investigating an increase of AFM cases in the U.S., with at least 50 cases reported by last August compared to 21 cases in all of 2015. In 2014, 120 cases of AFM were reported throughout the U.S. just between August and December. At the time, the CDC and other health agencies were investigating if a virus called enterovirus D68 was linked to the increase in cases. Enterovirus D68 spread rapidly in 2014 and infected many children. Some of the children developed AFM, but the CDC has not "consistently detected a pathogen" in the spinal fluid of infected patients, making the cause impossible to pinpoint.