Unknown Cause of Childrens' Neurologic Illness with Paralysis

The CDC is working closely with the Colorado Department of Public Health and Environment (CDPHE) and Children’s Hospital Colorado to investigate a cluster of nine pediatric patients hospitalized with acute neurologic illness of undetermined etiology. The illness is characterized by focal limb weakness and abnormalities of the spinal cord gray matter on MRI. These illnesses have occurred since August 1, 2014, coincident with an increase of respiratory illnesses among children in Colorado. The CDC is working to provide awareness of this neurologic syndrome under investigation with the aim of determining if children with similar clinical and radiographic findings are being cared for in other geographic areas.


The Children’s Hospital Colorado (CDPHE), and the CDC are investigating nine cases of acute neurologic illness among pediatric patients. The cases were identified between August 9 and September 17, 2014, among children aged one to 18 years (median age ten years). Most of the children were from the Denver metropolitan area. All were hospitalized.


Common features included acute focal limb weakness and specific findings on magnetic resonance imaging (MRI) of the spinal cord consisting of non-enhancing lesions largely restricted to the gray matter. In most cases, these lesions spanned more than one level of the spinal cord. Some also had acute cranial nerve dysfunction with correlating non-enhancing brainstem lesions on MRI. None of the children experienced altered mental status or seizures. None had any cortical, subcortical, basal ganglia, or thalamic lesions on MRI.


Most children reported a febrile respiratory illness in the two weeks preceding development of the neurologic symptoms. In most cases, cerebrospinal fluid (CSF) analyses demonstrated mild-moderate pleocytosis (increased cell count in the CSF) consistent with an inflammatory or infectious process. CSF testing to date has been negative for West Nile virus and enteroviruses, including poliovirus. Nasopharyngeal specimens were positive for rhinovirus/enterovirus in six out of eight patients that were tested. Of the six positive specimens, four were typed as EV-D68, and the other two are pending typing results. Testing of other specimens is still in process. Eight out of nine children have been confirmed to be up to date on polio vaccinations.


The United States is currently experiencing a nationwide outbreak of EV-D68 associated with severe respiratory disease. The possible linkage of this cluster of neurologic disease to this large EV-D68 outbreak is part of the current investigation. From mid-August to September 29, 2014, the CDC or state public health laboratories have confirmed a total of 443 people in 40 states and the District of Columbia with respiratory illness caused by EV-D68.


In August 2014, hospital officials in Kansas City, Missouri, and in Chicago, Illinois, notified the CDC of an increase in severe respiratory illness among children seen in the emergency rooms and admitted to the hospitals in those two cities. Specimens initially tested positive for rhinovirus and enterovirus. The CDC did further testing and identified Enterorvirus 68 in specimens from patients in hospitals in both Kansas City and Chicago. EV- D68 was identified in 19 of 22 specimens from Kansas City and 11 of 14 specimens from Chicago. Ages ranged from six weeks to 16 years with a median of four to five years. Well over half of the children in those two clusters had a previous history of asthma or wheezing. The CDC is working closely with Missouri, Illinois and other state health departments as they continue to investigate suspected clusters of respiratory illness in other facilities.


Enteroviruses in general are very common. There are more than 100 different types of enteroviruses, and it is estimated that 10 to 15 million enterovirus infections occur in the United States each year. Enteroviruses can cause respiratory illness, but they can also cause rashes and neurologic illnesses as well as aseptic meningitis. Most infected people have no symptoms or only mild symptoms but some infections with different enteroviruses can be serious. Infants, children and teenagers are most likely to get infected with enteroviruses and become sick, as opposed to adults with exposure to this virus.


Signs for parents to worry about in children are difficulty breathing and wheezing. That is the warning sign for parents. Runny nose and the sniffles are not unexpected and can be caused by many different things. If looks like a child is having difficulty breathing, seek medical help immediately.


Based on how EV-D68 is spreading, the CDC thinks that it is important to follow these common sense steps:


  • Washing hands often with soap and water for 20 seconds

  • Disinfecting frequently touched surfaces like toys and doorknobs, especially if someone in the home is ill

  • Avoiding touching eyes, nose and mouth with unwashed hands because something on the hands may enter the body through the eyes, nose, or mouth

  • Avoiding sharing utensils with people who are sick


While there is no vaccine for enterovirus that will prevent this and other respiratory infections, the CDC reminds readers that flu vaccination is going to be available soon, and preventing other respiratory infections can be important to protect people from the many other infections that are likely to be spreading.


The Center for Infectious Disease Research and Policy at the University of Minnesota noted that the Colorado cases show apparent parallels to between 20 and 25 reported, suspected cases of a polio-like illness in a cluster of children from California over a one-year period. This cluster was reported in a case report by Keith Van Haren, MD, with Stanford University in Palo Alto, California, and Emanuelle Waubant, MD, with the University of California-San Francisco at the annual meeting of the American Academy of Neurology (AAN). Dr. Van Haren stated, “In the past decade, newly identified strains of enterovirus have been linked to polio-like outbreaks among children in Asia and Australia. These … cases highlight the possibility of an emerging infectious polio-like syndrome in California.” The case report included cases if the children had paralysis affecting one or more limbs with abnormal MRI scans of the spinal cord that explained the paralysis.


The five children originally discovered in California experienced paralysis of one or more arms or legs that came on suddenly and reached the height of its severity within two days of onset. Three of the children had a respiratory illness before the symptoms began. All of the children had been previously vaccinated against poliovirus. The children were treated but their symptoms did not improve and they still had poor limb function after six months. Two children tested positive for enterovirus-68, a rare virus previously associated with polio-like symptoms. No cause was identified in the remaining three children, according to the AAN report.


The CDC is seeking information about other similar neurologic illnesses in all states, especially cases clustered in time and place. The CDC has particular interest in characterizing the epidemiology and etiology of the cases. Patients who meet the following case definition should be reported to state and local health departments:


  • Patients 21 years of age or younger with

  • Acute onset of focal limb weakness occurring on or after August 1, 2014; AND

  • An MRI showing a spinal cord lesion largely restricted to gray matter.


See the CDC Health Advisory


See the CDC’s National Center for Immunization and Respiratory Diseases Investigation Report


See the CDC’s Enterovirus D68 Outbreak Report


See the Center for Infectious Disease Research and Policy Article


See also Medical Law Perspectives, January 2013 Report: Vaccines: An Ounce of Prevention May Lead to a Pound of Injury