New research comes to the surprising conclusion that children with autism improve when they have a fever.
Although it may have grabbed fewer headlines compared to mercury and vaccines, many parents of autistic children have noticed that when their child has a fever, the severity of their autstic traits seems to diminish. Many will have dismissed te observation as a strange quirk but now scientists say there is something to it.
The research, involving 30 children with autism spectrum disorders, is published in the December issue of the journal Pediatrics. Parents were required to observe changes in symptoms during and immediately after their child experienced a fever of 100.4oF or greater, and for seven days once the fever had cleared up.
The parents were then asked to complete standardized questionnaires designed to capture data about the childrens behaviour as the fever progressed and once they had recovered. Parents of children with autism spectrum disorders who did not experience fever were also asked to complete the same questionnaires at three set time points to act as controls in the study.
When lead researcher Dr. Andrew Zimmerman and his team analysed the data they found that over 80% of the children who experienced a fever showed some improvement in behaviour during temperature elevations. Children showed less hyperactivity, improved communication, and less irritability during a fever.
Further analysis of the results showed that the level of improvement in behaviour did not depend on the degree of the fever. If a child's temperature was over 100.4oF they often showed improvement in autistic traits but this improvement was no greater if the temperature was higher.
While it is to be expected that a child with a fever would be calmer and less hyperactive, the improvements in communication, both in terms of language and social interaction, cannot be explained purely by the child's reaction to having a fever.
When discussing the study's findings Dr. Zimmerman said: "The improvement in symptoms may mean the underlying wiring of the brain (of an autistic child) develops more normally than we have thought."
The findings seem to agree with other recent research that suggests the problem lies in how the communication systems within the brain are functioning, or rather not function, instead of with the structure of the brain itself.
Dr. Zimmerman and colleagues are at this stage unsure why a fever would improve communication within the brain and lead to improvements in functioning but they do have a theory.
During a fever the immune-system ramps up production of certain signalling chemicals known as cytokines. These chemicals direct the various components of the immune-system so that a coherent response to an invading organism is produced. Cytokines are also known to interact with the brain and nervous system so could therefore be behind the behavioural improvements seen in the children.
Dr. Zimmerman said: "We'd like to interview more families to better understand this, and at the chemical level, we'd like to have blood samples from children while they have fever to analyze what is going on."
He went on to explain that if the theory about cytokines proves to be correct then this could be a potential target for treatment since it may be possible to regulate production of specific cytokines with medications.
Source: Curran LK (2007) Pediatrics 120:1386-1392.