Monday, December 03, 2007

Autism and the Fever Effect

Is there a fever effect in children with autism? Can a fever temporarily offer some temporary improvement to autistic children? Some parents have thought they actually noticed such a beneficial effect from fever when their autistic children were young. I know in the past I thought I saw such an effect from fever with Conor but I thought it was just my imagination. Now, a study published in Pediatrics, suggests there may in fact be something to it; a fever may have a beneficial effect on autistic children.

In Behaviors Associated With Fever in Children With Autism Spectrum Disorders Laura K. Curran, Craig J. Newschaffer, Li-Ching Lee, Stephen O. Crawford, Michael V. Johnston, and Andrew W. Zimmerman studies 30 autistic children aged 2-18 during and after an episode of fever and documented improvements in behavior. The researchers found less "aberrant" behavior in terms of irritability, hyperactivity, stereotypy and inappropriate speech. The study authors are careful to point out several limitations in the study including possible information bias arising from data collection by parent reports and possible selection bias resulting from participation by a small fraction of eligible families from recruitment sources and make suggestions for reducing these possible biases in future studies. They clearly indicate that further study is needed to prove conclusively that the improvements are fever-specific effects. The study offers several possible biological mechanism explanations for the effects involving immunologic and neurobiological pathways, intracellular signaling, and synaptic plasticityL:

(1) neurobiological effects of selected proinflammatory16 and/or antiinflammatory cytokines, which have been found to be increased in cerebrospinal fluid (in the absence of fever) and postmortem brain tissue of individuals with autism17 and may be generated during different phases of responses to fever, (2) modification of neuronal and synaptic function secondary to variations in body temperature that influence neural conduction velocities or synaptic transmission,18 (3) modification of dynamic neural networks as a result of changes in cellular signal transduction and gene transcription that regulate synapse formation and function,19 (4) increased production of other stress-related proteins, such as heat-shock proteins, during fever that might modify energy consumption and mitochondrial activity,20 and (5) stimulation of the hypothalamic-pituitary-adrenal axis leading to modifications of neurotransmitter production and interaction.

The Fever Effect may or may not be confirmed in future studies but it is another interesting new development in the Autism Knowledge Revolution.

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