Photosensitivity Rate Unexpectedly High with Autism-Epilepsy Co-morbidity
December 5, 2011
Epilepsy is common in children with autism spectrum disorder (ASD). A new study indicates their epilepsy can be surprisingly photosensitive as well. Photosensitivity in children with epilepsy alone is reported to range from 2-14%. A pilot study to determine the incidence of photosensitivity in children with ASD has found a significant and unexpected higher rate of nearly 30% photosensitivity in adolescents with epilepsy and autism co-morbidity. The study was presented at the American Epilepsy Society's 65th annual meeting and is the first report of this marked difference in response to intermittent photic stimulation.
Investigators at Children's Hospital Boston reviewed the records of children diagnosed with ASD between December 2010 and May 2011. Those given an EGG prior to or during the search period were included in the study. The EEG reports were examined to determine the presence or absence of a photoparoxysmal response (PPR), which is abnormal waves in the brain in response to intermittent photic stimulation, like flashing lights.
"Our study found a high overall incidence of photosensitivity in 25 percent of children over 15 years of age with autism spectrum disorder, and an even higher rate of 29.4 percent in that age group of children who had both epilepsy and autism," says lead author Jill Miller-Horn. "This finding has not been previously reported."
Children in the study ranged from 1 to 23 years of age. "When you subdivided the children with autism by age, we found there's an increased in PPR as they entered adolescence," says Dr. Miller-Horn. "The meaning of this is unclear right now. This is a new finding that may be a clue to some of the pathophysiology for children with ASD. There may be a brain irritability or a hypersensitivity in the brain of children with autism that's being revealed with this clue."
Dr. Miller-Horn noted the relatively small size of the study. "Larger scale prospective studies are needed to confirm this trend," she said. "Further study is also needed to identify the importance of these findings in the pathophysiology of epilepsy in children with autism spectrum disorder." Dr. Miller-Horn also noted this study does not provide enough information to make a recommendation to the general public regarding children with autism receiving an EEG or limiting their activities.
Featured in the picture are Masanori Takeoka and Jill Miller-Horn.
Photo take by Shelly Williams