It’s been long known that many children with autism also have epilepsy or some form of seizure disorder. Not so well understood was the relationship between the two.
But a new Penn study suggests that early life seizures may switch on synapses in the brain that can lead to further developmental delays in children with autism and other intellectual disorders.
The good news is that aggressively treating those seizures — with medicines that already exist or new treatments being developed — may keep those synapses “silent” and allow the brain to develop more normally.
“We now have evidence that seizures appear to be worsening the developmental disorder, and when you block those seizures, you reverse that,” said senior author Frances Jensen, chair of neurology at Penn’s Perelman School of Medicine.
“It appears seizures may exacerbate features common in autism,” said Jensen, whose research conducted with colleagues from Harvard and Carleton University was published online in the journal Cell Reports.
According to 2014 data from the Centers for Disease Control and Prevention, autism has a prevalence rate of 1 in 59 among 8-year-olds in 11 states surveyed, a 15 percent increase from 2012.
Up to 40 percent of children with autism and intellectual disabilities also have epilepsy, and about 35 percent of children who experience infantile spasms develop long-term intellectual disabilities, including autism, according to the researchers.
The study findings build on what is already known about brain development. During early childhood, the brain goes through so-called critical periods where synapses linked to language skills are activated gradually. But if the synapses are activated or “unsilenced” prematurely through seizures, they are less available for learning during those critical periods, the researchers said.
Working with mice, Jensen and her colleagues found that premature activation of the synapses through induced seizures created a disruption days later during a critical period of development for the mice.
The researchers treated the seizure-induced mice with an anti-epileptic, anti-convulsant drug that reduced the premature “unsilencing” of certain synapses and helped restore them, making them available when the mice entered a critical learning period later.
