Researchers have suggested that an existing drug may stop epileptic seizures leading to autism.
A team at Boston Children’s Hospital in the US has found that seizures over-activate a biochemical pathway previously linked to autism. Known as the mTOR pathway, it alters the fast-forming circuitry in infants’ developing brains.
The researchers used a rat model to show that early seizures not only resulted in epilepsy later in life, but often went on to produce autistic-like behaviours in children. Around 40 per cent of people with autism also have epilepsy.
The study found that disabling the brain’s mTOR pathway by administering the drug rapamycin before and after seizures prevented the development of abnormal patterns of connections (synapses) between brain cells. This reduced seizures in later life and may prevent autism from developing in children. The drug has already been shown to be safe in children.
The study found that the mTOR pathway increased in activation after a seizure, boosting signaling in the brain beyond levels that normally occur early in life. This disrupted the balance of synapse and circuit development, leading to epilepsy and altered social behaviour.
Frances Jensen, Professor of Neurology and the research team leader, said: “In children, there is overlap between epilepsy and autism and epilepsy early in life has been linked to later autism.”
She added: “Our findings show one of many pathways that are involved in this overlap – importantly, one that is already a therapeutic target and where treatment can reverse the later outcome.”
The mTOR pathway has already been known to be over-active in tuberous sclerosis complex (TSC), a genetic disorder that often includes epilepsy and autism. Boston Children’s Hospital is currently conducting a clinical trial of rapamycin in children with TSC.
Jensen explained: “Our study suggests that even without tuberous sclerosis, seizures are inducing the mTOR pathway and might on their own be contributing to the development of autism.”
She said that blocking the mTOR pathway briefly after the initial seizures may reduce the risk of later epilepsy and autism.
The professor pointed to the way seizures and autism can interact in a child’s early development and said: “This research also suggests that the fields of epilepsy and autism may inform each other about new treatment targets.”
Published: 10 May 2012
