Injury to a region of the brain involved in the processing of external and internal information in early life could help to better understand neurological conditions that later develop in children, especially autism.
Samuel Wang, PhD, of the Princeton Neuroscience Institute, New Jersey, and colleagues hypothesize that injury to the brain’s cerebellum leads to “developmental diaschisis,” which means that the loss of function in one part of the brain leads to problems in other regions.
Injury to the cerebellum at birth can make a person 36 times more likely to receive a high score on autism screening tests, the researchers wrote in Neuron. They also say that cerebellar injury causes disruptions in how other areas of the brain develop an ability to interpret external stimuli and organize internalprocesses.
“It is well known that the cerebellum is an information processor,” Wang said in a prepared statement. “Our neocortex [the largest part of the brain, responsible for much higher processing] does not receive information unfiltered. There are critical steps that have to happen between when external information is detected by our brain and when it reaches the neural cortex.
“In autism, something in that process goes wrong and one thing could be that sensory information is not processed correctly in the cerebellum,” he added.
A study published in Pediatrics in 2007 that found that individuals who experienced cerebellum damage at birth were 40 times more likely to score highly on autism screening tests. The researchers also reference studies published in 2004 and 2005 that found that the cerebellum is the most frequently disrupted brain region in people with autism.
Cerebellar research has focused principally on adult motor function. However, the cerebellum also maintains abundant connections with nonmotor brain regions throughout postnatal life. Here we review evidence that the cerebellum may guide the maturation of remote nonmotor neural circuitry and influence cognitive development, with a focus on its relationship with autism.
Specific cerebellar zones influence neocortical substrates for social interaction, and we propose that sensitive-period disruption of such internal brain communication can account for autism’s key features.