A team of neurobiologists and psychiatrists at Columbia University Irving Medical Center (United States) has discovered that certain peculiar structures of the cerebellum could be related to different autism spectrum disorders (ASD). This ailment causes communication and interaction problems, and leads to the development of repetitive and limited behavior patterns. Its symptoms usually appear in the first two years of life. Since they are numerous and present to a different degree in each individual, specialists prefer to avoid the use of the term “autism” to encompass them, and choose to use the term autism spectrum disorders.
The cerebellum, a mass of nerve tissue at the back of the brain, processes information from other regions of the brain, sensory receptors, and the spinal cord. Its objective: to manage the balance and movements of the musculoskeletal system. But it seems that its functions go further. Recent research indicates that it participates in the cognitive function and implicit learning, the one that allows us to find out social norms even if they do not make them explicit. They are two key aspects in the development of a personality without the communication and relationship problems typical of autistics.
The cerebellum, little great unknown
Until now, studies dedicated to autism based on neuroimaging techniques ignored the cerebellum, something that is a big mistake, according to Kristina Denisova, part of the team responsible for the study. This psychiatrist explains that the cerebellum makes up only 10 percent of the brain’s volume, but contains 80 percent of its neurons: “Imagine looking at just 20 percent of the brain’s neurons and constructing a theory of atypical personality development. from such a limited knowledge ”.
To examine the cerebellum, scientists at Columbia University applied 3D fractal analysis techniques to MRI images. Without getting into cumbersome explanations: this method allowed us to calculate the fractal dimension (a measure of structural complexity) of the outer layer of the cerebellum of 20 autistic boys between six and twelve years of age, and compare it with that of boys without this disorder.
They found that autistic children had a significantly smaller fractal dimension in the right cerebellar cortex than the others, implying that the surface of that area was flatter than normal. Given that this part of the cerebellum is involved in language processing, the finding suggests that a flatter surface of this structure could be linked to the communication difficulties typical of autism spectrum disorders.
Previous research had already found some relationship between the anatomy of the cerebellum and some symptoms of autism, but the evidence was weak. Those that this work contributes are stronger. For example, it has been found that autistic boys with a more similar structure of the cerebellum to the normal have greater communication skills than those usual in those who suffer from this disorder.
This study represents a further step in the knowledge of a disease still full of mysteries for science, and that affects around 1 in 100 born in Europe, according to epidemiological studies cited by the Autism Confederation of Spain.
