A dysfunctional cerebellum leads to implicit learning deficits in children with Duchenne muscular dystrophy (DMD), Italian researchers have suggested.
Their study, “Implicit learning deficit in children with Duchenne muscular dystrophy: Evidence for a cerebellar cognitive impairment?” appeared in the journal PLoS ONE.
DMD is an inherited disease caused by genetic mutations on the DMD gene, which encodes the dystrophin protein. These mutations are the cause of all clinical features of this disease, as well as for cognitive deficits reported since Duchenne was first described in 1868.
Some studies have suggested that intellectual disorders in DMD patients may be linked to dysfunction of the cerebellum. Although this region of the brain is mainly associated with movement control and balance, it might also control cognitive functions such as language, abstract reasoning, emotions and logic.
To better understand the cerebellum’s relationship to DMD, a group of Italian researchers evaluated 32 boys diagnosed with the disease and 37 age-matched volunteers using the Serial Reaction Time task. This test can analyze implicit sequence learning capacity while showing the cerebellum’s role in this function.
None of the children had global intellectual disability, though DMD boys were found to have poorer implicit learning of a temporal sequence of events than the control group. This finding may help explain why DMD individuals may have difficulties with speech, general learning and concentration.
A subgroup analysis failed to show any correlation between the position of the boys’ mutations and the implicit learning they presented. This result confirms that all DMD children had an implicit learning deficit and emphasizes a “possible role of dystrophin in the brain,” the researchers said.
These findings provide “further evidence of the involvement of specific aspects of cognitive function in DMD,” said researchers, adding that “this deficit may be interpreted as the expression of a dysfunction of the cerebellum.”