Stuttering is caused by reduced blood flow to an area of the brain associated with language, scientists have revealed.
A new study by researchers at Children’s Hospital Los Angeles (CHLA) discovered that people who stuttered had reduced blood flow to the Broca’s area - the region in the frontal lobe of the brain linked to speech production.
Those with more severe stuttering had even greater reductions in blood flow to this region, they found.
Experts labelled the findings as “a critical mass of evidence” towards the causes of stuttering.
Stuttering, also known as stammering, is a relatively common speech problem in childhood, which can persist into adulthood.
According to the NHS, roughly one in 20 young children will go through a phase of stammering and around four in five will grow out of it.
Among adults, it’s estimated that one in 100 will stutter, with men being four times more likely to experience it.
While it was previously thought that developmental and inherited factors may have been the cause, this latest study adds to an existing body of findings that it is, in fact, linked to the brain circuits controlling speech production.
First author of the study, Jay Desai, a clinical neurologist at CHLA, said: “Blood flow was inversely correlated to the degree of stuttering - the more severe the stuttering, the less blood flow to this part of the brain.”
He added that the findings were “quite striking”.