Dr Martin Sommer and colleagues from the Universities of Hamburg and Guettingen in Germany write that stuttering is caused by a structural abnormality in the left hemisphere of the brain. The German group used a magnetic resonance imaging technique to assess brain tissue structure in 15 people with stuttering and a control group of 15 people with normal speech.
The tissue structure of a region in the left hemisphere of the brain in stuttering patients was significantly different to that in controls. Fibre tracts in this region connect brain structures involved in the articulation and planning of speech, which could explain how disturbed signal transmission in this area prevents fluid speech production.
The authors of the study comment, 'This abnormality probably develops during the period of early language and speech acquisition, in which many children experience a transient phase of stuttering. Our methods could be used to ascertain why certain children develop persistent stuttering whereas others become fluent speakers.'
For more information on stuttering, including treatments for young children, see 'Tough talking', Nursery World, 8 November 2001.
