Public Release: 

Mechanism behind stuttering revealed

N. B. Please note that if you are outside North America the embargo date for all Lancet press material is 0001hours UK time 2 August 2002


Stuttering is caused by a structural abnormality in the left hemisphere of the brain, according to an article in this week's LANCET. Dr Martin Sommer and colleagues from the Universities of Hamburg and Göttingen in Germany report that persistent developmental stuttering results from a disconnection of speech-related areas in the cortex.

Persistent developmental stuttering affects 1% of people beyond puberty and has a genetic basis, but despite decades of research, the origin and structural basis of the disorder are unknown. 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 comment that: "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".


Contact: Dr. Christian Büchel, University of Hamburg, Martinstr 52, 20246 Hamburg, Germany; T) +49-40-42803-4726; F) +49-40-42803-9955; Mobile: +49-1755637407 E)

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