Regional cerebral blood flow in developmental stutterers
K. D. Pool, Sr. Devous MD, F. J. Freeman, B. C. Watson and T. Finitzo
Neuroscience Research Center, University of Texas, Southwestern Medical Center, Dallas.
Stuttering is a poorly understood communication disorder with a 1% global
prevalence. Recently, there has been a resurgence of interest in a
neurogenic origin for the disorder, although no research has established
clear neurological differences between "developmental" (stuttering onset in
childhood) stutterers and nonstutterers. We have used xenon 133
single-photon emission computed tomography to study regional cerebral blood
flow (rCBF) in 20 stutterers. Analysis revealed global, absolute flow
reductions. Relative flow asymmetries (left less than right) were
identified in three hemispheric regions: anterior cingulate and superior
and middle temporal gyri. Milder changes were found in the left inferior
frontal gyrus. Stutterers had rCBF values below median for either anterior
cingulate or middle temporal gyri. With one exception, severe stutterers
had rCBF values below median for the anterior cingulate gyrus. All
stutterers with rCBF values above median in the cingulate gyrus had rCBF
values below median in the middle temporal gyrus, and severity of their
disorder was either mild or moderate. Our findings suggest that stuttering
is a neurogenic disorder involving recognized cortical regions of
speech-motor control.
