Abstract
Stuttering has been the subject of much research, nevertheless its etiology remains incompletely understood. This article presents a critical review of the literature on stuttering, with particular reference to the role of the basal ganglia (BG). Neuroimaging and lesion studies of developmental and acquired stuttering, as well as pharmacological and genetic studies are discussed. Evidence of structural and functional changes in the BG in those who stutter indicates that this motor speech disorder is due, at least in part, to abnormal BG cues for the initiation and termination of articulatory movements. Studies discussed provide evidence of a dysfunctional hyperdopaminergic state of the thalamocortical pathways underlying speech motor control in stuttering. Evidence that stuttering can improve, worsen or recur following deep brain stimulation for other indications is presented in order to emphasize the role of BG in stuttering. Further research is needed to fully elucidate the pathophysiology of this speech disorder, which is associated with significant social isolation.
Highlights
INTRODUCTIONStuttering (stammering in British English) is a speech disorder characterized by disruptions in speech motor behavior (repeated or prolonged articulatory and phonatory actions) that result in sound and syllable repetitions, audible and inaudible sound prolongations and broken words (Max et al, 2004b)
Stuttering is a speech disorder characterized by disruptions in speech motor behavior that result in sound and syllable repetitions, audible and inaudible sound prolongations and broken words (Max et al, 2004b)
Stuttering has a negative impact upon quality of life, interpersonal relationships, employment opportunities and job performance, and it is associated with significant personal financial costs (Klein and Hood, 2004; Blumgart et al, 2010; Koedoot et al, 2011; Van Borsel et al, 2011)
Summary
Stuttering (stammering in British English) is a speech disorder characterized by disruptions in speech motor behavior (repeated or prolonged articulatory and phonatory actions) that result in sound and syllable repetitions, audible and inaudible sound prolongations and broken words (Max et al, 2004b). Key differences in PWS included overactivation of motor areas (M1, SMA, cerebellar vermis, cingulate), atypical right lateralization of activity in rolandic and frontal opercula and anterior insula, and absence of auditory activations associated with self-monitoring of speech. With regards to the suppression of motor cortical 20 Hz rhythm (a MEG correlate of task-related neuronal processing), stutterers showed a right hemisphere dominant response, whereas the controls showed a left dominant response (as expected in dextral subjects) This is consistent with PET studies showing higher rCBF in right rolandic areas in stutterers compared to controls (Fox et al, 1996; Braun et al, 1997). These observations suggest that the mesothalamus is part of a speech-regulating corticomesothalamic feedback pathway
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
