Özlem Öge Daşdöğen1, Çiğdem Ulaşoğlu Yıldız2, Elif Kurt3, Tamer Demiralp4

1Fenerbahce University Faculty of Health Sciences, Department of Speech, and Language Therapy, Istanbul, Türkiye
2Istanbul University, Hulusi Behcet Life Sciences Laboratory Neuroscience Unit, Istanbul, Türkiye
3Istanbul University, Aziz Sancar Institute of Experimental Medicine, Istanbul, Türkiye
4Istanbul University, Istanbul Faculty of Medicine, Department of Physiology, Istanbul, Türkiye

Keywords: Functional magnetic resonance imaging, lower limb movement, motor movement, speech fluency, simultaneous movement, stuttering


We present an adult case with severe persistent developmental stuttering (PDS) that improved dramatically with simultaneous lower limb movements (LMs). During speaking with simultaneous lower limb movement (SLM), her stuttering severity was considerably reduced. Using functional magnetic resonance imaging (fMRI), we investigated the neural basis of speech fluency during speaking with and without simultaneous LM. Bilateral (predominantly right) peri-rolandic cortices, supplementary motor areas (SMA), right fusiform gyrus (FFG), and left frontal gyrus were activated in the SLM compared to the ‘speaking only’ (S) and LM. There might be a subtype of PDS that benefits from rhythmic LMs to improve the speech fluency. Locomotor and respiratory coupling might temporarily induce cortical timing networks and, also induce activation, predominantly in the right hemisphere with a potential pacemaker effect. Further investigation in larger groups is required to elucidate whether rhythmic simultaneous LMs improve stuttering.

Dear editor,

Stuttering is a speech disorder characterized by disruption of either involuntary speech fluency patterns (e.g., blocks, repetitions, prolongations) or various involuntary movements of the face, head, limbs, and body, which can be secondary behaviors that may accompany stuttering (1). Stuttering is not restricted to only speech-motor functions. Recently, it has been indicated that there are subtle motor deficits beyond the stuttering speech domain (2). Extensive research has been conducted on stuttering to date, but the causal mechanism of stuttering remains elusive.

We present a case of a 27-year-old right-handed, bilingual female evaluated for severe developmental stuttering. The audiometric and neurological examinations were normal. The speech samples were recorded in two conditions: speaking while sitting (Video 1) and speaking while walking (Video 2). The samples were recorded before the functional magnetic resonance imaging (fMRI) procedure and were evaluated using Stuttering Severity Instrument-3 (3). As shown in Table 1, the speech sample while walking, including the total overall score, physical concomitants, frequency score, and duration score, was dramatically reduced, respectively, relative to the total overall score of the speech sample while sitting.

Further analysis of the physical concomitants showed that distracting sounds (e.g., noisy breathing) and facial grimaces (e.g., eye blinking) were observed more frequently than other physical concomitants. The secondary behaviors, specifically eye blinking while initiating the speech, were observed mainly in condition 2 (speaking while sitting). Contrarily, secondary behaviors were significantly decreased in condition 1 (speaking while walking).

The overall dysfluency rate was 8.4% in condition 1 and 19.3% in condition 2. The distribution of the dysfluency types was also different in both conditions (Figure 1).

The fMRI procedure acquired T1-weighted structural and functional images on a 3T-MRI scanner (Philips Achieva, Best, Netherlands). The experiment included three conditions: S (speaking only), LM (left and right ankle dorsiflexion, respectively), and SLM (speaking with simultaneous lower limb movement). The case comprised two runs of three blocks containing S, LM, and SLM, respectively. There were five questions per S and SLM. In total, the patient answered 20 questions (e.g., “Talk about your job”) along with two runs (Figure 2).

Whole-brain analysis [SLM > (S + LM) contrast] revealed significantly greater activation at four clusters in the SLM compared to the total of S and LM. The most significant cluster was in the right pre-and post-central gyri and right supplementary motor area (SMA). Increased activations were also observed in the left pre-and post-central gyri and left SMA, the right fusiform gyrus, and the left middle, medial, and superior frontal gyri (Figure 3).

There is no known cure for stuttering, though many treatment approaches may assist the person who has stuttering to some degree. There might be a subtype of stuttering that benefits from rhythmic lower limb movements to improve speech fluency. Locomotor movements or walking have a potential pacemaker effect on stuttering. Knowledge of this subtype of stuttering is crucial because of the potential contribution to the stuttering treatment.

Peer Review

Externally and internally peer-reviewed.

Author Contributions

Surgical and Medical Practices: Ö.Ö-D., Ç.U-Y., E.K., Concept: Ö.Ö-D., Ç.U-Y., E.K., T.D., Design: Ö.Ö-D., Ç.U-Y., E.K., T.D., Data Collection or Processing: Ö.Ö-D., Ç.U-Y., E.K., Analysis or Interpretation: Ö.Ö-D., Ç.U-Y., E.K., T.D., Literature Search: Ö.Ö-D., Writing: Ö.Ö-D., Ç.U-Y.

Conflict of Interest

No conflict of interest was declared by the authors.

Financial Disclosure

The authors declared that this study received no financial support.


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