Investigation of Risperidone Treatment Associated With Enhanced Brain Activity in Patients Who Stutter.

Gerald A Maguire,Shahriar Sheikhbahaei,Bo Ram Yoo

doi:10.3389/fnins.2021.598949

Abstract

Stuttering is a childhood onset fluency disorder that leads to impairment in speech. A randomized, double-blinded placebo-controlled study was conducted with 10 adult subjects to observe the effects of risperidone (a dopamine receptor 2/serotonin receptor 2 antagonist) on brain metabolism, using [18F] deoxyglucose as the marker. At baseline and after 6 weeks of taking risperidone (0.5–2.0 mg/day) or a placebo pill, participants were assigned to a solo reading aloud task for 30 min and subsequently underwent a 90-min positron emission tomography scan. Paired t-tests were performed to compare the pre-treatment vs. post-treatment in groups. After imaging and analysis, the blind was broken, which revealed an equal number of subjects of those on risperidone and those on placebo. There were no significant differences in the baseline scans taken before medication randomization. However, scans taken after active treatment demonstrated higher glucose uptake in the specific regions of the brain for those in the risperidone treatment group (p < 0.05). Risperidone treatment was associated with increased metabolism in the left striatum, which consists of the caudate and putamen, and the Broca’s area. The current study strengthens previous research that suggests the role of elevated dopamine activity and striatal hypometabolism in stuttering. We propose that the mechanism of risperidone’s action in stuttering, in part, involves increased metabolism of striatal astrocytes. We conclude that using neuroimaging techniques to visualize changes in the brain of those who stutter can provide valuable insights into the pathophysiology of the disorder and guide the development of future interventions.

Highlights

Stuttering is a neurodevelopmental disorder characterized by frequent disruptions during speech, silent blocks, and repetitions or prolongations of sounds and syllables (Maguire et al, 2020)
Treatment efficacy, determined by %SS, was significantly higher in the risperidone treatment group compared to the placebo group (p = 0.025) for the original study sample (Maguire et al, 2000a)
Data presented in this study suggest that risperidone treatment is associated with increased activity of the striatum and Broca’s area in persons who stutter

Summary

Introduction

Stuttering is a neurodevelopmental disorder characterized by frequent disruptions during speech, silent blocks, and repetitions or prolongations of sounds and syllables (Maguire et al, 2020). Risperidone Brain Activity Stuttering (Maguire et al, 2020). Those with developmental stuttering generally exhibit symptoms by the age of six and about 65–85% recover from dysfluency by the age of 16 (Maguire et al, 2020). Twin and family studies have shown that genetics may account for about 50–80% of stuttering, with a higher concordance for stuttering in monozygotic twins than dizygotic twins and a higher risk of stuttering in those with affected first degree biological relatives (Yairi and Ambrose, 2013)

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