Speech Fluency Disorders: A Review of Studies Conducted Over the Past Five Decades (1970-2020)

Background: Speech fluency disorder(SFD), a common disorder is reported in all age groups of people but most commonly in children around the world.

Objective: This study aimed to review critically several aspects of SFD, specifically epidemiological parameters, etiological foundations, clinical and treatment perspectives.

Methods: Electronic searches of relevant data published (1970-2020) in PubMed, MEDLINE, Google Scholar, and Science Direct databases were made using the Boolean operators and keywords and following iterative process 194 papers selected for this review.

Results: Speech fluency disorder presents in a variety of forms including acquired neurogenic and psychogenic stuttering is a complex, challenging neurological disorder. SFD is determined by diverse biopsychosocial and cultural etiologies, commonly afflicts male children at age 2-3 years compared to their counterparts (4:1 ratio). SFD manifests a variety of signs and symptoms, and up to 85% children who stutter improves spontaneously with or without intervention. Childhood developmental stuttering (CDS) persists in 1-2% of adults and persistent developmental stuttering (PDS) is again male-gender condition. Persons who stutter (PWS) are managed by non-pharmacological especially speech therapy and pharmacological interventions in particular dopamine antagonists. Gender, early intervention, chronicity, severity, language skills, and comorbid conditions mainly determine the prognosis and outcome of stuttering.

Conclusion: Extensive data concerning different perspectives of SFD is published globally, and projected better understanding of most speech disfluencies. Nonetheless, research need to be conducted to develop and provide better quality services to all PWS and to reduce the discrimination against PWS around the world.