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Pasculli G, Busan P, Jackson ES, Alm PA, De Gregorio D, Maguire GA, Goodwin GM, Gobbi G, Erritzoe D, Carhart-Harris RL. Psychedelics in developmental stuttering to modulate brain functioning: a new therapeutic perspective? Front Hum Neurosci 2024; 18:1402549. [PMID: 38962146 PMCID: PMC11221540 DOI: 10.3389/fnhum.2024.1402549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Accepted: 05/27/2024] [Indexed: 07/05/2024] Open
Abstract
Developmental stuttering (DS) is a neurodevelopmental speech-motor disorder characterized by symptoms such as blocks, repetitions, and prolongations. Persistent DS often has a significant negative impact on quality of life, and interventions for it have limited efficacy. Herein, we briefly review existing research on the neurophysiological underpinnings of DS -specifically, brain metabolic and default mode/social-cognitive networks (DMN/SCN) anomalies- arguing that psychedelic compounds might be considered and investigated (e.g., in randomized clinical trials) for treatment of DS. The neural background of DS is likely to be heterogeneous, and some contribution from genetically determinants of metabolic deficiencies in the basal ganglia and speech-motor cortical regions are thought to play a role in appearance of DS symptoms, which possibly results in a cascade of events contributing to impairments in speech-motor execution. In persistent DS, the difficulties of speech are often linked to a series of associated aspects such as social anxiety and social avoidance. In this context, the SCN and DMN (also influencing a series of fronto-parietal, somato-motor, and attentional networks) may have a role in worsening dysfluencies. Interestingly, brain metabolism and SCN/DMN connectivity can be modified by psychedelics, which have been shown to improve clinical evidence of some psychiatric conditions (e.g., depression, post-traumatic stress disorder, etc.) associated with psychological constructs such as rumination and social anxiety, which also tend to be present in persistent DS. To date, while there have been no controlled trials on the effects of psychedelics in DS, anecdotal evidence suggests that these agents may have beneficial effects on stuttering and its associated characteristics. We suggest that psychedelics warrant investigation in DS.
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Affiliation(s)
- Giuseppe Pasculli
- Department of Computer, Control, and Management Engineering (DIAG), La Sapienza University, Rome, Italy
- Italian Society of Psychedelic Medicine (Società Italiana di Medicina Psichedelica–SIMePsi), Bari, Italy
| | | | - Eric S. Jackson
- Department of Communicative Sciences and Disorders, New York University, New York, NY, United States
| | - Per A. Alm
- Department of Communicative Sciences and Disorders, New York University, New York, NY, United States
- Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden
| | - Danilo De Gregorio
- IRCCS, San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Gerald A. Maguire
- School of Medicine, American University of Health Sciences, Signal Hill, CA, United States
- CenExel CIT Research, Riverside, CA, United States
| | - Guy M. Goodwin
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - David Erritzoe
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, United Kingdom
| | - Robin L. Carhart-Harris
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, United Kingdom
- Psychedelics Division, Neuroscape, University of California, San Francisco, CA, United States
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Franken MC, Oonk LC, Bast BJEG, Bouwen J, De Nil L. Erasmus clinical model of the onset and development of stuttering 2.0. JOURNAL OF FLUENCY DISORDERS 2024; 80:106040. [PMID: 38493582 DOI: 10.1016/j.jfludis.2024.106040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 12/25/2023] [Accepted: 02/11/2024] [Indexed: 03/19/2024]
Abstract
A clinical, evidence-based model to inform clients and their parents about the nature of stuttering is indispensable for the field. In this paper, we propose the Erasmus Clinical Model of Stuttering 2.0 for children who stutter and their parents, and adult clients. It provides an up-to-date, clinical model summary of current insights into the genetic, neurological, motoric, linguistic, sensory, temperamental, psychological and social factors (be it causal, eliciting, or maintaining) related to stuttering. First a review is presented of current insights in these factors, and of six scientific theories or models that have inspired the development of our current clinical model. Following this, we will propose the model, which has proven to be useful in clinical practice. The proposed Erasmus Clinical Model of Stuttering visualizes the onset and course of stuttering, and includes scales for stuttering severity and impact, to be completed by the (parent of) the person who stutters. The pathway of the model towards stuttering onset is based on predisposing and mediating factors. In most children with an onset of stuttering, stuttering is transient, but if stuttering continues, its severity and impact vary widely. The model includes the circle of Engel (1977), which visualizes unique interactions of relevant biological, psychological, and social factors that determine the speaker's experience of stuttering severity and its impact. Discussing these factors and their interaction with an individual client can feed into therapeutic targets. The model is supplemented by a lifeline casus.
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Affiliation(s)
- Marie-Christine Franken
- Department of Otorhinolaryngology and Head and Neck Surgery, Erasmus University Medical Center, Rotterdam, the Netherlands.
| | - Leonoor C Oonk
- StotterFonds, Nijkerk, the Netherlands; University of Applied Sciences, Department of Speech-Language Therapy, Utrecht, the Netherlands
| | | | - Jan Bouwen
- Department of Otorhinolaryngology and Head and Neck Surgery, Erasmus University Medical Center, Rotterdam, the Netherlands.
| | - Luc De Nil
- Department of Speech-Language Pathology, University of Toronto, Canada; Rehabilitation Sciences Institute, University of Toronto, Canada.
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Erdemir A, Walden TA, Tilsen S, Mefferd AS, Jones RM. A Preliminary Study of Speech Rhythm Differences as Markers of Stuttering Persistence in Preschool-Age Children. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2023; 66:931-950. [PMID: 36827517 PMCID: PMC10205104 DOI: 10.1044/2022_jslhr-22-00126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 09/15/2022] [Accepted: 12/01/2022] [Indexed: 05/25/2023]
Abstract
PURPOSE The purpose of this study was twofold: (a) to determine whether there are speech rhythm differences between preschool-age children who stutter that were eventually diagnosed as persisting (CWS-Per) or recovered (CWS-Rec) and children who do not stutter (CWNS), using empirical spectral analysis and empirical mode decomposition of the speech amplitude envelope, and (b) to determine whether speech rhythm characteristics close to onset are predictive of later persistence. METHOD Fifty children (3-4 years of age) participated in the study. Approximately 2-2.5 years after the experimental testing took place, children were assigned to the following groups: CWS-Per (nine boys, one girl), CWS-Rec (18 boys, two girls), and CWNS (18 boys, two girls). All children produced a narrative based on a text-free storybook. From the audio recordings of these narratives, fluent utterances were selected for each child from which seven envelope-based measures were extracted. Group-based differences on each measure as well as predictive analyses were conducted to identify measures that discriminate CWS-Per versus CWS-Rec. RESULTS CWS-Per were found to have a relatively higher degree of power in suprasyllabic oscillations and greater variability in the timing of syllabic rhythms especially for longer utterances. A logistic regression model using two speech rhythm measures was able to discriminate the eventual outcome of recovery versus persistence, with 80% sensitivity and 75% specificity. CONCLUSION Findings suggest that envelope-based speech rhythm measures are a promising approach to assess speech rhythm differences in developmental stuttering, and its potential for identification of children at risk of developing persistent stuttering should be investigated further.
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Affiliation(s)
- Aysu Erdemir
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
| | - Tedra A. Walden
- Department of Psychology, Vanderbilt University, Nashville, TN
| | - Sam Tilsen
- Department of Linguistics, Cornell University, Ithaca, NY
| | - Antje S. Mefferd
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
| | - Robin M. Jones
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
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Alm PA. The Dopamine System and Automatization of Movement Sequences: A Review With Relevance for Speech and Stuttering. Front Hum Neurosci 2021; 15:661880. [PMID: 34924974 PMCID: PMC8675130 DOI: 10.3389/fnhum.2021.661880] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 10/12/2021] [Indexed: 12/28/2022] Open
Abstract
The last decades of research have gradually elucidated the complex functions of the dopamine system in the vertebrate brain. The multiple roles of dopamine in motor function, learning, attention, motivation, and the emotions have been difficult to reconcile. A broad and detailed understanding of the physiology of cerebral dopamine is of importance in understanding a range of human disorders. One of the core functions of dopamine involves the basal ganglia and the learning and execution of automatized sequences of movements. Speech is one of the most complex and highly automatized sequential motor behaviors, though the exact roles that the basal ganglia and dopamine play in speech have been difficult to determine. Stuttering is a speech disorder that has been hypothesized to be related to the functions of the basal ganglia and dopamine. The aim of this review was to provide an overview of the current understanding of the cerebral dopamine system, in particular the mechanisms related to motor learning and the execution of movement sequences. The primary aim was not to review research on speech and stuttering, but to provide a platform of neurophysiological mechanisms, which may be utilized for further research and theoretical development on speech, speech disorders, and other behavioral disorders. Stuttering and speech are discussed here only briefly. The review indicates that a primary mechanism for the automatization of movement sequences is the merging of isolated movements into chunks that can be executed as units. In turn, chunks can be utilized hierarchically, as building blocks of longer chunks. It is likely that these mechanisms apply also to speech, so that frequent syllables and words are produced as motor chunks. It is further indicated that the main learning principle for sequence learning is reinforcement learning, with the phasic release of dopamine as the primary teaching signal indicating successful sequences. It is proposed that the dynamics of the dopamine system constitute the main neural basis underlying the situational variability of stuttering.
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Affiliation(s)
- Per A Alm
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
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