Abnormal neural response to phonological working memory demands in persistent developmental stuttering - NEUROCIÊNCIAS
Hum Brain Mapp. 2019 Jan;40(1):214-225. Epub 2018 Aug 26.
Yang Y, Jia F, Fox PT, Siok WT, Tan LH.
Shenzhen University, Shenzhen, China; Shenzhen Institute of Neuroscience, Shenzhen, China; University of Texas Health Science Center at San Antonio, San Antonio, Texas; University of Hong Kong, Pokfulam Road, Hong Kong.
Persistent developmental stuttering is a neurological disorder that commonly manifests as a motor problem. Cognitive theories, however, hold that poorly developed cognitive skills are the origins of stuttering. Working memory (WM), a multicomponent cognitive system that mediates information maintenance and manipulation, is known to play an important role in speech production, leading us to postulate that the neurophysiological mechanisms underlying stuttering may be associated with a WM deficit. Using functional magnetic resonance imaging, we aimed to elucidate brain mechanisms in a phonological WM task in adults who stutter and controls. A right-lateralized compensatory mechanism for a deficit in the rehearsal process and neural disconnections associated with the central executive dysfunction were found. Furthermore, the neural abnormalities underlying the phonological WM were independent of memory load. This study demonstrates for the first time the atypical neural responses to phonological WM in PWS, shedding new light on the underlying cause of stuttering.
PMID: 30145850 DOI: 10.1002/hbm.24366
A single case report of a patient with stuttering who improved after open label TMS.
Brain Stimul. 2019 Jan 19. [Epub ahead of print]
Mejías G, Prieto J.
Hospital General Universitario Gregorio Marañón, Madrid, Spain.
No abstract available.
PMID: 30704893 DOI: 10.1016/j.brs.2019.01.011
Disfluency clusters in speakers with and without neurogenic stuttering following traumatic brain injury - GAGUEIRA ADQUIRIDA
J Fluency Disord. 2019 Jan 11;59:33-51. [Epub ahead of print]
Penttilä N, Korpijaakko-Huuhka AM, Kent RD.
University of Tampere, Tampere, Finland; University of Wisconsin-Madison, Madison WI, United States.
PURPOSE: Analyze the characteristics and rate of disfluency clusters in adults with and without neurogenic stuttering after traumatic brain injury (TBI).
METHOD: Twenty adults with TBI participated in this study, including 10 with neurogenic stuttering (Group B) and 10 without -stuttering (Group A). Disfluency clusters in speech samples were classified into three types: Stuttering-like (SLD), other (OD), and mixed (MIX).
RESULTS: Speakers with and without neurogenic stuttering produced the same mean number of disfluency clusters. In addition, the mean length of clusters did not differ between these speaker groups although the longest clusters did. The most frequently occurring cluster type for people with neurogenic stuttering was MIX and OD for people without stuttering. Although the speakers in Group A produced stuttering-like disfluencies, these never occurred together to form a SLD type cluster. For Group B, the starter units of the clusters were usually stuttering-like disfluencies, while for Group A, the starter units were mostly interruptions.
CONCLUSIONS: Compared to non-stuttering speakers, stuttering after TBI did not increase the number of clusters, but rather lengthened them. In speakers with neurogenic stuttering, the number and length of clusters were related to the manifestation of other communication deficits, not to the frequency of stuttering-like disfluencies. Still, SLD clusters occurred only in those people with neurogenic stuttering. These findings raise questions about the nature of both neurogenic stuttering and the dynamics of disfluency clustering.
PMID: 30641458 DOI: 10.1016/j.jfludis.2019.01.001
Dissociating motor-speech from lexico-semantic systems in the left frontal lobe: insight from a series of 17 awake intraoperative mappings in glioma patients - NEUROCIÊNCIAS
Brain Struct Funct. 2019 Jan 14.. [Epub ahead of print]
Corrivetti F, de Schotten MT, Poisson I, Froelich S, Descoteaux M, Rheault F, Mandonnet E.
Lariboisière Hospital, APHP, Paris, France; Université Paris, Paris, France; Université de Sherbrooke, Sherbrooke, Canada.
Functional brain mapping during awake surgery procedures is the gold standard technique in the management of left frontal lobe tumors. Nevertheless, a unified picture of the language subsystems encountered during left frontal lobe mapping is still lacking. We retrospectively analyzed the 49 cortical and the 33 axonal sites of functional language mapping performed in 17 patients operated for a left frontal lobe glioma under awake conditions. Sites were tagged on the postoperative MRI, based on anatomical landmarks and intraoperative photography. All MRIs and tags were then registered in the MNI template. Speech disturbances related to motor functions (speech arrest-with or without superior limb arrest-, stuttering, and vocalization) were grouped together as "motor-speech" responses. Anomias, semantic paraphasia, perseverations, and PPTT errors were classified as "lexico-semantic" responses. MNI-registered axonal sites were used as seed for computing disconnectome maps from a tractogram atlas of ten healthy individuals, as implemented in the BCB toolkit. The cortical distribution of lexico-semantic responses appeared to be located anteriorly (pars triangularis of the inferior frontal gyrus and posterior end of the middle and superior frontal gyrus) compared to motor-speech responses (lower end of the precentral gyrus and pars opercularis). Within the white matter, motor-speech responses and lexico-semantic responses overlapped on the trajectory of the aslant and fronto-striatal tracts, but the lexico-semantic sites were located more anteriorly (mean Y coordinate on the MNI system was 21.2 mm for lexico-semantic sites and 14.3 mm for the motor-speech sites; Wilcoxon test: W = 60.5, p = 0.03). Moreover, disconnectome maps evidenced a clear distinction between the two subsystems: posterior fronto-striatal and frontal aslant tracts, corpus callosum and cortico-spinal tract were related to the motor-speech sites, whereas anterior frontal aslant tract, inferior-fronto-occipital fasciculus (IFOF) and anterior thalamic radiations were related to the lexico-semantic sites. Hence, we evidenced distinct anatomical substrates for the motor-speech and lexico-semantic systems. Regarding the aslant/fronto-striatal system, an anterior to posterior gradient was found, with a lexico-semantic role for the anterior part and a motor-speech involvement for the posterior part. For tumors abutting the precentral sulcus, posterior boundaries of the resection are made of motor-speech sites, meaning that the anteriorly located lexico-semantic system is no more functional, as a result of network reorganization by plasticity.
PMID: 30637492 DOI: 10.1007/s00429-019-01827-7
Novel PANK2 mutation in a Chinese boy with PANK2-associated neurodegeneration: A case report and review of Chinese cases.- GENÉTICA
Medicine (Baltimore). 2019 Jan;98(4):e14122.
Zhang Y, Zhou D, Yang T.
West China Hospital, Sichuan University, Chengdu, China
RATIONALE: Pantothenate kinase-associated neurodegeneration (PKAN), also called Hallervorden-Spatz Syndrome (HSS), is a rare neurodegeneration with brain iron accumulation from pantothenate kinase 2 gene (PANK2) mutation characterized as extrapyramidal symptoms. However, few studies involving PKAN patients were reported in China. This study was conducted to identify the genetic mutations in a Chinese boy with PKAN, and to review all PANK2 mutations reported in Chinese cases with PKAN.
PATIENT CONCERN: We reported a 23-year-old Chinese boy with PKAN, exhibiting difficulty in writing and manipulation using right hand with slow progression for 12 years. He spoke with a severe stutter when he was 15 years old.
DIAGNOSIS: Considering results of magnetic resonance images, brain computed tomography and medical history, the case was suspected to be related to genetic factors.
INTERVENTIONS: Whole exome sequencing was arranged, and the mutations were identified in his parents' genome.
OUTCOMES: In the present study, whole exome sequencing revealed 2 novel mutations (c.1696C > G in exon 7 and c.1160_c.1161insG in exon3) of the PANK2 gene in the proband. c.1696C > G and c.1160_c.1161insG, respectively, were confirmed in his father and mother. We also reviewed 14 different PANK2 mutations, most of which were missense type in Chinese cases. Those mutations did not show apparent hotspots, but exon 3 and 4 were frequently involved.
LESSONS: Two novel compound heterozygous mutations were identified and considered to be pathogenic in PKAN patients. This review of the reports indicated that atypical PKAN is the more common phenotype in China and no apparent genotype-phenotype correlation was found.
PMID: 30681573 DOI: 10.1097/MD.0000000000014122
The lived experience of stuttering: a synthesis of qualitative studies with implications for rehabilitation - TERAPIA
Disabil Rehabil. 2019 Jan 29:1-11. [Epub ahead of print]
Connery A, McCurtin A, Robinson K.
University of Limerick , Limerick , Ireland; HSE Dublin South West , Dublin , Ireland.
PURPOSE: Stuttering is a chronic communication disorder resulting in challenging life experiences for many individuals. This review aimed to integrate qualitative findings on the lived experiences of people who stutter and identify implications for rehabilitation.
MATERIALS AND METHODS: A systematic literature search of electronic databases for studies published since 2000 was completed to identify research papers that used qualitative methods to explore the lived experiences of adults who stutter. Forty-five papers were read in full and a final seventeen papers were synthesised using a meta-ethnographic approach.
RESULTS: Five themes are described: (i) Avoidance is used to manage stuttering; (ii) Stuttering unfavourably impacts employment experiences; (iii) Stuttering shapes self-identity; (iv) Stuttering leads to negative reactions; and (v) Stuttering impacts relationships adversely.
CONCLUSIONS: This review identifies the profound and predominantly negative impact that stuttering has on individuals' experiences. Avoidance is a commonly used strategy to manage stuttering with further negative consequences for the individual. To promote person-centred care and enhance treatment outcomes, clinicians should be cognizant of the profound impact of stuttering on the individual's life experience and incorporate targeted goals to reflect this when intervening.
IMPLICATIONS FOR REHABILITATION Clinicians should be aware of and understand the extent of the impact of stuttering on an individual's life which is typified by various forms of avoidance and challenges in a number of domains including employment, identity formation, relationship development and others' perceptions of the person who stutters. An impairment-based approach to stuttering treatment with adults focusing on the overt aspects of stuttering (i.e., speech behaviours) is not holistic and does not do justice to the spectrum of covert features such as avoidance, and internalised thoughts and feelings that are associated with the condition. Therefore, the adoption of a holistic approach to stuttering intervention is recommended. An understanding of adults' lived experience of stuttering has the potential to inform programme developments for children and adolescents with the same condition and thus employ preventative strategies to reduce the development of negative life experiences at an earlier age. Clinicians should engage with the field of disability studies to strengthen their practice and consider their role in addressing socially-imposed barriers such as negative attitudes impacting on people who stutter.
PMID: 30696288 DOI: 10.1080/09638288.2018.1555623