Angela T. Morgan

Procedural learning deficits in specific language impairment (SLI): a meta-analysis of serial reaction time task performance.

Meta-analysis and meta-regression were used to evaluate whether evidence to date demonstrates deficits in procedural memory in individuals with specific language impairment (SLI), and to examine reasons for inconsistencies of findings across studies. The Procedural Deficit Hypothesis (PDH) proposes that SLI is largely explained by abnormal functioning of the frontal-basal ganglia circuits that support procedural memory. It has also been suggested that declarative memory can compensate for at least some of the problems observed in individuals with SLI. A number of studies have used Serial Reaction Time (SRT) tasks to investigate procedural learning in SLI. In this report, results from eight studies that collectively examined 186 participants with SLI and 203 typically-developing peers were submitted to a meta-analysis. The average mean effect size was .328 (CI95: .071, .584) and was significant. This suggests SLI is associated with impairments of procedural learning as measured by the SRT task. Differences among individual study effect sizes, examined with meta-regression, indicated that smaller effect sizes were found in studies with older participants, and in studies that had a larger number of trials on the SRT task. The contributions of age and SRT task characteristics to learning are discussed with respect to impaired and compensatory neural mechanisms in SLI.

Neural bases of childhood speech disorders: Lateralization and plasticity for speech functions during development

Current models of speech production in adults emphasize the crucial role played by the left perisylvian cortex, primary and pre-motor cortices, the basal ganglia, and the cerebellum for normal speech production. Whether similar brain-behaviour relationships and leftward cortical dominance are found in childhood remains unclear. Here we reviewed recent evidence linking motor speech disorders (apraxia of speech and dysarthria) and brain abnormalities in children and adolescents with developmental, progressive, or childhood-acquired conditions. We found no evidence that unilateral damage can result in apraxia of speech, or that left hemisphere lesions are more likely to result in dysarthria than lesion to the right. The few studies reporting on childhood apraxia of speech converged towards morphological, structural, metabolic or epileptic anomalies affecting the basal ganglia, perisylvian and rolandic cortices bilaterally. Persistent dysarthria, similarly, was commonly reported in individuals with syndromes and conditions affecting these same structures bilaterally. In conclusion, for the first time we provide evidence that longterm and severe childhood speech disorders result predominantly from bilateral disruption of the neural networks involved in speech production.

Incidence, characteristics, and predictive factors for Dysphagia after pediatric traumatic brain injury.

Objective(1) To establish an incidence figure for dysphagia in a population of pediatric traumatic brain injury (TBI) cases; (2) to provide descriptive data on the admitting characteristics, patterns of resolution, and outcomes of children with and without dysphagia after TBI; and (3) to identify any factors present at admission that may predict dysphagia. ParticipantsA total of 1,145 children consecutively admitted to an acute care setting for traumatic brain injury between July 1995 and July 2000. Main outcome measureMedical parameters relating to dysphagia based on medical chart review. Results(1) Dysphagia incidence figure of 5.3% across all pediatric head injury admissions. Incidence figures of 68% for severe TBI, 15% for moderate TBI, and only 1% for mild brain injury. (2) Statistically significant differences were found between the dysphagic and nondysphagic subgroups on the variables of length of stay, length of ventilation, Glasgow Coma Scale (GCS), computed tomography classification, duration of speech pathology intervention, supplemental feeding duration, duration until initiation of oral intake (DIOF), duration to total oral intake (DTOF), and period of time from the initiation of intake until achievement of total oral intake (DI-TOF). (3) Significant predictive factors for dysphagia included GCS < 8.5 and a ventilation period in excess of 1.5 days. ConclusionThe provision of incidence data and predictive factors for dysphagia will enable clinicians in acute care settings to allocate resources necessary to deal with the predicted number of dysphagia cases in a pediatric population, and assist in predicting patients who are at risk for dysphagia following TBI. Early detection of patients with swallowing dysfunction will be aided by these data, in turn helping to facilitate effective medical and speech pathology intervention via assisting the reduction of medical complications such as aspiration pneumonia.

GRIN2A An aptly named gene for speech dysfunction

Objective: To delineate the specific speech deficits in individuals with epilepsy-aphasia syndromes associated with mutations in the glutamate receptor subunit gene GRIN2A. Methods: We analyzed the speech phenotype associated with GRIN2A mutations in 11 individuals, aged 16 to 64 years, from 3 families. Standardized clinical speech assessments and perceptual analyses of conversational samples were conducted. Results: Individuals showed a characteristic phenotype of dysarthria and dyspraxia with lifelong impact on speech intelligibility in some. Speech was typified by imprecise articulation (11/11, 100%), impaired pitch (monopitch 10/11, 91%) and prosody (stress errors 7/11, 64%), and hypernasality (7/11, 64%). Oral motor impairments and poor performance on maximum vowel duration (8/11, 73%) and repetition of monosyllables (10/11, 91%) and trisyllables (7/11, 64%) supported conversational speech findings. The speech phenotype was present in one individual who did not have seizures. Conclusions: Distinctive features of dysarthria and dyspraxia are found in individuals with GRIN2A mutations, often in the setting of epilepsy-aphasia syndromes; dysarthria has not been previously recognized in these disorders. Of note, the speech phenotype may occur in the absence of a seizure disorder, reinforcing an important role for GRIN2A in motor speech function. Our findings highlight the need for precise clinical speech assessment and intervention in this group. By understanding the mechanisms involved in GRIN2A disorders, targeted therapy may be designed to improve chronic lifelong deficits in intelligibility.Objective:To delineate the specific speech deficits in individuals with epilepsy-aphasia syndromes associated with mutations in the glutamate receptor subunit gene GRIN2A. Methods:We analyzed the speech phenotype associated with GRIN2A mutations in 11 individuals, aged 16 to 64 years, from 3 families. Standardized clinical speech assessments and perceptual analyses of conversational samples were conducted. Results:Individuals showed a characteristic phenotype of dysarthria and dyspraxia with lifelong impact on speech intelligibility in some. Speech was typified by imprecise articulation (11/11, 100%), impaired pitch (monopitch 10/11, 91%) and prosody (stress errors 7/11, 64%), and hypernasality (7/11, 64%). Oral motor impairments and poor performance on maximum vowel duration (8/11, 73%) and repetition of monosyllables (10/11, 91%) and trisyllables (7/11, 64%) supported conversational speech findings. The speech phenotype was present in one individual who did not have seizures. Conclusions:Distinctive features of dysarthria and dyspraxia are found in individuals with GRIN2A mutations, often in the setting of epilepsy-aphasia syndromes; dysarthria has not been previously recognized in these disorders. Of note, the speech phenotype may occur in the absence of a seizure disorder, reinforcing an important role for GRIN2A in motor speech function. Our findings highlight the need for precise clinical speech assessment and intervention in this group. By understanding the mechanisms involved in GRIN2A disorders, targeted therapy may be designed to improve chronic lifelong deficits in intelligibility.

Role of cerebellum in fine speech control in childhood: Persistent dysarthria after surgical treatment for posterior fossa tumour

Dysarthria following surgical resection of childhood posterior fossa tumour (PFT) is most commonly documented in a select group of participants with mutism in the acute recovery phase, thus limiting knowledge of post-operative prognosis for this population of children as a whole. Here we report on the speech characteristics of 13 cases seen long-term after surgical treatment for childhood PFT, unselected for the presence of post-operative mutism (mean time post-surgery=6y10m, range 1;4-12;6 years, two had post-operative mutism), and examine factors affecting outcome. Twenty-six age- and sex- matched healthy controls were recruited for comparison. Participants in both groups had speech assessments using detailed perceptual and acoustic methods. Over two-thirds of the group (69%) with removal of PFT had a profile of typically mild dysarthria. Prominent speech deficits included consonant imprecision, reduced rate, monopitch and monoloudness. We conclude that speech deficits may persist even up to 10 years post-surgery in participants who have not shown mutism in the acute phase. Of cases with unilateral lesions, poorer outcomes were associated with right cerebellar tumours compared to left, consistent with the notion based on adult data that speech is controlled by reciprocal right cerebellar/left frontal interactions. These results confirm the important role of the cerebellum in the control of fine speech movements in children.

The phenotype of Floating–Harbor syndrome in 10 patients†

Floating–Harbor syndrome (FHS) is a rare condition typified by short stature, speech impairment, delayed bone age, and characteristic facies. The diagnosis can be difficult as the facial changes are subtle in infancy, and the features of short stature, delayed speech, and delayed bone age are frequently encountered in clinical practice. We refine the phenotype in FHS by reporting clinical findings in 10 typically affected individuals ranging in age from 7 to 34 years and present a mother and daughter who display some features of FHS. Bone age measurements were delayed when measured from age 6 months to 6 years but in some patients were normal between 6 and 12 years. Dysmorphic features at different ages are characterized. The lateral profile of the face and the characteristic body habitus aided diagnosis. Significant behavioral problems of hyperactivity, short attention span and aggression during childhood were reported for most individuals. The children studied had a severe and incapacitating disorder of speech and language. Intellectual functioning ranged from borderline normal to moderate intellectual disability. Early puberty was noted. Adult heights were 140–155 cm. Microarray analysis in eight of the patients provided no evidence that FHS is caused by a large‐scale copy‐number genomic change.

Speech sound disorder at 4 years: prevalence, comorbidities, and predictors in a community cohort of children

The epidemiology of preschool speech sound disorder is poorly understood. Our aims were to determine: the prevalence of idiopathic speech sound disorder; the comorbidity of speech sound disorder with language and pre‐literacy difficulties; and the factors contributing to speech outcome at 4 years.

Incidence and clinical presentation of dysarthria and dysphagia in the acute setting following paediatric traumatic brain injury

BACKGROUND A lack of data on dysarthria and dysphagia outcomes for children following traumatic brain injury (TBI) limits our clinical evidence base, and poses daily challenges for the speech language pathologist (SLP) managing this group. The present study aimed to examine dysarthria and dysphagia incidence and the clinical presentation of children with these disorders in the acute phase following TBI. METHODS Incidence and characteristics were determined via a comprehensive retrospective medical chart review of children consecutively referred to a tertiary paediatric hospital over an 8-year period. Cases (n= 22 dysarthria, n= 72 dysphagia) and matched controls were compared across ancillary variables (e.g. age, severity of TBI, motor impairment). RESULTS Incidence across the entire cohort was low [i.e. dysarthria (1.2%, 22/1895), dysphagia (3.8%, 72/1895)], but was markedly higher for the sub-category of children with severe TBI [e.g. dysphagia (76%, 63/83)]. Speech deficits were reported across respiration, phonation, resonance, articulation and prosody. Swallowing deficits included reduced lip closure, delayed swallow initiation, wet voice and coughing. Language and swallowing deficits were often co-morbid with dysarthria. Motor impairment was frequently co-morbid with both dysarthria and dysphagia. Cases had longer periods of hospitalization, ventilation and supplementary feeding compared with controls. CONCLUSION Despite the low incidence of dysarthria and dysphagia across the entire TBI cohort, this sub-group may place longer-term burden on SLP services, having prolonged periods of ventilation, extended periods of hospitalization and a complex co-morbid clinical presentation compared with controls. The prevalence of co-morbid communication and swallowing impairments suggests a need for integrated rather than single discipline (i.e. dysphagia stream only) SLP services.

Evaluation of communication assessment practices during the acute stages post stroke.

RATIONALE, AIMS AND OBJECTIVES Early detection of communication impairment post stroke is an important prognostic indicator and promotes the use of individualized treatment protocols. Therefore, the methods for speech and language assessment used by communication experts in acute settings following stroke were investigated. METHODS A survey was conducted among 254 speech and language pathologists providing acute care for patients following stroke in all states and territories across Australia and New Zealand. Respondent attitudes and practices in speech and language assessment post stroke were recorded with a standardized questionnaire collected online. RESULTS A total of 174 (68.5%) speech and language pathologists responded. Over 70% of participants assessed language and 80% assessed speech using their own clinical assessments. Respondents identified limited test repeatability and poor sensitivity to change over acute periods as key areas of concern for currently available standardized assessments. CONCLUSIONS Subjective and/or un-standardized assessments were the most commonly used measures of communication during the acute phases post stroke. These results highlight a critical need for the development of population-specific communication assessments that build on existing clinician derived techniques and expertise while considering the acute time demands and transient nature of patients communicative functioning.

Dysarthria and dysphagia as long-term sequelae in a child treated for posterior fossa tumour

The current case report provides a comprehensive description of the persistent dysarthria and dysphagia evident in a 7.5 year old child treated for recurrent posterior fossa tumour (PFT). AC was assessed on a comprehensive perceptual and instrumental test battery incorporating all components of the speech production system (respiration, phonation, resonance, articulation and prosody) 2 years and 4 months following completion of her treatment. The nature of her swallowing impairment was investigated through the use of videofluoroscopic evaluation of swallowing (VFS). A mild dysarthria with ataxic and LMN components was identified, although overall speech intelligibility was not affected. A moderate dysphagia was also identified with impairment in all three phases of the swallowing process; oral preparatory, oral and pharyngeal. Dysarthria and dysphagia as persistent sequelae in children treated for PFT have implications for the long-term management of these children. The need for appropriate treatment regimes, as well as pre-surgical counselling regarding dysarthria and dysphagia as possible outcomes following surgery are highlighted.