Monthly Archives: August 2011
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.
The scale for the assessment and rating of ataxia correlates with dysarthria assessment in Friedreich’s ataxia
Dysarthria is an acquired neurogenic sensorimotor speech symptom and an integral part within the clinical spectrum of ataxia syndromes. Ataxia measurements and disability scores generally focus on the assessment of motor functions. Since comprehensive investigations of dysarthria in ataxias are sparse, we assessed dysarthria in ataxia patients using the Frenchay Dysarthria Assessment. The Frenchay Dysarthria Assessment is a ten-item validated test in which eight items focus on the observation of oral structures and speech functions. Fifteen Friedreich’s ataxia patients and 15 healthy control individuals were analyzed using clinical and logopedic methodology. All patients underwent neurological assessment applying the Scale for the Assessment and Rating of Ataxia. In Friedreich’s ataxia patients, the Frenchay sub-item voice showed to be most affected compared to healthy individuals followed by items such as reflexes, palate, tongue, and intelligibility. Scoring of lips, jaw, and respiration appeared to be mildly affected. Ataxia severity in Friedreich’s ataxia patients revealed a significant correlation with the Frenchay dysarthria sum score. The introduction of a binary Adapted Dysarthria Score additionally allowed allocation to distinct dysarthria pattern in ataxias. The Frenchay Dysarthria Assessment proved to be a valid dysarthria measure in Friedreich’s ataxia. Its availability in several languages provides a major advantage regarding the applicability in international clinical studies. Shortcomings of the Frenchay test are the multiplicity of items tested and its alphabetic coding. Numerical scoring and condensation of assessments in a modified version may, however, provide an excellent clinical tool for the measurement and scoring of dysarthria in ataxic speech disorders.
from the Journal of Neurology
Neural correlates in the processing of phoneme-level complexity in vowel production
We investigated how articulatory complexity at the phoneme level is manifested neurobiologically in an overt production task. fMRI images were acquired from young Korean-speaking adults as they pronounced bisyllabic pseudowords in which we manipulated phonological complexity defined in terms of vowel duration and instability (viz., COMPLEX: /tii/ >> MID-COMPLEX: /tiye/ >> SIMPLE: /tii/). Increased activity in the left inferior frontal gyrus (Brodmann Areas (BA) 44 and 47), supplementary motor area and anterior insula was observed for the articulation of COMPLEX sequences relative to MID-COMPLEX; this was the case with the articulation of MID-COMPLEX relative to SIMPLE, except that the pars orbitalis (BA 47) was dominantly identified in the Broca’s area. The differentiation indicates that phonological complexity is reflected in the neural processing of distinct phonemic representations, both by recruiting brain regions associated with retrieval of phonological information from memory and via articulatory rehearsal for the production of COMPLEX vowels. In addition, the finding that increased complexity engages greater areas of the brain suggests that brain activation can be a neurobiological measure of articulo-phonological complexity, complementing, if not substituting for, biomechanical measurements of speech motor activity.
from Brain and Language
Artifacts of the electrode in cochlea implantation and limits in analysis of deep insertion in cone beam tomography (CBT)
Until now more than 250,000 cochlea implantations have been performed worldwide. The surgical procedure is well standardized. A discussion about the kind of postoperative radiological control has started since cone beam tomography (CBT) has been established in ENT and hearing preservation operations have come more into the focus. Further research has been concentrated on the role of CBT and the insertion of the basal turn. The aim of this study was to look for the possibilities of CBT and deep insertion. The second aim was to analyze the artifacts of cochlea implants in CBT. Three human cadaver ears were implanted with a flex soft electrode of MedEl© in a standard operation procedure with round window insertion and a full insertion. Afterwards 72 CBT sets per ear were performed with different X-ray-tube currents (2–10 mA), voltages (72–90 kV), and exposure times (9 and 17 s). On each data set, the radiological diameter of the electrode 9 (basal), electrode 2 (apical), the diameter of the cable next to the electrodes 9 and 2, and the associated diameter of the cochlea next to the electrodes 9 and 2 were evaluated. Additionally, a comparison to the real diameter was done. The mean radiological diameters of the measure point at electrode 9 were: electrode = 1.19 mm; cable = 0.65 mm; cochlea = 1.77 mm. Results for measure point at electrode 2 were: electrode = 0.98 mm; cable = 0.48 mm; cochlea = 1.21 mm. The real diameters were at electrode 9 in lateral view 0.58 mm and in top view 0.63 mm and at electrode 2 in lateral view 0.36 mm and in top view 0.50 mm. Differences between the diameters of the electrode 9 and 2 were highly significant. Interestingly, the real diameter of the electrode is half in comparison to the radiological one. Also in comparison to the diameter of the cable and the associated electrode is nearly half. Nearly 50% artifact exists on radiologic evaluation of the diameter of the electrode. Varying the X-ray adjustments did not lead to optimized results. The difficulties in evaluating a cochlea electrode with CBT could be shown. The high rate of artifacts (50%) makes it extremely difficult to predict the inserted scale, especially when evaluating the intracochlear position in the medial and apical turn of the cochlea. In conclusion, until now CBT allows a relatively safe evaluation of the electrode in the basal turn, whereas in deep insertion it is not really a useful tool to answer the question of insertion trauma, implanted scale, or scale displacements.
Cricopharyngeal Dilatation for the Long-term Treatment of Dysphagia in Oculopharyngeal Muscular Dystrophy
Oculopharyngeal muscular dystrophy (OPMD) is a rare autosomal dominant, progressive degenerative muscle disorder featuring dysphagia with limited therapeutic options. The aim of this study was to evaluate the safety and efficacy of repeated endoscopic dilatation for OPMD over a 15-year period. All patients seen at our Regional Swallowing Clinic with OPMD confirmed by genetic analysis were included. Cricopharyngeal dilatation was performed as an outpatient procedure using a wire-guided 18-mm (54 Fr) Savary-Gilliard bougie with the patient under sedation. Patients were offered repeat endoscopic dilatation when symptoms recurred. Symptom severity prior to initial dilatation and at follow-up was evaluated using the Sydney Swallow Questionnaire (SSQ). Nine patients (7 female, 2 male) were included for analysis. Median total treatment period was 13 years (range = 3–15), median number of dilatations per patient was 7.2 (range = 1–16), and median interval between treatments was 15 months (range = 4.5–45). All patients recorded sustained symptom improvement. Mean SSQ score (out of 1,700) was 1,108.11 (SD ± 272.85) prior to first dilatation and 297.78 (SD ± 189.14) at last follow-up, representing a 73% decrease (95% CI = 52–94) in degree of dysphagia symptoms (paired t-test, P = 0.0001). All mean scores for individual questions also showed significant improvement (P < 0.05). No adverse events were reported with all patients maintaining oral feeding at last follow-up. Repeated cricopharyngeal dilatation is a safe, effective, well-tolerated, and long-lasting treatment for dysphagia in OPMD.
from Dysphagia
A study to determine the correlation between clinical, fiber-optic endoscopic evaluation of swallowing and videofluoroscopic evaluations of swallowing after prolonged intubation.
Conclusion: Cough is a reliable sign of swallowing disorder but does not exclude silent aspiration and contraindicates oral feeding. Cough induced by liquid water should lead to modification of diet in terms of consistency and viscosity with cough reassessment.
Effects of Task Analysis and Self-Monitoring for Children With Autism in Multiple Social Settings
In this study, written task analyses with self-monitoring were used to teach functional skills and verbal interactions to two high-functioning students with autism in social settings with peers. A social script language intervention was included in two of the activities to increase the quantity of verbal interaction between the students and peers. Analysis of the results leads to the conclusion that the intervention package increased independent task completion, peer-directed verbal interaction, and activity engagement for the students with autism during social, game, and cooking activities. Improvements in task completion persisted after the written task analyses were faded. The percentage of intervals with appropriate language use remained consistent as the social scripts were faded during the game activities.
Comparison Of Pausing Behavior In Children Who Stutter And Children Who Have Asperger Syndrome
Results
: Both groups presented grammatical and non-grammatical pauses and the former predominated. The children with Asperger Syndrome produced a greater number of pauses than the stutterers.
Relationship Between Occlusion and Lisping in Children with Cleft Lip and Palate.
DISCUSSION: This study failed to reveal an association between lisping and dental arch relationship in children with operated UCLP. Multiple variables may play a role in determining occurrence of lisping, warranting further investigation.
from the Cleft Palate-Craniofacial Journal
Voice Low Tone to High Tone Ratio, Nasalance and Nasality Ratings in Connected Speech of Native-Mandarin Speakers: A Pilot Study.
Conclusion: The significant correlations of VLHR with nasalance and perceptual ratings of nasality using connected speech show that these approaches have a potential value in terms of basic and clinical application.
from the Cleft Palate-Craniofacial Journal
When two and too don’t go together: A selective phonological deficit sparing number words
We report the case of an Italian speaker (GBC) with classical Wernicke’s aphasia syndrome following a vascular lesion in the left posterior middle temporal region. GBC exhibited a selective phonological deficit in spoken language production (repetition and reading) which affected all word classes irrespective of grammatical class, frequency, and length. GBC’s production of number words, in contrast, was error free. The specific pattern of phonological errors on non-number words allows us to attribute the locus of impairment at the level of phonological form retrieval of a correctly selected lexical entry. These data support the claim that number words are represented and processed differently from other word categories in language production.
from Cortex
Reduced intracortical inhibition and facilitation in the primary motor tongue representation of adults who stutter
Conclusions
In persistent stuttering intracortical excitability of the primary motor tongue representation is altered with a deviant time course for inhibitory activity in the right hemisphere and reduced paired-pulse facilitation.
Assessment of hearing organ activity in a group of neonates with central nervous system impairment
Conclusions
The combined use of CEOAEs and ABR in neonates with central nervous system impairment involvement revealed the existence of abnormalities in cochlear micromechanics and retrocochlear auditory pathway. Etiology seems to be multifactoral.
from the International Journal of Pediatric Otorhinolaryngology
Benefits and costs of lexical decomposition and semantic integration during the processing of transparent and opaque English compounds
Six lexical decision experiments were conducted to examine the influence of complex structure on the processing speed of English compounds. All experiments revealed that semantically transparent compounds (e.g., rosebud) were processed more quickly than matched monomorphemic words (e.g., giraffe). Opaque compounds (e.g., hogwash) were also processed more quickly than monomorphemic words. However, when the experimental materials and/or procedure encouraged decomposition/integration, this advantage disappeared. This research suggests that morphological decomposition initiated by the existence of complex structure results in the availability of both the lexical and semantic representations of compound constituents, regardless of whether the compounds are transparent or opaque, and that meaning composition is attempted. This meaning composition further speeds up transparent compound processing beyond lexical facilitation but slows down opaque compound processing because the computed meaning for opaque compounds conflicts with the retrieved meaning.
from the Journal of Memory and Language
Isolated words enhance statistical language learning in infancy
Infants are adept at tracking statistical regularities to identify word boundaries in pause-free speech. However, researchers have questioned the relevance of statistical learning mechanisms to language acquisition, since previous studies have used simplified artificial languages that ignore the variability of real language input. The experiments reported here embraced a key dimension of variability in infant-directed speech. English-learning infants (8–10 months) listened briefly to natural Italian speech that contained either fluent speech only or a combination of fluent speech and single-word utterances. Listening times revealed successful learning of the statistical properties of target words only when words appeared both in fluent speech and in isolation; brief exposure to fluent speech alone was not sufficient to facilitate detection of the words’ statistical properties. This investigation suggests that statistical learning mechanisms actually benefit from variability in utterance length, and provides the first evidence that isolated words and longer utterances act in concert to support infant word segmentation.
