Break Time

I won’t be posting again until May 22. Thanks for reading COMD News.

How Evidence-Based Are the Recommendations in Evidence-Based Guidelines?

from PLoS Medicine

Background

Treatment recommendations for the same condition from different guideline bodies often disagree, even when the same randomized controlled trial (RCT) evidence is cited. Guideline appraisal tools focus on methodology and quality of reporting, but not on the nature of the supporting evidence. This study was done to evaluate the quality of the evidence (based on consideration of its internal validity, clinical relevance, and applicability) underlying therapy recommendations in evidence-based clinical practice guidelines.

Methods and Findings

A cross-sectional analysis of cardiovascular risk management recommendations was performed for three different conditions (diabetes mellitus, dyslipidemia, and hypertension) from three pan-national guideline panels (from the United States, Canada, and Europe). Of the 338 treatment recommendations in these nine guidelines, 231 (68%) cited RCT evidence but only 105 (45%) of these RCT-based recommendations were based on high-quality evidence. RCT-based evidence was downgraded most often because of reservations about the applicability of the RCT to the populations specified in the guideline recommendation (64/126 cases, 51%) or because the RCT reported surrogate outcomes (59/126 cases, 47%).

Conclusions

The results of internally valid RCTs may not be applicable to the populations, interventions, or outcomes specified in a guideline recommendation and therefore should not always be assumed to provide high-quality evidence for therapy recommendations.

Functional segregation of the inferior frontal gyrus for syntactic processes: A functional magnetic-resonance imaging study

from Neuroscience Research

No abstract available.

Event-related potentials reflect spectral differences in speech and non-speech stimuli in children and adults

from Clinical Neurophysiology

Objective
Event-related brain potentials (ERP) may provide tools for examining normal and abnormal language development. To clarify functional significance of auditory ERPs, we examined ERP indices of spectral differences in speech and non-speech sounds.

Methods
Three Spectral Items (BA, DA, GA) were presented as three Stimulus Types: syllables, non-phonetics, and consonant–vowel transitions (CVT). Fourteen 7- to 10-year-old children and 14 adults were presented with equiprobable Spectral Item sequences blocked by Stimulus Type.

Results
Spectral Item effect appeared as P1, P2, N2, and N4 amplitude variations. The P2 was sensitive to all Stimulus Types in both groups. In adults, the P1 was also sensitive to transitions while the N4 was sensitive to syllables. In children, only the 50-ms CVT stimuli elicited N2 and N4 spectral effects. In both groups, non-phonetic stimuli elicited larger N1–P2 amplitudes while speech stimuli elicited larger N2–N4 amplitudes.

Conclusions
Auditory feature processing is reflected by P1–P2 and N2–N4 peaks and matures earlier than supra-sensory integrative mechanisms, reflected by N1–P2 peaks. Auditory P2 appears to pertain to both processing types.

Significance
These results delineate an orderly processing organization whereby direct feature mapping occurs earlier in processing and, in part, serves sound detection whereas relational mapping occurs later in processing and serves sound identification.

Aerodynamic and Acoustic Characteristics of Voice Before and After Adduction Arytenopexy and Medialization Laryngoplasty with GORE-TEX in Patients with Unilateral Vocal Fold Immobility

from the Journal of Voice

Multiple surgical techniques have been developed to restore function in patients with vocal fold paralysis (VFP), ranging from open laryngeal framework procedures to endoscopic injection techniques. In our experience, adduction arytenopexy (AA) and medialization laryngoplasty with GORE-TEX (MLG), with or without cricothyroid subluxation (CTS), together offer patients optimal improvement in voice, based on the subjective change in voice quality and patient feedback obtained. In this study, we analyze objective voice parameters in these patients before and after surgery. The objective of this retrospective chart review is to demonstrate the change in aerodynamic and acoustic properties of voice in patients with VFP who undergo combined AA and MLG, with or without CTS. Seventy-five patients underwent combined AA and MLG between May 2001 and September 2006; 28 completed both preoperative and postoperative voice evaluation including aerodynamic and acoustic testing. Retrospective chart review is used to compare pre- and postoperative voice parameters in these patients. Statistically significant increases in mean maximum phonation time (MPT) and mean intensity of “/pæ/” during aerodynamic testing, with a statistically significant decrease in mean glottal airflow were observed. A notable increase in mean glottal resistance was not statistically significant. No significant change was observed in the other parameters tested. Mean MPT increased and mean glottal airflow decreased. These objective results correlate with patients’ subjective improvement. However, while “objective,” acoustic and aerodynamic testing are effort dependent, and thus may not be as reliable as other tools in measuring postsurgical voice outcomes. Patient surveys may be the best means of gauging surgical success.

Child Voice and Noise: A Pilot Study of Noise in Day Cares and the Effects on 10 Children’s Voice Quality According to Perceptual Evaluation

from the Journal of Voice

The purpose of this investigation was to study children’s exposure to background noise at the ears during a normal day at the day care center and also to relate this to a perceptual evaluation of voice quality. Ten children, from three day care centers, with no history of hearing and speech problems or frequent infections were selected as subjects. A binaural recording technique was used with two microphones placed on both sides of the subject’s head, at equal distance from the mouth. A portable digital audio tape (DAT) recorder (Sony TCD-D 100, Stockholm, Sweden) was attached to the subject’s waist. Three recordings were made for each child during the day. Each recording was calibrated and started with three repetitions of three sentences containing only sonorants. The recording technique allowed separate analyses of the background noise level and of the sound pressure level (SPL) of each subjects’ own voice. Results showed a mean background noise level for the three day care centers at 82.6 dBA Leq, ranging from 81.5 to 83.6 dBA Leq. Day care center no. 2 had the highest mean value and also the highest value at any separate recording session with a mean background noise level of 85.4 dBA Leq during the noontime recordings. Perceptual evaluation showed that the children attending this day care center also received higher values on the following voice characteristics: hoarseness, breathiness, and hyperfunction. Girls increased their loudness level during the day, whereas for boys no such change could be observed.

Effects of Muscle Tension Dysphonia on Tone Phonation: Acoustic and Perceptual Studies in Vietnamese Female Teachers

from the Journal of Voice

Muscle tension dysphonia (MTD) is a hyperfunctional voice disorder commonly seen in professional voice users. To date, published acoustic studies of this disorder have mainly focused on nontonal language speakers, and no publication has documented its impact on lexical tone characteristics. In this study, we examined whether and how this voice disorder affected acoustically and perceptually the characteristics of tones in Vietnamese teachers. Voice data were obtained from 42 Vietnamese female primary school teachers diagnosed with MTD and 30 vocally healthy teachers. Tonal data were analyzed using Computerized Speech Lab (CSL-4300B) and Speech Analyzer. Parameters analyzed included the two most important acoustic cues in Vietnamese tones, that is, tonal fundamental frequency (F0) and laryngealization. Tonal F0 was assessed using a factorial analysis of variance with group and career durations as independent variables. Tonal samples were also perceptually assessed by a panel of native speakers of the same dialect. The results showed that MTD lowered tonal F0 in high tones and tones with extensive fundamental frequency variation. There was also a significant main effect for career duration; in MTD group, tonal F0 was lower in teachers with longer career duration. The teachers with MTD showed different patterns of laryngealization compared with the control group. Tone perception was poorer for tones with extensive fundamental frequency variation and without a typical phonation type. The results in this group of teachers supported our hypothesis that MTD impairs lexical tone phonation.

Genetic and pharmacological intervention for treatment/prevention of hearing loss

from the Journal of Communication Disorders

Twenty years ago it was first demonstrated that birds could regenerate their cochlear hair cells following noise damage or aminoglycoside treatment. An understanding of how this structural and functional regeneration occurred might lead to the development of therapies for treatment of sensorineural hearing loss in humans. Recent experiments have demonstrated that noise exposure and aminoglycoside treatment lead to apoptosis of the hair cells. In birds, this programmed cell death induces the adjacent supporting cells to undergo regeneration to replace the lost hair cells. Although hair cells in the mammalian cochlea undergo apoptosis in response to noise damage and ototoxic drug treatment, the supporting cells do not possess the ability to undergo regeneration. However, current experiments on genetic manipulation, gene therapy, and stem cell transplantation suggest that regeneration in the mammalian cochlea may eventually be possible and may 1 day provide a therapeutic tool for hearing loss in humans.

Asymmetry of voice onset time-processing in adult developmental dyslexics

from Clinical Neurophysiology

Methods
Auditory-evoked potentials (AEPs) to voiced (/ba/) and voiceless (/pa/) speech stimuli were recorded from 10 DD-history+ adults and 8 controls. Source modelling of the “release component” (RC: 240 ms; time-locked to voiced consonantal release and considered reflective of VOT-processing) was conducted to explore VOT asymmetries.

Results
Controls demonstrated L > R RC source probe amplitude asymmetry in the auditory cortex. DD-history+ subjects with little persistent reading deficit (n = 5) demonstrated normal temporal coding but rightward asymmetry. DD-history+ subjects with severe persistent deficits (n = 5) exhibited numerous supplemental AEP components (notably left hemispheric) and inconsistent asymmetry (leftward or alternating).

Conclusions
These preliminary findings suggest that DD-history+ adults process auditory speech cues differently than adults without previous DD. The nature of this processing may relate to the severity of persistent reading deficits.

Significance
Previous dyslexics with little persistent deficit can exhibit atypical functional asymmetry with normal auditory temporal coding. Source modelling represents an effective, non-invasive means of exploring processing asymmetries in clinical populations.

Congenital aural atresia: Transmastoid approach; an old technique with good results

from the International Journal of Pediatric Otorhinolaryngology

Objective
Congenital aural atresia prevents sound conduction to the inner ear, so the child may suffer learning problems. Transmastoid approach is a safe method to create functional pathway by which sound can reach the cochlear fluids but it leaves mastoid cavity which may be problematic. The purpose of this study is to assess the feasibility of improving hearing in those patients on the expense of mastoid cavity.

Methods
Forty children with congenital aural atresia were included in this study. All had functioning cochlea on evoked response audiometry and normal cochlear morphology with pneumatized mastoid on CT scan. Transmastoid approach was used for reconstruction of the external auditory canal with covering of the newly created canal using split thickness skin graft. Reconstruction of the tympanic membrane was carried out by temporalis fascia graft. Follow-up of the patients for 3 years was carried out.

Results
Surgical success is considered on restoration of hearing and maintenance of a patent, infection-free ear canal. This study showed a successful hearing result in 85% of patients at 3 months postoperatively, this result diminished to 65% after 3 years. The incidence of canal restenosis was 17.5%; the narrowing was in the outer cartilaginous part. No cases developed facial nerve paralysis or sensorineural hearing loss postoperatively.

Conclusions
Congenital aural atresia is one of the most difficult and challenging surgeries for the otologic surgeon. However, in the hands of experienced otologists, repair of this deformity can be performed safely and with predictable results using transmastoid approach.

Launch of new Web Resource – SOUNDING BOARD

from the Ear Foundation

Sounding Board is a new service which is now available to anyone interested in the education of deaf children.

The Ear Foundation was set up in 1989, initially to bring cochlear implantation to profoundly deaf children in the UK. Since then the work of the Foundation has moved on and it is now committed to providing education and resources to support the success of children and young people with cochlear implants. This includes supporting professionals who are working with these children, enabling them to stay abreast of the changing technology and current best practice in all aspects of education and language development.

This new project is part of that commitment to educators. Set up with the sponsorship of Advanced Bionics, the main aim of Sounding Board is to provide clear and easily accessible information on a range of topics relevant to the education of all children with cochlear implants. This will be done in two different ways.

The first is an interactive forum where participants can post any question they have about any aspect of this work. Answers will be provided by The Ear Foundation and then the question will be opened up for others to contribute their responses. There will be an archive of questions and answers for people who have time to peruse this. Participants will be invited to share ideas and resources that they have found useful.
In addition there is an information section where useful information about implants, latest technology, current research, assessment and best practice will be provided in a simple and straightforward format. Simple links will be made with relevant sections of websites and there will be details about where to get more information or to obtain the appropriate resources.

Simulation of talking faces in the human brain improves auditory speech recognition

from the Proceedings of the National Academy of Sciences of the United States of America

Human face-to-face communication is essentially audiovisual. Typically, people talk to us face-to-face, providing concurrent auditory and visual input. Understanding someone is easier when there is visual input, because visual cues like mouth and tongue movements provide complementary information about speech content. Here, we hypothesized that, even in the absence of visual input, the brain optimizes both auditory-only speech and speaker recognition by harvesting speaker-specific predictions and constraints from distinct visual face-processing areas. To test this hypothesis, we performed behavioral and neuroimaging experiments in two groups: subjects with a face recognition deficit (prosopagnosia) and matched controls. The results show that observing a specific person talking for 2 min improves subsequent auditory-only speech and speaker recognition for this person. In both prosopagnosics and controls, behavioral improvement in auditory-only speech recognition was based on an area typically involved in face-movement processing. Improvement in speaker recognition was only present in controls and was based on an area involved in face-identity processing. These findings challenge current unisensory models of speech processing, because they show that, in auditory-only speech, the brain exploits previously encoded audiovisual correlations to optimize communication. We suggest that this optimization is based on speaker-specific audiovisual internal models, which are used to simulate a talking face.

MGH researchers report successful new laser treatment for vocal-cord cancer

from EurekAlert.org

An innovative laser treatment for early vocal-cord cancer, developed at Massachusetts General Hospital (MGH), successfully restores patients’ voices without radiotherapy or traditional surgery, which can permanently damage vocal quality. This new option for patients, which has now been used in more than 25 patients, was reported on May 1 at the annual meeting of the American Broncho-Esophagological Association, and the data will soon be published as a supplement to the Annals of Otology, Rhinology, & Laryngology.

Expected Test Scores for Preschoolers With a Cochlear Implant Who Use Spoken Language

from the American Journal of Speech-Language Pathology

Purpose: The major purpose of this study was to provide information about expected spoken language skills of preschool-age children who are deaf and who use a cochlear implant. A goal was to provide “benchmarks” against which those skills could be compared, for a given age at implantation. We also examined whether parent-completed checklists of children’s language were correlated with results of standardized language tests and whether scores increased linearly with decreasing age of implantation and increasing duration of cochlear implant use.

Method: Participants were a nationwide sample of 76 children who were deaf and orally educated and who received an implant by 38 months of age. Formal language tests were administered at age 4.5 years. The MacArthur–Bates Communicative Development Inventories (CDI) instrument was completed by parents when children were ages 3.5 and 4.5 years.

Results: Based on regression analyses, expected scores for each age at implant were provided for 2 commonly administered language tests at 4.5 years of age and CDI subscale scores at 3.5 and 4.5 years. Concurrent test scores were significantly correlated on all measures. A linear relation was found that predicted increasing test scores with younger ages at implantation for all scales administered.

Conclusions: While the expected scores reported here should not be considered as normative data, they are benchmarks that may be useful for evaluating spoken language progress of children with cochlear implants who are enrolled in spoken language–based programs.

Auditory/Verbal hallucinations, speech perception neurocircuitry, and the social deafferentation hypothesis

from Clinical EEG and Neuroscience

Auditory/verbal hallucinations (AVHs) are comprised of spoken conversational speech seeming to arise from specific, nonself speakers. One hertz repetitive transcranial magnetic stimulation (rTMS) reduces excitability in the brain region stimulated. Studies utilizing 1-Hz rTMS delivered to the left temporoparietal cortex, a brain area critical to speech perception, have demonstrated statistically significant improvements in AVHs relative to sham simulation. A novel mechanism of AVHs is proposed whereby dramatic pre-psychotic social withdrawal prompts neuroplastic reorganization by the “social brain” to produce spurious social meaning via hallucinations of conversational speech. Preliminary evidence supporting this hypothesis includes a very high rate of social withdrawal emerging prior to the onset of frank psychosis in patients who develop schizophrenia and AVHs. Moreover, reduced AVHs elicited by temporoparietal 1-Hz rTMS are likely to reflect enhanced long-term depression. Some evidence suggests a loss of long-term depression following experimentally-induced deafferentation. Finally, abnormal cortico-cortical coupling is associated with AVHs and also is a common outcome of deafferentation. Auditory/verbal hallucinations (AVHs) of spoken speech or “voices” are reported by 60-80% of persons with schizophrenia at various times during the course of illness. AVHs are associated with high levels of distress, functional disability, and can lead to violent acts. Among patients with AVHs, these symptoms remain poorly or incompletely responsive to currently available treatments in approximately 25% of cases. For patients with AVHs who do respond to antipsychotic drugs, there is a very high likelihood that these experiences will recur in subsequent episodes. A more precise characterization of underlying pathophysiology may lead to more efficacious treatments.