COMD News

Events and Research in Speech, Language, and Hearing Disorders

Study finds some kids are being misdiagnosed with asthma

from EurekAlert.org

Vocal cord dysfunction (VCD) is the sudden, abnormal narrowing of the vocal cords during inhalation causing obstruction of the airflow, and is characterized by a noise that can mimic the sound of wheezing. A VCD attack can easily be mistaken for an asthma attack though it does not respond to asthma medications.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

Characteristics and reversibility of dementia in Normal Pressure Hydrocephalus

from Behavioural Neurology

Studies of the cognitive outcome after shunt insertion for treatment of Normal Pressure Hydrocephalus have reported widely mixed results. We prospectively studied performance of 60 patients with Normal Pressure Hydrocephalus on a comprehensive battery of neuropsychological tests before and after shunt surgery to determine which cognitive functions improve with shunt insertion. We also administered a subset of cognitive tests before and after temporary controlled drainage of cerebrospinal fluid to determine if change on this brief subset of tests after drainage could predict which patients would show cognitive improvement three to six months after shunt insertion. There was a significant improvement in learning, retention, and delayed recall of verbal memory three to six months after surgery (using paired t-tests). The majority (74%) of patients showed significant improvement (by at least one standard deviation) on at least one of the memory tests. Absence of improvement on verbal memory after temporary drainage of cerebrospinal fluid had a high negative predictive value for improvement on memory tests at 3–6 months after surgery (96%; p=0.0005). Also, the magnitude of improvement from Baseline to Post-Drainage on few specific tests of learning and recall significantly predicted the magnitude of improvement after shunt surgery on the same tests (r^{2}=0.32–0.58; p=0.04–0.001). Results indicate that testing before and after temporary drainage may be useful in predicting which patients are less likely to improve in memory with shunting.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

NYU study points to lasting impact of mild hearing loss on neurological processes

from EurekAlert.org

Mild to moderate forms of hearing loss can have a lasting impact on the auditory cortex, according to findings by researchers at New York University’s Center for Neural Science. The study, which is the first to show central effects of mild hearing loss, appears in the latest issue of the Journal of Neuroscience.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

Nigeria: Deaf Artisans Advocate National Policy on Deaf Rehabilitation

from AllAfrica.com

Deaf artisans are advocating for a national policy on deaf rehabilitation.

A statement signed by the executive chairman of the society, Mr. Ajakaiye Mohammad Sani and made available to City News yesterday, said lack of such policy brought about neglect of the deaf artisans which make them unemployable.

Mr. Ajakaiye stressed that their continual neglect by the federal government and the absence of such policy had created a vacuum which makes them irrelevant to the society.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

Plasticity in high-order cognition: Evidence of dissociation in aphasia

from Behavioral and Brain Sciences

High-order constructs such as intelligence result from the interaction of numerous processing systems, one of which is language. However, in determining the role of language in intelligence, attention must be paid to evidence from lesion studies and, in particular, evidence of dissociation of functions where high-order cognition can be demonstrated in face of profound aphasia.

August 31, 2007 Posted by Callier Library | Uncategorized | , | No Comments

The Pars Interna/Media Anatomy and Histology in the Human Larynx

from Folia Phoniatrica et Logopaedica

The pars interna/media (PIM) is a small muscle found in the human larynx that has not been successfully described in contemporary literature on laryngeal structure. The objective of this study was to describe the PIM’s anatomy in detail. Thirteen human larynges obtained from postmortem examination were cleaned and preserved. Exposure of the PIM was through a lateral disarticulation of the cricothyroid joint and reflection of the cricothyroid muscle and the thyroid lamina. In the human, the PIM was found to be strap-like in form and to have two bellies with attachments to the medial surface of the thyroid cartilage at the root of the inferior horn and anteriosuperior cricoid arch. It appears to be innervated by a middle division, vestibular branch, of the internal superior laryngeal nerve. The average fiber diameter is 40 µm. Its type 1-to-type 2 fiber ratio places it within the range of other intrinsic laryngeal muscles. A muscle spindle was identified in medial bundle at the PIM’s thyroid attachment. Thyroid medial surface attachment is within few millimeters of the muscular process of the arytenoid cartilage. These data show that the PIM is a robust muscle and deserves attention anatomically. Its orientation within the thyroid and nonrecurrent laryngeal nerve innervations of the human PIM may place it in the vocal fold tensor group rather than the laryngeal sphincter group. It is possible the PIM reports on cricothyroid distance and right versus left cricothyroid joint stresses. Electromyographic examination of the PIM in the Rhesus larynx may help elucidate its physiology to elaborate its human physiology.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

The Effects of Gated Speech on the Fluency of Speakers Who Stutter

from Folia Phoniatrica et Logopaedica

It is known that the speech of people who stutter improves when the speaker’s own vocalization is changed while the participant is speaking. One explanation of these effects is the disruptive rhythm hypothesis (DRH). The DRH maintains that the manipulated sound only needs to disturb timing to affect speech control. The experiment investigated whether speech that was gated on and off (interrupted) affected the speech control of speakers who stutter. Eight children who stutter read a passage when they heard their voice normally and when the speech was gated. Fluency was enhanced (fewer errors were made and time to read a set passage was reduced) when speech was interrupted in this way. The results support the DRH.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

Subjective Burden in Mothers of Speech-Impaired Children

from Folia Phoniatrica et Logopaedica

Objective: Evaluation of perceived subjective burden in mothers of speech-impaired children against the presence or absence of an emotional disorder. Methods: 89 mothers (age 33;3 ± 5;5 years, range: 19;6-43;8 years) of 89 preschool children (23 girls, 66 boys, age: 3;9 ± 1;5 years, range: 1;6- 7;1 years) with specific speech impairment were investigated. German versions of the Hospital Anxiety and Depression Scale (HADS) and the Burden Scale for Family Caregivers (BSFC) were applied. Results: 11% of the mothers met criteria for a depressive disorder (normal controls: 2.5%; p = 0.008). Twenty-eight percent of the mothers met criteria for anxiety disorders (normal controls: 9.6%; p = 0.000). The HADS depression subscore and the BSFC correlate with r = 0.75. The HADS anxiety subscore and the BSFC correlate with r = 0.59. Conclusions: Results suggest the need for routine clinical assessment of mothers’ well-being when their children are affected by speech impairment.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

Perceptual Voice Characteristics in Chronic Cough and Paradoxical Vocal Fold Movement

from Folia Phoniatrica et Logopaedica

Voice problems have been reported in chronic cough (CC) and paradoxical vocal fold movement (PVFM), however, there is a lack of a systematic description of voice characteristics in these conditions. This study examined the perceptual voice characteristics of 56 individuals with CC, 8 with PVFM and 55 with both CC and PVFM, compared to 25 people with muscle tension dysphonia (MTD) and 27 healthy controls. There was a high prevalence of abnormal voice quality in the CC and PVFM groups compared with healthy controls. More than one third of participants with CC and PVFM demonstrated strained, rough and/or breathy voices to a moderate or severe degree. The perceptual features in CC and PVFM were similar to those in MTD with greater severity evident in MTD. Possible mechanisms for abnormalities in voice quality include the presence of muscle tension and the frequency of coughing. These results have implications for the identification and management of voice disorders in CC and PVFM and suggest that clinicians should be alert to the incidence of voice abnormalities in these populations.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

Early Phonological Development in Arabic Egyptian Children: 12-30 Months

from Folia Phoniatrica et Logopaedica

Phonological development is a dynamic process that operates on three levels: universal development, specific language development, and specific child development. An intricate relationship between the three factors delineates the course of acquisition of each child’s phonemic inventory. This study is designed to investigate the phonemic inventory and the phonological processes used by Arabic Egyptian children in order to evaluate cross-linguistic similarities and differences. Thirty Egyptian children with Cairene dialect, in the age period between 12 and 30 months, were included and divided into three groups, each covering a 6-month interval. A 1-hour tape recording for each child was done, followed by analysis of the phonemic inventory and phonological processes. Phonemic inventories showed universal similarities, with frequent occurrence of stops, nasals, and glides mostly in the form of bilabial and alveolar sounds. This is besides a specific tendency for early frequent production of laryngeal phonemes. Glottal replacement was found to be a common and naturally occurring phonological process, leading to frequent occurrence of glottal stop /U/ in the inventories of Egyptian children. The final position of the word showed the highest degree of correct phoneme production.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

Cortical Auditory Evoked Potentials to Acoustic Changes in Speech Stimuli in Children

from Folia Phoniatrica et Logopaedica

Objective: To compare the maturation of speech-evoked N170 components of cortical auditory evoked potentials with that of tone-evoked N1 components. Patients and Methods: Cortical auditory evoked potentials to speech and tone stimuli were derived in 42 children from age 4 to 14 years. The N170 was derived from the difference curve of responses to monosyllabic words with initial consonant-to-vowel transitions and their intensity-equivalent noise signals. Results: The incidence of N1 increased from 71% below age 9 to 91% above, that of N170 tended to increase from 40 to 67% above. From age 9, adult-like morphologies of the difference waveforms were found and the time constants of N1 and N170 latency maturation were nearly identical. Conclusion: The N170 component is interpreted as a response to speech-specific acoustic changes such as the consonant-vowel transition. The late appearance of N170 indicates an electrophysiological correlate of speech perception that continues to develop into adolescence. Its clinical application, however, is limited due to the low incidence of N170.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

Comfortable Effort Level in Young Children’s Speech

from Folia Phoniatrica et Logopaedica

The variability in comfortable effort level across experimental sessions as assessed by measures of speaking fundamental frequency (SFF) and vocal intensity (VI) has been reported for normal adult speakers. However, no such data are available for young children. The goal of this study was to determine the variability in SFF and VI seen in normally developing young children. Fifteen males and 14 females between the ages of 3 and 4 years were asked to repeat a vowel, a sentence, and four words at a comfortable speaking level on 3 separate days, each 1 week apart. SFF and VI were determined for each utterance. Statistical treatment of the data revealed that when combining all the data, there were no significant differences for mean SFF or VI across test sessions. However, the young females generally spoke with greater VI than young males. These results suggest that normal-speaking children at a very young age are, on the average, similar in the degree of variability to adults for SFF and VI across experimental sessions when asked to set their own level of output. These findings provide a baseline for the extent of variability in SFF and VI seen in normally developing young children.

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

Diagnostic Value of Nasometry - Representative Study of Patients with Cleft Palate and Normal Subjects

from Folia Phoniatrica et Logopaedica

In the rehabilitation of cleft palate patients the quality of spoken language represents one of the most important aspects of successful social integration. It is therefore necessary to direct special attention to phoniatric care and speech therapy following operative reconstruction. One of the main problems is the comparison of subjective and objective measures of the degree and type of nasal disorder. In an interdisciplinary project at the University of Jena nasometry was assessed. Due to a lack of norm values for German a representative sample for the calibration of cleft palate patients and normal subjects was collected. Speech was elicited using standardized and phonetically validated reading materials. Nasalance measurements were compared with judgements made by a group of trained listeners who were asked to assess voice quality (RBH) and nasality. A database containing nasalance values and acoustic signals from 120 subjects was built up. The results generally exhibited highly significant correlations between instrumental measurements and auditory judgements. Profiles of norm values for a phonetically and statistically reliable standard for German were obtained, which in turn can be used as a comparative basis for further studies. (Article in German)

August 31, 2007 Posted by Callier Library | Uncategorized | | No Comments

A Patient With Bipolar Illness and Her Neuropsychological Signature

from Clinical Case Studies

This article describes a case study in which neuropsychological assessment was carried out on a 30-year-old, previously diagnosed, bipolar female to determine existence of specific deficits in cognitive function. The patient, whose mood cycles were 12 hours to 24 hours, was subsequently evaluated 8 hours per day for 5 consecutive days (a complete work week of neuropsychological assessment). Neuropsychological results showed motor slowing, right hemispheric dysfunctioning, and memory problems during depressive periods and attentional and executive problems during hypomanic and manic periods. The most normal performance was found during euthymic periods. In addition, left and right hemi visual neglect, aphasia, and sensorimotor problems were present across all mood states. Treatment implications are subsequently described.

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Vestibular signal processing in a proprioceptively deafferented subject: The case of sitting posture

from BMC Neurology

Background

The vestibular system of the inner ear provides information about head translation/rotation in space and about the orientation of the head with respect to the gravitoinertial vector. It also largely contributes to the control of posture through vestibulospinal pathways. Testing an individual severely deprived of somatosensory information below the nose, we investigated if equilibrium can be maintained while seated on the sole basis of this information.

Results

Although she was unstable, the deafferented subject (DS) was able to remain seated with the eyes closed in the absence of feet, arm and back supports. However, with the head unconsciously rotated towards the left or right shoulder, the DS’s instability markedly increased. Small electrical stimulations of the vestibular apparatus produced large body tilts in the DS contrary to control subjects who did not show clear postural responses to the stimulations.

Conclusions

The results of the present experiment show that in the lack of vision and somatosensory information, vestibular signal processing allows the maintenance of an active sitting posture (i.e. without back or side rests). When head orientation changes with respect to the trunk, in the absence of vision, the lack of cervical information prevents the transformation of the head-centered vestibular information into a trunk-centered frame of reference of body motion. For the normal subjects, this latter frame of reference enables proper postural adjustments through vestibular signal processing, irrespectively of the orientation of the head with respect to the trunk.

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Effects of Selective Attention on the Electrophysiological Representation of Concurrent Sounds in the Human Auditory Cortex

from the Journal of Neuroscience

In noisy environments, we use auditory selective attention to actively ignore distracting sounds and select relevant information, as during a cocktail party to follow one particular conversation. The present electrophysiological study aims at deciphering the spatiotemporal organization of the effect of selective attention on the representation of concurrent sounds in the human auditory cortex. Sound onset asynchrony was manipulated to induce the segregation of two concurrent auditory streams. Each stream consisted of amplitude modulated tones at different carrier and modulation frequencies. Electrophysiological recordings were performed in epileptic patients with pharmacologically resistant partial epilepsy, implanted with depth electrodes in the temporal cortex. Patients were presented with the stimuli while they either performed an auditory distracting task or actively selected one of the two concurrent streams. Selective attention was found to affect steady-state responses in the primary auditory cortex, and transient and sustained evoked responses in secondary auditory areas. The results provide new insights on the neural mechanisms of auditory selective attention: stream selection during sound rivalry would be facilitated not only by enhancing the neural representation of relevant sounds, but also by reducing the representation of irrelevant information in the auditory cortex. Finally, they suggest a specialization of the left hemisphere in the attentional selection of fine-grained acoustic information. 

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Hearing from Inside: The Latest on Otologics Prosthesis

from MedGadget.com

To update our readers, The MIT Technology Review has an article on a fully implantable hearing prosthesis from Otologics that we wrote about a year ago.

The device is powered by a battery that is recharged when the user places a small radio transmitter against his or her head for 60 to 90 minutes. The transmitter is held to the skin by a magnet in the implant. An inductive coil in the implant converts the radio energy to electricity and recharges the battery with it. The battery can stay inside the body for at least five years, according to the company, before it needs to be replaced. The implanted components are hermetically sealed together to protect against leaks, so the electronics, microphone, and inductive coil are replaced as well. However, the piston in the middle ear remains in place.The results of a phase I clinical trial of the hearing aid were reported in the August 2007 issue of Otolaryngology–Head and Neck Surgery. Twenty subjects with moderate to severe hearing loss were implanted in one ear. (Seventeen of the subjects had worn conventional hearing aids prior to the study.) The subjects did somewhat worse than with the hearing aid they had previously worn: their ability to hear a range of single-frequency tones dropped between 5 and 12 decibels, and mean word-recognition scores dropped from the low 80 percent range to the high 60 percent range.

On the other hand, a satisfaction survey found that the subjects felt that the device not only improved their hearing, but also sounded more natural than their old hearing aid. The authors of the study speculated that new processing algorithms would improve the test results. Otologics has indicated that it is already working on this.

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Aid boost for hearing research

from News-Medical.net

Research at the University of Essex into aiding people with hearing impairments has won a grant of nearly half a million pounds.

Professor Ray Meddis of the Department of Psychology and his team of Wendy Lecluyse and Robert Ferry, have been awarded £447,000 by the Engineering and Physical Sciences Research Funding council to develop a computerised hearing dummy. In addition, they have been given £50,000 by the Deafness Research Council.

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Young children associate novel words with complex objects rather than salient parts

from Developmental Psychology

How do children learn associations between novel words and complex perceptual displays? Using a visual preference procedure, the authors tested 12- and 19-month-olds to see whether the infants would associate a novel word with a complex 2-part object or with either of that object’s parts, both of which were potentially objects in their own right and 1 of which was highly salient to infants. At both ages, children’s visual fixation times during test were greater to the entire complex object than to the salient part (Experiment 1) or to the less salient part (Experiment 2)–when the original label was requested. Looking times to the objects were equal if a new label was requested or if neutral audio was used during training (Experiment 3). Thus, from 12 months of age, infants associate words with whole objects, even those that could potentially be construed as 2 separate objects and even if 1 of the parts is salient. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

This cat has nine lives? Children’s memory for genericity in language

from Developmental Psychology

Generic noun phrases (”Birds lay eggs”) are important for expressing knowledge about abstract kinds. The authors hypothesized that genericity would be part of gist memory, such that young children would appropriately recall whether sentences were presented as generic or specific. In 4 experiments, preschoolers and college students (N = 280) heard a series of sentences in either generic form (e.g., “Bears climb trees”) or specific form (e.g., “This bear climbs trees”) and were asked to recall the sentences following a 4-min distractor task. Participants in all age groups correctly distinguished between generic and specific noun phrases (NPs) in their recall, even when forgetting the details of the NP form. Memory for predicate content (e.g., “climb trees”) was largely unaffected by genericity, although memory for category labels (e.g., “bear”) was at times better for those who heard sentences with generic wording. Overall, these results suggest that generic form is maintained in long-term memory even for young children and thus may serve as the foundation for constructing knowledge about kinds. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

The varieties of speech to young children

from Developmental Psychology

This article examines caregiver speech to young children. The authors obtained several measures of the speech used to children during early language development (14-30 months). For all measures, they found substantial variation across individuals and subgroups. Speech patterns vary with caregiver education, and the differences are maintained over time. While there are distinct levels of complexity for different caregivers, there is a common pattern of increase across age within the range that characterizes each educational group. Thus, caregiver speech exhibits both long-standing patterns of linguistic behavior and adjustment for the interlocutor. This information about the variability of speech by individual caregivers provides a framework for systematic study of the role of input in language acquisition. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Language access and theory of mind reasoning: Evidence from deaf children in bilingual and oralist environments

from Developmental Psychology

This investigation examined whether access to sign language as a medium for instruction influences theory of mind (ToM) reasoning in deaf children with similar home language environments. Experiment 1 involved 97 deaf Italian children ages 4-12 years: 56 were from deaf families and had LIS (Italian Sign Language) as their native language, and 41 had acquired LIS as late signers following contact with signers outside their hearing families. Children receiving bimodal/bilingual instruction in LIS together with Sign-Supported and spoken Italian significantly outperformed children in oralist schools in which communication was in Italian and often relied on lipreading. Experiment 2 involved 61 deaf children in Estonia and Sweden ages 6-16 years. On a wide variety of ToM tasks, bilingually instructed native signers in Estonian Sign Language and spoken Estonian succeeded at a level similar to age-matched hearing children. They outperformed bilingually instructed late signers and native signers attending oralist schools. Particularly for native signers, access to sign language in a bilingual environment may facilitate conversational exchanges that promote the expression of ToM by enabling children to monitor others’ mental states effectively. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

It’s a sign of the kind: Gestures and words guide infants’ inductive inferences

from Developmental Psychology

The role of words and gestures in guiding infants’ inductive inferences about nonobvious properties was examined. One hundred seventy-two 14-month-olds and 22-month-olds were presented with novel target objects followed by test objects that varied in similarity to the target. Objects were introduced with a novel word or a novel gesture or with no label. When target and test objects were highly similar in shape, both 14- and 22-month-olds inferred that these objects shared a nonobvious property, regardless of whether the objects were labeled with a word or a gesture or with no label. When objects were labeled with the same word, both 14- and 22-month-olds generalized the nonobvious properties to objects that shared minimal perceptual similarity. Finally, when objects were labeled with the same gesture, 14-month-olds, but not 22-month-olds, generalized the nonobvious properties to objects that shared minimal perceptual similarity. These results indicate that 14-month-olds possess a more generalized symbolic system as they will rely on both words and gestures to guide their inferences. By 22-months of age, infants treat words as a privileged referential form when making inductive inferences. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Do 9-month-old infants expect distinct words to refer to kinds?

from Developmental Psychology

In 3 experiments, 9-month-old infants’ expectations for what distinct count noun labels refer to were investigated. In Experiment 1, a box was opened to reveal 2 objects inside during familiarization: either 2 identical objects or 2 different objects. Test trials followed the same procedure, except before the box was opened, the contents were described using 2 distinct labels (”I see a wug! I see a dak!”) or the same label twice (”I see a zav! I see a zav!”). Infants who heard a label repeated twice looked longer at 2 different objects versus 2 identical objects, whereas infants who heard 2 distinct labels showed a different pattern of looking. Experiments 2 and 3 presented infants with object pairs that only differed in shape or color, and it was found that infants expected the different-shaped (but not the different-colored) objects to be labeled by distinct count nouns. Because the property of shape is a cue to kind membership and the property of color is not, these results suggest that even at the beginning of word learning, infants may expect distinct labels to refer to distinct kinds of objects. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

A role for epigenetics in hearing: Establishment and maintenance of auditory specific gene expression patterns

from Hearing Research

Epigenetics is a large and diverse field encompassing a number of different mechanisms essential to development, DNA stability and gene expression. DNA methylation and histone modifications work individually and in conjunction with each other leading to phenotypic changes. An overwhelming amount of evidence exists demonstrating the essential nature of epigenetics to human biology and pathology. This field has spawned a vast array of knowledge, techniques and pharmaceuticals designed to investigate and manipulate epigenetic phenomena. Despite its centricity to molecular biology, little work has been conducted examining how epigenetics affects hearing. In this review, we discuss both the basic tenets of epigenetics and highlight the most recent advances in this field. We discuss its importance to human development, genomic stability, gene expression, epigenetic modifying agents as well as briefly introduce the expansive field of cancer epigenetics. We then examine the evidence of a role for epigenetics in hearing related processes and hearing loss. The article concludes with a discussion of areas of epigenetic research that could be applied to hearing research.

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Effects of fast head turns on head, trunk and pelvis motions during standing and walking in patients with unilateral vestibular deficit

from the Journal of Vestibular Research

Patients with unilateral vestibular deficit (UVD) report difficulties with maintaining balance while executing fast head turns. Our aim was to determine whether head, trunk, and pelvis angular displacements were symmetrical in patients with UVD as they executed voluntary yaw rotation of the head towards or away from the side of the vestibular lesion, during standing and walking. Eight patients who underwent surgical resection of an acoustic neuroma stood with feet together or walked at comfortable pace across a 10-meter walkway. They turned the head as quickly and as fast as possible in the direction indicated by an illuminating arrow (left, right or none). The head angular displacement was similar towards the affected and intact sides. Acceleration tended to be larger during head rotations towards the affected versus the intact side by 13% at the head, 42% at the trunk and 37% at the pelvis (p> 0.05, NS). The pelvis rotated opposite to the head in 65% of trials towards the affected side and 56% of the trials towards the intact side during standing and 81% and 69%, respectively during walking. Overall, the UVD had only a minor influence on the symmetry of head, trunk and pelvis kinematics during fast yaw rotation of the head executed during standing and walking.

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Vestibular evoked myogenic potential threshold and seasickness susceptibility

from the Journal of Vestibular Research

Numerous attempts have been made to find physiological parameters that might predict susceptibility to seasickness. However, to date, no physiological index has been found that can serve as a diagnostic tool for individual susceptibility to motion sickness at the personnel selection stage. A number of studies have demonstrated that linear acceleration in the vertical plane is the most provocative stimulus of motion sickness. The main physiological sensory modality responsible for monitoring vertical acceleration is the saccule. Over the last decade, vestibular evoked myogenic potentials (VEMP) have come to be recognized as a reliable procedure for the evaluation of saccular function. We used the VEMP test to assess otolith responses in 15 seasickness-susceptible (SS) and 15 non-seasickness-susceptible (NSS) healthy male crew members. The SS group exhibited a significantly higher VEMP threshold and a significantly lower peak-to-peak p13-n23 amplitude interval compared with the NSS group. Further analysis by logistic regression found threshold to be the dominant factor associated with seasickness susceptibility. The study demonstrated differences in the VEMP reflex of the SS and NSS groups. The threshold difference may represent an intrinsic mechanistic difference between the vestibular systems of the two groups. Theoretically, increased susceptibility to seasickness may be due to a discrepancy between the various neural systems as a result of reduced otolith responses.

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

Modification of compensatory saccades after aVOR gain recovery

from the Journal of Vestibular Research

The recruitment of extra-vestibular mechanisms to assist a deficient angular vestibulo-ocular reflex (aVOR) during ipsilesional head rotations is well established and includes saccades of reduced latency that occur in the direction of the lesioned aVOR, termed compensatory saccades (CS). Less well known is the functional relevance of these unique saccades. Here we report a 42 y.o. male diagnosed with right unilateral vestibular hypofunction due to vestibular neuronitis who underwent a vestibular rehabilitation program including gaze stabilization exercises. After three weeks, he had a significant improvement in his ability to see clearly during head rotation. Our data show a reduction in the recruitment and magnitude of CS as well as improved peripheral aVOR gain (eye velocity/head velocity) and retinal eye velocity. Our data suggest an inverse, dynamic relationship between the recruitment of CS and the gain of the aVOR.

August 30, 2007 Posted by Callier Library | Uncategorized | | No Comments

To “EE” or Not to “EE”

from the Journal of Otolaryngology

OBJECTIVE:

To assess whether /i:/ (“ee”) is the best sound to use during indirect laryngoscopy to produce the optimal view of the larynx.

DESIGN:

Prospective study.

SETTING:

District general hospital otolaryngology outpatient clinic.

PATIENTS:

Eighty-seven patients from a general otolaryngology clinic with no laryngeal or pharyngeal symptoms or pathology.

MAIN OUTCOME MEASURES:

The views obtained during indirect laryngoscopy and vocalization of /i:/ (“ee”), /ei/ (“ay”), /з:/ (“err”), /a:/ (“ah”), and /eă/ (“air”) were graded according to a laryngoscopy grading system.

RESULTS:

The greatest number of adequate views of the larynx was achieved by using the sounds /i:/ and /з:/. There was no significant difference between /i:/ and /з:/ (p  =  .740), but there were significant differences between /i:/ and /ei/ (p  =  .019), /i:/ and /a:/ (p  =  .00000), and /i:/ and /eă/ (p  =  .00013).

CONCLUSION:

For the optimal view of the larynx during indirect laryngoscopy, we recommend the use of the sounds /i:/ (“ee”) and /з:/ (“err”).

August 29, 2007 Posted by Callier Library | Uncategorized | , | No Comments

Shopping for Perfection: Ethics and Deafness in the 21st Century

from the Journal of Deaf Studies and Deaf Education

No abstract available.

August 29, 2007 Posted by Callier Library | Uncategorized | | No Comments