March 1, 2013 Departments

From the Journals: March 2013

Relative Frequency Predicts Presence of Voice Disorders

Relative fundamental frequency—that is, voice frequency immediately before and after production of voiceless consonants—more accurately indicates the presence of a voice disorder than does voice quality severity or vocal effort, according to a study published in the December 2012 issue of the Journal of Speech, Language, and Hearing Research.

The authors aimed to determine the relationship between relative fundamental frequency and listeners' perception of vocal effort in people with varying degrees of vocal hyperfunction. Thirty women diagnosed with voice disorders commonly associated with vocal hyperfunction and 10 healthy women provided speech samples that were used to obtain parameters of relative fundamental frequency. Twelve listeners judged the speech samples for overall severity and vocal effort using rating scales.

Researchers found significant but relatively weak negative correlations between perceptual measures and offset relative fundamental frequency parameters. Although offset relative fundamental frequency was increased in healthy participants relative to speakers with voice disorders, listeners perceived no differences in relative fundamental frequency as a function of severity of vocal effort in people with voice disorders.

Researchers noted a statistically significant correlation between offset relative fundamental frequency and vocal effort, but examination of the data as a function of both vocal effort and health status indicated that relative fundamental frequency more accurately predicts a voice disorder. Further research is needed to investigate the clinical utility of relative fundamental frequency measures for assessment of rehabilitation progress.

Technology-Assisted Voice Treatment Effective for Parkinson's

A study published in the American Journal of Speech-Language Pathology shows the benefits of assistive software, the Lee Silverman Voice Treatment Companion, as an aid in treating hypokinetic dysarthria in people with Parkinson's disease.

The Companion software is designed to collect data on the variables trained during Lee Silverman Voice Treatment®, a system that uses motor and sensory retraining to target vocal loudness, which triggers improved function and coordination across the various subsystems of speech.

Researchers investigated the feasibility of using the Companion as an "at-home" clinician for a portion of treatment sessions. Researchers randomized 16 people with Parkinson's disease into immediate and delayed treatment groups. They participated in nine LSVT sessions and seven Companion sessions, independently administered at home.

Researchers compared the data on changes in vocal sound pressure level to data from a historical treatment group of people with Parkinson's who were treated with standard, in-person LSVT. All 16 participants were able to use the Companion independently, and showed therapeutic gains in sound pressure level similar to those in the historical treatment group.

Word Lists Aid Writing for Children With Complex Communication Needs

Word lists are helpful to inform vocabulary selection, organization and instruction for students who are beginning writers and have complex communication needs, according to a study published in the January 2013 issue of Language, Speech, and Hearing Services in Schools. The study extends previous research by examining the vocabulary used in different genres, and underlines the importance of providing access to genre-appropriate vocabulary choices to students with complex communication needs.

Researchers examined the vocabulary words and multiword sequences used by 124 typically developing kindergarten and first-grade students when they wrote about self-selected topics. Using the Child Language Analysis software program, they analyzed a total of 457 writing samples, classified according to nine genres: label, story, narrative recount, plan, procedure, description, report, opinion or explanation.

The authors found that 140 words represented 70 percent of the vocabulary produced. The most common genre types were narrative recounts and opinions, and the patterns of frequency for words and multiword sequences varied across genres. The degree of variation was greater for particular vocabulary words. For instance, the word "going" was used predominantly in one genre. In contrast, the word "mom" was used in every genre except three. Students tended to use structure words (e.g., determiners, pronouns, auxiliaries) with high frequency across genres.

Early Intervention for Granulomatosis With Polyangiitis Preserves Hearing

Early recognition and treatment for granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis) can reverse hearing loss and reduce the possibility of disease progression, complications and the need for aggressive treatment, according to a study published in the December 2012 issue of the American Journal of Audiology. The study contrasts the reversal of hearing loss and prevention of disease progression with early recognition and treatment.

A rare disorder, granulomatosis with polyangiitis is a systemic, necrotizing granulomatous vasculitis that can affect, in particular, the lungs, sinuses and kidneys. The authors report two contrasting cases with antineutrophil cytoplasmic antibodies, which were positive for granulomatosis with polyangiitis, but presented initially in the form of both conductive and sensorineural hearing loss without systemic features.

Researchers measured changes in hearing using a GSI 61 audiometer, as well as guidelines from the British Society of Audiology, and detected serum antineutrophil cytoplasmic antibodies by indirect immunofluorescence and formalin fixed neutrophils. They also measured proteinase 3 and myeloperoxidase antibodies using a fluoroenzyme immunoassay.

The study's results suggest that deafness and systemic disease are more likely, and more aggressive therapy is required, when the diagnosis of granulomatosis with polyangiitis is delayed. Even in the absence of systemic symptoms, clinicians should consider granulomatosis with polyangiitis in cases of acute or subacute deafness presenting over days to weeks.

Negative or weak antineutrophil cytoplasmic antibodies should not exclude the possible diagnosis of granulomatosis with polyangiitis, and clinicians should maintain a high degree of suspicion.

Virtual Reality a Better Predictor of Cognitive Impairment?

Compared with paper-and-pencil tests, a virtual reality test developed at the University of Toronto Scarborough may better predict whether a cognitive impairment will have real-world consequences, according to a study in the June 2012 issue of Applied Neuropsychology Adult.

The Multitasking in the City Task asks participants to navigate their way through a computer-game-like virtual world in which they perform tasks such as delivering packages or running errands. Researchers administered a battery of standard tests as well as the virtual reality test to 13 people who had suffered stroke or traumatic brain injury. Participants also completed a questionnaire on how severely their cognitive deficits affected their daily lives. The standard tests didn't predict how big an impact the participants' cognitive deficits had on their daily lives as accurately as the virtual test.

Patients With Post-Concussion Syndrome Show Brain Disruptions

Magnetic resonance imaging reveals changes in the brains of people with post-concussion syndrome, according to a study published online in the December 2012 issue of Radiology. Researchers hope the results point the way to improved detection and treatment for the disorder.

Post-concussion syndrome affects approximately 20 to 30 percent of people who suffer mild traumatic brain injury, defined by the World Health Organization as a traumatic event causing brief loss of consciousness and/or transient memory dysfunction or disorientation. Symptoms include headache, poor concentration and memory difficulty. Conventional neuroimaging cannot distinguish which patients with mild TBI will develop post-concussion syndrome.

The study used MRI to examine the brains of 23 patients with mild TBI who had post-traumatic symptoms shortly after injury and 18 age-matched healthy controls. MRIs were taken during a resting state—when the brain is not engaged in a specific task—such as when the mind wanders or while daydreaming. The resting state is thought to involve connections among a number of regions, with the default mode network playing a particularly important role.

Results showed that after mild head injury, communication and information integration in the brain were disrupted among key neural structures. Researchers hypothesize that the brain may tap into different neural resources to compensate for the impaired function.

Discovery of Alzheimer's Molecular Pathway Reveals New Drug Targets

The detection of the molecular pathway that drives the changes seen in the brains of Alzheimer's patients has revealed new targets for drug discovery that could be exploited to combat the disease. The study, published in the Nov. 2012 issue of Molecular Psychiatry, gives the most detailed understanding yet of the complex processes leading to Alzheimer's.

The exact mechanisms of Alzheimer's disease remain somewhat of a mystery. Recent genome-wide association studies have identified the gene for a molecule called clusterin as a susceptibility factor for late-onset Alzheimer's disease. Because clusterin levels are also known to be elevated in the blood of patients with early-stage Alzheimer's, researchers wanted to explore its role in the progression of disease.

The team, led by researchers at King's College London Institute of Psychiatry, found amyloid—a molecule that builds up between brain cells—in mouse brain cells grown in the laboratory, and noted that its presence alters the amount of clusterin in these cells. Clusterin switches on a signaling pathway that drives changes associated with the formation of tangles inside the cells, another hallmark of the disease. When this signaling pathway was switched on in mice, the researchers observed an increase in tangle formation and evidence of cognitive defects. They also detected the signature of clusterin activation in the brains of people with Alzheimer's but not in the brains of people with other forms of dementia.

The signaling pathway turned on by clusterin involves interactions among a number of different molecules that could prove to be useful targets for the development of new drugs targeted at the progression—rather than the symptoms—of Alzheimer's.


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