Adductor focal laryngeal Dystonia: correlation between clinicians’ ratings and subjects’ perception of Dysphonia

Background Although considerable research has focused on the etiology and symptomology of adductor focal laryngeal dystonia (AD-FLD), little is known about the correlation between clinicians’ ratings and patients’ perception of this voice disturbance. This study has five objectives: first, to determine if there is a relationship between subjects’ symptom-severity and its impact on their quality of life; to compare clinicians’ ratings with subjects’ perception of the individual characteristics and severity of AD-FLD; to document the subjects’ perception of changes in dysphonia since diagnosis; to record the frequency of voice arrest during connected speech; and, finally, to calculate inter-clinician reliability based on results from the Unified Spasmodic Dysphonia Rating Scale (USDRS) (Stewart et al, J Voice 1195-10, 1997). Methods Sixty subjects with AD-FLD who were receiving ongoing injections of BoNT participated in this study. Subjects’ mean age was 60.78 years and their mean duration of symptoms was 16.1 years. Subjects completed the Disease Symptom Questionnaire (DSQ) (specifically designed for this study) and the Voice Handicap Index-10 (VHI-10) (Jacobson et al, Am J Speech Lang Pathol 6:66–70, 1997) to measure the symptoms of their dysphonia and the impact of the disease on their quality of life. Two speech-language pathologists and two laryngologists used the Voice Arrest Measure (VAM) (specifically designed for this study) and the USDRS to independently rate voice recordings of 56/60 subjects. Results The mean VHI-10 score was 21.3 which is clinically significant. The results of the DSQ and the USDRS were highly correlated. The most severe symptoms identified by both subjects and clinicians were roughness, strain-strangled voice quality, and increased expiratory effort. Voice arrest, aphonia, and tremor were uncommon. Subjects rated their current voice quality at the time of reinjection (i.e., at the time of the study) as significantly better than at the time of their initial AD-FLD diagnosis (p < 0.0001). Inter-clinician reliability on the USDRS was significant at the 0.001 level. Conclusions The findings from the VHI-10 suggest that AD-FLD has a profound impact on quality of life. The results of the DSQ and the USDRS suggest that there is a strong correlation between subjects’ perception and clinicians’ assessment of the individual symptoms and the severity of the dysphonia. The findings from the VAM suggest that voice arrests are infrequent in subjects with AD-FLD who are receiving ongoing BoNT injections. The strong inter-clinician reliability on the USDRS suggests that it is an appropriate measure for identifying symptoms and severity of AD-FLD

The imperative to invest in science has never been greater

In order to sustain and improve the health of Americans, to ensure our ability to overcome new health challenges, and to realize the economic benefits of a vigorous scientific economy, we encourage our government to implement three actions. First, establish predictable, managed growth in the US scientific enterprise by establishing a sustainable and predictable real annual increase in science funding. This will require additional investments in the proven NIH-university partnership to maintain our world-leading position in biomedical science. Second, preserve the current cadre of well-trained junior scientists, including physician-scientists, and maintain a pipeline of young scientists motivated to innovate and improve health. Third, analyze changing health needs and priorities for health science–related investments in order to address ongoing shifts in population demographics and diseases, opportunities for improved prevention or treatment, and the availability of new scientific tools and disciplines. It is in the nation’s best interests -- for good health, for a robust economy, and for scientific leadership -- to advocate for strong federal support of biomedical science in America’s great research universities. Translation of this science yields enormous benefits to our nation’s health and to the economy

Environmentalism, pre-environmentalism, and public policy

In the last decade, thousands of new grassroots groups have formed to oppose environmental pollution on the basis that it endangers their health. These groups have revitalized the environmental movement and enlarged its membership well beyond the middle class. Scientists, however, have been unable to corroborate these groups' claims that exposure to pollutants has caused their diseases. For policy analysts this situation appears to pose a choice between democracy and science. It needn't. Instead of evaluating the grassroots groups from the perspective of science, it is possible to evaluate science from the perspective of environmentalism. This paper argues that environmental epidemiology reflects ‘pre-environmentalist’ assumptions about nature and that new ideas about nature advanced by the environmental movement could change the way scientists collect and interpret data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45449/1/11077_2005_Article_BF01006494.pd

Crystal Structure of the West Nile Virus Envelope Glycoprotein

The envelope glycoprotein (E) of West Nile virus (WNV) undergoes a conformational rearrangement triggered by low pH that results in a class II fusion event required for viral entry. Herein we present the 3.0-Å crystal structure of the ectodomain of WNV E, which reveals insights into the flavivirus life cycle. We found that WNV E adopts a three-domain architecture that is shared by the E proteins from dengue and tick-borne encephalitis viruses and forms a rod-shaped configuration similar to that observed in immature flavivirus particles. Interestingly, the single N-linked glycosylation site on WNV E is displaced by a novel α-helix, which could potentially alter lectin-mediated attachment. The localization of histidines within the hinge regions of E implicates these residues in pH-induced conformational transitions. Most strikingly, the WNV E ectodomain crystallized as a monomer, in contrast to other flavivirus E proteins, which have crystallized as antiparallel dimers. WNV E assembles in a crystalline lattice of perpendicular molecules, with the fusion loop of one E protein buried in a hydrophobic pocket at the DI-DIII interface of another. Dimeric E proteins pack their fusion loops into analogous pockets at the dimer interface. We speculate that E proteins could pivot around the fusion loop-pocket junction, allowing virion conformational transitions while minimizing fusion loop exposure

Laryngopharyngeal Sensory Discrimination Testing and the Laryngeal Adductor Reflex

Laryngopharyngeal sensory capacity has been determined by endoscopically administering air pulse stimuli to the mucosa innervated by the superior laryngeal nerve and asking the patient if he or she feels the stimulus. A potential shortcoming of this psychophysical testing (PT) procedure is that it is a subjective test, and patients with impaired cognition may not be able to perform the required task. In the search for an objective measure of laryngeal sensory function, we have observed that the laryngeal adductor reflex (LAR) is evoked at stimulus intensities similar to those capable of eliciting the psychophysical, or perceptual, response. The purpose of this study is to determine if the threshold for eliciting the LAR is the same as that of the sensory threshold. A specially designed endoscope was used to present air pulse stimuli (range 0.0 to 10 mm Hg) to the laryngopharynx in 20 healthy subjects and in 80 patients with dysphagia, using both PT and the LAR. The patients had a variety of underlying diagnoses, with stroke and chronic neurologic disease predominating (n = 65). In the control group and in the group of patients with dysphagia, there was no statistically significant difference between the median laryngopharyngeal sensory thresholds whether we used PT or the LAR (p > .05, Wilcoxon signed-rank test). The intraclass correlation for the total sample was .999 (U = .999, L = .998). Since psychophysical and sensorimotor reflex thresholds were not statistically significantly different and the intraclass correlation was close to a perfect correlation, we conclude that the LAR can be used as an objective and accurate clinical method of endoscopically assessing laryngopharyngeal sensory capacity

FEESST: A New Bedside Endoscopic Test of the Motor and Sensory Components of Swallowing

We here introduce an office or bedside method of evaluating both the motor and sensory components of swallowing, called fiberoptic endoscopic evaluation of swallowing with sensory testing (FEESST). FEESST combines the established endoscopic evaluation of swallowing with a technique that determines laryngopharyngeal (LP) sensory discrimination thresholds by endoscopically delivering air pulse stimuli to the mucosa innervated by the superior laryngeal nerve. Endoscopic assessment of LP sensory capacity followed by endoscopic visualization of deglutition was prospectively performed 148 times on 133 patients with dysphagia over an 8-month period. The patients had a variety of underlying diagnoses, with stroke and chronic neurologic disease predominating (n = 94). Subsequent to LP sensory testing, a complete dysphagia evaluation was conducted. Various food and liquid consistencies were dyed green, and attention was paid to their management throughout the pharyngeal stage of swallowing. Evidence of latent swallow initiation, pharyngeal pooling and/or residue, laryngeal penetration, laryngeal aspiration, and/or reflux was noted. Recommendations for therapeutic intervention were based on information obtained during the FEESST and often involved the employment of compensatory swallowing strategies, modification of the diet or its presentation, placement on non-oral feeding status, and/or referral to other related specialists. All patients successfully completed the examination. In 111 of the evaluations (75%), severe (>6.0 mm Hg air pulse pressure [APP]) unilateral or bilateral LP sensory deficits were found. With puree consistencies, 31% of evaluations with severe deficits, compared to 5% of evaluations with either normal sensitivity or moderate (4.0 to 6.0 mm Hg APP) LP sensory deficits, displayed aspiration (p <.001, χ2 test). With puree consistencies, 69% of evaluations with severe deficits, compared to 24% with normal or moderate deficits, displayed laryngeal penetration (p <.001, χ2 test). FEESST allows the clinician to obtain a comprehensive bedside assessment of swallowing that is performed as the initial swallowing evaluation for the patient with dysphagia

Supraglottic and Pharyngeal Sensory Abnormalities in Stroke Patients with Dysphagia

Dysphagia and aspiration are two devastating sequelae of stroke, accounting for nearly 40,000 deaths from aspiration pneumonia each year in the United States. While motor deficits in the larynx and pharynx are thought responsible for dysphagia and aspiration in stroke patients, no prior study has evaluated whether these patients also have sensory deficits. The aim of this study was to evaluate the sensory capacity of the laryngopharynx (LP) in supratentorial or brain stem stroke patients who presented with dysphagia. Fifteen stroke patients (mean age, 66.7 ± 13.8 [SD] years) were prospectively evaluated by means of our previously described method whereby air pulse stimuli were delivered via a flexible fiberoptic telescope to the mucosa innervated by the superior laryngeal nerve. There were 15 age-matched controls. No LP sensory deficits were found in any of the age-matched controls. In all stroke patients studied, either unilateral (n = 9) or bilateral (n=6) sensory deficits were identified. Deficits were defined as either a moderate impairment in sensory discrimination thresholds (3.5 to 6.0 mm Hg) or a severe sensory impairment (>6.0 mm Hg). These sensory discrimination thresholds were significantly greater than in age-matched controls (7.05 ± 0.17 mm Hg for the supratentorial group and 6.05 ± 1.22 mm Hg for the infratentorial group versus 2.61 ± 0.69 mm Hg for the controls). Among patients with unilateral deficits, sensory thresholds were moderately to severely elevated in all 9 cases on the affected side compared with the unaffected side (p < .01, Fisher's exact test). Moreover, the sensory thresholds of the unaffected side were not significantly different from those of age-matched controls (2.51 ± 0.25 mm Hg versus 2.61 ± 0.69 mm Hg, respectively). All 6 patients with bilateral deficits had severe impairments. The results of an outcome assessment in 13 of 15 patients revealed that 2 out of 5 patients with moderate LP sensory impairment and 5 out of 8 with severe impairment developed aspiration. Our results show for the first time that stroke patients with dysphagia have significant sensory deficits in the LP and that these impairments are likely to contribute to the development of aspiration

Silent Laryngopharyngeal Sensory Deficits after Stroke

Dysphagia and aspiration are two devastating sequelae of stroke. Recent work has shown that laryngopharyngeal (LP) sensory deficits are associated with aspiration in stroke patients with dysphagia. The phenomenon of silent LP sensory deficits, where the patient exhibits no subjective or objective evidence of dysphagia, yet has an LP sensory deficit, has not been previously described. The aim of this study was to evaluate the sensory capacity of the laryngopharynx in stroke patients who had no subjective or objective complaints of dysphagia. We determined the sensory threshold in the laryngopharynx using air pulse stimulation of the mucosa of the pyriform sinus and aryepiglottic fold. Eighteen stroke patients (mean age 65.6 ± 11.5 years) and 18 age-matched controls were prospectively evaluated. Normal thresholds were defined as 6.0 mm Hg APP). Stroke patients were followed up for 1 year to determine the incidence of aspiration pneumonia (AP) as verified by chest radiography. In 11 of the stroke patients studied, either unilateral (n = 6) or bilateral (n = 5) severe sensory deficits were identified. The elevations in sensory discrimination thresholds were significantly greater than those in age-matched controls (7.1 ± 0.6 mm Hg APP versus 2.5 mm Hg APP; p < .01, Wilcoxon score). Among patients with unilateral deficits, sensory thresholds were severely elevated in all cases on the affected side compared with the unaffected side (p < .01, Wilcoxon score). Moreover, the sensory thresholds of the unaffected side were not significantly different from those of age-matched controls. Aspiration pneumonia did not occur in the patients with normal LP sensation or in the patients with unilateral severe LP sensory deficits. However, in the 5 patients with bilateral, severe LP sensory deficits, 2 developed AP, both within 3 months of their LP sensory test. The results of this study showed, for the first time, that stroke patients without subjective or objective clinical evidence of dysphagia could have silent LP sensory deficits. These impairments could contribute to the development of AP following stroke. The findings in this study suggest that LP sensory discrimination threshold testing should not be restricted only to patients with clinical dysphagia