Prevalence of Self-Reported Voice Concerns and Associated Risk Markers in a Nonclinical Sample of Military Service Members.

INTRODUCTION: Difficult communication environments are common in military settings, and effective voice use can be critical to mission success. This study aimed to estimate the prevalence of self-reported voice disorders among U.S. military service members and to identify factors that contribute to their voice concerns. METHOD: A nonclinical sample of 4,123 active-duty service members was recruited across Department of Defense hearing conservation clinics. During their required annual hearing evaluation, volunteers provided responses to voice-related questions including a slightly adapted version of the Voice Handicap Index-10 (VHI-10) as part of a larger survey about communication issues. Changepoint detection was applied to age and years of service to explore cohort effects in the reporting of voice concerns. Logistic regression analyses examined multiple available factors related to communication to identify factors associated with abnormal results on the VHI-10. RESULTS: Among the respondents, 41% reported experiencing vocal hoarseness or fatigue at least several times per year, and 8.2% (n = 336) scored above the recommended abnormal cut-point value of 11 on the VHI-10. Factors independently associated with the greatest risk for self-reported voice concerns were sex (female), cadmium exposure, vocal demands (the need for a strong, clear voice), and auditory health measures (frequency of experiencing temporary threshold shifts; self-reported hearing difficulties). CONCLUSIONS: Based on self-reported voice concerns and false negative rates reported in the literature, the prevalence of dysphonia in a large sample of active-duty service members is estimated to be 11.7%, which is higher than that in the general population. Certain predictors for voice concerns were expected based on previous literature, like female sex and voice use, but frequency of temporary threshold shifts and exposure to cadmium were surprising. The strong link between voice and auditory problems has particular implications regarding the need for effective communication in high-noise military and other occupational environments.

Orofacial Muscle Strength across the Dysarthrias.

This study compared orofacial muscle strength between normal and dysarthric speakers and across types of dysarthria, and examined correlations between strength and dysarthria severity. Participants included 79 speakers with flaccid, spastic, mixed spastic-flaccid, ataxic, or hypokinetic dysarthria and 33 healthy controls. Maximum pressure generation (Pmax) by the tongue, lips, and cheeks represented strength. Pmax was lower for speakers with mixed spastic-flaccid dysarthria for all tongue and lip measures, as well as for speakers with flaccid or spastic dysarthria for anterior tongue elevation and lip compression. Anterior tongue elevation and cheek compression tended to be lower than normal for the hypokinetic group. Pmax did not differ significantly between controls and speakers with ataxic dysarthria on any measure. Correlations were generally weak between dysarthria severity and orofacial weakness but were stronger in the dysarthria groups with more prominent orofacial weakness. The results generally support predictions that orofacial weakness accompanies flaccid and/or spastic dysarthria but not ataxic dysarthria. The findings support including type of dysarthria as a variable of interest when examining orofacial weakness in motor speech disorders.

Resting Respiratory Resistance in Female Teenage Athletes With and Without Exercise-Induced Laryngeal Obstruction.

OBJECTIVE: Exercise-induced laryngeal obstruction (EILO) occurs with paradoxical vocal fold motion or supraglottic collapse during moderate to vigorous exercise. Previously, Gallena et al (2015) reported lower-than-normal inspiratory (Ri) and expiratory (Re) resistances during resting tidal breathing (RTB) in female teenage athletes with EILO. This study aimed to replicate that unexpected result. METHOD: The Airflow Perturbation Device measured Ri and Re during three 1-minute trials of RTB in 16 teenage female athletes with EILO and 16 sex-, age-, and height-matched controls. Multiple linear regression examined group, age, height, and weight as predictors of Ri and Re. RESULTS: Ri and Re tended to be lower in the EILO group than the control group [Ri: F(1,30) = 3.58, P = 0.068, d = 0.686; Re: F(1,30) = 3.28, P = 0.080, d = 0.640], but there was no statistically significant difference in the overall effect [F(2,29) = 1.75, P = 0.192]. After one outlier for Re from the EILO group and her matched control were removed, the overall difference was statistically significant, F(2,27) = 3.38, P = 0.049, with Re primarily contributing to the difference [Ri: F(1,28) = 3.66, P = 0.066, d = 0.719; Re: F(1,28) = 5.69, P = 0.024, d = 0.899]. CONCLUSION: These results did not replicate the robust differences found previously between Ri and Re during RTB in teenage girls with and without EILO, but the results trended in the same direction and met criterion for statistical significance once an outlier was removed from analysis. Overall, the observation that resting respiratory resistances were lower in most teenage girls with EILO suggests that reduced tone of the laryngeal and/or lower airways may predispose young athletes to EILO.

Analysis of Discourse Production to Assess Cognitive Communication Deficits Following Mild Traumatic Brain Injury With and Without Posttraumatic Stress.

PURPOSE: Cognitive communication deficits can be difficult to assess in individuals with mild traumatic brain injury (mTBI). However, the use of discourse analysis as a direct and sensitive metric of cognitive communication skills has shown promising clinical utility for other TBI severity levels. This exploratory study investigated discourse production in service members and veterans (SMVs) with uncomplicated mTBI with and without posttraumatic stress disorder (PTSD) and SMVs with neither mTBI or PTSD. METHOD: Fifteen SMVs with mTBI and PTSD, 26 with mTBI, and 25 controls with no brain injury (NBI) and without PTSD were given a wordless picture story to elicit spontaneous discourse. Discourse samples were analyzed for global coherence, word count, the use of negative emotion words, cognitive process words, nonfluencies, and story completeness. RESULTS: Results revealed a significant difference between the mTBI (Mdn = 3.33) and NBI (Mdn = 3.50) groups, χ2(3) = 6.044, p = .017, ε2 = .03, for global coherence. Word count differed significantly between the mTBI + PTSD (Mdn = 135) and NBI (Mdn = 195) groups, χ2(3) = 7.968, p = .006, ε2 = .06. No other group differences were observed. DISCUSSION: Structural features of discourse production may serve as potential markers of cognitive communication deficits in mTBI. Furthermore, PTSD may contribute to verbal fluency deficits in individuals with mTBI. Additional research is needed to develop discourse-related measures that are more sensitive to the effects of mTBI and PTSD.

Syllabic Diadochokinesis in Adults With and Without Traumatic Brain Injury: Severity, Stability, and Speech Considerations.

Purpose Syllabic diadochokinesis (DDK) is a standard assessment task for motor speech disorders. This study aimed to compare rate and regularity of DDK according to the presence or absence of traumatic brain injury (TBI) and severity of TBI, examine the stability of DDK over time, and explore associations between DDK and extemporaneous speech. Method Military service members and veterans were categorized into three groups: no history of TBI (control), uncomplicated mild TBI (mTBI), and moderate through severe (including penetrating) TBI (msTBI). Participants produced rapid alternating-motion and sequential-motion syllable repetitions during one or two sessions. A semi-automated protocol determined syllabic rate and regularity. Perceptual ratings of selected participants' connected speech samples were compared to DDK results. Results Two hundred sixty-three service members and veterans provided data from one session and 69 from two sessions separated by 1.9 years (SD = 1.0). DDKs were significantly slower overall for mTBI and msTBI groups compared to controls. Regularity of productions did not differ significantly across groups. A significant Group × Task interaction revealed that the msTBI group produced sequential-motion syllable repetitions but not alternating-motion repetitions with greater regularity, whereas the opposite occurred for control and mTBI groups. DDK results did not differ significantly between sessions. Perceptual speech analysis for 30 participants, including 20 with atypical or questionable DDK performance, revealed two participants with mildly abnormal speech. Conclusions Overall, DDK productions are slower than normal in adults with moderate, severe, and penetrating TBI and are stable over time. Regularity of productions did not differentiate groups, although this result differed according to task. There were surprisingly few people identified with disordered speech, making comparisons to DDK data tenuous, and indicating that dysarthria is a rare complication in a population of adults with mostly uncomplicated mTBI who are not selected from referrals to a speech-language pathology clinic.

Predictors of swallowing outcomes in patients with combat-injury related dysphagia.

BACKGROUND: Traumatic injuries, such as those from combat-related activities, can lead to complicated clinical presentations that may include dysphagia. METHODS: This retrospective observational database study captured dysphagia-related information for 215 US military service members admitted to the first stateside military treatment facility after sustaining combat-related or combat-like traumatic injuries. A multidimensional relational database was developed to document the nature, course, and management for dysphagia in this unique population and to explore variables predictive of swallowing recovery using Bayesian statistical modeling and inferential statistical methods. RESULTS: Bayesian statistical modeling revealed the importance of maxillofacial fractures and soft tissue loss as primary predictors of poor swallowing outcomes. The presence of traumatic brain injury (TBI), though common, did not further complicate dysphagia outcomes. A more detailed examination and rating of videofluoroscopic swallow studies from a subset of 161 participants supported greater impairment for participants with maxillofacial trauma and no apparent relationship between having sustained a TBI and swallow functioning. CONCLUSION: These analyses revealed that maxillofacial trauma is a stronger indicator than TBI of dysphagia severity and slower or incomplete recovery following combat-related injuries. LEVEL OF EVIDENCE: Therapeutic/Care Management study, level IV.

Laryngeal Diadochokinesis Across the Adult Lifespan.

OBJECTIVE: Diadochokinetic tasks provide valuable clinical information regarding neuromuscular control and coordination. Laryngeal diadochokinesis (LDDK) has the potential to provide insight into the neuromotor functioning of the larynx, but interpretation is limited because of sparse normative data. This study provides normative data for LDDK tasks across the adult lifespan in men and women. METHOD: Neurologically and vocally normal women (n = 216) and men (n = 188), ages 20-89 years, produced rapid repetitions of /ʔʌ/ and /hʌ/ to assess adductory and abductory laryngeal articulatory coordination, respectively. Outcome variables included average rate and regularity (% jitter) from a 5-second sample using a commercially available data acquisition and analysis system and verified by hand. Analyses of variance examined the data for task, sex, and age by decade. RESULTS: LDDK rate decreased significantly with age (F[6,390] = 10.67, P < 0.001) but variability did not differ systematically across age (F[6,390] = 0.595, P = 0.734). Neither LDDK rate nor variability differed significantly between the sexes (F[1,390] = 0.938, P = 0.334; F[1,390] = 0.050, P = 0.824, respectively). The tasks differed in that LDDK for /ʔʌ/ was significantly faster than for /hʌ/ (F[1,390] = 7.237, P = 0.007), but they did not differ significantly for variability (F[1,390] = 0.695, P = 0.405). No significant interactions were revealed. CONCLUSION: Normative data for LDDK tasks can be combined across the sexes. Separate norms should be used across age groups, especially for adults in their 20s and 80s, and across the two LDDK tasks.

Clear versus casual consonant identification by hearing-impaired and normal-hearing listeners.

Hearing-impaired (HI) listeners who benefit from hearing-aid use in quiet often continue to have difficulty understanding speech in noise. Requesting talkers to speak clearly is one strategy to overcome this deficit. Paradoxically, one feature of clear speech is a shift to higher frequencies, which may move speech energy into a frequency range that is inaudible or more distorted for some HI listeners. Casual (or conversational) speech, on the other hand, may shift speech energy into a lower frequency range that is more audible or less distorted. This study examined the intelligibility of 21 amplified, casually- and clearly-spoken, US English coda consonants in nonsense syllables for 10 normal-hearing (NH) and 17 HI listeners. Most clear-speech consonants yielded higher recognition scores as expected. However, certain phonological processes common in casual speech, such as palatalization of higher frequency alveolar into lower frequency postalveolar consonants, generated significantly higher scores than their clear counterparts for some HI listeners in noise. These results have implications for coaching conversational partners of aided HI listeners. For the military, talkers can be instructed how to speak to Service members with hearing loss or in noisy environments.

Taste Manipulation and Swallowing Mechanics in Trauma-Related Sensory-Based Dysphagia.

Purpose This study explored the effects of high-concentration taste manipulation trials on swallow function in persons with sensory-based dysphagia. Method Dysphagia researchers partnered with clinical providers to prospectively identify traumatically injured U.S. military service members (N = 18) with sensory-based dysphagia as evidenced by delayed initiation and/or decreased awareness of residue/penetration/aspiration. Under videofluoroscopy, participants swallowed trials of 3 custom-mixed taste stimuli: unflavored (40% weight/volume [wt/vol] barium sulfate in distilled water), sour (2.7% wt/vol citric acid in 40% wt/vol barium suspension), and sweet-sour (1.11% wt/vol citric acid plus 8% wt/vol sucrose in 40% wt/vol barium suspension). Trials were analyzed and compared via clinical rating tools (the Modified Barium Swallow Impairment Profile [Martin-Harris et al., 2008] and the Penetration-Aspiration Scale [Rosenbek, Robbins, Roecker, Coyle, & Wood, 1996]). Additionally, a computational analysis of swallowing mechanics (CASM) was applied to a subset of 9 swallows representing all 3 tastants from 3 participants. Results Friedman's tests for the 3 stimuli revealed significantly (p < .05) improved functional ratings for Penetration-Aspiration Scale and pharyngoesophageal opening. CASM indicated differences in pharyngeal swallowing mechanics across all tastant comparisons (p ≤ .0001). Eigenvectors revealed increased tongue base retraction, hyoid elevation, and pharyngeal shortening for sweet-sour and, to a lesser extent, sour than for unflavored boluses. Conclusion Advantageous changes in certain parameters of oropharyngeal swallowing physiology were noted with high-intensity tastants per both clinical ratings and subsequent CASM, suggesting potential therapeutic application for taste manipulation.

Saliva Production and Enjoyment of Real-Food Flavors in People with and Without Dysphagia and/or Xerostomia.

Non-food gustatory stimulation has multiple potential therapeutic benefits for people with dysphagia and xerostomia. This study examined palatability and saliva flow associated with dissolvable flavored films. Taste strips with real-food flavors dissolved on the tongues of 21 persons with dysphagia and/or xerostomia and 21 healthy age- and sex-matched adults while sublingual gauze pads absorbed saliva over randomized 3-min trials. Participants rated taste enjoyment for each trial on a hedonic general labeled magnitude scale. Flavored strips elicited more saliva than baseline for both groups, and production was higher for controls than patients (M = 2.386 and 1.091 g, respectively; p = 0.036). Main effects of flavor were observed for saliva production (p = 0.002) and hedonics (p < 0.001). Hedonic ratings and saliva production were weakly correlated (r = 0.293, p < 0.001). Results support dissolvable taste strips as a tool for providing low-risk taste stimulation in dysphagia and for eliciting an increase in saliva flow that may provide temporary relief from dry mouth symptoms. The preferred flavors were, on average, also the ones that elicited greater saliva production. Taste strips have the potential to be beneficial for swallowing-related neural activity, timing, and safety in dysphagia. Further, they may ameliorate complications of xerostomia.

Swallowing Mechanics Associated With Artificial Airways, Bolus Properties, and Penetration-Aspiration Status in Trauma Patients.

Purpose: Artificial airway procedures such as intubation and tracheotomy are common in the treatment of traumatic injuries, and bolus modifications may be implemented to help manage swallowing disorders. This study assessed artificial airway status, bolus properties (volume and viscosity), and the occurrence of laryngeal penetration and/or aspiration in relation to mechanical features of swallowing. Method: Coordinates of anatomical landmarks were extracted at minimum and maximum hyolaryngeal excursion from 228 videofluoroscopic swallowing studies representing 69 traumatically injured U.S. military service members with dysphagia. Morphometric canonical variate and regression analyses examined associations between swallowing mechanics and bolus properties based on artificial airway and penetration-aspiration status. Results: Significant differences in swallowing mechanics were detected between extubated versus tracheotomized (D = 1.32, p < .0001), extubated versus decannulated (D = 1.74, p < .0001), and decannulated versus tracheotomized (D = 1.24, p < .0001) groups per post hoc discriminant function analysis. Tracheotomy-in-situ and decannulated subgroups exhibited increased head/neck extension and posterior relocation of the larynx. Swallowing mechanics associated with (a) penetration-aspiration status and (b) bolus properties were moderately related for extubated and decannulated subgroups, but not the tracheotomized subgroup, per morphometric regression analysis. Conclusion: Specific differences in swallowing mechanics associated with artificial airway status and certain bolus properties may guide therapeutic intervention in trauma-based dysphagia.

Neurogenic Orofacial Weakness and Speech in Adults With Dysarthria.

PURPOSE: This study compared orofacial strength between adults with dysarthria and neurologically normal (NN) matched controls. In addition, orofacial muscle weakness was examined for potential relationships to speech impairments in adults with dysarthria. METHOD: Matched groups of 55 adults with dysarthria and 55 NN adults generated maximum pressure (Pmax) against an air-filled bulb during lingual elevation, protrusion and lateralization, and buccodental and labial compressions. These orofacial strength measures were compared with speech intelligibility, perceptual ratings of speech, articulation rate, and fast syllable-repetition rate. RESULTS: The dysarthria group demonstrated significantly lower orofacial strength than the NN group on all tasks. Lingual strength correlated moderately and buccal strength correlated weakly with most ratings of speech deficits. Speech intelligibility was not sensitive to dysarthria severity. Individuals with severely reduced anterior lingual elevation Pmax (< 18 kPa) had normal to profoundly impaired sentence intelligibility (99%-6%) and moderately to severely impaired speech (26%-94% articulatory imprecision; 33%-94% overall severity). CONCLUSIONS: Results support the presence of orofacial muscle weakness in adults with dysarthrias of varying etiologies but reinforce tenuous links between orofacial strength and speech production disorders. By examining individual data, preliminary evidence emerges to suggest that speech, but not necessarily intelligibility, is likely to be impaired when lingual weakness is severe.

Dysphagia Management and Research in an Acute-Care Military Treatment Facility: The Role of Applied Informatics.

PURPOSE: This report describes the development and preliminary analysis of a database for traumatically injured military service members with dysphagia. METHODS: A multidimensional database was developed to capture clinical variables related to swallowing. Data were derived from clinical records and instrumental swallow studies, and ranged from demographics, injury characteristics, swallowing biomechanics, medications, and standardized tools (e.g., Glasgow Coma Scale, Penetration-Aspiration Scale). Bayesian Belief Network modeling was used to analyze the data at intermediate points, guide data collection, and predict outcomes. Predictive models were validated with independent data via receiver operating characteristic curves. RESULTS: The first iteration of the model (n = 48) revealed variables that could be collapsed for the second model (n = 96). The ability to predict recovery from dysphagia improved from the second to third models (area under the curve = 0.68 to 0.86). The third model, based on 161 cases, revealed "initial diet restrictions" as first-degree, and "Glasgow Coma Scale, intubation history, and diet change" as second-degree associates for diet restrictions at discharge. CONCLUSION: This project demonstrates the potential for bioinformatics to advance understanding of dysphagia. This database in concert with Bayesian Belief Network modeling makes it possible to explore predictive relationships between injuries and swallowing function, individual variability in recovery, and appropriate treatment options.

The Effect of Jaw Position on Perceptual and Acoustic Characteristics of Speech.

Bite blocks are used to stabilize the jaw and to isolate tongue and lip movements from that of the mandible during speech and nonspeech activities. Ten normally speaking young adults produced sentences with an unconstrained jaw and with unilateral placement of 2-mm and 5-mm bite blocks. Six listeners rated sentences spoken without either bite block as the most natural sounding. Spectral characteristics of /s/, /ʃ/ and /t/ (sibilant frication and stop bursts) differed significantly with than without bite blocks, such that mean spectral energy decreased, and variation and skew of spectral energy increased. Spectral kurtosis did not change for the group, but 2 participants exhibited highly kurtotic /s/ spectra without a bite block that normalized with bite blocks. The second formant frequency for the high vowel /i/ was lower with bite blocks; there was no systematic difference in F2 slope for diphthongs. Segmental and suprasegmental timing of speech articulation was not affected significantly by these small bite blocks. This study provides support for using small bite blocks to isolate the tongue from the jaw without large effects on speech, but cautions that speech is likely to sound less natural than when produced with an unconstrained jaw.

THE INFLUENCE OF LEXICAL FACTORS ON VOWEL DISTINCTIVENESS: EFFECTS OF JAW POSITIONING.

The phonetic characteristics of words are influenced by lexical characteristics, including word frequency and phonological neighborhood density (Baese-Berke & Goldrick, 2009; Wright, 2004). In our previous research, we replicated this effect with neurologically healthy young adults (Munson & Solomon, 2004). In research with the same set of participants, we showed that speech sounded less natural when produced with bite blocks than with an unconstrained jaw (Solomon, Makashay, & Munson, 2016). The current study combined these concepts to examine whether a bite-block perturbation exaggerated or reduced the effects of lexical factors on normal speech. Ten young adults produced more challenging lexical stimuli (i.e. infrequent words with many phonological neighbors) with shorter vowels and more disperse F1/F2 spaces than less challenging words (i.e. frequent words with few phonological neighbors). This difference was exaggerated when speaking with a 10-mm bite block, though the interaction between jaw positioning and lexical competition did not achieve statistical significance. Results indicate that talkers alter vowel characteristics in response both to biomechanical and linguistic demands, and that the effect of lexical characteristics is robust to the articulatory reorganization required for successful bite-block compensation.

Effects of Age, Sex, and Body Position on Orofacial Muscle Tone in Healthy Adults.

PURPOSE: Quantification of tissue stiffness may facilitate identification of abnormalities in orofacial muscle tone and thus contribute to differential diagnosis of dysarthria. Tissue stiffness is affected by muscle tone as well as age-related changes in muscle and connective tissue. METHOD: The Myoton-3 measured tissue stiffness in 40 healthy adults, including equal numbers of men and women in each of two age groups: 18-40 years and 60+ years. Data were collected from relaxed muscles at the masseter, cheek, and lateral tongue surfaces in two positions: reclined on the side and seated with head tilted. RESULTS: Tissue stiffness differed across age, sex, and measurement site with multiple interaction effects. Overall, older subjects exhibited higher stiffness coefficients and oscillation frequency measures than younger subjects whereas sex differences varied by tissue site. Effects of body position were inconsistent across tissue site and measurement. CONCLUSIONS: Although older subjects were expected to have lower muscle tone, age-related nonmuscular tissue changes may have contributed to yield a net effect of higher stiffness. These data raise several considerations for the development of accurate normative data and for future diagnostic applications of tissue stiffness assessment.

The Effect of Exercise on Respiratory Resistance in Athletes With and Without Paradoxical Vocal Fold Motion Disorder.

PURPOSE: An investigational, portable instrument was used to assess inspiratory (R(i)) and expiratory (R(e)) resistances during resting tidal breathing (RTB), postexercise breathing (PEB), and recovery breathing (RB) in athletes with and without paradoxical vocal fold motion disorder (PVFMD). METHOD: Prospective, controlled, repeated measures within-subject and between-groups design. Twenty-four teenage female athletes, 12 with and 12 without PVFMD, breathed into the Airflow Perturbation Device for baseline measures of respiratory resistance and for two successive 1-min trials after treadmill running for up to 12 min. Exercise duration and dyspnea ratings were collected and compared across groups. RESULTS: Athletes with PVFMD had lower than control R(i) and R(e) values during RTB that significantly increased at PEB and decreased during RB. Control athletes' R(e) decreased significantly from RTB to PEB but not from PEB to RB, whereas R(i) did not change from RTB to PEB but decreased from PEB to RB. Athletes without PVFMD ran longer, providing lower dyspnea ratings. CONCLUSION: Immediately following exercise, athletes with PVFMD experienced increased respiratory resistance that affected their exercise performance. The difference in resting respiratory resistances between groups is intriguing and could point to anatomical differences or neural adaptation in teenagers with PVFMD. The Airflow Perturbation Device appears to be a clinically feasible tool that can provide insight into PVFMD and objective data for tracking treatment progress.

Speech-related fatigue and fatigability in Parkinson's disease.

This study tested the assumption that speech is more susceptible to fatigue than normal in persons with dysarthria. After 1 h of speech-like exercises, participants with Parkinson's disease (PD) were expected to report increased perceptions of fatigue and demonstrate fatigability by producing less precise speech with corresponding acoustic changes compared to neurologically normal participants. Twelve adults with idiopathic PD and 13 neurologically normal adults produced sentences with multiple lingual targets before and after six 10-min blocks of fast syllable or word productions. Both groups reported increasing self-perceived fatigue over time, but trained listeners failed to detect systematic differences in articulatory precision or speech naturalness between sentences produced before and after speech-related exercises. Similarly, few systematic acoustic differences occurred. These findings do not support the hypothesis that dysarthric speakers are particularly susceptible to speech-related fatigue; instead, speech articulation generally appears to be resistant to fatigue induced by an hour of moderate functional exercises.

Computer-based cognitive rehabilitation research in a military treatment facility: Recruitment, compliance, and lessons learned.

BACKGROUND: Evidence-based approaches to cognitive rehabilitation are limited; however, new technologies such as brain-training computer programs provide opportunities for novel interventions. OBJECTIVE: This paper describes a randomized controlled training study in a military treatment facility with service members who had combat-related cognitive symptoms. It examines challenges in study design and implementation, and provides "lessons learned" with proposed solutions. METHODS: Participants were randomly assigned to one of two 6-week computer-based cognitive training (CBCT) programs or a treatment-as-usual (TAU) control group. Feasibility assessments included reasons for consent refusal, compliance, and drop-out rates. RESULTS: The intended sample size for the study was 114 participants before attrition. Of 291 patients referred over 2.5 years, 120 were eligible, 38 consented to participate, and 18 completed the study. Forty-two percent of the participants assigned to CBCT groups completed the required 30 sessions in 6.5 to 32 weeks. Study-design factors that affected enrollment and compliance included eligibility restrictions, lack of a computer-based control condition, and inflexible scheduling. CONCLUSIONS: Successful implementation of a high-dose computer-based clinical trial will require design changes such as expanded inclusion criteria, control by sham computer program or wait-list, dosing flexibility, and web-based options.

Perceptual and instrumental assessments of orofacial muscle tone in dysarthric and normal speakers.

Clinical assessment of orofacial muscle tone is of interest for differential diagnosis of the dysarthrias, but standardized procedures and normative data are lacking. In this study, perceptual ratings of tone were compared with instrumental measures of tissue stiffness for facial, lingual, and masticatory muscles in 70 individuals with dysarthria. Perceptual and instrumental tone data were discordant and failed to discriminate between five dysarthria types. These results raised concerns about the validity of Myoton-3 stiffness measures in the orofacial muscles. Therefore, a second study evaluated contracted and relaxed orofacial muscles in 10 neurotypical adults. Results for the cheek, masseter, and lateral tongue surface followed predictions, with significantly higher tissue stiffness during contraction. In contradiction, stiffness measures from the superior surface of the tongue were lower during contraction. Superior-to-inferior tongue thickness was notably increased during contraction. A third study revealed that tissue thickness up to ~10 mm significantly affected Myoton-3 measures. Altered tissue thickness due to neuromuscular conditions like spasticity and atrophy may have undermined the detection of group differences in the original sample of dysarthric speakers. These experiments underscore the challenges of assessing orofacial muscle tone and identify considerations for quantification of tone-related differences across dysarthria groups in future studies.