A Novel Tactile Function Assessment Using a Miniature Tactile Stimulator.

Several methods for the measurement of tactile acuity have been devised previously, but unexpected nonspatial cues and intensive manual skill requirements compromise measurement accuracy. Therefore, we must urgently develop an automated, accurate, and noninvasive method for assessing tactile acuity. The present study develops a novel method applying a robotic tactile stimulator to automatically measure tactile acuity that comprises eye-opened, eye-closed training, and testing sessions. Healthy participants judge the orientation of a rotating grating ball presented on their index fingerpads in a two-alternative forced-choice task. A variable rotation speed of 5, 10, 40, or 160 mm/s was used for the tactile measurement at a variety of difficulties. All participants met the passing criteria for the training experiment. Performance in orientation identification, quantified by the proportion of trials with correct answers, differed across scanning directions, with the highest rotation speed (160 mm/s) having the worst performance. Accuracy did not differ between vertical and horizontal orientations. Our results demonstrated the utility of the pre-test training protocol and the functionality of the developed procedure for tactile acuity assessment. The novel protocol performed well when applied to the participants. Future studies will be conducted to apply this method to patients with impairment of light touch.

Baseline Global Cognitive Function Affects Cognitive and Functional Outcomes of Combined Physical and Cognitive Training Among Older Adults With Cognitive Decline.

IMPORTANCE: Baseline global cognitive function may affect cognitive and functional outcomes during combined physical and cognitive training; however, how it influences the effects of combined training remains uncertain. OBJECTIVE: To determine the impact of baseline global cognitive function on cognitive and functional outcomes after combined physical and cognitive training among older adults with cognitive decline. DESIGN: Observational. SETTING: Local communities and senior centers. PARTICIPANTS: Older adults with mild cognitive decline (MCD; n = 51) and moderate to severe cognitive decline (MSCD; n = 40). INTERVENTION: Participants received 45 to 55 min of physical exercise training followed by 45 to 55 min of cognitive training in one session per week for 12 wk. Outcomes and Measures: Montreal Cognitive Assessment (MoCA), Lawton-Brody Instrumental Activities of Daily Living Scale (Lawton-Brody IADL), Word Recall Test (WRT), Stroop Color and Word Test (SCWT), Digital Symbol Substitution Test (DSST), and Trail Making Test (TMT) scores were assessed and compared between the MCD and MSCD groups. RESULTS: Significant interaction effects were found for the WRT, SCWT, MoCA, and Lawton-Brody IADL. WRT and SCWT scores significantly improved in the MCD group, whereas MoCA and Lawton-Brody IADL scores significantly improved in the MSCD group. DSST scores increased among all participants, but TMT scores improved only in the MCD group. CONCLUSIONS AND RELEVANCE: Older adults' baseline global cognitive function affected cognitive and instrumental activities of daily living (IADL) outcomes regarding combined training. High-level cognitive function, including inhibition and shifting abilities and working memory capacity, improved among older adults with MCD, whereas general cognitive function and IADLs improved among older adults with MSCD. What This Article Adds: Findings revealed domain-specific changes with respect to baseline cognitive function, which may help to refine current combined training protocols and facilitate development of personalized combined training programs for older adults with cognitive impairments.

Neuromodulatory Effects of Transcranial Direct Current Stimulation on Motor Excitability in Rats.

Transcranial direct current stimulation (tDCS) is a noninvasive technique for modulating neural plasticity and is considered to have therapeutic potential in neurological disorders. For the purpose of translational neuroscience research, a suitable animal model can be ideal for providing a stable condition for identifying mechanisms that can help to explore therapeutic strategies. Here, we developed a tDCS protocol for modulating motor excitability in anesthetized rats. To examine the responses of tDCS-elicited plasticity, the motor evoked potential (MEP) and MEP input-output (IO) curve elicited by epidural motor cortical electrical stimulus were evaluated at baseline and after 30 min of anodal tDCS or cathodal tDCS. Furthermore, a paired-pulse cortical electrical stimulus was applied to assess changes in the inhibitory network by measuring long-interval intracortical inhibition (LICI) before and after tDCS. In the results, analogous to those observed in humans, the present study demonstrates long-term potentiation- (LTP-) and long-term depression- (LTD-) like plasticity can be induced by tDCS protocol in anesthetized rats. We found that the MEPs were significantly enhanced immediately after anodal tDCS at 0.1 mA and 0.8 mA and remained enhanced for 30 min. Similarly, MEPs were suppressed immediately after cathodal tDCS at 0.8 mA and lasted for 30 min. No effect was noted on the MEP magnitude under sham tDCS stimulation. Furthermore, the IO curve slope was elevated following anodal tDCS and presented a trend toward diminished slope after cathodal tDCS. No significant differences in the LICI ratio of pre- to post-tDCS were observed. These results indicated that developed tDCS schemes can produce consistent, rapid, and controllable electrophysiological changes in corticomotor excitability in rats. This newly developed tDCS animal model could be useful to further explore mechanical insights and may serve as a translational platform bridging human and animal studies, establishing new therapeutic strategies for neurological disorders.

Voice aerodynamics following office-based hyaluronate injection laryngoplasty.

OBJECTIVES: Neuromuscular control, glottal conformation and aerodynamics are the major factors affecting voice performance. We aimed to characterise the degree to which voice improvements following office-based intracordal hyaluronate injection laryngoplasty (HIL) depend on changes in voice aerodynamics in patients with unilateral vocal fold paralysis (UVFP), by assessing the correlations between these parameters. DESIGN: Prospective case series. SETTING: Otolaryngology Clinics in a Medical Center. PARTICIPANTS: Patients with UVFP within 6 months of their first outpatient visit who received single HIL. MAIN OUTCOME MEASURES: Videolaryngostroboscopy, aerodynamics and laboratory voice analysis were evaluated at baseline and 1 month after HIL. Quantitative laryngeal electromyography was evaluated at baseline to confirm UVFP. RESULTS: Seventy-five newly diagnosed patients with UVFP were analysed. The normalised glottal gap area (NGGA) decreased (P < 0.001) (Cohen's dz  = 0.94) and all aerodynamic parameters improved (all P < 0.05) (Cohen's dz  = 0.38-1.02) following HIL. Patients undergoing thoracic surgery had more profound aerodynamic impairments both before and after HIL. After adjusting for improvements in NGGA, the improvement in aerodynamics was correlated with voice improvement and most notably with maximum phonation time and jitter/shimmer. CONCLUSIONS: Hyaluronate injection laryngoplasty improved glottal conformation, aerodynamics and voice, highlighting the benefit of early HIL intervention for patients with UVFP. Patients with UVFP caused by thoracic surgery continued to have poorer aerodynamics post-HIL, indicating the importance of speech therapy in these patients.

Intraoperative linguistic performance during awake brain surgery predicts postoperative linguistic deficits.

INTRODUCTION: Awake craniotomy pursues a balance between extensive tumor resection and preservation of postoperative language function. A dilemma exists in patients whose tumor resection is restricted due to signs of language impairment observed during awake craniotomy. In order to determine the degree to which recovery of language function caused by tumor resection can be achieved by spontaneous neuroplasticity, the change in postoperative language function was compared to quantified intraoperative linguistic performance. METHODS: The modified, short-form Boston Diagnostic Aphasia Examination (sfBDAE) was used to assess pre- and postoperative language functions; visual object naming (DO 80) and semantic-association (Pyramid and Palm Tree Test, PPTT) tests assessed intraoperative linguistic performance. DO 80 and PPTT were performed alternatively during subcortical functional monitoring while performing tumor resection and sfBDAE was assessed 1-week postoperatively. RESULTS: Most patients with observed language impairment during awake surgery showed improved language function postoperatively. Both intraoperative DO 80 and PPTT showed significant correlation to postoperative sfBDAE domain scores (p < 0.05), with a higher correlation observed with PPTT. A linear regression model showed that only PPTT predicted the postoperative sfBDAE domain scores with the adjusted R2 ranging from 0.51 to 0.89 (all p < 0.01). Receiver operating characteristic analysis showed a cutoff value of PPTT that yielded a sensitivity of 80% and specificity of 100%. CONCLUSION: PPTT may be a feasible tool for intraoperative linguistic evaluation that can predict postoperative language outcomes. Further studies are needed to determine the extent of tumor resection that optimizes the postoperative language following neuroplasticity.

The neural basis of tactile motion perception.

The manipulation of objects commonly involves motion between object and skin. In this review, we discuss the neural basis of tactile motion perception and its similarities with its visual counterpart. First, much like in vision, the perception of tactile motion relies on the processing of spatiotemporal patterns of activation across populations of sensory receptors. Second, many neurons in primary somatosensory cortex are highly sensitive to motion direction, and the response properties of these neurons draw strong analogies to those of direction-selective neurons in visual cortex. Third, tactile speed may be encoded in the strength of the response of cutaneous mechanoreceptive afferents and of a subpopulation of speed-sensitive neurons in cortex. However, both afferent and cortical responses are strongly dependent on texture as well, so it is unclear how texture and speed signals are disambiguated. Fourth, motion signals from multiple fingers must often be integrated during the exploration of objects, but the way these signals are combined is complex and remains to be elucidated. Finally, visual and tactile motion perception interact powerfully, an integration process that is likely mediated by visual association cortex.

Diagnostic Accuracy of Deep Learning for the Prediction of Osteoporosis Using Plain X-rays: A Systematic Review and Meta-Analysis.

(1) Background: This meta-analysis assessed the diagnostic accuracy of deep learning model-based osteoporosis prediction using plain X-ray images. (2) Methods: We searched PubMed, Web of Science, SCOPUS, and Google Scholar from no set beginning date to 28 February 2023, for eligible studies that applied deep learning methods for diagnosing osteoporosis using X-ray images. The quality of studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 criteria. The area under the receiver operating characteristic curve (AUROC) was used to quantify the predictive performance. Subgroup, meta-regression, and sensitivity analyses were performed to identify the potential sources of study heterogeneity. (3) Results: Six studies were included; the pooled AUROC, sensitivity, and specificity were 0.88 (95% confidence interval [CI] 0.85-0.91), 0.81 (95% CI 0.78-0.84), and 0.87 (95% CI 0.81-0.92), respectively, indicating good performance. Moderate heterogeneity was observed. Mega-regression and subgroup analyses were not performed due to the limited number of studies included. (4) Conclusion: Deep learning methods effectively extract bone density information from plain radiographs, highlighting their potential for opportunistic screening. Nevertheless, additional prospective multicenter studies involving diverse patient populations are required to confirm the applicability of this novel technique.

Predicting osteoporosis from kidney-ureter-bladder radiographs utilizing deep convolutional neural networks.

Osteoporosis is a common condition that can lead to fractures, mobility issues, and death. Although dual-energy X-ray absorptiometry (DXA) is the gold standard for osteoporosis, it is expensive and not widely available. In contrast, kidney-ureter-bladder (KUB) radiographs are inexpensive and frequently ordered in clinical practice. Thus, it is a potential screening tool for osteoporosis. In this study, we explored the possibility of predicting the bone mineral density (BMD) and classifying high-risk patient groups using KUB radiographs. We proposed DeepDXA-KUB, a deep learning model that predicts the BMD values of the left hip and lumbar vertebrae from an input KUB image. The datasets were obtained from Taiwanese medical centers between 2006 and 2019, using 8913 pairs of KUB radiographs and DXA examinations performed within 6 months. The images were randomly divided into training and validation sets in a 4:1 ratio. To evaluate the model's performance, we computed a confusion matrix and evaluated the sensitivity, specificity, accuracy, precision, positive predictive value, negative predictive value, F1 score, and area under the receiver operating curve (AUROC). Moderate correlations were observed between the predicted and DXA-measured BMD values, with a correlation coefficient of 0.858 for the lumbar vertebrae and 0.87 for the left hip. The model demonstrated an osteoporosis detection accuracy, sensitivity, and specificity of 84.7 %, 81.6 %, and 86.6 % for the lumbar vertebrae and 84.2 %, 91.2 %, and 81 % for the left hip, respectively. The AUROC was 0.939 for the lumbar vertebrae and 0.947 for the left hip, indicating a satisfactory performance in osteoporosis screening. The present study is the first to develop a deep learning model based on KUB radiographs to predict lumbar spine and femoral BMD. Our model demonstrated a promising correlation between the predicted and DXA-measured BMD in both the lumbar vertebrae and hip, showing great potential for the opportunistic screening of osteoporosis.

Shape invariant coding of motion direction in somatosensory cortex.

Invariant representations of stimulus features are thought to play an important role in producing stable percepts of objects. In the present study, we assess the invariance of neural representations of tactile motion direction with respect to other stimulus properties. To this end, we record the responses evoked in individual neurons in somatosensory cortex of primates, including areas 3b, 1, and 2, by three types of motion stimuli, namely scanned bars and dot patterns, and random dot displays, presented to the fingertips of macaque monkeys. We identify a population of neurons in area 1 that is highly sensitive to the direction of stimulus motion and whose motion signals are invariant across stimulus types and conditions. The motion signals conveyed by individual neurons in area 1 can account for the ability of human observers to discriminate the direction of motion of these stimuli, as measured in paired psychophysical experiments. We conclude that area 1 contains a robust representation of motion and discuss similarities in the neural mechanisms of visual and tactile motion processing.

Cross-modal sensory integration of visual-tactile motion information: instrument design and human psychophysics.

Information obtained from multiple sensory modalities, such as vision and touch, is integrated to yield a holistic percept. As a haptic approach usually involves cross-modal sensory experiences, it is necessary to develop an apparatus that can characterize how a biological system integrates visual-tactile sensory information as well as how a robotic device infers object information emanating from both vision and touch. In the present study, we develop a novel visual-tactile cross-modal integration stimulator that consists of an LED panel to present visual stimuli and a tactile stimulator with three degrees of freedom that can present tactile motion stimuli with arbitrary motion direction, speed, and indentation depth in the skin. The apparatus can present cross-modal stimuli in which the spatial locations of visual and tactile stimulations are perfectly aligned. We presented visual-tactile stimuli in which the visual and tactile directions were either congruent or incongruent, and human observers reported the perceived visual direction of motion. Results showed that perceived direction of visual motion can be biased by the direction of tactile motion when visual signals are weakened. The results also showed that the visual-tactile motion integration follows the rule of temporal congruency of multi-modal inputs, a fundamental property known for cross-modal integration.

Synergic Effect of Robot-Assisted Rehabilitation and Antispasticity Therapy: A Narrative Review.

BACKGROUND: Stroke and spinal cord injury are neurological disorders that cause disability and exert tremendous social and economic effects. Robot-assisted training (RAT), which may reduce spasticity, is widely applied in neurorehabilitation. The combined effects of RAT and antispasticity therapies, such as botulinum toxin A injection therapy, on functional recovery remain unclear. This review evaluated the effects of combined therapy on functional recovery and spasticity reduction. MATERIALS AND METHODS: Studies evaluating the efficacy of RAT and antispasticity therapy in promoting functional recovery and reducing spasticity were systemically reviewed. Five randomized controlled trials (RCTs) were included. The modified Jadad scale was applied for quality assessment. Functional assessments, such as the Berg Balance Scale, were used to measure the primary outcome. Spasticity assessments, such as the modified Ashworth Scale, were used to measure the secondary outcome. RESULTS: Combined therapy improves functional recovery in the lower limbs but does not reduce spasticity in the upper or lower limbs. CONCLUSIONS: The evidence supports that combined therapy improves lower limb function but does not reduce spasticity. The considerable risk of bias among the included studies and the enrolled patients who did not receive interventions within the golden period of intervention are two major factors that should be considered when interpreting these results. Additional high-quality RCTs are required.

A protocol for tactile function assessment using JVP domes: Feasibility study and preliminary results.

BACKGROUND: Touch is a crucial sense for perceiving the spatial characteristics of objects. The JVP dome was developed to evaluate tactile spatial acuity using a grating orientation task. There were few studies depicting sequences and details for the entire task, including practice, training, and testing sessions. Therefore, we proposed and elaborated a protocol for the grating orientation task using the staircase method, which required fewer testing trials compared with the method of constant stimuli. METHODS: Twenty-three healthy participants were enrolled in this experiment. The JVP domes with 11 different groove widths were used. Tactile discrimination thresholds were estimated using a two-down-one-up staircase method. The experiment comprised practice, training, and testing sessions, conducted by trained examiners who performed grating stimulation on participants' index fingerpads. RESULTS: All participants passed the required accuracy in the practice and training sessions. Eight transition points were obtained in the testing session for each participant. The tactile discrimination thresholds were determined from the last six transition points. We obtained the mean tactile discrimination threshold as 1.8 ± 0.75 mm (n = 23). The results demonstrated that the proposed protocol was successfully applied to assess tactile discrimination thresholds. CONCLUSIONS: The present study investigated the protocol of grating orientation tasks requiring a small number of testing trials with the assurance of the task quality. The feasibility study and preliminary results indicated the potentiality of this protocol for future clinical application.

Pathophysiological Mechanisms Underlying Unilateral Vocal Fold Paralysis in Female Patients: An Ultrasonographic Study.

OBJECTIVES: Laryngeal ultrasonography (LUS) has been suggested as an alternative diagnostic tool for unilateral vocal fold paralysis (UVFP). The present study applied LUS and quantitative laryngeal electromyography (LEMG) in female UVFP patients to investigate the pathophysiologic mechanisms of UVFP. METHODS: In this cross-sectional study, vocal fold (VF) length parameters included resting and phonating VF length measured using B-mode LUS, and color Doppler vibrating length (CDVL) measured using the color Doppler mode. RESULTS: Forty female patients with UVFP were enrolled, among whom 11 and 29 were assigned to the thyroarytenoid (TA) muscle+cricothyroid (CT) muscle group (with CT involvement) and the TA (without CT involvement) group, respectively. In the TA group, the turn frequency in thyroarytenoid-lateral cricoarytenoid (TA-LCA) on the paralyzed side, as observed through LEMG, correlated with the VF length during the resting phase (R=0.368, P=0.050) and CDVL values (R=0.627, P=0.000) on the paralyzed side. In the TA+CT group, the turn ratio in the CT muscle correlated with the normalized phonatory vocal length change (nPLC; R=0.621, P=0.041) on the paralyzed side. CONCLUSION: CDVL and nPLC are two parameters that can be utilized to predict the turn frequencies of TA-LCA in UVFP cases without CT involvement, and the turn ratio of CT in cases of UVFP with CT involvement, respectively. The findings suggest that LUS, as a noninvasive tool, can serve as an alternative method for assessing the severity of laryngeal nerve injury and offer valuable insights into the pathophysiology of UVFP.

Recovery of walking ability in stroke patients through postacute care rehabilitation.

BACKGROUND: Walking entails orchestration of the sensory, motor, balance, and coordination systems, and walking disability is a critical concern after stroke. How and to what extent these systems influence walking disability after stroke and recovery have not been comprehensively studied. METHODS: We retrospectively analyzed patients with stroke in the Post-acute care-Cerebrovascular Diseases (PAC-CVD) program. We compared the characteristics of patient groups stratified by their ability to complete the 5-m walk test across various time points of rehabilitation. We then used stepwise linear regression to examine the degree to which each stroke characteristic and functional ability could predict patient gait performance. RESULTS: Five hundred seventy-three patients were recruited, and their recovery of walking ability was defined by the timing of recovery in a 5-m walk test. The proportion of patients who could complete the 5-m walk test at admission, at 3 weeks of rehabilitation, at 6 weeks of rehabilitation, between 7 and 12 weeks of rehabilitation, and who could not complete the 5-m walk test after rehabilitation was 52.2%, 21.8%, 8.7%, 8.7%, and 8.6%, respectively. At postacute care discharge, patients who regained walking ability earlier had a higher chance of achieving higher levels of walking activity. Stepwise linear regression showed that Berg Balance Scale (BBS) (ß: 0.011, p < .001), age (ß: -0.005, p = .001), National Institutes of Health Stroke Scale (NIHSS) (6a + 6b; ß: -0.042, p = .018), Mini-Nutritional assessment (MNA) (ß: -0.007, p < .027), and Fugl-Meyer upper extremity assessment (FuglUE) (ß: 0.002, p = .047) scores predicted patient's gait speed at discharge. CONCLUSION: Balance, age, leg strength, nutritional status, and upper limb function before postacute care rehabilitation are predictors of walking performance after stroke.

Cricothyroid Dysfunction in Unilateral Vocal Fold Paralysis Females Impairs Lexical Tone Production.

In this cross-sectional study, we compared voice tone and activities relating to the laryngeal muscle between unilateral vocal fold paralysis (UVFP) patients with and without cricothyroid (CT) muscle dysfunction to define how CT dysfunction affects language tone. Eighty-eight female surgery-related UVFP patients were recruited and received acoustic voice analysis and laryngeal electromyography (LEMG) when the patient was producing the four Mandarin tones. The statistical analysis was compared between UVFP patients with (CT+ group, 17 patients) and without CT muscle (CT- group, 71 patients) involvement. When producing Mandarin Tone 2, the voice tone in the CT+ group had smaller rise range (p = 0.007), lower rise rate (p = 0.002), and lower fundamental frequency (F0) at the offset point of the voice (p = 0.023). When producing Mandarin Tone 4, the voice tone in the CT+ group had smaller drop range (p = 0.019), lower drop rate (p = 0.005), and lower F0 at voice onset (p = 0.025). The CT+ group had significantly lower CT muscle activity when producing the four Mandarin tones. In conclusion, CT dysfunction causes a limitation of high-rising tone in Tone 2 and high-falling tone in Tone 4, a property that dramatically limits the tonal characteristics in Mandarin, a tonal language. This limitation could further impair the patient's communication ability.

Bilateral Sensorimotor Cortical Communication Modulated by Multiple Hand Training in Stroke Participants: A Single Training Session Pilot Study.

Bi-manual therapy (BT), mirror therapy (MT), and robot-assisted rehabilitation have been conducted in hand training in a wide range of stages in stroke patients; however, the mechanisms of action during training remain unclear. In the present study, participants performed hand tasks under different intervention conditions to study bilateral sensorimotor cortical communication, and EEG was recorded. A multifactorial design of the experiment was used with the factors of manipulating objects (O), robot-assisted bimanual training (RT), and MT. The sum of spectral coherence was applied to analyze the C3 and C4 signals to measure the level of bilateral corticocortical communication. We included stroke patients with onset <6 months (n = 6), between 6 months and 1 year (n = 14), and onset >1 year (n = 20), and their Brunnstrom recovery stage ranged from 2 to 4. The results showed that stroke duration might influence the effects of hand rehabilitation in bilateral cortical corticocortical communication with significant main effects under different conditions in the alpha and beta bands. Therefore, stroke duration may influence the effects of hand rehabilitation on interhemispheric coherence.

Robot-Assisted Bimanual Training Improves Hand Function in Patients With Subacute Stroke: A Randomized Controlled Pilot Study.

Study Design: A randomized controlled pilot study. Background: Bimanual therapy (BMT) is an effective neurorehabilitation therapy for the upper limb, but its application to the distal upper limb is limited due to methodological difficulties. Therefore, we applied an exoskeleton hand to perform robot-assisted task-oriented bimanual training (RBMT) in patients with stroke. Objective: To characterize the effectiveness of RBMT in patients with hemiplegic stroke with upper limb motor impairment. Interventions: A total of 19 patients with subacute stroke (1-6 months from onset) were randomized and allocated to RBMT and conventional therapy (CT) groups. The RBMT and CT groups received 90 min of training/day (RBMT: 60 min RBMT + 30 min CT; CT: 60 min CT for hand functional training + 30 min regular CT), 5 days/week, for 4 weeks (20 sessions during the experimental period). Assessments: Clinical assessments, including the Fugl-Meyer assessment of the upper extremity (FMA-UE), action research arm test (ARAT), and wolf motor arm function test (WMFT), were conducted before and after the intervention. Results: Within-group analysis showed a significant improvement in the FMA-UE and WMFT in both the CT and RBMT groups. A significant improvement in the Fugl-Meyer assessment (FMA) of the wrist and hand for the distal part in the RBMT group occurred earlier than that in the CT group. A significant improvement in WMFT time was found in both groups, but the WMFT functional ability assessment was only found in the RBMT group. No significant improvements in ARAT assessment were observed in either the CT or RBMT groups. Compared with CT, significant improvements were found in terms of the proportion of minimally clinically important differences after RBMT in FMA-UE (χ2 = 4.34, p = 0.037). No adverse events were reported by any of the participants across all sessions. Conclusions: This study is the first to apply RBMT to the distal part of the upper limb. Both RBMT and CT are effective in improving the upper limb function in patients with subacute stroke. RBMT shows superior potential efficacy in facilitating recovery of the distal part of upper extremity (UE) motor function in the early stage. Future randomized control studies with a large sample size and follow-up assessments are needed to validate the present conclusions.

Deep Learning-Based Grimace Scoring Is Comparable to Human Scoring in a Mouse Migraine Model.

Pain assessment is essential for preclinical and clinical studies on pain. The mouse grimace scale (MGS), consisting of five grimace action units, is a reliable measurement of spontaneous pain in mice. However, MGS scoring is labor-intensive and time-consuming. Deep learning can be applied for the automatic assessment of spontaneous pain. We developed a deep learning model, the DeepMGS, that automatically crops mouse face images, predicts action unit scores and total scores on the MGS, and finally infers whether pain exists. We then compared the performance of DeepMGS with that of experienced and apprentice human scorers. The DeepMGS achieved an accuracy of 70-90% in identifying the five action units of the MGS, and its performance (correlation coefficient = 0.83) highly correlated with that of an experienced human scorer in total MGS scores. In classifying pain and no pain conditions, the DeepMGS is comparable to the experienced human scorer and superior to the apprentice human scorers. Heatmaps generated by gradient-weighted class activation mapping indicate that the DeepMGS accurately focuses on MGS-relevant areas in mouse face images. These findings support that the DeepMGS can be applied for quantifying spontaneous pain in mice, implying its potential application for predicting other painful conditions from facial images.

Persistence of lower vocal intensity in vocal fold paralysis with cricothyroid impairment after hyaluronate injection.

Background: Unilateral vocal fold paralysis (UVFP) affects the glottal gap, voice, and aerodynamics, whereas injection laryngoplasty (IL) using hyaluronate is an effective treatment for UVFP by decreasing the glottal gap to improve voice. Previous studies have shown that the involvement of cricothyroid (CT) muscle in UVFP patients further affects patients' aerodynamics, but it remains unclear whether the difference remains after IL. This study investigates whether the aerodynamic features observed in UVFP with CT involvement could still be observed after IL. Methods: This study recruited UVFP patients with dysphonia, and IL was performed within 6 months of initial symptoms. All subjects received assessments including videolaryngoscopy, voice analysis, and aerodynamics at three time points: before IL, 1 month after IL, and 6 months after IL. The glottal gap, voice, and aerodynamics between patients with and without CT involvement (the CT+ and CT- groups) were compared, and the change (Δ) before and after IL and repeated-measures analysis of variance (ANOVA) were also compared between the two groups. Result: A total of 71 patients with UVFP (22 in the CT+ group and 49 in the CT- group) were analyzed. After IL, the CT+ group showed a lower sound pressure level (SPL), higher Δair pressure, and smaller Δaerodynamic power than the CT- group. Conclusion: The CT+ group had a lower SPL, even after elevating air pressure to attempt to achieve a higher vocal intensity. The results suggest that although closure of the glottal gap was achieved by IL, the CT+ group still had a lower loudness and needed to sustain a higher peak air pressure when producing voice. Level of evidence: Level 4.

Aerodynamic Performance and Neuromuscular Control in Patients with Unilateral Vocal Fold Paralysis.

Unilateral vocal fold paralysis (UVFP) causes glottal incompetence and poor vocal efficiency. The influence of laryngeal neuromuscular control on aerodynamics in UVFP remains unclear. This study investigated the relationship between laryngeal muscle activities using quantitative laryngeal electromyography (LEMG) and aerodynamics in UVFP. This prospective study recruited patients with UVFP, and the diagnosis was confirmed with videolaryngostroboscopy and LEMG. The patient received aerodynamic assessment and LEMG of the thyroarytenoid-lateral cricoarytenoid (TA-LCA) muscle complex and the cricothyroid (CT) muscle. The relationship between quantitative LEMG and aerodynamic parameters was analyzed. A total of 134 UVFP patients without concurrent CT muscle involvement were enrolled. Compared with the normal side, the peak turn frequency of the lesioned side was lower in the TA-LCA (p < 0.001) and CT (p = 0.048) muscles. Stepwise linear regression revealed that the turn ratio of TA-LCA muscles was a robust factor in the decrease in peak expiratory airflow (ß = −0.34, p = 0.036), mean airflow during voicing (ß = −0.28, p = 0.014), and aerodynamic power (ß = −0.42, p = 0.019), and an increase in aerodynamic efficiency (ß = 27.91, p = 0.012). In addition, the turn ratio of CT muscles was a potent factor in inducing an increase in aerodynamic resistance (ß = 14.93, p = 0.029). UVFP without CT involvement still showed suppression of CT muscles on the lesioned side, suggesting that neurological impairment of the TA-LCA complex could cause asymmetrical compensation of CT muscles, further impeding aerodynamics. The residual function of TA-LCA muscle complexes facilitates less air leakage and power dissipation, enhancing aerodynamic efficiency. On the other hand, the symmetrical compensation of the CT muscles improves aerodynamic resistance.