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.

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.

Cricothyroid Muscle Dysfunction Affects Aerodynamic Performance in Patients with Unilateral Vocal Fold Paralysis

BACKGROUND

Emerging evidence has revealed that cricothyroid (CT) muscle dysfunction in unilateral vocal fold paralysis (UVFP) further impairs patients' voices. Given that CT muscle dysfunction does not influence vocal fold position, the mechanism of voice dysfunction induced by dysfunction of CT muscle in UVFP patients remains controversial. This study compares aerodynamics between UVFP patients with and without CT muscle involvement.

METHODS

This cross-sectional study recruited patients with UVFP manifesting dysphonia, and UVFP was confirmed with videolaryngoscopy and laryngeal electromyography (LEMG). Voice analysis and aerodynamic tests were further performed. Patients with (CT+ group) and without (CT- group) CT muscle involvement were compared.

RESULT

A total of 175 patients (40 in the CT+ group and 135 in the CT- group) with UVFP were analyzed. The CT+ group showed lower maximal sound pressure level (SPL) (P=0.039), mean SPL (P=0.042), peak air pressure (P<0.001), mean peak air pressure (P<0.001) and aerodynamic power (P=0.004) than the CT- group.

CONCLUSION

The decrease in SPL, peak air pressure, and aerodynamic power in UVFP patients with CT muscle dysfunction suggests that the effect of CT muscle dysfunction is mediated by a change in aerodynamics.

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) (β: 0.011, p < .001), age (β: -0.005, p = .001), National Institutes of Health Stroke Scale (NIHSS) (6a + 6b; β: -0.042, p = .018), Mini-Nutritional assessment (MNA) (β: -0.007, p < .027), and Fugl-Meyer upper extremity assessment (FuglUE) (β: 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.

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.

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.

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.

Application of deep learning neural network in predicting bone mineral density from plain X-ray radiography

DeepDXA is a deep learning model designed to infer bone mineral density data from plain pelvis X-ray, and it can achieve good predicted value for clinical use.

PURPOSE

Osteoporosis is defined as a systemic disease of the bone characterized by a decrease in bone strength and deterioration of bone structure at the microscopic level, leading to bone fragility and increased risk of fracture. Bone mineral density (BMD) is the preferred method for the diagnosis of osteoporosis, and dual-energy x-ray absorptiometry (DXA) is the gold standard for diagnosing osteoporosis. Conventional radiography is more suited for the screening of osteoporosis rather than diagnosis, and osteoporosis can be detected on radiographs by experienced physicians only. This study explored the possibility of predicting BMD relative to DXA using patient radiographs.

METHODS

A deep learning algorithm of convolutional neural network (CNN) was used for the purpose. The method includes image segmentation, CNN learning, and a convolution-based regression model (DeepDXA) that links the isolated images of the femur bone to predict BMD value. Data were obtained in a single medical center from 2006 to 2018, with a total amount of 3472 pairs of pelvis X-ray and DXA examination within 1 year.

RESULTS

The proposed workflow successfully predicted BMD values of the femur bone with the correlation coefficient (R) of 0.85 (P < 0.001) and the accuracy of 0.88 for prediction osteoporosis, a finding that could be reliably ready for further clinical use.

CONCLUSION

When suspicious osteoporosis is seen on plain films using the deep learning method we developed, further referral to DXA for the definite diagnosis of osteoporosis is indicated.

Alternation of Neuronal Feature Selectivity Induced by Paired Optogenetic-Mechanical Stimulation in the Barrel Cortex

Paired stimulation has been applied to modulate neuronal functions in the primary somatosensory cortex but its utility in the alternation of tuning function, such as direction tuning for whisker stimuli, remains unclear. In the present study, we attempted to manipulate feature preferences in barrel cortical neurons using repetitive paired whisker deflection combined with optogenetic stimulation and to obtain optimal parameters that can induce neuroplasticity. We found no significant response changes across stimulus parameters, such as onset asynchronies and paired directions. Only when paired stimulation was applied in the nonpreferred direction of the principal whisker of a neuron, were the neuron’s responses enhanced in that direction. Importantly, this effect was only observed when the optogenetic stimulus preceded the mechanical stimulus. Our findings indicate that repetitive paired optogenetic-mechanical stimulation can induce in vivo neuroplasticity of feature selectivity in limited situations.

Speech Performance after Anterolateral Thigh Phonatory Tube Reconstruction for Total Laryngectomy

OBJECTIVE

Traditionally, after total laryngopharyngectomy (TLP), patients cannot speak without a prosthesis or an artificial larynx. In Taiwan, most patients use a commercialized pneumatic laryngeal device (PLD). Phonatory tube reconstruction with the anterolateral thigh (ALT) flap is a novel, modified version of synchronous digestive and phonatory reconstruction involving a free muscular cutaneous flap. This study reviewed and compared speech performance between patients who underwent novel flap reconstruction and conventional PLD users.

METHOD

We retrospectively reviewed patients with laryngeal or hypopharyngeal cancer who underwent TLP from August 2017 to September 2019. The voice handicap index (VHI), speech intelligibility, acoustic and aerodynamic analysis results, and speech range profile (SRP) were compared between patients who underwent ALT phonatory tube reconstruction (ALT group) and those using PLDs (PLD group).

RESULTS

Twenty patients were included; 13 patients were included in the ALT group, and 7 patients were included in the PLD group. Compared to the PLD group, the ALT group had a better fundamental frequency range (P < .001) and semitone range (P < .001) during speech but showed worse jitter, shimmer, and harmonic-to-noise ratios. The two groups showed comparable VHI and speech intelligibility performance.

CONCLUSIONS

The ALT phonatory tube, a novel flap for reconstruction, can restore digestive and voice functions simultaneously. Compared with PLD use, ALT phonatory tube reconstruction yields an improved speech range and comparable levels of voice handicap and speech intelligibility, suggesting that the technique is a good alternative for patients after TLP.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1349-1357, 2021.

Two trajectories of functional recovery in thyroid surgery related unilateral vocal cord paralysis

BACKGROUND

Iatrogenic unilateral vocal fold paralysis caused by thyroid surgery induces profound physical and psychosocial distress in patients. The natural course of functional recovery over time differs substantially across subjects, but the mechanisms underlying this difference remain unclear. In this study, we examined whether the anatomic site of the lesion affected the trajectory of recovery.

METHODS

In this prospective case series study in a single medical center, patients with thyroid surgery-related unilateral vocal fold paralysis were evaluated using quantitative laryngeal electromyography, videolaryngostroboscopy, voice acoustic analysis, the Voice Outcome Survey, and the Short Form-36 quality-of-life questionnaire. Patients with and without superior laryngeal nerve injuries were compared.

RESULTS

Forty-two patients were recruited, among whom 15 and 27 were assigned to the with and without superior laryngeal nerve injury groups, respectively. Compared with the group without superior laryngeal nerve injury, the group with superior laryngeal nerve injury group demonstrated less improvement in the recruitment of vocal fold adductors, and the group also had more severe impairment of vocal fold vibration, maximum phonation time, jitter, shimmer, and harmony-to-noise ratio at the first evaluation. This difference was also found in the glottal gap and maximum phonation time 12 months after the injury.

CONCLUSION

Among patients with thyroid surgery-related unilateral vocal fold paralysis, superior laryngeal nerve injury induces a distinctively different recovery trajectory compared with those without superior laryngeal nerve injury characterized by less reinnervation of vocal fold adductors and worse presentation in terms of the glottal gap and maximum phonation time. This study emphasizes the importance of superior laryngeal nerve function and its preservation in thyroid surgery.

Clinical and functional characteristics of lung surgery-related vocal fold palsy

Background

Unilateral vocal fold paralysis (UVFP) caused by lung surgery is associated with prolonged hospital stay and increased postoperative comorbidities. We evaluated lung surgery-related UVFP and compared its characteristics with UVFP caused by esophageal and thyroid surgeries, as the most common surgical causes of UVFP. We also evaluated the outcomes of intracordal hyaluronate injection laryngoplasty in these patients.

Methods

Patients with surgery-related UVFP were evaluated by quantitative laryngeal electromyography, videolaryngostroboscopy, voice acoustic analysis, Voice Outcome Survey (VOS) questionnaire, and Short Form-36 Health Survey (SF-36) quality-of-life questionnaire. Data for the lung, esophageal, and thyroid surgery groups were compared and changes in outcome measurements induced by hyaluronate injection were compared among the three groups.

Results

A total of 141 patients were recruited, including 21, 46, and 74 in the lung, esophageal, and thyroid surgery groups, respectively. Compared with the other two groups, lung surgery patients had predominantly left-sided UVFP, less involvement of the external branch of the superior laryngeal nerve, and higher jitter. Most outcome measurements improved in all three groups after office-based hyaluronate injection, with the greatest improvement in jitter in the lung surgery group.

Conclusions

Lung surgery-related UVFP showed a distinct disease presentation, and patients' voice parameters and quality of life recovered dramatically after office-based hyaluronate injection. We recommend evaluation of lung surgery-related UVFP and early intervention, such as office-based hyaluronate injection, to improve patients' voice function and quality of life.

Comparison of the effects between lasers applied to myofascial trigger points and to classical acupoints for patients with cervical myofascial pain syndrome

Background

To compare the immediate effectiveness of low-level laser therapy (LLLT) applied to classical acupoints versus trigger points for patients with cervical myofascial pain syndrome (MPS).

Methods

This was a single-blinded, randomized, placebo-controlled trial. This study was performed in a university-affiliated medical center. One hundred participants with cervical myofascial pain syndrome were randomly allocated to four treatment groups, including (1) acupoint therapy (AcuT), (2) acupoint control (AcuC), (3) trigger point therapy (TriT), and (4) trigger point control (TriC) groups. Low-level laser (810-nm) therapy was used in both therapy groups, while the same procedure was performed without laser in the acupoint control groups. The patients were evaluated based on visual analogue scale (VAS) pain score, pressure pain threshold, and cervical range of motion (ROM) before and after the therapy.

Results

Immediate pain relief was observed in the TriT group (p < 0.01). The TriT group showed improved cervical ROM in ipsilateral bending (p < 0.01), while the AcuT group did not.

Conclusions

LLLT applied to trigger points could significantly relieve myofascial pain and was effective in relieving cervical ROM limitations. Considering the risk of pneumothorax, laser therapy at trigger points for patients with cervical MPS may be a choice when acupuncture therapy is unavailable.

Trial registration

ClinicalTrials.gov ID: NCT01516502.

Development of a Novel Task-oriented Rehabilitation Program using a Bimanual Exoskeleton Robotic Hand

A robot-assisted hand is used for the rehabilitation of patients with impaired upper limb function, particularly for stroke patients with a loss of motor control. However, it is unclear how conventional occupational training strategies can be applied to the use of rehabilitation robots. Novel robotic technologies and occupational therapy concepts are used to develop a protocol that allows patients with impaired upper limb function to grasp objects using their affected hand through a variety of pinching and grasping functions. To conduct this appropriately, we used five types of objects: a peg, a rectangular cube, a cube, a ball, and a cylindrical bar. We also equipped the patients with a robotic hand, the Mirror Hand, an exoskeleton hand that is fitted to the subject's affected hand and follows the movement of the sensor glove fitted to their unaffected hand (bimanual movement training (BMT)). This study had two stages. Three healthy subjects were first recruited to test the feasibility and acceptability of the training program. Three patients with hand dysfunction caused by stroke were then recruited to confirm the feasibility and acceptability of the training program, which was conducted on 3 consecutive days. On each day, the patient was monitored during 5 min of movement in a passive range of motion, 5 min of robot-assisted bimanual movement, and task-oriented training using the five objects. The results showed that both healthy subjects and subjects who had suffered a stroke in conjunction with the robotic hand could successfully grasp the objects. Both healthy subjects and those who had suffered a stroke performed well with the robot-assisted task-oriented training program in terms of feasibility and acceptability.

Relative posture between head and finger determines perceived tactile direction of motion

The hand explores the environment for obtaining tactile information that can be fruitfully integrated with other functions, such as vision, audition, and movement. In theory, somatosensory signals gathered by the hand are accurately mapped in the world-centered (allocentric) reference frame such that the multi-modal information signals, whether visual-tactile or motor-tactile, are perfectly aligned. However, an accumulating body of evidence indicates that the perceived tactile orientation or direction is inaccurate; yielding a surprisingly large perceptual bias. To investigate such perceptual bias, this study presented tactile motion stimuli to healthy adult participants in a variety of finger and head postures, and requested the participants to report the perceived direction of motion mapped on a video screen placed on the frontoparallel plane in front of the eyes. Experimental results showed that the perceptual bias could be divided into systematic and nonsystematic biases. Systematic bias, defined as the mean difference between the perceived and veridical directions, correlated linearly with the relative posture between the finger and the head. By contrast, nonsystematic bias, defined as minor difference in bias for different stimulus directions, was highly individualized, phase-locked to stimulus orientation presented on the skin. Overall, the present findings on systematic bias indicate that the transformation bias among the reference frames is dominated by the finger-to-head posture. Moreover, the highly individualized nature of nonsystematic bias reflects how information is obtained by the orientation-selective units in the S1 cortex.

Early transcranial direct current stimulation treatment exerts neuroprotective effects on 6-OHDA-induced Parkinsonism in rats

BACKGROUND

Transcranial direct current stimulation (tDCS) has been proven to be able to modulate motor cortical plasticity might have potential as an alternative, adjunctive therapy for Parkinson's disease (PD). However, the efficacy of tDCS in PD is still uncertain. A disease animal model may be useful to clarify the existence of a treatment effect and to explore an effective therapeutic strategy using tDCS protocols.

OBJECTIVE

The current study was designed to identify the comprehensive therapeutic effects of tDCS in 6-hydroxydopamine (6-OHDA)-lesioned PD rats.

METHODS

Following early and long-term tDCS application (starting 24 h after PD lesion, 300 μA anodal tDCS, 20 min/day, 5 days/week) in awake PD animals for a total of 4 weeks, the effects of tDCS on motor and non-motor behaviors as well as dopaminergic neuron degeneration levels, were identified.

RESULTS

We found that the 4-week tDCS intervention significantly alleviated 6-OHDA-induced motor deficits in locomotor activity, akinesia, gait pattern and anxiety-like behavior, but not in apomorphine-induced rotations, recognition memory and depression-like behavior. Immunohistochemically, tyrosine hydroxylase (TH)-positive neurons in the substantia nigra were significantly preserved in the tDCS intervention group.

CONCLUSIONS

These results suggest that early and long-term tDCS could exert neuroprotective effects and reduce the aggravation of motor dysfunctions in a 6-OHDA-induced PD rat model. Furthermore, this preclinical model may enhance the promising possibility of the potential use of tDCS and serve as a translational platform to further identify the therapeutic mechanism of tDCS for PD or other neurological disorders.

Functional Recovery Patterns of Hemorrhagic and Ischemic Stroke Patients Under Post-Acute Care Rehabilitation Program

BACKGROUND

Tailored rehabilitation programs for stroke patients cannot be made without knowledge of their recovery potential. The aim of this study is to characterize the functional recovery patterns of ischemic stroke (IS) and intracerebral hemorrhage (ICH) patients under post-acute care stroke rehabilitation.

METHODS

This retrospective study analyzed the data of patients enrolled in the Post-Acute Care-Cerebrovascular Disease (PAC-CVD) rehabilitation program, which provides an individualized 1- to 3-hour intensive physical, occupational, and speech and language therapy for post-acute stroke patients in Taoyuan Chang Gung Memorial hospital in Taiwan. Our primary endpoint measure was Barthel Index (BI), and secondary endpoint measures included other 12 functional measures.

RESULTS

A total of 489 patients were included for analysis. Patients with stroke history had less BI improvement than those who suffered their first-ever stroke. In first-ever stroke patients who had completed 6 to 12 weeks of PAC-CVD program, subcortical ICH patients had greater BI, quality of life, sensation, and balance improvements, and had greater late-phase recovery than their IS counterparts. In IS patients, those with age >75 had less BI improvement; those with National Institute of Health Stroke Scale (NIHSS) score 1-5 had greater Motor Activity Log quality of use (MAL-quality) improvement than those with NIHSS score >5; those with Mini-Mental State Examination (MMSE) score ≥24 had greater BI and instrumental activities of daily living (IADL) improvement. Using the general linear model, previous stroke (ß: -6.148, p=0.01) and subcortical ICH (ß: 5.04, p=0.03) were factors associated with BI improvement.

CONCLUSION

Subcortical ICH patients have greater functional improvement and greater late-phase recovery than their IS counterparts following PAC rehabilitation. More studies are needed to validate our findings and unravel the underlying mechanisms of stroke recovery to optimize the treatment strategy following a stroke.

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.

Modified lymph node ratio improves the prognostic predictive ability for breast cancer patients compared with other lymph node staging systems

Background

Metastatic regional lymph nodes (LN) is a strong predictor of worse long-term outcome. Therefore, different LN staging systems have been proposed in recent years. In this study, we proposed a modified lymph node ratio (mLNR) as a new lymph node staging system and then compared the prognostic performance of mLNR with American Joint Committee on Cancer N stage, lymph node ratio (LNR) and log odds of metastatic lymph nodes in breast cancer patients.

Methods

Breast cancer patients who underwent surgery between 2004 and 2012 were identified from the Surveillance, Epidemiology, and End Results database. Restricted cubic spline functions were calculated to characterize the association between variables and the risk of death. The Cox proportional hazards models were constructed to assess the predictive ability of different lymph node staging systems using the Akaike’s Information Criterion (AIC) and Harrell’s concordance index (C-index).

Results

A total of 264,096 breast cancer patients were enrolled and 187,785 (71.1%) patients had a limited number of LNs harvested. In the limited LN harvest cohort, the prognostic performance of LNR decreased and mLNR could greatly solve this problem. In addition, among the entire cohort, mLNR modeled as a continuous value had the best predictive ability (AIC: 922021.9 and C-index: 0.727) than other lymph node staging systems.

Conclusions

The predictive ability of LNR is restricted by a limited LN harvest. However, mLNR shows superiority to LNR and other lymph node staging systems especially in a limited LN harvest cohort, making mLNR the most powerful lymph node staging systems.

•

We selected 264,096 patients, which is enough to support our conclusion.

•

We used two indexes to fully verify the fit of different lymph staging systems.

•

The mLNR improved the prognostic predictive ability best.

Illusory Motion Reversal in Touch

Psychophysical visual experiments have shown illusory motion reversal (IMR), in which the perceived direction of motion is the opposite of its actual direction. The tactile form of this illusion has also been reported. However, it remains unclear which stimulus characteristics affect the magnitude of IMR. We closely examined the effect of stimulus characteristics on IMR by presenting moving sinusoid gratings and random-dot patterns to 10 participants’ fingerpads at different spatial periods, speeds, and indentation depths. All participants perceived a motion direction opposite to the veridical direction some of the time. The illusion was more prevalent at spatial periods of 1 and 2 mm and at extreme speeds of 20 and 320 mm/s. We observed stronger IMR for gratings and much weaker IMR for a random-dot pattern, indicating that edge orientation might be a major contributor to this illusion. These results show that the optimal parameters for IMR are consistent with the characteristics of motion-selective neurons in the somatosensory cortex, as most of these neurons are also orientation-selective. We speculate that these neurons could be the neural substrate that accounts for tactile IMR.

Features of trunk muscle weakness in patients with ankylosing spondylitis: A cross-sectional study

BACKGROUND

Ankylosing spondylitis (AS) is an inflammatory autoimmune disorder that manifested with sacroiliitis at its early stage and developed extensive inflammation with syndesmophytes of the lumbar, thoracic and cervical spines at its later stage. In the present study, we characterized the trunk isometric strength in patients with AS with different disease severity, defined by the radiological images.

METHODS

In a cross-sectional study conducted in a university-affiliated hospital, thirty-eight male AS patients (23 in the early AS group whose radiological findings showed no syndesmophyte, Modified Stoke Ankylosing Spinal Score (m-SASSS <3); and 15 in the syndesmophyte group, m-SASSS ≥24), and 22 healthy controls were recruited. All subjects received assessments of maximum isometric strength of trunk flexor and extensor muscles at a variety of trunk postures measured by an isokinetic device.

RESULTS

Under all examined trunk postures, the syndesmophyte AS patient group had the lowest isometric trunk muscle strength among the three groups. The flexion/extension ratio, defined by the ratio between isometric trunk flexor and extensor strengths, was highest among the three groups.

CONCLUSIONS

Trunk muscle strength significantly decreases in patients with syndesmophyte AS. The decrease of trunk muscle is inhomogeneous, which is more profound in extensor than in flexor muscles.

The impact of cricothyroid involvement on adductor recovery in unilateral vocal fold paralysis

OBJECTIVES/HYPOTHESIS

Wide variation in postinjury functional recovery is a hallmark of unilateral vocal fold paralysis (UVFP), ranging from zero to full recovery. The present study examined the impact of cricothyroid (CT) muscle involvement on recovery using quantitative laryngeal electromyography (LEMG) of the thyroarytenoid-lateral cricoarytenoid (TA-LCA) muscle complex at multiple times postinjury.

STUDY DESIGN

Prospective cohort study in a medical center.

METHODS

Eighty-one patients with UVFP (37 males and 44 females) received an initial assessment of quantitative LEMG, stroboscope, acoustic voice analysis and 36-Item Short Form Survey quality-of-life questionnaire at 3 to 6 months after UVFP onset and a follow-up assessment at 12 months after UVFP onset.

RESULTS

The initial and follow-up assessments were performed at 4.3 ± 1.9 and 12.5 ± 1.3 months after UVFP onset, respectively. The peak turn frequency of the TA-LCA muscle complex on the lesion side was improved at the follow-up (470 ± 294 Hz) compared with the initial assessment (300 ± 204 Hz) (P < .001). Patients were also divided into two groups with (n = 27) and without (n = 54) CT involvement, respectively. TA-LCA muscle complex turn frequency improved in patients without CT involvement (from 277 ± 198 to 511 ± 301 Hz; P < .001), but not in those with CT involvement (from 345 ± 211 to 386 ± 265 Hz; P = .46). Seventy-one of all patients received early intervention with intracordal hyaluronate injection, showing similar therapeutic effects in those with and without CT involvement.

CONCLUSIONS

Acute UVFP with combined TA-LCA muscle complex and CT muscle involvement has a poor prognosis, with poorer recovery of TA-LCA muscle complex recruitment. Early interventions should be considered in patients with UVFP with CT involvement.

LEVEL OF EVIDENCE

2 Laryngoscope, 130:139-145, 2020.

Usability Assessment of a Cable-Driven Exoskeletal Robot for Hand Rehabilitation

Study design: Case series.

Background: Robot-assisted rehabilitation mediated by exoskeletal devices is a popular topic of research. The biggest difficulty in the development of rehabilitation robots is the consideration of the clinical needs. This study investigated the usability of a novel cable-driven exoskeletal robot specifically designed for hand rehabilitation.

Methods: The study consists of three steps, including prototype development, spasticity observation, and usability evaluation. First, we developed the prototype robot DexoHand to manipulate the patient's fingers based on the clinical needs and the cable-driven concept established in our previous work. Second, we applied DexoHand to patients with different levels of spasticity. Finally, we obtained the system usability scale (SUS) and assessed its usability.

Results: Two healthy subjects were recruited in the pre-test, and 18 patients with stroke and four healthy subjects were recruited in the formal test for usability. The total SUS score obtained from the patients and healthy subjects was 94.77 ± 2.98 (n = 22), indicating an excellent level of usability. The satisfaction score was 4.74 ± 0.29 (n = 22), revealing high satisfaction with DexoHand. The tension profile measured by the cables showed the instantaneous force used to manipulate fingers among different muscle tone groups.

Conclusions:DexoHand meets the clinical needs with excellent usability, satisfaction, and reliable tension force monitoring, yielding a feasible platform for robot-assisted hand rehabilitation.

An electroneurography-based assay for identifying injured nerve segment during surgery: design and in vivo application in the rat

OBJECTIVE

Nerve injury is the main reason for nerve reconstruction surgery, during which the surgeon must determine the location of the injured nerve segment, resect it, and reconnect the remaining healthy nerve stump ends within a limited time. Given this importance, an assay needed to determine the exact location of the injured nerve segment, but no tool has yet fulfilled this need so that a visual inspection of the nerve is still the primary method of identifying the injured segment.

APPROACH

We designed a flexible multi-electrode array sensor that records the electroneurographic signal (ENG) as the action potential elicited by electrical stimulation that propagates along the nerve upon both orthodromic and antidromic stimulation. Its utility was validated by in vivo experiments in injured sciatic nerves of rats.

MAIN RESULTS

The results showed that the first post stimulus negative electroneurographic component (N1) is the most valid neural correlate, as its amplitude decreased, and latency increased as the action potential propagated across the injured segment. Gradual recovery of nerve conduction was observed when measured immediately, 7, and 30 d after injury. The locations of the identified injured segments were validated by histological findings.

SIGNIFICANCE

The sensor and the algorithm developed in this study are breakthroughs in surgical nerve assessment accomplished by determining the specific nerve segment that should be resected, enabling the optimal surgical outcome.

Risk factors for thyroid surgery-related unilateral vocal fold paralysis

Objectives/Hypothesis

We aimed to identify the risk factors for iatrogenic unilateral vocal fold paralysis (UVFP) caused by thyroid surgery, to allow the identification of patients requiring nerve‐protection procedures and monitoring technologies.

Study Design

Retrospective case study in a medical center.

Methods

Patients who underwent thyroid surgery from April 2011 to February 2016 and who were diagnosed with UVFP by laryngoscopy and laryngeal electromyography were included. Patient demographics, types of surgery, and characteristics of the thyroid lesions were analyzed.

Results

Sixty (2.1%) of 2,815 patients who received thyroid surgery developed UVFP. The risk of UVFP was higher in patients over 60 years old (odds ratio, 1.89; 95% confidence interval, 1.01‐3.26; P = .01). Involvement of the external branch of superior laryngeal nerve (EBSLN) occurred in 19 (31.7%) of the 60 UVFP patients, and was more likely to occurr in patients with diabetes mellitus (odds ratio, 14.19; 95% confidence interval, 3.80‐52.94; P < .001). The incidence of UVFP and involvement of the EBSLN differed among surgery types, and was the highest among patients undergoing total thyroidectomy with neck dissection (TTND) (10/158, 6.3% and 5/158, 3.2%, respectively).

Conclusions

The risk of thyroid surgery–related UVFP is higher in older patients. EBSLN involvement is more likely in patients with diabetes mellitus. TTND is associated with higher risks of UVFP and EBSLN injury than other types of surgery, implying the need of intraoperative nerve monitoring in these high‐risk characteristics.

Level of Evidence

4 Laryngoscope, 129:275–283, 2019

Acceptance of different design exergames in elders

For promoting the successful aging of elderly residents of Chang Gung Silver Village in Taiwan, five interactive exergames were developed to promote the well-being of the elderly. The exergames included both physical games and cognitive games, and were implemented using various computer-based technologies in the Chang Gung Silver Village. The exergames were trialed by 39 elderly residents (15 male, 24 female; mean age 79.5 ± 17.5 years) of Chang Gung Silver Village. Following the trials, the participants were requested to complete a Technology Acceptance Model 2 (TAM2) questionnaire. The results showed that the perceived playfulness and perceived usefulness of the exergames were significantly related to the users’ usage behavior and intention to use for both the physical games and the cognitive games. However, a relationship between the output quality of the game and the usage behavior was apparent only in the case of the cognitive exergames. Finally, the impact of social influence on the intention to use and the usage behavior was more pronounced for the physical exergames. Overall, the results revealed that the acceptance of exergames by the elderly depends not so much on the awareness of fun in using the game, but the perceived usefulness of the related physical and cognitive abilities.

Musical dual-task training in patients with mild-to-moderate dementia: a randomized controlled trial

BACKGROUND/AIMS

Dual-task training may improve dual-task gait performance, balance, and cognition in older adults with and without cognitive impairment. Although music has been widely utilized in dementia management, there are no existing protocols for music-based dual-task training. This randomized controlled study developed a Musical Dual-Task Training (MDTT) protocol that patients with dementia can use to practice walking and making music simultaneously, to enhance attention control in patients during dual-tasking.

METHODS

Twenty-eight adults diagnosed with mild-to-moderate dementia were assigned to the MDTT (n=15) or control groups (n=13). The MDTT group received MDTT, while the control group participated in non-musical cognitive and walking activities. The effects of MDTT were evaluated through the primary outcome of attention control, and secondary outcomes of dual-task performance, balance, falls efficacy, and agitation.

RESULTS

The MDTT group showed a significant improvement in attention control, while the control group did not (P<0.001). A significant effect favored MDTT over control treatment for the secondary outcome of falls efficacy (P=0.02) and agitation (P<0.01).

CONCLUSION

MDTT, a music therapy intervention that demands a high level of cognitive processing, enhances attention control, falls efficacy, and helps alleviate agitation in patients with mild-to-moderate dementia.

Voice Range Change After Injection Laryngoplasty for Unilateral Vocal Fold Paralysis

OBJECTIVES

Patients with unilateral vocal fold paralysis (UVFP) caused by nerve injury manifest with voice changes. This study investigated vocal performance measured by voice range profile (VRP) in patients with UVFP and changes in VRP in response to intracordal hyaluronate injection.

METHODS

Eighty-five patients with UVFP were enrolled prospectively, among whom 68 received intracordal hyaluronate injections. The outcome measurements included VRP, acoustic and aerodynamic analyses, peak turn frequency of thyroarytenoid-lateral cricoarytenoid muscle complex (TA-LCA) measured by laryngeal electromyography, and normalized glottal gap area by videolaryngostroboscopy.

RESULTS

The peak turn frequency of the paralyzed TA-LCA showed a modest correlation with max fundamental frequency (F0) and F0 range. Closed-phase normalized glottal gap area showed modest negative correlations with max F0 and F0 semitone range. Regarding conventional acoustic and aerodynamic analyses, the paralyzed TA-LCA peak turn frequency was only correlated with maximal phonation time. Intracordal hyaluronate injection improved VRP performance by increasing max F0, decreasing min F0, increasing F0 range, and increasing semitone range (all P <0.01) with small or medium strength of effect size (Cohen d, 0.39-0.76).

CONCLUSIONS

Change in voice pitch in patients with UVFP can partly predict impairment of neuromuscular functions and glottal gap. VRP provides a more sensitive reflection of the severity of neuromuscular impairment, compared with conventional voice analysis. The validity of VRP is further supported by a robust response to voice improvements following injection laryngoplasty.

Hemodynamic stability during laryngeal electromyography procedures

BACKGROUND

Laryngeal electromyography (LEMG) is accepted as safe, with minimal side effects. However, patient hemodynamic stability, during these procedures, has not been reported. This study aimed to investigate the hemodynamics in patients undergoing LEMG and determine the risk factors for hemodynamic changes.

METHODS

We recruited 89 consecutive patients who underwent LEMG. Baseline and postprocedural changes in vital signs were analyzed.

RESULTS

Diastolic blood pressure (DBP) increased from 75.08 ± 11.54 mmHg preprocedure to 77.4 ± 11.91 mmHg postprocedure (p = .006); pulse rate (PR) increased from 78.1 ± 13.3 beats per minute preprocedure to 80.02 ± 13.69 postprocedure (p = .027). Systolic blood pressure (SBP) and oxygen saturation were unchanged after the procedure. However, about 17% of patients experienced profound changes in vital signs of >20% above baseline during LEMG. The hemodynamic changes did not differ between sexes or between surgical and non-surgical etiologies of vocal fold paralysis. Two patients experienced profound but reversible near-syncope during the procedure.

CONCLUSIONS

LEMG is a safe procedure with few immediate complications, though it may affect the patient's hemodynamic status by increasing DBP and PR. The hemodynamic monitoring is recommended so that timely intervention can be applied in case any warning sign occurs.

Implications of Synkinesis in Unilateral Vocal Fold Paralysis

Objectives

In patients with unilateral vocal fold paralysis (UVFP), laryngeal electromyography (LEMG) occasionally observes synkinesis in laryngeal muscles, a condition that could impair vocal fold mobility and voice control. This study aims to evaluate the impact of synkinesis on UVFP patients.

Study Design

A retrospective case-control study.

Setting

Medical center.

Subjects and Methods

Patients with UVFP onset >6 months were recruited (N = 104). The outcome measurements included LEMG, quantitative LEMG analysis of thyroarytenoid–lateral cricoarytenoid (TA-LCA) muscle complex, glottal gap measured by videolaryngostroboscopy, voice-related quality of life, and voice acoustic analysis.

Results

According to the LEMG analysis, 8 patients (8%) had synkinesis, and 96 (92%) did not. In the synkinesis group, TA-LCA turn frequency in the lesioned side was comparable to that in the healthy side ( P = .52). Patients in the synkinesis group had higher TA-LCA turn frequency ( P = .001), higher probability of cricothyroid muscle dysfunction ( P = .04), and better voice-related quality of life ( P = .01) but objective voice outcomes comparable to those in the nonsynkinesis group.

Conclusions

Patients with synkinesis will have near-complete restoration in TA-LCA turn frequency but still experience voice impairment, a finding that is compatible with the mechanism of aberrant reinnervation. However, patients with synkinesis have better disease-related quality of life than do those without synkinesis.

An Evaluation of the Design and Usability of a Novel Robotic Bilateral Arm Rehabilitation Device for Patients with Stroke

STUDY DESIGN

Case series.

EVIDENCE LEVEL

IV (case series).

INTRODUCTION

Robot-assisted therapy for upper limb rehabilitation is an emerging research topic and its design process must integrate engineering, neurological pathophysiology, and clinical needs.

PURPOSE OF THE STUDY

This study developed/evaluated the usefulness of a novel rehabilitation device, the MirrorPath, designed for the upper limb rehabilitation of patients with hemiplegic stroke.

METHODS

The process follows Tseng's methodology for innovative product design and development, namely two stages, device development and usability assessment. During the development process, the design was guided by patients' rehabilitation needs as defined by patients and their therapists. The design applied synchronic movement of the bilateral upper limbs, an approach that is compatible with the bilateral movement therapy and proprioceptive neuromuscular facilitation theories. MirrorPath consists of a robotic device that guides upper limb movement linked to a control module containing software controlling the robotic movement.

RESULTS

Five healthy subjects were recruited in the pretest, and 4 patients, 4 caregivers, and 4 therapists were recruited in the formal test for usability. All recruited subjects were allocated to the test group, completed the evaluation, and their data were all analyzed. The total system usability scale score obtained from the patients, caregivers, and therapists was 71.8 ± 11.9, indicating a high level of usability and product acceptance.

DISCUSSION AND CONCLUSION

Following a standard development process, we could yield a design that meets clinical needs. This low-cost device provides a feasible platform for carrying out robot-assisted bilateral movement therapy of patients with hemiplegic stroke.

CLINICAL TRIAL REGISTRATION

identifier NCT02698605.

Distinct Disease and Functional Characteristics of Thyroid Surgery-Related Vocal Fold Palsy

BACKGROUND

Iatrogenic trauma induced by thyroid surgery is the most common etiology of unilateral vocal fold paralysis (UVFP). UVFP after thyroid surgery may lead to profound physical and psychosocial distress. This study comprehensively evaluated UVFP caused by thyroid surgery, and compared the results with those caused by other surgical trauma.

METHODS

Patients with surgery-related UVFP were evaluated using quantitative laryngeal electromyography, videolaryngostroboscopy, voice acoustic analysis, the Voice Outcome Survey, and the Short Form-36 Health Survey quality-of-life questionnaire. Patients with thyroid surgery and other surgeries were compared.

RESULTS

A total of 105 patients were recruited, of whom 52 and 53 were assigned to the thyroid surgery and the other surgery group, respectively. Patients in the thyroid surgery group had a higher proportion of external branch of superior laryngeal nerve (eSLN) involvement, longer duration from disease onset to the first laryngeal electromyography examination, lower jitter, higher harmonic-to-noise ratio, and better quality of life compared with the other surgery group. Specifically for patients in the thyroid surgery group, those with eSLN involvement tended to have more pronounced impairment in jitter and shimmer compared with patients without eSLN involvement.

CONCLUSION

UVFP caused by thyroid surgery has a distinct clinical presentation with relatively high involvement in the eSLN, better voice acoustics, longer waiting time before asking for evaluation, and less impact on quality of life. The involvement of eSLN in these patients further impaired their voice. Early referral is suggested for these patients, especially with suspected eSLN injury.

Early hyaluronate injection improves quality of life but not neural recovery in unilateral vocal fold paralysis: an open-label randomized controlled study

PURPOSE

To investigate the neurologic and functional effect of intracordal hyaluronate injections in acute unilateral vocal fold paralysis (UVFP) in a randomized controlled trial.

METHODS

In this open-label, randomized controlled study, 29 patients with UVFP were recruited within 6 months of their first outpatient visit and were randomized to receive either single hyaluronate injection (HI group) or conservative management (CM group). Quantitative laryngeal electromyography, videolaryngostroboscopy, UVFP-related quality of life (Voice Outcomes Survey, VOS), laboratory voice analysis, and health-related quality of life (SF-36) were evaluated at baseline, and at 1, 3 and 6 months post-injection in the HI group, and at baseline and 6 months in the CM group.

RESULTS

Improvements in most quality of life domains and other assessments were comparable between the HI and CM groups; however, the HI group had a greater improvement in the mental health domain of quality of life at the end of follow-up.

CONCLUSIONS

Early hyaluronate injection cannot improve nerve regeneration but can result in long-lasting improvements in patients' psychosocial well-being, thus highlighting the importance of early intervention for patients with UVFP.

Botulinum Toxin type A injections for patients with painful hallux valgus: a double-blind, randomized controlled study

Hallux valgus (HV) related pain and disability remains a medical challenge to date. We have evaluated the therapeutic effect of intramuscular Botulinum Toxin type A (BTX-A) injection on painful HV in a double-blind randomized controlled trial. Sixteen patients having painful HV in at least one foot from the Department of Physical Medicine and Rehabilitation at a medical center in northern Taiwan have participated. Patients were randomized into two groups to receive intramuscular injections of either BTX-A or normal saline (NS) to the oblique and transverse heads of the adductor hallucis, flexor hallucis brevis and extensor hallucis longus muscles. Primary outcome measurements were selected from the Taiwan Chinese version of the Foot Function Index subscales on pain (questions 1-6, 9) and disability (question 10-18). The secondary outcome measurement was the HV angle. Patients were assessed at baseline and at 1, 2, 3, and 6 months after treatment. The demographic data and measurements were comparable between the two groups at baseline (p>0.05). BTX-A and NS reduced pain and disability one month after injection. Pain reduction induced by BTX-A injection lasted for at least 6 months while that induced by NS lasted for only 1 month. In addition, patients in the BTX-A group showed greater improvement in pain score (p<0.001), disability score (p<0.05), and HV angle (p<0.05) than patients in the NS group. The results reflected that HV-related muscle injection of BTX-A resulted in a marked reduction in pain for up to 6 months.

Neuromodulation accompanying focused ultrasound-induced blood-brain barrier opening

Burst-mode focused ultrasound (FUS) induces microbubble cavitation in the vasculature and temporarily disrupts the blood-brain barrier (BBB) to enable therapeutic agent delivery. However, it remains unclear whether FUS-induced BBB opening is accompanied by neuromodulation. Here we characterized the functional effects of FUS-induced BBB opening by measuring changes in somatosensory evoked potentials (SSEPs) and blood-oxygen-level dependent (BOLD) responses. Rats underwent burst-mode FUS (mechanical index (MI) of 0.3, 0.55 or 0.8) to the forelimb region in the left primary somatosensory cortex to induce BBB opening. Longitudinal measurements were followed for up to 1 week to characterize the temporal dynamics of neuromodulation. We observed that 0.8-MI FUS profoundly suppressed SSEP amplitude and prolonged latency, and this effect lasted 7 days. 0.55-MI FUS resulted in minimal and short-term suppression of SSEP for less than 60 minutes and didn’t affect latency. BOLD responses were also suppressed in an MI-dependent manner, mirroring the effect on SSEPs. Furthermore, repetitive delivery of 0.55-MI FUS every 3 days elicited no accumulative effects on SSEPs or tissue integrity. This is the first evidence that FUS-induced BBB opening is accompanied by reversible changes in neuron responses, and may provide valuable insight toward the development of FUS-induced BBB opening for clinical applications.

Quantitative laryngeal electromyography assessment of cricothyroid function in patients with unilateral vocal fold paralysis

OBJECTIVES/HYPOTHESIS

Determination of superior laryngeal nerve (SLN) involvement in addition to recurrent laryngeal nerve (RLN) paralysis in patients with unilateral vocal fold paralysis (UVFP) relies on traditional, qualitative laryngeal electromyography (LEMG) examination. It is necessary to develop a quantitative measurement that reflects the degree of denervation of the cricothyroid (CT) muscle. The present study aimed to establish a standard quantitative assessment of CT function in patients with UVFP by measuring the turn frequency.

STUDY DESIGN

Case series study performed in an otolaryngology outpatient clinic.

METHODS

Twenty healthy subjects and 103 patients with UVFP were recruited. The main outcome measures for the patients included acoustic analysis using traditional LEMG examination, quantitative LEMG analysis, and acoustic analysis based on fundamental frequency contours.

RESULTS

Acoustic reliability was examined in the healthy subjects, and the peak fundamental frequency in an upward glissando showed good test-retest reliability, especially for the offset fundamental frequency. LEMG indicated that 33 patients had RLN and SLN lesions (RLN+SLN group) and 70 had only RLN lesions (RLN group). When patients produced a standard upward glissando sound, the peak turn frequency reflecting the recruitment of the CT muscle was significantly lower in the RLN+SLN group compared with the RLN group (406±256 vs. 778±238 Hz; P<.001).

CONCLUSIONS

We conclude that quantitative measurement of the interference pattern when voicing a standard upward glissando sound may provide a feasible reflection of the degree of a SLN injury.

LEVEL OF EVIDENCE

4.

Increased risk of posterior circulation infarcts among ischemic stroke patients with cervical spondylosis

BACKGROUND

Cervical spondylosis is one of the extrinsic factors causing vertebral artery stenosis. Several case studies have reported compression of the vertebral artery induced by cervical osteophytes that has resulted in posterior circulation infarcts (POCI). However, to the best of our knowledge, no studies have yet analyzed differences in the risk factors and stroke subtypes between ischemic stroke patients with cervical spondylosis and those without.

PURPOSE

In the case-controlled study reported here, we analyzed the risk factors and stroke subtypes in ischemic stroke patients with and without cervical spondylosis. Characteristics in all the recruited patients with POCI and non-POCI were further compared to extract other risk factors that could predict the occurrence of POCI.

METHODS AND PATIENTS

We filtered out ischemic stroke patients with cervical spondylosis ("Stroke+C" group) by International Classification of Diseases, Ninth Revision codes. We analyzed the data of 38 subjects in the Stroke+C group and 152 sex- and age-comparable ischemic stroke patients without cervical spondylosis ("Stroke-C" group). We recorded the demographic characteristics including sex and age, and stroke risk factors, including diabetes mellitus, hypertension, heart disease, hyperlipidemia, and smoking habits. The stroke classifications were defined by the Oxford Community Stroke Project classification. All subjects were further categorized into POCI or non-POCI groups. The ultrasound findings of the vertebral arteries (extracranial and intracranial) in the Stroke+C group were also recorded.

RESULTS

More patients in the Stroke+C group tended to have POCI (34.2%) than patients in the Stroke-C group (17.5%) (odds ratio [OR] =2.41, P<0.05). Furthermore, hypertension (OR=3.41, P<0.01) and cervical spondylosis (OR=2.41, P<0.05) were two independent risk factors for POCI in ischemic stroke patients.

CONCLUSION

Ischemic stroke patients with cervical spondylosis are more prone to POCI than those without cervical spondylosis. Hypertension is another identified risk factor for POCI in ischemic stroke patients. The occurrence of POCI should be highlighted for patients with cervical spondylosis.

Aging-related changes in swallowing, and in the coordination of swallowing and respiration determined by novel non-invasive measurement techniques

AIM

Previous studies have shown that the process of swallowing changes with aging, a phenomenon known as presbyphagia. These subtle and subclinical age-related changes make older adults more vulnerable to dysphagia during disease insults. However, there are limited studies of the swallowing process in older adults, because measurements are typically invasive or require exposure to X-rays. In the present study, we used integrated non-invasive measurements to determine aging-related changes of swallowing, and in the coordination of swallowing and respiration for a population of healthy participants.

METHODS

The non-invasive system provided measurements of larynx movement with piezoelectric sensors, submental muscle activity with surface electromyography and respiration-swallowing coordination by measurement of nasal airflow. We recruited 112 healthy participants from the community, 35 in a young-age group (age 20-30 years), 38 in a middle-age group (age 31-50 years) and 39 in an old-age group (age 51-70 years).

RESULTS

The oropharyngeal swallowing parameters of the old-age group had delayed onset latency and longer swallowing apnea duration relative to the other groups, and these differences were greater for larger boluses. The middle- and old-age groups had less expiratory-expiratory respiratory phase pattern than the young-age group. The probability of piecemeal deglutition was highest in the old-age group and lowest in the young-age group. These results show that the phases of oropharyngeal swallowing and the coordination of swallowing with respiration gradually change with aging.

CONCLUSIONS

We used integrated non-invasive measurements to document age-related changes in swallowing, and in the coordination of swallowing and respiration in healthy adults.

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.

Motor impairments screened by the movement assessment battery for children-2 are related to the visual-perceptual deficits in children with developmental coordination disorder

This study was to examine to what extent the motor deficits of children with Developmental Coordination Disorder (DCD) verified by the Movement Assessment Battery for Children-2 (MABC-2) are linked to their visual-perceptual abilities. Seventeen children with DCD and seventeen typically developing children (TD) aged 5-10 years screened from a total of 250 children were recruited. The assessments included MABC-2, traditional test of visual perceptual skills (TVPS-R), and computerized test for sequential coupling of eye and hand as well as motion coherence. The results indicated that children with DCD scored lower than TD in MABC-2, and their total scores were highly correlated with manual dexterity component scores. DCD group also showed poor visual-perceptual abilities in various aspects. The visual discrimination and visual sequential memory from the TVPS-R, the sequential coupling of eye and hand, and the motion coherence demonstrated a moderate or strong correlation with the MABC-2 in the DCD rather than the TD group. It was concluded that the motor problems screened by MABC-2 were significantly related to the visual-perceptual deficits of children with DCD. MABC-2 is suggested to be a prescreening tool to identify the visual-perceptual related motor deficits.

A multi-digit tactile motion stimulator

BACKGROUND

One of the hallmarks of haptic exploration is that it typically involves movement between skin and object. Explored objects may contact multiple digits simultaneously so information about motion must be integrated across digits, a process about which little is known.

NEW METHOD

To fill this gap, we have developed a stimulator that allows for the simultaneous and independent delivery of motion stimuli to multiple digits. The stimulator consists of individual units that deliver motion with three degrees of freedom: rotation (to produce motion), vertical excursion (to control depth of indentation into the skin) and arm orientation (to control the direction of motion). Each degree of freedom is controlled by a single motor. The compact design of the simulator allows for the side-by-side arrangement of the stimulator units such that they impinge upon adjacent fingers.

RESULTS

To demonstrate the functionality of the stimulator, we performed a series of psychophysical experiments that investigate the perception of motion on multiple fingers. We find that, while the sensitivity to changes in motion direction is equivalent whether stimuli are presented to the same or to different fingers, the perceived direction of motion depends on the relative configuration of the digits.

COMPARISON WITH EXISTING METHODS

We replicated the results of previous experiments investigating motion discrimination with a single digit and were able to extend these findings by investigating motion perception across multiple digits.

CONCLUSION

The novel motion stimulator will be an invaluable tool to investigate how motion information is integrated across multiple digits.

Global motion percept mediated through integration of barber poles presented in bilateral visual hemifields

How is motion information that has been obtained through multiple viewing apertures integrated to form a global motion percept? We investigated the mechanisms of motion integration across apertures in two hemifields by presenting gratings through two rectangles (that form the dual barber poles) and recording the perceived direction of motion by human observers. To this end, we presented dual barber poles in conditions with various inter-component distances between the apertures and evaluated the degree to which the hemifield information was integrated by measuring the magnitude of the perceived barber pole illusion. Surprisingly, when the inter-component distance between the two apertures was short, the perceived direction of motion of the dual barber poles was similar to that of a single barber pole formed by the concatenation of the two component barber poles, indicating motion integration is achieved through a simple concatenation mechanism. We then presented dual barber poles in which the motion and contour properties of the two component barber poles differed to characterize the constraints underlying cross-hemifield integration. We found that integration is achieved only when phase, speed, wavelength, temporal frequency, and duty cycle are identical in the two barber poles, but can remain robust when the contrast of the two component barber poles differs substantially. We concluded that a motion stimulus presented in bilateral hemifields tends to be integrated to yield a global percept with a substantial tolerance for spatial distance and contrast difference.