Paralyzed Side Research Articles

Comparison of gait recovery patterns according to the paralyzed side in stroke patients: An observational study based on a retrospective chart review (STROBE compliant).

Gait rehabilitations have been abundantly performed for post-stroke patients, because gait is the most important factor for the return of post-stroke patients to daily life. However, conventional uniform gait rehabilitations tend to be tedious and reduce motivation. The aim of this study was to contribute to the development of personalized rehabilitation of gait by identifying differences in gait recovery pattern according to the paralyzed side of post-stroke patients.The gait analysis was performed on stroke patients who are right-handed and can walk independently. We retrospectively analyzed the results of pelvic movements and displacement of center of pressure (COP) during gait using corresponding equipments. To show the difference of gait recovery pattern according to the paralyzed side, we divided subjects into two groups, right (n = 19) and left (n = 20) hemiparesis group. The measured variables were as follows: tilt, obliquity, and rotation symmetries of pelvis; area, velocity, and lateral symmetry of COP.First, in the left hemiparesis group, obliquity (P < .01) and rotation (P < .01) symmetries of the movement of the pelvis were significantly improved in the follow-up compared to the initial gait analysis. In the right hemiparesis group, tilt (P < .001), obliquity (P < .001), and rotation (P < .05) symmetries were significantly improved in the follow-up compared to the initial gait analysis. Second, COP area and COP velocity values in the follow-up were significantly smaller than those in the initial gait analysis in the left (P < .001, P < .05) and right (P < .001, P < .01) hemiparesis groups. The positive value of lateral symmetry increased, although not a significant difference statistically, as walking ability improved in both groups. In the correlation analysis among variables obtained using Treadmill, there were significant positive linear relationships between the lateral symmetry and the COP area (P < .05), and between the COP velocity and the lateral symmetry (P < .001) of the follow-up gait analysis in the right hemiparesis group.It was confirmed that the gait recovery pattern differs according to the paralyzed side of post-stroke patients and the role of the intact side, such as moving the COP to the intact side, is important for the improvement of gait function in both groups.This study was registered with the Clinical Research Information Service (CRIS) of the Korea National Institute of Health (NIH), Republic of Korea (KCT0002984) and was approved by the Institutional Review Board (IRB) of the WKUGH (WKIRB [2018-25], November 28, 2018).

Effect of Distal Masseter to Facial Nerve Transfer in Paralytic Patients with Preserved Facial Nerve Continuity on Improving Scaled Measurement of Improvement in Lip Excursion (SMILE): A Vectoral Analysis.

Distal masseter-to-facial neurorrhaphy is an option to improve smile excursion in facial paralysis patients in the early period without truncating the facial nerve truncus and by ensuring the continuity of the facial nerve. This study aimed to study the effect of distal masseter-to-facial neurorrhaphy on smile excursion. Charts of eight patients were retrospectively examined. Screenshots showing the best possible smiles were taken from preoperative videos. Screenshots were taken from postoperative videos showing the best combination of a natural smile on the healthy side and a smile with clenched teeth on the paralytic side. Emotrics and Photoshop software were used for computing vertical, horizontal, and overall excursion from facial landmarks. Scaled measurements of improvement in lip excursion and lip angle was evaluated. Symmetry was evaluated by accepting the healthy side as 100 percent, and the paralytic side was calculated as a percentage of the healthy side. Five patients had total facial paralysis and three had facial paresis. Mean postoperative follow-up period was 15.0±10.2 months. The average interval between facial denervation and nerve repair was 14.0±4.1 months (range, 11-23). All neurorrhaphies were coapted end-to-end to either the zygomatic or the buccal branch without an interposition graft. Mean postoperative initial movement occurred at 95.5±20.5 days (range, 72-138). Paralytic side to healthy side horizontal excursion changed from preoperative 72.5±17.4% to postoperative 93.4±6.9%. Vertical excursion changed from preoperative 38.4±24.6% to postoperative 89.3±11.8%. Overall excursion changed from preoperative 68.4±19.6% to postoperative 92.9±10.4%. Paralytic side to healthy side mean lip angle changed from 64.7% preoperative to 95.2% postoperatively. All changes were statistically significant (p<0.05). Facial paralysis patients with an asymmetric smile benefit from distal masseter-to-facial nerve transfer and it improves smile excursion dramatically. This effect was especially prominent in the vertical component of the smiling vector.

Comparison of Facial Muscle Activation Patterns Between Healthy and Bell's Palsy Subjects Using High-Density Surface Electromyography.

Facial muscle activities are essential for the appearance and communication of human beings. Therefore, exploring the activation patterns of facial muscles can help understand facial neuromuscular disorders such as Bell’s palsy. Given the irregular shape of the facial muscles as well as their different locations, it should be difficult to detect the activities of whole facial muscles with a few electrodes. In this study, a high-density surface electromyogram (HD sEMG) system with 90 electrodes was used to record EMG signals of facial muscles in both healthy and Bell’s palsy subjects when they did different facial movements. The electrodes were arranged in rectangular arrays covering the forehead and cheek regions of the face. The muscle activation patterns were shown on maps, which were constructed from the Root Mean Square (RMS) values of all the 90-channel EMG recordings. The experimental results showed that the activation patterns of facial muscles were distinct during doing different facial movements and the activated muscle regions could be clearly observed. Moreover, two features of the activation patterns, 2D correlation coefficient (corr2) and Centre of Gravity (CG) were extracted to quantify the spatial symmetry and the location of activated muscle regions respectively. Furthermore, the deviation of activated muscle regions on the paralyzed side of a face compared to the healthy side was quantified by calculating the distance between two sides of CGs. The results revealed that corr2 of the activated facial muscle region (classified into forehead region and cheek region) in Bell’s palsy subjects was significantly (p < 0.05) lower than that in healthy subjects, while CG distance of activated facial region in Bell’s palsy subjects was significantly (p < 0.05) higher than that in healthy subjects. The correlation between corr2 of these regions and Bell’s palsy [assessed by the Facial Nerve Grading Scale (FNGS) 2.0] was also significant (p < 0.05) in Bell’s palsy subjects. The spatial information on activated muscle regions may be useful in the diagnosis and treatment of Bell’s palsy in the future.

Evaluation of Bell's palsy in the cerebellopontine angle: An MRI study.

Evaluation of cranial nerve morphology through measuring cross-sectional area (CSA) on magnetic resonance imaging (MRI) is increasing day-by-day in clinical diseases. In Bell's palsy (BP), the manifestation of the enlarged CSA of the facial nerve (FN) may be used for diagnosis. This study aims to evaluate whether there is an enlargement of the cisternal FN in BP. This retrospective study included 43 patients diagnosed with BP. In the reconstructed MRI, the long (LD) and short (SD) diameters of the paralytic and normal sides of the FNs located in the cerebellopontine angle were measured, and the CSA was calculated using the Radinsky formula. Before the radiologic measurement, a preliminary experiment was carried out on the rat sciatic nerve to be able to determine the actual nerve boundary on MRI. There was a statistically significant relationship between paralytic and normal sides in the measurements of LD, SD, and CSA. The paralytic side was larger than the normal side in the cisternal FN. According to the Receiver Operating Characteristic (ROC) curve, BP can be estimated with 60% sensitivity and 70% specificity by the CSA of the FN more than 1.04 mm2 . As a result of the preliminary experiment, it was found that the actual nerve boundary was at approximately 50% intensity between the minimum and maximum values. Although entrapment of FN in the labyrinthine segment in BP was known, this study showed that the cisternal FN, which could be evaluated more conveniently, enlarged in the paralytic side compared with the normal side, and revealed the necessity of performing the comparison amongst the MRI studies on BP patients by a standardised measurement method. This study will also help clinicians to make a decision in the diagnosis of BP by giving a cut-off value for the CSA.

Relationship between Energy Intake and Changes in Thigh Echo Intensity during the Acute Phase of Stroke in Older Patients with Hemiplegia

Objective: The aim of this study was to investigate the relationship between energy intake and changes in thigh echo intensity (TEI) during the acute phase of stroke in older patients with hemiplegia. Subjects and Methods: Older hemiplegic inpatients with stroke were enrolled in this post hoc analysis of a prospective observational study. Patients were divided into 2 groups according to energy intake during the 7 days after admission as follows: energy sufficient (ES) and energy insufficient (EIS) groups. The outcome was the rate of changes in TEI of the paralyzed and nonparalyzed sides between admission and after 4 weeks. A decrease in skeletal muscle quality is defined as an increase in intramuscular adipose tissues, which shows as an increase in echo intensity. Results: The study included 44 males and 39 females (median age 81 years). The rate of change of TEI in each group was as follows: +4.5% in the ES/paralyzed group, +6.7% in the EIS/paralyzed group, −0.9% in the ES/nonparalyzed group, and +4.4% in the EIS/nonparalyzed group. The univariate analyses showed no significant difference in the rate of change in TEI between ES and EIS groups in both paralyzed side (p = 0.190) and nonparalyzed side (p = 0.183). Multivariate analysis showed that higher energy intake was associated with a smaller increase in the rate of change in TEI on the nonparalyzed side (B = −4.115, 95% confidence interval, −7.127 to −1.103). Conclusions: Higher energy intake during 7 days after admission was associated with a smaller increase in the rate of change in TEI on the nonparalyzed side upon admission and after 4 weeks.

Occupational Therapy with the Screw Block® Kit for Improving Upper Limb Function in Stroke Patients: A Quasi-randomized Controlled Trial.

ABSTRACTObjectives: A pilot study was conducted primarily to examine the effect of rehabilitation using the Screw Block® kit on the upper limb function of hemiplegic stroke patients.Methods: In this pilot, single-center, quasi-randomized, controlled trial, 30 stroke patients were randomly allocated to either the experimental group or the control group. They received training with either Screw Block® for 20 min in addition to conventional occupational therapy (20–40 min) or conventional occupational therapy, which included upper limb functional training for 40–60 min. In both groups, training was conducted 5 days a week for 3 weeks (15 sessions in total). Upper extremity function on the paralyzed side, which was the primary outcome, was evaluated using the Simple Test for Evaluating Hand Function (STEF) before and after the interventions.Results: The study sample included 28 men and 2 women (mean age, 62.5 years). The experimental group showed a significant improvement in mean STEF score compared with the control group (T=2.252, P=0.032, Cohen’s d=0.82).Conclusion: Occupational therapy using Screw Block® was more effective than conventional occupational therapy alone in improving the upper limb function in stroke patients.

Effectiveness of a knee-ankle-foot orthosis with a knee extension aid in gait training for stroke patients.

To evaluate the effectiveness of a knee-ankle-foot orthosis (KAFO) with a newly developed knee extension aid in gait training for stroke patients with severe leg paralysis. The participants were 7 recovering stroke patients prescribed a KAFO. With the KAFO knee joint set to allow free flexion, knee flexion angle, lower limb muscle activity, and time of plantar ground contact were measured during assisted walking with the knee extension aid or a conventional support loop. When first using the knee extension aid, knee flexion angle at initial ground contact was significantly decreased and time from heel strike on the paralyzed side to forefoot strike was prolonged compared with the support loop. After using the knee extension aid for 1 week, in addition to the two parameters above, maximum knee flexion angle during the swing phase, knee extension displacement from the maximum flexion angle to initial ground contact, and the muscle activity ratio of the biceps femoris during the swing phase were significantly increased compared with the support loop. This knee extension aid may be indicated for patients who have difficulty in initial heel strike due to excessive knee flexion at the end of the swing phase.

A Case Report of Functional Acupuncture in the Treatment of Senile Left Persistent Facial Paralysis

Introduction: Idiopathic facial palsy, also known as Bell's palsy (BP) or facial neuritis, is an acute onset of peripheral facial neuropathy. The onset of this disease is rapid, and there is a history of cold, mostly on one side of the face. Objective: to introduce and analyze the method and curative effect of functional acupuncture on one case of senile left persistent facial paralysis. Methods: focus on the functional parts of the affected area that need to be improved, select the acupuncture areas with improved trigger function, and select the stimulation dose of electroacupuncture. In other words, functional acupuncture is the main acupuncture method in the treatment process, that is, to take a functional position before acupuncture on the paralyzed side of the cheek, that is, to lift the patient's left corner of the mouth outward to above the functional position with a surgical small retractor (the largest lifting mouth angle is tilted to the left side), to determine the left cheek muscle functional area (needle entry area), and to make corresponding adjustment on the left cheek Acupoints selected in functional areas: Xiaguan, zygomatic Luo, buccal Che, Yingxiang, Renzhong, Taiyang, sizhukong, Chengzhi, yangbai. The needle of 0.35 mm × 40 mm was selected, and 0.3-1 inch flat needling was used with electroacupuncture. The waveform was density wave. Five times a week, 10 times for a course of treatment. Results: after two courses of functional acupuncture treatment, the patient's left eyelid was basically closed, and the air leakage during the left cheek bulging was significantly improved. After eating, the food left in the left cheek disappeared, the left nasolabial groove appeared, the left frontal lines appeared, and the symptoms of the left mouth angle slanting to the right were significantly improved (see the figure below). Conclusion: the essence of functional acupuncture improvement is to re form a strong neuromuscular effect in muscles, destroy the paralysis and weakness of target muscles, and reconstruct the normal neuromuscular coupling mode. The aim of this balance mechanism is to destroy the reflex pattern of abnormal muscle paralysis and muscle weakness and reconstruct an orderly and normal neuromuscular reflex.

Optimal current intensity for supramaximal stimulation during electroneurography for facial palsy

ObjectiveTo determine the optimal current intensity for supramaximal stimulation during electroneurography (ENoG) for facial palsy. MethodsForty patients with unilateral facial palsy (32 Bell's palsy, 7 Ramsay Hunt syndrome, and 1 temporal bone fracture) were enrolled. All patients were initially treated with intravenous steroid injections and examined using ENoG. Compound muscle action potentials (CMAPs) of the orbicularis oris muscle were measured on the paralyzed and healthy sides. Stimulation current intensity was varied every 5 mA from 20 mA to 50 mA using two recording methods (the midline and standard methods). The CMAPs of both sides were monitored to see whether they would saturate under the high current intensity stimulation or not. ResultsNo obvious saturation of CMAPs was observed in either side with the midline or standard methods. Statistically, a current of 35 mA and above in the healthy side, and 30 mA and above in the paralytic side, resulted in no difference to each side when using the midline recording method. On the other hand, a current of 35 mA and above in the healthy side, and 25 mA and above in the paralytic side, resulted in no difference to each side when using the standard recording method. ConclusionsThese results indicate that a current intensity of at least 35 mA is required to achieve supramaximal stimulation on the healthy side in a patient with unilateral facial nerve palsy. Clinically, for simplicity or standardization purposes, if the same current intensity is introduced bilaterally for ENoG measurements, adopting 40 mA (35 mA plus 10-20%) stimulation would be appropriate for supramaximal stimulation, while being cognizant of the potential effects of artifacts from other muscles.

Predicting Resting Oral Commissure Tone Outcomes Following Masseter Nerve Transfer in Facial Reanimation.

Objective: To quantify the degree of oral commissure resting tone improvement in patients undergoing masseter to facial nerve transfer. Methods: A retrospective cohort study was completed in a tertiary academic medical practice. Consecutive cases of masseter nerve transfer patients within a patient database were evaluated from 6/2012 to 9/2017. Inclusion criteria were patients >18 years of age, with complete unilateral paralysis, receiving a masseter to facial nerve transfer, with at least 12 months of recovery, and possessing complete pre- and postoperative data. Patients were excluded if a simultaneous adjunctive procedure was performed so that tone could not be attributed to masseter transfer alone. The main outcome measure was the facial asymmetry index (FAI): the measured difference in distance between the medial canthus and oral commissure of the healthy and paralyzed sides. Results: Twenty-nine patients met inclusion and exclusion criteria and were further analyzed for this study. The oral commissure symmetry improved from 4.7 ± 2.8 mm preoperatively to 2.2 ± 2.3 mm postoperatively. In multivariate analysis, the preoperative FAI was the only significant predictive factor for improvement in commissure symmetry at rest (r = 0.589). This suggests that for each 1.0 mm of worse preoperatively oral commissure asymmetry, the improvement postoperatively was 0.6 mm. Age, gender, body mass index, side of paralysis, duration of paralysis, and recipient branch of facial nerve were not significant predictors in a multivariate analysis. Conclusion: Masseter to facial nerve transfer yields an estimated 60% correction in the oral commissure asymmetry. This estimation may be helpful in determining if adjunctive procedures should be utilized.

Application of Artificial Intelligence for Real-Time Facial Asymmetry Analysis.

Application of Artificial Intelligence for Real-Time Facial Asymmetry Analysis.

A Haptic-Based Perception-Empathy Biofeedback System with Vibration Transition: Verifying the Attention Amount.

In this paper, a perception-empathy biofeedback (PEBF) system is proposed that supplements the foot pressure status of a paralyzed foot with a wearable vibrotactile biofeedback (BF) vest to the back. Improvements in the ankle dorsiflexion and push-off movement in the swing phase and pre-swing phase, respectively, can be expected after using the proposed system. However, the results of the 3 week pilot clinical tests suggest that significant improvement is only observed for the push-off movement. It is assumed that the attention required to recognize the BF was beyond the ability of the patients. In this paper, a dual task (40 s walking and performing mental arithmetic at the same time) was conducted with the following conditions: no vibrations and providing BF to the lower back and the entire back. According to the results, the ankle joint angle of the paralyzed side at push-off under the entire back condition is statistically significant (p = 0.0780); however, there are no significant changes under the lower back condition (p = 0.4998). Moreover, the ankle joint angle of the paralyzed side at the initial contact is statistically significant with respect to the lower back condition (p = 0.0233) and shows a significant trend for the entire back condition (p = 0.0730). The results suggest that the limited attention capacity of hemiplegic patients fails to improve both dorsiflexion and push-off movements; moreover, ankle motion can be promoted if attention is concentrated on recognizing focalized vibratory feedback patterns.

Pedaling improves gait ability of hemiparetic patients with stiff-knee gait: fall prevention during gait

Background and PurposeStiff-knee gait, which is a gait abnormality observed after stroke, is characterized by decreased knee flexion angles during the swing phase, and it contributes to a decline in gait ability. This study aimed to identify the immediate effects of pedaling exercises on stiff-knee gait from a kinesiophysiological perspective. MethodsTwenty-one patients with chronic post-stroke hemiparesis and stiff-knee gait were randomly assigned to a pedaling group and a walking group. An ergometer was set at a load of 5 Nm and rotation speed of 40 rpm, and gait was performed at a comfortable speed; both the groups performed the intervention for 10 min. Kinematic and electromyographical data while walking on flat surfaces were immediately measured before and after the intervention. ResultsIn the pedaling group, activity of the rectus femoris significantly decreased from the pre-swing phase to the early swing phase during gait after the intervention. Flexion angles and flexion angular velocities of the knee and hip joints significantly increased during the same period. The pedaling group showed increased step length on the paralyzed side and gait velocity. ConclusionsPedaling increases knee flexion during the swing phase in hemiparetic patients with stiff-knee gait and improves gait ability.

Study on the matching feature of current parameters for inducing contraction of orbicularis oris muscle by artificial facial nerve in rabbit with peripheral facial paralysis

Objective: To explore the optimal matching of the current parameters about artificial facial nerve (AFN) for inducing contraction of the orbicularis oris muscle (OOM) in rabbit with peripheral facial paralysis. Methods: According to the combinations of different stimulus parameters, at different time points, we used AFN to induce contraction of the affected side OOM of the paralyzed rabbit in waking state. We recorded the current amplitudes of the threshold stimulation and peak stimulation under each combination, then compared the total charge of the stimulus consumption under different combinations. Results: Compared the total stimulus charge consumption of the AFN threshold stimulation and that in the peak stimulation respectively under different stimulus frequency and pulse width matching combinations, we found that the frequency, the pulse width and the interaction of the frequency and pulse width among different groups could affect the total charge, the differences were statistically significant (P<0.05). Conclusions: When AFN stimulus frequency is 60 Hz and the stimulus pulse width is 100 μs, the output current intensity is relatively lowest and the total consumed charge is the lowest under the premise of effectively inducing the paralytic side OOM contraction. Thus we recommend this stimulus parametric combination as the optimal combination for meeting the low power consumption of AFN.

Unilateral Hemihyperhidrosis in a Stroke Patient and Literature Review on Its Clinicoanatomical Correlation

Contralateral hyperhidrosis from the cardiovascular accident has been infrequently described in the stroke literature. The clinical significance and pathogenesis are yet well understood. This is a case of a 60-year-old man who developed excessive sweating of the paralyzed side with a pure division along the midline of the body secondary to a subcortical stroke, which region is supplied by branches of middle cerebral artery territory known as deep perforating lenticulostriate. To the best of our knowledge, a precise clinicoanatomic correlation between hyperhidrosis and subcortical stroke has not been widely reported. In this review, we summarize the existing literature of post-stroke hyperhidrosis to evaluate the correlation between clinical manifestation and its neuroanatomical location. According to the location of the infarction and clinical features, it can be concluded that both tracks en route through the ipsilateral internal capsule, after originating in the opercular cortex before crossing the brain stem and terminal connections with the contralateral thoracic spinal cord. Therefore, the phenomenon of hyperhidrosis in anterior circulation stroke might be postulated as due to the disruption of the sympathoinhibitory pathway that controls sweat glands, similarly like posterior circulation stroke.

Effects of rehabilitation training of core muscle stability on stroke patients with hemiplegia.

Objective:To evaluate the effects of rehabilitation training of core muscle stability on stroke patients with hemiplegia.Methods:A total of 180 stroke patients who were hospitalized from December 2017 to December 2018 were enrolled. They were randomly divided into an observation group and a control group (n=90) that both received conventional hemiplegia rehabilitation therapy. On this basis, the observation group was subjected to training for core muscle stability, five times a week for a total of eight weeks. The balance functions before and after training were assessed using the Berg Balance Scale (BBS). The functions of hemiplegic lower limbs were evaluated by Brunnstrom staging and the Fugl-Meyer motor assessment (FMA) scale. The walking speed was estimated using the 10 m walking test. Musculoskeletal ultrasonography was performed to measure the thicknesses of three abdominal muscles of the paralytic side, i.e. transverse abdominis, internal oblique and external oblique muscles.Results:After treatment, the BBS scores of the two groups were significantly higher than those before treatment, with significant differences (P<0.05). The BBS score of the observation group was significantly higher than that of the control group (P<0.05). After treatment, the Brunnstrom stage and FMA scale score, and standing and stepping scores were significantly higher than those before treatment (P<0.05). The Brunnstrom stage, FMA scale score, stepping score and walking speed of the observation group significantly exceeded those of the control group (P<0.05). After treatment, the thicknesses all increased compared with those before treatment, but the thicknesses of internal oblique and external oblique muscles were not significantly different (P>0.05). The thickness of transverse abdominis muscle of the observation group significantly surpassed that before treatment (P<0.05), whereas the thicknesses of the control group were similar (P>0.05). The thickness of transverse abdominis muscle of the observation group was significantly higher than that of the control group (P<0.05).Conclusion:Rehabilitation training of core muscle stability can effectively improve the balance function and walking speed of stroke patients, probably by increasing the thickness of transverse abdominis muscle.

Ultrasound Diagnostic Value in Assessment of Vocal Cord Mobility before Neck Surgery

AbstractBackground: The preoperative assessment of vocal cord mobility in patient scheduled for neck surgery is mandatory. The diagnostic approach differs from traditional ones as flexible fiberoptic, indirect laryngoscopy, to less tradition ones as CT and MRI.Ultrasound is non invasive, safe, repeatable, bedside, non ionizing radiation dependent technique together with the advancement of technology providing high resolution real time images and short cine videos. This is hand to hand with good patient compliance for the technique.Aim of Study: To evaluate the diagnostic value of ultra-sound in the assessment of vocal cords mobility before neck surgeries.Patients and Methods: This cross section study was carried out between October 2016 and November 2018 on 60 patients (25 males and 35 females) in Ain Shams University Hospitals. They were all scheduled for neck surgeries for different reasons. After taking full clinical history, complete head and neck examination, flexible fiberoptic and/or indirect laryn-goscopy, patients underwent sonographic examination. Patients were divided into two groups. The first group (I) with no clinical symptoms or signs suggestive of vocal foldparalysis. The second group (II) with unilateral abductor vocal fold paralysis. The acquired static photos and dynamic cine videos were accurately examined to delineate various laryngeal structures and to assess interarytenoid distances and arytenoid cartilage mobility during full inspiration and during phonation.Results: After identification of laryngeal structures, we could identify in recorded cine videos immobile arytenoids cartilage on the paralytic side during both inspiration and phonation with sensitivity (80%), specificity (90%), PPV (80%) and NPV (90%). Another important finding is noted that the percent of change in interarytenoid distances was much less in group II than in group I.Conclusion: Preoperative ultrasound examination of vocal cord mobility proved to be valid identifying the various laryngeal structures with high potency in judging vocal cord mobility either by short real time cine videos or measuring interarytenoid distances. We recommend to consider laryngeal ultrasound as reliable imaging modality in preoperative as-sessment of vocal cord mobility prior to neck surgery.

Natural Course of Unilateral Vocal Fold Paralysis and Optimal Timing of Permanent Treatment

Permanent surgical treatment for unilateral vocal fold paralysis (UVFP) should be performed when further neural recovery is improbable. Conservative delay of the surgical procedure may cause unnecessary deterioration of the patient's quality of life. Knowledge of the natural course of UVFP is important for better management and counseling. To evaluate the natural course of UVFP, focusing on the recovery time according to the injury level to assess the optimal timing for permanent surgical intervention. This retrospective case series enrolled 1264 patients with UVFP who visited the voice clinic of Seoul National University Hospital, Seoul, Korea, from November 1, 2005, through December 31, 2016. Medical records and stroboscopic video images were reviewed to obtain data on demographic characteristics, vocal fold movement, onset and recovery time, follow-up duration, and cause. Cases of UVFP were classified into 5 groups based on the location of injury: distal to the thyroid level, thyroid level, esophagus and mediastinum level, heart and lung level, and proximal to the thorax level. Data analysis was performed from January 23, 2018, to May 21, 2018. Recovery of vocal fold movement defined as more than vocal fold twitching confirmed by stroboscopy video images, estimated injury level, and start time of recovery. The recovery time was analyzed according to age, sex, paralytic side, and 5 injury levels. Of 1264 eligible patients with UVFP (655 [51.8%] male; median age, 56 years [range, 1-90 years]), 208 had evidence of recovery with the recovery time relatively accurate. The maximum recovery time for the group with distal to the thyroid-level injury was 120 days; the group with thyroid-level injury, 157 days; the group with esophagus and mediastinum-level injury, 244 days; the group with heart and lung-level injury, 328 days; and the group with proximal to the thorax-level injury, 333 days with the exception of 1 outlier value (482 days). Recovery time did not differ according to age, sex, or paralytic side. As distance between the vocal fold and injury level increased, the maximum recovery time increased, plateauing at 1 year. Among the patients who showed recovery of the vocal fold movement, most patients with injuries distal to or at the level of the thyroid recovered within 6 months, whereas those with injury more distant from the vocal fold recovered within approximately 1 year. A linear association between injury level and maximum recovery time was observed. The findings suggest that the decision to proceed with permanent phonosurgical treatment should be based on the level of injury associated with UVFP.

Significance of the Marginal Mandibular Branch in Relation to Facial Palsy Reconstruction

The marginal mandibular branch (MMB) of the facial nerve provides lower lip symmetry apparent during human smile or crying and is mandatory for vocal phonation. In treating facial palsy patients, so far, little attention is directed at the MMB in facial reanimation surgery. However, isolated paralysis may occur congenital, in Bell's palsy or iatrogenic during surgery, prone to its anatomical course. A variety of therapies address symmetry with either weakening of the functional side or reconstruction of the paralyzed side. To further clarify the histoanatomic basis of facial reanimation procedures using nerve transfers, we conducted a human cadaver study examining macroanatomical and microanatomical features of the MMB including its axonal capacity. Nerve biopsies of the MMB were available from 96 facial halves. Histological processing, digitalization, nerve morphometry investigation, and semiautomated axonal quantification were performed. Statistical analysis was conducted with P < 0.05 as level of significance. The main branch of 96 specimens contained an average of 3.72 fascicles 1 to 12, and the axonal capacity was 1603 ± 849 (398-5110, n = 85). Differences were found for sex (P = 0.018), not for facial sides (P = 0.687). Diameters were measured with 1130 ± 327 μm (643-2139, n = 79). A significant difference was noted between sexes (P = 0.029), not for facial sides (P = 0.512.) One millimeter in diameter corresponded to 1480 ± 630 axons (n = 71). A number of 900 axons was correlated with 0.97 mm (specificity, 90%; sensitivity, 72%). Our morphometric results for the MMB provide basic information for further investigations, among dealing with functional reconstructive procedures such as nerve transfers, nerve grafting for direct neurotization or babysitter procedures, and neurectomies to provide ideal power and authenticity.

IBlink: A Wearable Device Facilitating Facial Paralysis Patients to Blink

Facial paralysis makes patients lose their facial movements, which can incur eye damage even blindness since patients are incapable of blinking. We design and implement a pair of smart glasses iBlink to assist facial paralysis patients to blink. The basic idea is to monitor the normal side of the face with a camera and stimulate the paralyzed side, so that the blink of the both eyes become symmetric. Our contributions are: First, we propose an eye-blink detection mechanism based on support vector machine (SVM), which can detect asymmetric blinks of patients under various illumination conditions with an accuracy above 99 percent. Our eye-image library for training the model is published online for further related studies, which contains more than 30,000 eye images. Second, we design and implement an automatic stimulation circuits to generate electrical impulse for stimulating the patient's facial nerve branches, which can configure operational parameters in a self-adaptive manner for different patients. Third, we implement the entire iBlink system, which integrates the two functions above and a communication function module for tele-medicine applications. We conduct experiments in a hospital to obtain the design basis and verify effectiveness of our device.