Cognitive-motor interference during walking with modified leg mechanics: a dual-task walking study

Background

The use of mobile exoskeletons as assistive walking devices has the potential to affect the biomechanics of the musculoskeletal system due to their weight and restricted range of motion. This may result in physical and cognitive load for the user. Understanding how lower extremity loading affects cognitive-motor interference is crucial for the design of wearable devices, including powered exoskeletons, and the development of effective training interventions.

Objective

This study aims to examine the effects of modified leg mechanics on cognitive-motor interference in dual-task walking. Gait variability, as an indicator of motor control, was analyzed to investigate its relation to cognitive task difficulty and to determine whether lower extremity loading modifies this relationship. Additionally, the impact on the gait pattern, as represented by the mean values of spatio-temporal gait parameters were investigated.

Method

Fifteen healthy young adults walked on a treadmill with and without weight cuffs bilaterally attached to their thighs and shanks while performing a visual-verbal Stroop test (simple task) and a serial subtraction task (difficult task). Dependent variables include mean values and variability (coefficients of variation) of step length, step width, stride time and double support time. Additionally, secondary task performance as correct response rates and perceived workload were assessed.

Results

Double support time variability decreased during dual-task walking, but not during walking with modified leg mechanics while performing the difficult secondary task. Walking with modified leg mechanics resulted in increased gait variability compared to normal walking, regardless of cognitive load. During walking with modified leg mechanics, step length, step width, and stride time increased, while double support time decreased. The secondary tasks did not affect the gait pattern.

Conclusion

The interplay between an external focus of attention and competition for attentional resources may influence the variability of double support time. The findings suggest that walking with modified leg mechanics could increase cognitive-motor interference for healthy young adults in demanding dual-task situations. Therefore, it is important to analyze the underlying mechanisms of cognitive-motor interference in the context of human-exoskeleton interaction.

[Impact of the COVID-19 pandemic on the diagnosis and treatment of patients with head and neck cancer in Brandenburg and Berlin]

BACKGROUND

The impact of the COVID-19 pandemic on potential limitations to the diagnosis and treatment of patients with head and neck tumours has not yet been adequately investigated. There are contradictory data on this subject. Data from larger patient collectives do not exist for Germany so far.

OBJECTIVE

The aim of the survey was to clarify in a large cohort whether the COVID-19 pandemic had an influence on the diagnosis and treatment of patients with head and neck tumours.

METHODS

A retrospective data analysis of the reporting data of the Clinical and Epidemiological Cancer Registry of Brandenburg and Berlin (Klinisch-epidemiologischen Krebsregisters Brandenburg-Berlin, KKRBB) of 4831 cases with head and neck tumours from 2018 to 2020 was performed. The period before April 01, 2020, was evaluated as a prepandemic cohort and compared with the cases of the pandemic cohort from April 1, 2020, until December 31, 2020, in terms of patient-related baseline data, tumour location, tumour stage, tumour board and treatments administered.

RESULTS

No differences were observed between the prepandemic and pandemic cohorts with regard to patient-related baseline data, tumour localisation and tumour stage. Likewise, no temporal delay in diagnosis, tumour board and treatment was evident during the pandemic period. On the contrary, the time interval between diagnosis and start of therapy was shortened by an average of 2.7 days in the pandemic phase. Tumours with T4 stage were more frequently treated surgically during the pandemic compared to the period before (20.8% vs. 29.6%), whereas primary radio(chemo)therapy decreased during the pandemic (53.3% vs. 40.4%). For all other tumour stages and entities, there were no differences in treatment.

CONCLUSION

Contrary to initial speculation that the COVID-19 pandemic may have led to a decrease in tumour cases, larger tumour stages at initial presentation and a delay in diagnosis and treatment, the cohort studied for Brandenburg and Berlin showed neither a delay in tumour treatment nor an increase in tumour size and stage at initial presentation. The treatments performed, however, were subject to a change in favour of surgery and it remains to be seen whether this trend will be maintained in the long term.

Evaluating Contrast Sensitivity in Early and Intermediate Age-Related Macular Degeneration With the Quick Contrast Sensitivity Function

Purpose

The purpose of this study was to describe, validate, and compare the contrast sensitivity functions (CSFs) acquired with the novel quick CSF (qCSF) method from patients with early and intermediate age-related macular degeneration (eAMD and iAMD) and healthy controls.

Methods

This is a cross-sectional analysis of contrast sensitivity (CS) and visual acuity (VA) baseline data from the prospective Multimodal Functional and Structural Visual System Characterization (MUMOVI) study. The qCSF testing was conducted with the manifold contrast vision meter (Adaptive Sensory Technology, San Diego, CA, USA). CS levels at spatial frequencies from 1 cycle per degree (CPD) to 18 CPD, the area underneath the logarithmic contrast sensitivity function (AULCSF), and contrast acuity (CA) were analyzed. The association of functional metrics with variables of interest was tested with linear models.

Results

Ninety-four study eyes from 94 study patients were included in the analysis (13 patients with eAMD, 33 patients with iAMD, and 48 healthy controls). Significant differences between the eAMD and the iAMD model estimates were only found for CS at 1 CPD (t value = -2.9, P value = 0.006) and CS at 1.5 CPD (-2.7, 0.01). A specific association between smoking years and CS at 1 CPD (P = 0.02) and CS at 1.5 CPD (P = 0.03) could be described in patients with AMD.

Conclusions

The qCSF testing allows the fast measurement of the whole CSF, enabling the integration into clinical routine. We showed that novel qCSF-derived metrics detect slight functional differences between AMD stages, which testing by Pelli-Robson charts or VA testing would miss. This study, therefore, yields novel qCSF-derived candidate metrics for therapeutic trials in AMD.

Rollator usage lets young individuals switch movement strategies in sit-to-stand and stand-to-sit tasks

The transitions between sitting and standing have a high physical and coordination demand, frequently causing falls in older individuals. Rollators, or four-wheeled walkers, are often prescribed to reduce lower-limb load and to improve balance but have been found a fall risk. This study investigated how rollator support affects sit-to-stand and stand-to-sit movements. Twenty young participants stood up and sat down under three handle support conditions (unassisted, light touch, and full support). As increasing task demands may affect coordination, a challenging floor condition (balance pads) was included. Full-body kinematics and ground reaction forces were recorded, reduced in dimensionality by principal component analyses, and clustered by k-means into movement strategies. Rollator support caused the participants to switch strategies, especially when their balance was challenged, but did not lead to support-specific strategies, i.e., clusters that only comprise light touch or full support trials. Three strategies for sit-to-stand were found: forward leaning, hybrid, and vertical rise; two in the challenging condition (exaggerated forward and forward leaning). For stand-to-sit, three strategies were found: backward lowering, hybrid, and vertical lowering; two in the challenging condition (exaggerated forward and forward leaning). Hence, young individuals adjust their strategy selection to different conditions. Future studies may apply this methodology to older individuals to recommend safe strategies and ultimately reduce falls.

Individual computer-assisted 3D planning for placement of auricular prosthesis anchors in combination with an implantable transcutaneous bone conduction hearing device in patients with aural atresia

BACKGROUND

The simultaneous implantation of the Bonebridge (MED-EL, Innsbruck, Austria), a semi-implantable active transcutaneous bone conduction hearing device and anchors for auricular prostheses can be challenging as both implants contain magnets and compete for the narrow space in the designated implantation area.

MATERIAL AND METHODS

A preoperative planning tool (virtual surgery) was used with individual 3D computer models of the skull and implants for finding optimal implant positions for both the floating mass transducer (FMT) and the anchors for the auricular prosthesis. The interaction between the magnetic prosthesis anchors and the FMT was measured by means of static magnetic forces. A retrospective data analysis was conducted to evaluate the surgical and audiological outcome.

RESULTS

Between 2014 and 2021, a 3D planning of a simultaneous implantation of the Bonebridge with auricular prosthesis anchors was conducted on 6 ears of 5 patients (3 males, 2 females; age range 17-56 years). The individual preoperative planning was considered very useful for the optimal placement of bone anchors in combination with the Bonebridge. Audiological data showed a clear benefit for hearing 3 months and > 11 months after implantation. No adverse interactions between the magnetic prosthesis anchors and the FMT were observed. In two patients, revision surgery was carried out due to skin inflammation or wound healing problems. No long-term complications were observed 3-5 years after surgery.

CONCLUSION

Preoperative 3D planning represents a clear benefit for the simultaneous audiological and esthetic rehabilitation using the Bonebridge and anchors for auricular prostheses.

Treatment of tracheoesophageal fistulas following laryngectomy by customized prostheses—A bicentric case series

Objective

Tracheoesophageal fistulas (TEF) following laryngectomy cause immense restrictions due to the inability of oral feeding, loss of voice rehabilitation, penetration of saliva, and permanent need of inflatable tracheal cannulas. Patients are consistently in threat of fatal aspiration pneumonias. The failure rate of surgical approaches to close the fistulas is high and an ultima ratio option by customized silicone prostheses can be considered.

Methods

A retrospective analysis of 26 patients with a TEF was performed.

Results

The fistulas occurred in average 40 months after laryngectomy caused by an enlargement of the voice fistula in 17 patients and problems in wound healing in 6 patients. The mean diameter of the fistula was 32 × 18 mm. Eight patients were treated by a button-shaped and 18 by a tube-shaped prosthesis. Complete oral feeding was possible in 8 and additional feeding by percutaneous endoscopic gastrostomy tube in 16 patients. Voice rehabilitation by voice prostheses was possible in 18 cases. Fifteen patients died in the course of the treatment either due to oncological progression or other reasons. The median follow-up time of the patients alive was 36 months (max 88 months) with 2.2 protheses replacements in mean (max 11).

Conclusion

The treatment of TEF by customized prostheses can be considered as an ultima ration option if other approaches had failed. At least, partial oral nutrition and voice rehabilitation as well as protection from aspiration can be achieved in the majority of the patients.

Level of Evidence

4-Case series.

[Olfactory rehabilitation via retronasal olfaction using a tracheoesophageal voice prosthesis after total laryngectomy. German version]

BACKGROUND

Despite the variety of existing methods for olfactory rehabilitation after total laryngectomy, olfactory disability remains one of the main factors limiting quality of life for laryngectomees.

OBJECTIVE

Considering the need for a socially acceptable rehabilitation method that is suitable for everyday use, this study sought to elucidate whether retronasal olfaction during phonation through a tracheoesophageal voice prosthesis is possible.

MATERIALS AND METHODS

The odor identification of 22 laryngectomees was assessed using the Sniffin' Sticks test battery (12 odors), while performing an established method of olfactory rehabilitation-"polite yawning"-or while transnasal expiration or phonation through the tracheoesophageal fistula (TF). To facilitate the latter, a novel Expiratory Nasal Airflow M‑Maneuver (ENAMM) was developed.

RESULTS

All 21 non-anosmic laryngectomees included in the study were able to identify odors retronasally. While only 6 of 22 patients (27.3%) could perform the nasal expiration through the TF, all patients could easily perform phonation using ENAMM after proper instruction. The odor identification scores with the ENAMM technique did not statistically differ from ones with "polite yawning" (5.4 ± 3.1 vs. 6.4 ± 3.2, p = 0.279). The ENAMM was easy to learn and showed a tendency of increasing olfactory scores over time, possibly due to a learning effect.

CONCLUSIONS

Study results show that retronasal olfaction using a voice prosthesis after total laryngectomy is possible and suggest the potential of ENAMM as a method of olfactory rehabilitation for laryngectomy patients.

Young Individuals Are More Stable and Stand More Upright When Using Rollator Assistance During Standing up and Sitting Down

Four-wheeled walkers or rollators are often used to assist older individuals in maintaining an independent life by compensating for muscle weakness and reduced movement stability. However, limited biomechanical studies have been performed to understand how rollator support affects posture and stability, especially when standing up and sitting down. Therefore, this study examined how stability and posture change with varying levels of rollator support and on an unstable floor. The aim was to collect comprehensive baseline data during standing up and sitting down in young participants. In this study, 20 able-bodied, young participants stood up and sat down both 1) unassisted and assisted using a custom-made robot rollator simulator under 2) full support and 3) touch support. Unassisted and assisted performances were analyzed on normal and unstable floors using balance pads with a compliant surface under each foot. Using 3D motion capturing and two ground-embedded force plates, we compared assistive support and floor conditions for movement duration, the relative timing of seat-off, movement stability (center of pressure (COP) path length and sway area), and posture after standing up (lower body sagittal joint angles) using ANOVA analysis. The relative event of seat-off was earliest under full support compared to touch and unassisted conditions under normal but not under unstable floor conditions. The duration of standing up and sitting down did not differ between support conditions on normal or unstable floors. COP path length and sway area during both standing up and sitting down were lowest under full support regardless of both floor conditions. Hip and knee joints were least flexed under full support, with no differences between touch and unassisted in both floor conditions. Hence, full rollator support led to increased movement stability, while not slowing down the movement, during both standing up and sitting down. During standing up, the full support led to an earlier seat-off and a more upright standing posture when reaching a stable stance. These results indicate that rollator support when handles are correctly aligned does not lead to the detrimental movement alterations of increased forward-leaning. Future research aims to verify these findings in older persons with stability and muscle weakness deficiencies.

Random Practice Enhances Retention and Spatial Transfer in Force Field Adaptation

The contextual-interference effect is a frequently examined phenomenon in motor skill learning but has not been extensively investigated in motor adaptation. Here, we first tested experimentally if the contextual-interference effect is detectable in force field adaptation regarding retention and spatial transfer, and then fitted state-space models to the data to relate the findings to the “forgetting-and-reconstruction hypothesis”. Thirty-two participants were divided into two groups with either a random or a blocked practice schedule. They practiced reaching to four targets and were tested 10 min and 24 h afterward for motor retention and spatial transfer on an interpolation and an extrapolation target, and on targets which were shifted 10 cm away. The adaptation progress was participant-specifically fitted with 4-slow-1-fast state-space models accounting for generalization and set breaks. The blocked group adapted faster (p = 0.007) but did not reach a better adaptation at practice end. We found better retention (10 min), interpolation transfer (10 min), and transfer to shifted targets (10 min and 24 h) for the random group (each p < 0.05). However, no differences were found for retention or for the interpolation target after 24 h. Neither group showed transfer to the extrapolation target. The extended state-space model could replicate the behavioral results with some exceptions. The study shows that the contextual-interference effect is partially detectable in practice, short-term retention, and spatial transfer in force field adaptation; and that state-space models provide explanatory descriptions for the contextual-interference effect in force field adaptation.

[Teaching during the COVID-19 pandemic: how do medical students evaluate interactive video-based distance bedside teaching in otorhinolaryngology?]

Hintergrund

Der Beginn der ersten SARS-CoV-2-Pandemie-Welle im März 2020 erforderte erhebliche Umstellungsmaßnahmen in der medizinischen Lehre mit vollständigem Verzicht auf direkten Kontakt von Studierenden und Patienten. Vor diesem Hintergrund wurde das Lehrformat „Unterricht am Patienten“ (UaP) als interaktiver, videobasierter Distanzunterricht am Patienten etabliert und durchgeführt.

Fragestellung

Ziel der Studie war die Erfassung der studentischen Beurteilung dieses Lehrkonzeptes im Fach Hals-Nasen-Ohren-Heilkunde.

Material und Methoden

Die Live-Übertragung erfolgte aus einem HNO-Untersuchungsraum zu den im Hörsaal befindlichen Studierenden, welche mit den Patienten interagieren konnten. Makro-, mikro- und endoskopische Untersuchungsbefunde wurden in Echtzeit in den Hörsaal übertragen. Die Evaluation erfolgte anhand eines Online-Fragebogens, welcher 13 geschlossene Fragen (Likert-Skala) beinhaltete, sowie als offenes Feedback in freier Textform.

Ergebnisse

Die Rücklaufquote lag bei 16,8 % (42 von 250 Studierenden). Davon hatten 85,7 % einen positiven Gesamteindruck, und Tenor war, dass das Konzept angesichts der Umstände gut umgesetzt wurde. Dennoch könne auf einen direkten Patientenkontakt eher nicht verzichtet werden, auch wenn eine teilweise Kompensation durch Videoschaltung möglich sei. Insgesamt wurde das Lehrkonzept als lehrreich empfunden, und die Studierenden konnten sich vorstellen, zukünftig häufiger auch ein solches UaP-Lehrkonzept zu nutzen.

Schlussfolgerung

Dieses Lehrkonzept kann den direkten Patientenkontakt nicht ersetzen, stellt jedoch speziell im HNO-Gebiet eine gute Alternative dar, wenn durch pandemiebedingte Umstände ein „klassischer“ UaP nicht möglich ist. Aspekte des interaktiven, videobasierten Distanzunterrichts am Patienten könnten auch zukünftig in andere Lehrformate integriert werden.

Course of social support and associations with distress after partial laryngectomy

PURPOSE

Social support has been shown to be positively associated with quality of life and adjustment after a cancer diagnosis. The present study investigates the course of social support up to one year after partial laryngectomy and its association with distress.

DESIGN

Longitudinal questionnaire study.

SAMPLE

A total of 428 patients after partial laryngectomy (mean age: 64, SD = 11, 91% male).

METHODS

Patients completed questionnaires before treatment (t1), one week after a partial laryngectomy (t2), 3 months (t3), and one year (t4) thereafter. Social support was evaluated at t2, t3, and t4 using a brief version of the Social Support Questionnaire. Distress was measured at t2, t3, and t4 using the HADS. Descriptive statistics for social support were computed across the three measurement points. Changes were analyzed by Wilcoxon signed-rank tests. Associations with distress were identified using linear regression analyses.

FINDINGS

Social support increased between t2 and t3 and decreased to baseline level between t3 and t4. Distress at t2 was associated with social support at t2 (B = -0.15, p < 0.01) and distress at t3 with social support at t3 (B = -0.19, p < 0.01). Distress at t4 was related to social support at t2 (B = -0.10, p = 0.05).

CONCLUSIONS

Although perceived social support increases after partial laryngectomy, it decreases again during the course of aftercare.

IMPLICATIONS FOR PSYCHOSOCIAL PROVIDERS OR POLICY

Social support resources should be assessed to identify patients at risk for worse psychological well-being.

[The first year of the SARS-CoV-2 pandemic-impact on otorhinolaryngology]

BACKGROUND

The first year of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has already affected our public health care system to an enormous extent and will continue to do so in the future. Otorhinolaryngologists (ORLs) are suspected to be at high risk of infection, due to the high viral load in the mucosa of the upper airways. The current review evaluates the impact of the pandemic on ORLs' activities and assesses the risk infection.

METHODS

A selective literature research was conducted using relevant English and German terms for ORL, SARS-CoV‑2, risk, and infection at PubMed, medRxiv, and bioRxiv, as well as in the Deutsches Ärzteblatt and on the websites of the Robert Koch Institute and the Johns Hopkins University.

RESULTS

Protection recommendations for ORL include general hygiene measures and wearing KN95 masks for routine professional activities. When in contact with coronavirus disease 2019 (COVID-19) patients, it is recommended to extend the personal protective equipment by eye protection, gloves, cap, and gown. International otorhinolaryngology societies have released guidelines for procedures (e.g., tracheostomy, sinus surgery), propagating personal protection for the surgical team and reduction of aerosols. Testing for SARS-CoV‑2 in patients and medical staff can contribute to reducing the risk of infection. Vaccination would provide some additional protection for ORLs and other health care professionals with increased exposure to aerosols. There is increasing evidence that ORLs are at a high risk of contracting SARS-CoV‑2.

CONCLUSION

Consequent personal protection, frequent testing of patients and health care professionals, and the promised SARS-CoV‑2 vaccinations may provide adequate protection for highly exposed persons.

Follow-up of a national web-based survey on the SARS-CoV-2 infectious state of otorhinolaryngologists in Germany

Purpose

The SARS-CoV‑2 pandemic has affected the health and practice of otorhinolaryngologists (ORLs) for over 1 year. Follow-up data of a national survey with German ORLs were evaluated regarding differences between the two waves of the pandemic.

Methods

As in the initial survey, German ORLs were addressed via e‑mail through the German Society of ORL, Head and Neck Surgery and the German ENT Association. All ORLs afflicted with SARS-CoV‑2 were invited to participate in a web-based survey. General data on infections and concomitant parameters were evaluated.

Results

Since the start of the pandemic, 129 ORLs reported testing positive for SARS-CoV‑2 in Germany. The ORLs infected during the first wave had a relative risk (RR) of 4.07 (95% CI: 3.20; 5.19) of contracting SARS-CoV‑2. During the second wave, the RR decreased to 0.35 (95% CI: 0.28; 0.45). The availability of personal protective equipment (PPE) increased from the first to the second wave along with an increased perception of protection in the professional environment. The source of infection shifted from infections via medical staff during the first wave to patients and household exposure during the second wave. Regular medical practice was resumed by clinicians and general practitioners in the second wave. Nevertheless, a proportionally lower infection rate was observed compared with the German population as a whole.

Conclusion

The data reflect a unique long-term survey of ORLs during the pandemic. Differences in the source of infection were seen between the first and second wave, confirming the need for appropriate PPE for medical professionals working in high-risk environments. Further strategies to reduce the risk of infection include consistent testing for SARS-CoV‑2 in healthcare professionals, patients, and the general public as well as vaccination of high-risk medical groups.

Supplementary Information

The online version of this paper (10.1007/s00106-021-01075-4) contains the German version of the COVID-19 questionnaire. The article and supplementary material are available at www.springermedizin.de. Please enter the title of the article in the search field. The additional material can be found at the article under “Ergänzende Inhalte”.

Results of a national web-based survey on the SARS-CoV-2 infectious state of otorhinolaryngologists in Germany

PURPOSE

SARS-CoV-2 is detected on the mucosa of the upper airways to a high degree. In the course of the COVID-19 pandemic, otorhinolaryngologists (ORL) are assumed to be at high risk due to close contact with the mucosa of the upper airways. No data are yet available providing evidence that ORLs have an increased risk of infection.

METHODS

German ORLs were invited via e-mail through the German Society of ORL, Head and Neck Surgery and the German ENT Association to participate in a web-based survey about infection with SARS-CoV-2 and development of COVID-19. Data of infections and concomitant parameters in German ORLs were collected and compared to the total number of infections in Germany.

RESULTS

Out of 6383 German ORLs, 970 (15%) participated. 54 ORLs reported testing positive for SARS-CoV-2. Compared to the total population of Germany, ORLs have a relative risk of 3.67 (95% CI 2.82; 4.79) of contracting SARS-CoV-2. Domestic quarantine was conducted in 96.3% of cases. Two individuals were admitted to hospital without intensive care. No casualties were reported. In 31 cases, the source of infection was not identifiable whereas 23 had a clear medical aetiology: infected patients: n = 5, 9.26%; medical staff: n = 13, 14.1%. 9.26% (n = 5) of the identified cases were related to contact to infected family members (n = 3), closer neighbourhood (n = 1) or general public (n = 1). There was no identified increased risk of infection due to performing surgery.

CONCLUSION

German ORLs have an almost 3.7-fold risk of contracting SARS-CoV-2 compared to the population baseline level. Appropriate protection appears to be necessary for this occupational group.

A new concept for temporal gating of synchrotron X-ray pulses

A new concept for temporal gating of synchrotron X-ray pulses based on laser-induced thermal transient gratings is presented. First experimental tests of the concept yield a diffraction efficiency of 0.18%; however, the calculations indicate a theoretical efficiency and contrast of >30% and 10-5, respectively. The full efficiency of the pulse picker has not been reached yet due to a long-range thermal deformation of the sample after absorption of the excitation laser. This method can be implemented in a broad spectral range (100 eV to 20 keV) and is only minimally invasive to an existing setup.

[Functional results after soft palate reconstruction in oropharyngeal cancer patients]

BACKGROUND

Surgery of the soft palate in patients with oropharyngeal cancer can result in functional deficiencies of swallowing and speech. Reconstruction of the resected structures can contribute to regaining sufficient functionality after therapy.

OBJECTIVE

The current study used frequency analysis to evaluate the change in speech characteristics after resection and reconstruction of the soft palate during post-therapeutic follow-up.

MATERIALS AND METHODS

In 18 patients with oropharyngeal carcinoma and involvement of the soft palate, resection and reconstruction by free radial forearm graft (FRFG) and adjuvant chemoradiotherapy was conducted. The spoken German numbers "eins", "zwei", "drei", "vier", "fünf" were recorded during follow-up and objectively assessed by frequency analysis. Additionally, food intake status and the necessity of a tracheostomy were evaluated.

RESULTS

The maximum peak frequencies of the numbers analysed increased from 150-300 Hz before up to 1000 Hz after therapy. Two years post therapy, the peak frequencies again declined to levels comparable to those before tumour therapy. One year after therapy, complete oral nutrition was possible in two thirds of patients and the tracheostomy was closed in 80%.

CONCLUSION

Reconstruction of the soft palate by FRFG during the course of oropharyngeal cancer treatment allows function to be regained with respect to speech and swallowing. In the majority of patients, it is possible to reach a level of function comparable to the state before tumour treatment.

Reciprocal space slicing: A time-efficient approach to femtosecond x-ray diffraction

An experimental technique that allows faster assessment of out-of-plane strain dynamics of thin film heterostructures via x-ray diffraction is presented. In contrast to conventional high-speed reciprocal space-mapping setups, our approach reduces the measurement time drastically due to a fixed measurement geometry with a position-sensitive detector. This means that neither the incident (ω) nor the exit ( 2 θ ) diffraction angle is scanned during the strain assessment via x-ray diffraction. Shifts of diffraction peaks on the fixed x-ray area detector originate from an out-of-plane strain within the sample. Quantitative strain assessment requires the determination of a factor relating the observed shift to the change in the reciprocal lattice vector. The factor depends only on the widths of the peak along certain directions in reciprocal space, the diffraction angle of the studied reflection, and the resolution of the instrumental setup. We provide a full theoretical explanation and exemplify the concept with picosecond strain dynamics of a thin layer of NbO₂.

Modularity in Motor Control: Similarities in Kinematic Synergies Across Varying Locomotion Tasks

Kinematic synergies (kSYN) provide an approach to quantify the covariation of joint motions and to explain the mechanisms underlying human motor behavior. A low-dimensional control strategy by means of the activation of a moderate number of kSYN would simplify the performance of complex motor tasks. The purpose of this study was to examine similarities between the kSYN of varying locomotion tasks: straight-line walking, walking a 90° spin turn and walking upstairs. Task-specific kSYN were extracted from full body kinematic recordings of 13 participants by principal component analysis. The first five kSYN accounting for most of the variance within each task were selected for further analysis following previous studies. The similarities between the kSYN of the three different locomotion tasks were quantified by calculating cosine similarities (SIM), as a vector-based similarity measure ranging from 0 (no similarity) to 1 (high similarity), between absolute principal component loading vectors. A SIM between two kSYN > 0.8 was interpreted as highly similar. Two to three highly similar kSYN were identified when comparing two individual tasks with each other. One kSYN, primarily characterized by anteversion and retroversion of the arms and legs, were found to be similar in all three tasks. Additional kSYN that occurred between individual tasks reflected mainly an upwards/downwards movement of the body or a countercyclical knee flexion/extension. The results demonstrate that the three investigated locomotion tasks are characterized by kSYN and that certain kSYN repeatedly occur across the three locomotion tasks. PCA yields kSYN which are in descent order according to their amount of total variance accounted for. Referring to the placing of a kSYN within the order as priorization, we found a change in priorization of repeatedly occurring kSYN across the individual tasks. The findings support the idea that movements can be efficiently performed through a flexible combination of a lower number of control-relevant variables.

Depth of sedation during drug induced sedation endoscopy monitored by BiSpectral Index® and Cerebral State Index®

PURPOSE

Drug induced sedation endoscopy (DISE) is performed to investigate patterns and sites of obstruction in patients with sleep-disordered breathing (SDB). During DISE the patients are sedated to obtain a muscular relaxation of the upper airway which mimics the relaxation during natural sleep. Different sleep stages are intended to be simulated by drug induced sedation, and it is helpful to measure the depth of sedation. The BiSpectral Index® (BIS) is often used for this procedure. Besides the BIS, other means of sedation depth monitoring exist in anaesthesiology but have not yet been investigated with respect to DISE. Monitoring of the Cerebral State Index® (CSI) is one of these methods. The aim of the study was to compare the BIS and CSI for sedation depth monitoring during DISE.

METHODS

Sixty patients underwent DISE monitored by the BIS and CSI in parallel. The BIS and CSI values were compared using the Bland-Altman analysis.

RESULTS

The BIS and CSI values differed during the course of sedation during DISE by a mean of - 6.07. At light sedation (BIS 60-80), lower values by 10 scale points of CSI compared with BIS were detectable. At deeper sedation levels (BIS 40-50), the CSI turned to present equal and even higher values compared with the BIS.

CONCLUSION

Sedation depth measurement during DISE can be performed by the BIS or CSI, but the differences should be interpreted carefully as comparable data for sleep stages in natural sleep are available only for BIS.

International registry of otolaryngologist-head and neck surgeons with COVID-19

BACKGROUND

It has become clear that healthcare workers are at high risk, and otolaryngology has been theorized to be among the highest risk specialties for coronavirus disease 2019 (COVID-19). The purpose of this study was to detail the international impact of COVID-19 among otolaryngologists, and to identify instructional cases.

METHODS

Country representatives of the Young Otolaryngologists-International Federation of Otolaryngologic Societies (YO-IFOS) surveyed otolaryngologists through various channels. Nationwide surveys were distributed in 19 countries. The gray literature and social media channels were searched to identify reported deaths of otolaryngologists from COVID-19.

RESULTS

A total of 361 otolaryngologists were identified to have had COVID-19, and data for 325 surgeons was available for analysis. The age range was 25 to 84 years, with one-half under the age of 44 years. There were 24 deaths in the study period, with 83% over age 55 years. Source of infection was likely clinical activity in 175 (54%) cases. Prolonged exposure to a colleague was the source for 37 (11%) surgeons. Six instructional cases were identified where infections occurred during the performance of aerosol-generating operations (tracheostomy, mastoidectomy, epistaxis control, dacryocystorhinostomy, and translabyrinthine resection). In 3 of these cases, multiple operating room attendees were infected, and in 2, the surgeon succumbed to complications of COVID-19.

CONCLUSION

The etiology of reported cases within the otolaryngology community appear to stem equally from clinical activity and community spread. Multiple procedures performed by otolaryngologists are aerosol-generating procedures (AGPs) and great care should be taken to protect the surgical team before, during, and after these operations.

Diagnosis and treatment of isolated snoring-open questions and areas for future research

STUDY OBJECTIVES

Snoring is a common phenomenon which is generated by vibration of soft tissue of the upper airway during sleep. Due to the high incidence of isolated snoring and the substantial burden for the patient and the bed partner, a thorough examination and appropriate therapy are required. Many recommendations for the treatment of isolated snoring are either not evidence-based or are derived from recommendations for the management of obstructive sleep apnea. Therefore, the aim of this study is the identification and description of open questions in the diagnosis and treatment of isolated snoring and the illustration of areas for further research.

METHODS

In the context of the development of the new version of the German guideline "Diagnosis and treatment of isolated snoring in adults," a multidisciplinary team of experts performed a systematic literature search on the relevant medical data and rated the current evidence regarding the key diagnostic and therapeutic measures for snoring.

RESULTS

The systematic literature review identified 2293 articles. As a major inclusion criterion, only studies on primary snoring based on objective sleep medical assessment were selected. After screening and evaluation, 33 full-text articles remained for further analysis. Based on these articles, open questions and areas for future research were identified for this review.

CONCLUSION

Several major gaps in the literature on the diagnosis and treatment of isolated snoring were identified. For the majority of diagnostic and therapeutic measures for snoring, high-level scientific evidence is still lacking.

Comparison of Femto-LASIK With Combined Accelerated Cross-linking to Femto-LASIK in High Myopic Eyes: A Prospective Randomized Trial

PURPOSE

To evaluate the safety and efficacy of femtosecond (fs) laser-assisted in situ keratomileusis (LASIK) combined with accelerated corneal cross-linking (LASIK Xtra) compared to conventional fs-LASIK (convLASIK) in high myopic patients.

DESIGN

Prospective, randomized, fellow-eye controlled clinical trial.

METHODS

Setting: Department of Ophthalmology, Goethe University, Frankfurt/Germany. StudyPopulation: Twenty-six patients with high myopia and/or myopic astigmatism received randomized treatment with LASIK Xtra (30 mW/cm², 90 seconds with continuous ultraviolet-A) in 1 eye and convLASIK in the other eye. MainOutcomeMeasures: Uncorrected distance visual acuity (UDVA), best spectacle-corrected VA (BSCVA), manifest refractive spherical equivalent (MRSE), endothelial cell count (ECC), and corneal thickness.

RESULTS

The UDVA improved from 1.26 ± 0.13 logMAR preoperative to -0.02 ± 0.15logMAR in LASIK Xtra eyes and from 1.27 ± 0.12 logMAR to 0.01 ± 0.15 logMAR in the convLASIK eyes (P > .05). The MRSE changed from -7.35 ± 1.15 diopters (D) and -7.5 ± 1.12 D to -0.17 ± 0.43 D and -0.25 ± 0.46 D, respectively. There was no significant difference in outcomes between both groups during the 12 months follow-up except for the convLASIK eyes' showing slightly better BSCVA after 1 week (P < .05). ConvLASIK eyes revealed a nonsignificant trend toward myopic regression from 3 to 12 months postoperative with a change in MRSE of -0.15 D compared to -0.1 D in LASIK Xtra eyes. Topography showed stability of corneal curvature with no signs of keratectasia in both groups at 12 months.

CONCLUSION

While apparently safe, LASIK Xtra showed no advantages over conventional LASIK. At 12 months, both groups showed no difference regarding UDVA and refractive stability, and no signs of keratectasia.

Comparison of 9 modern intraocular lens power calculation formulas for a quadrifocal intraocular lens

PURPOSE

To evaluate the accuracy of 9 formulas (Barrett Universal II, Haigis, Hill-Radial Basis Function [RBF], Hoffer Q, Holladay 1, Holladay 2, Olsen, Sanders-Retzlaff-Kraff/theoretical [SRK/T], and T2) calculating the power of the quadrifocal Acrysof IQ Panoptix TFNT00 intraocular lens (IOL).

SETTING

Department of Ophthalmology, Goethe University, Frankfurt, Germany.

DESIGN

Retrospective case series.

METHODS

The study included patients having cataract surgery with insertion of a quadrifocal IOL over 15 months. Preoperative biometry measurements were obtained from an IOLMaster 500. Optimized IOL constants were calculated to reduce the mean refractive prediction error. The primary outcomes were differences in mean absolute prediction error between the formulas. Median and maximum absolute prediction errors were evaluated as well as percentages of eyes within prediction errors of ±0.25 diopters (D), ±0.50 D, ±1.00 D, and ±2.00 D.

RESULTS

The study comprised 75 eyes of 38 patients. The formulas were ranked by the mean absolute refractive prediction error as follows: Barrett Universal II (0.294 D), Hill-RBF (0.332 D), Olsen (0.339 D), T2 (0.351 D), Holladay 1 (0.381 D), Haigis (0.382 D), SRK/T (0.393 D), Holladay 2 (0.399 D), and Hoffer Q (0.410 D). The differences in absolute errors between the formulas were significant (P < .001). The lowest maximum absolute prediction error was obtained with the Barrett Universal II.

CONCLUSION

The most accurate predictions of actual postoperative refraction were achieved using the Barrett Universal II, Hill-RBF, Olsen, or T2 formula. Thus, one of these formulas should be used for IOL power calculation of the quadrifocal IOL.

Measurement of relative lung perfusion with electrical impedance and positron emission tomography: an experimental comparative study in pigs

BACKGROUND

Electrical impedance tomography (EIT) with indicator dilution may be clinically useful to measure relative lung perfusion, but there is limited information on the performance of this technique.

METHODS

Thirteen pigs (50-66 kg) were anaesthetised and mechanically ventilated. Sequential changes in ventilation were made: (i) right-lung ventilation with left-lung collapse, (ii) two-lung ventilation with optimised PEEP, (iii) two-lung ventilation with zero PEEP after saline lung lavage, (iv) two-lung ventilation with maximum PEEP (20/25 cm H₂O to achieve peak airway pressure 45 cm H₂O), and (v) two-lung ventilation under unilateral pulmonary artery occlusion. Relative lung perfusion was assessed with EIT and central venous injection of saline 3%, 5%, and 10% (10 ml) during breath holds. Relative perfusion was determined by positron emission tomography (PET) using ⁶⁸Gallium-labelled microspheres. EIT and PET were compared in eight regions of equal ventro-dorsal height (right, left, ventral, mid-ventral, mid-dorsal, and dorsal), and directional changes in regional perfusion were determined.

RESULTS

Differences between methods were relatively small (95% of values differed by less than 8.7%, 8.9%, and 9.5% for saline 10%, 5%, and 3%, respectively). Compared with PET, EIT underestimated relative perfusion in dependent, and overestimated it in non-dependent, regions. EIT and PET detected the same direction of change in relative lung perfusion in 68.9-95.9% of measurements.

CONCLUSIONS

The agreement between EIT and PET for measuring and tracking changes of relative lung perfusion was satisfactory for clinical purposes. Indicator-based EIT may prove useful for measuring pulmonary perfusion at bedside.

Tracking picosecond strain pulses in heterostructures that exhibit giant magnetostriction

We combine ultrafast X-ray diffraction (UXRD) and time-resolved Magneto-Optical Kerr Effect (MOKE) measurements to monitor the strain pulses in laser-excited TbFe₂/Nb heterostructures. Spatial separation of the Nb detection layer from the laser excitation region allows for a background-free characterization of the laser-generated strain pulses. We clearly observe symmetric bipolar strain pulses if the excited TbFe₂ surface terminates the sample and a decomposition of the strain wavepacket into an asymmetric bipolar and a unipolar pulse, if a SiO₂ glass capping layer covers the excited TbFe₂ layer. The inverse magnetostriction of the temporally separated unipolar strain pulses in this sample leads to a MOKE signal that linearly depends on the strain pulse amplitude measured through UXRD. Linear chain model simulations accurately predict the timing and shape of UXRD and MOKE signals that are caused by the strain reflections from multiple interfaces in the heterostructure.

Unterkieferprotrusionsschiene bei obstruktivem Schlafapnoesyndrom getestet

Marco Pitarch R et al. Effectiveness of a mandibular advancement device in obstructive sleep apnea patients: a prospective clinical trial. Eur Arch Otorhinolaryngol 2018; 275: 1903–1911

In einer prospektiven Studie wurde die Effektivität einer Unterkieferprotrusionsschiene (mandibular advancement device, MAD) bei Patienten mit obstruktivem Schlafapnoesyndrom getestet. Evaluiert wurden dabei verschiedene Merkmale der Patienten und der MAD als Prädiktoren des Behandlungsergebnisses.

European position paper on drug-induced sleep endoscopy: 2017 Update

BACKGROUND

The first edition of the European position paper (EPP) on drug-induced sleep endoscopy (DISE) was published in 2014 with the aim to standardise the procedure, to provide an in-depth insight into the main aspects of this technique and to have a basis for future research. Since 2014, new studies have been published concerning new sedative agents or new insights into the pattern/levels of the obstruction depending on the depth of sedation. Therefore, an enlarged group of European experts in the field of sleep breathing disorders (SBD), including the most of the first DISE EPP main authors, has decided to publish an update of the European position paper on DISE, in order to include new evidence and to find a common language useful for reporting the findings of this endoscopic evaluation in adult population affected by SBD.

METHODS

The authors have evaluated all the available evidence reported in the literature and have compared experience among various departments in leading European centres in order to provide an update regarding the standardisation of the DISE procedure and an in-depth insight into the main aspects of this technique.

RESULTS

After the first European Position Consensus Meeting on DISE and its update, consensus was confirmed for indications, required preliminary examinations, where to perform DISE, technical equipment required, staffing, local anaesthesia, nasal decongestion, other medications, patient positioning, basics and special diagnostic manoeuvres, drugs and observation windows. So far, no consensus could be reached on a scoring and classification system. However, regarding this aim, the idea of an essential classification, such as VOTE with the possibility of its graded implementation of information and descriptions, seems to be the best way to reach a universal consensus on DISE classification at this stage. A common DISE language is mandatory, and attempts to come to a generally accepted system should be pursued.

Visual Outcomes After Implantation of a Segmental Refractive Multifocal Intraocular Lens Following Cataract Surgery

PURPOSE

To evaluate visual outcomes, with particular attention to intermediate visual acuity (VA), of a segmental refractive multifocal intraocular lens (IOL) with optimized depth of focus (DoF).

DESIGN

Prospective, nonrandomized, noncomparative case series.

METHODS

Setting: Department of Ophthalmology, Goethe University, Frankfurt/Germany. Patient or Study Population: Fifty eyes (25 patients) were included. Inclusion criteria were bilateral cataract, age > 45 years, corneal astigmatism ≤ 0.75 diopter (D) postoperatively, pupil size 3-6 mm (mesopic), and center shift < 1 mm (Pentacam). Exclusion criteria were ocular surgeries, amblyopia, or potential postoperative distance-corrected VA (DCVA) > 0.3 logMAR. Intervention or Observation: Uncorrected (UCVA) and DCVA in 4 m, 80 cm, 40 cm; contrast sensitivity (CS); reading skills; defocus curve; and questionnaire on optical quality (OQ) and spectacle independence were assessed after 3 months.

MAIN OUTCOME MEASURES

UCVA and DCVA in 4 m, 80 cm, 40 cm; defocus curve.

RESULTS

UCVA was 0.05 ± 0.122 logMAR at 4 m, 0.18 ± 0.164 logMAR at 80 cm, and 0.16 ± 0.140 logMAR at 40 cm. Defocus curve testing showed, respectively, a flat monocular and binocular VA range from 0.00 to -2.00 D (-0.03 to 0.11 logMAR, -0.05 to 0.05 logMAR). Median CS under photopic and mesopic conditions without and with glare was 1.81 logCS, 1.65 logCS, 1.52 logCS, and 1.14 logCS, respectively. Reading speed at 40 cm showed a reading acuity of 0.100 logRAD with 94 words/minute.

CONCLUSION

This segmental multifocal IOL provides good VA at all distances (<0.20 logMAR), particularly providing good intermediate visual acuity and DoF. It showed good reading skills, OQ, and CS and high spectacle independence.

Progressive ratio (PR) schedules and the sipometer: Do they measure wanting, liking, and/or reward? A tribute to Anthony Sclafani and Karen Ackroff

This paper honors the contributions made by Anthony (Tony) Sclafani and Karen Ackroff to both the Columbia University Seminar on Appetitive Behavior and to the field of ingestive behavior in general. We review their use of the progressive ratio (PR) licking paradigm, to determine whether the taste of sucrose, independent of its post-ingestive effects, is always positively reinforcing in animals. They demonstrated a monotonic increase in licking as concentration increased, and obtained results identical to those obtained with a lever-pressing paradigm, but licking was easier and more natural than lever pressing. The PR paradigm was translated to evaluate liquid food reward value in humans. An instrument (the sipometer) was devised that initially permitted a few seconds access to small amounts of a sweet beverage as the participants increased the time to obtain it in 3-5-sec increments. The device went through two refinements and currently delivers the reinforcer and measures the pressure exerted to obtain it. The sipometer is compared with other techniques for measuring motivation and reward. The use of the sipometer and the PR method are discussed in relation to the theoretical challenges inherent in measuring motivation and pleasure, from both psychological and behavioral economics perspectives, and why it is or is not important to separate these processes for both theoretical and practical applications.

Visual Performance of a Quadrifocal (Trifocal) Intraocular Lens Following Removal of the Crystalline Lens

PURPOSE

To evaluate visual performance after implantation of a quadrifocal intraocular lens (IOL).

METHODS

Setting: Department of Ophthalmology, Goethe University, Frankfurt, Germany.

STUDY POPULATION

Twenty-seven patients (54 eyes) received bilateral implantation of the PanOptix IOL (AcrySof IQ PanOptixTM; Alcon Research, Fort Worth, Texas, USA) pre-enrollment. Exclusion criteria were previous ocular surgeries, corneal astigmatism of >1.5 diopter (D), ocular pathologies, or corneal abnormalities. Intervention or Observational Procedure(s): Postoperative examination at 3 months including manifest refraction; uncorrected visual acuity (UCVA) and distance-corrected visual acuity (DCVA) in 4 m, 80 cm, 60 cm, and 40 cm slit-lamp examination; defocus testing; contrast sensitivity (CS) under photopic and mesopic conditions; and a questionnaire on subjective quality of vision, optical phenomena, and spectacle independence was performed.

MAIN OUTCOME MEASURE(S)

At 3 months postoperatively, UCVA and DCVA in 4 m, 80 cm, 60 cm, and 40 cm (logMAR), defocus curves, CS, and quality-of-vision questionnaire results.

RESULTS

Mean spherical equivalent was -0.04 ± 0.321 D 3 months postoperatively. Binocular UCVA at distance, intermediate (80 cm, 60 cm), and near was 0.00 ± 0.094 logMAR, 0.09 ± 0.107 logMAR, 0.00 ± 0.111 logMAR, and 0.01 ± 0.087 logMAR, respectively. Binocular defocus curve showed peaks with best visual acuity (VA) at 0.00 D (-0.07 logMAR) and -2.00 D (-0.02 logMAR).

CONCLUSION

Visual performance of the PanOptix IOL showed good VA at all distances; particularly good intermediate VA (logMAR > 0.1), with best VA at 60 cm; and high patient satisfaction and spectacle independence 3 months postoperatively.

Snore sound recognition: On wavelets and classifiers from deep nets to kernels

In this paper, we present a comprehensive comparison of wavelet features for the classification of snore sounds. Wavelet features have proven to be efficient in our previous work; however, the benefits of wavelet transform energy (WTE) and wavelet packet transform energy (WPTE) features were not clearly established. In this study, we firstly present our updated snore sounds database, expanded from 24 patients (collected by one medical centre) to 40 patients (collected by three medical centres). We then study the effects of varying frame sizes and overlaps for extraction of the wavelet low-level descriptors, the effect of which have yet to be fully established. We also compare the performance of the WTE and WPTE features when fed into multiple classifiers, namely, Support Vector Machines (SVM), K-Nearest Neighbours, Linear Discriminant Analysis, Random Forests, Extreme Learning Machines, Kernel Extreme Learning Machines, Multilayer Perceptron, and Deep Neural Networks. Key results presented indicate that, when fed into a SVM, WTE outperforms WPTE (one-tailed z-test, p<;0.002). Further, WPTE can achieve a significant improvement when trained by a k-nearest neighbours classifier (one-tailed z-test, p <; 0.001).