Association of Misfolded α-Synuclein Derived from Neuronal Exosomes in Blood with Parkinson's Disease Diagnosis and Duration

Background

Misfolded α-synuclein can be detected in blood samples of Parkinson's disease (PD) patients by a seed amplification assay (SAA), but the association with disease duration is not clear, yet.

Objective

In the present study we aimed to elucidate whether seeding activity of misfolded α-synuclein derived from neuronal exosomes in blood is associated with PD diagnosis and disease duration.

Methods

Cross-sectional samples of PD patients were analyzed and compared to samples of age- and gender-matched healthy controls using a blood-based SAA. Presence of α-synuclein seeding activity and differences in seeding parameters, including fluorescence response (in arbitrary units) at the end of the amplification assay (F60) were analyzed. Additionally, available PD samples collected longitudinally over 5-9 years were included.

Results

In the cross-sectional dataset, 79 of 80 PD patients (mean age 69 years, SD = 8; 56% male) and none of the healthy controls (n = 20, mean age 70 years, SD = 10; 55% male) showed seeding activity (sensitivity 98.8%). When comparing subgroups divided by disease duration, longer disease duration was associated with lower α-synuclein seeding activity (F60: p <  0.001). In the longitudinal analysis 10/11 patients showed a gradual decrease of α-synuclein seeding activity over time.

Conclusions

This study confirms the high sensitivity of the blood-based α-synuclein SAA applied here. The negative association of α-synuclein seeding activity in blood with disease duration makes this parameter potentially interesting as biomarker for future studies on the pathophysiology of disease progression in PD, and for biologically oriented trials in this field.

Detecting Misfolded α-Synuclein in Blood Years before the Diagnosis of Parkinson's Disease

BACKGROUND

Identifying individuals with Parkinson's disease (PD) already in the prodromal phase of the disease has become a priority objective for opening a window for early disease-modifying therapies.

OBJECTIVE

The aim was to evaluate a blood-based α-synuclein seed amplification assay (α-syn SAA) as a novel biomarker for diagnosing PD in the prodromal phase.

METHODS

In the TREND study (University of Tuebingen) biennial blood samples of n = 1201 individuals with/without increased risk for PD were taken prospectively over 4 to 10 years. We retrospectively analyzed blood samples of 12 participants later diagnosed with PD during the study to detect and amplify pathological α-syn conformers derived from neuronal extracellular vesicles using (1) immunoblot analyses with an antibody against these conformers and (2) an α-syn-SAA. Additionally, blood samples of n = 13 healthy individuals from the TREND cohort and n = 20 individuals with isolated rapid eye movement sleep behavior disorder (iRBD) from the University Hospital Cologne were analyzed.

RESULTS

All individuals with PD showed positive immunoblots and a positive α-syn SAA at the time of diagnosis. Moreover, all PD patients showed a positive α-syn SAA 1 to 10 years before clinical diagnosis. In the iRBD cohort, 30% showed a positive α-syn SAA. All healthy controls had a negative SAA.

CONCLUSIONS

We here demonstrate the possibility to detect and amplify pathological α-syn conformers in peripheral blood up to 10 years before the clinical diagnosis of PD in individuals with and without iRBD. The findings of this study indicate that this blood-based α-syn SAA assay has the potential to serve as a diagnostic biomarker for prodromal PD. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The interplay of sensory feedback, arousal, and action tremor amplitude in essential tremor

Essential tremor (ET) amplitude is modulated by visual feedback during target driven movements and in a grip force task. It has not been examined yet whether visual feedback exclusively modulates target force tremor amplitude or if other afferent inputs like auditory sensation has a modulatory effect on tremor amplitude as well. Also, it is unknown whether the enhanced sensory feedback causes an increase of arousal in persons with ET (p-ET). We hypothesized that (1) amplitude of tremor is modulated by variation of auditory feedback in the absence of visual feedback in a force tremor paradigm; (2) increase of tremor amplitude coincides with pupillary size as a measure of arousal. 14 p-ET and 14 matched healthy controls (HC) conducted a computer-based experiment in which they were asked to match a target force on a force sensor using their thumb and index finger. The force-induced movement was fed back to the participant visually, auditory or by a combination of both. Results showed a comparable deviation from the target force (RMSE) during the experiment during all three sensory feedback modalities. The ANOVA revealed an effect of the high vs. low feedback condition on the tremor severity (Power 4-12 Hz) for the visual- and also for the auditory feedback condition in p-ET. Pupillometry showed a significantly increased pupil diameter during the auditory involved high feedback conditions compared to the low feedback conditions in p-ET. Our findings suggest that action tremor in ET is firstly modulated not only by visual feedback but also by auditory feedback in a comparable manner. Therefore, tremor modulation seems to be modality independent. Secondly, high feedback was associated with a significant pupil dilation, possibly mirroring an increased arousal/perceived effort.

The Past, Present, and Future of the Brain Imaging Data Structure (BIDS)

The Brain Imaging Data Structure (BIDS) is a community-driven standard for the organization of data and metadata from a growing range of neuroscience modalities. This paper is meant as a history of how the standard has developed and grown over time. We outline the principles behind the project, the mechanisms by which it has been extended, and some of the challenges being addressed as it evolves. We also discuss the lessons learned through the project, with the aim of enabling researchers in other domains to learn from the success of BIDS.

Visuomotor Adaptation Deficits in Patients with Essential Tremor

Essential tremor (ET) is a progressive movement disorder whose pathophysiology is not fully understood. Current evidence supports the view that the cerebellum is critically involved in the genesis of the tremor in ET. However, it is still unknown whether cerebellar dysfunction affects not only the control of current movements but also the prediction of future movements through dynamic adaptation toward a changed environment. Here, we tested the capacity of 28 patients with ET to adapt in a visuomotor adaptation task known to depend on intact cerebellar function. We found specific impairments in that task compared to age-matched healthy controls. Adaptation to the visual perturbation was disrupted in ET patients, while de-adaptation, the phase after abrupt removal of the perturbation, developed similarly to control subjects. Baseline tremor-independent motor performance was as well similar to healthy controls, indicating that adaptation deficits in ET patients were not rooted in an inability to perform goal-directed movements. There was no association between clinical severity scores of ET and early visuomotor adaptation abilities. These results provide further evidence that the cerebellum is dysfunctional in ET.

Cognitive parameters can predict change of walking performance in advanced Parkinson's disease - Chances and limits of early rehabilitation

Introduction

Links between cognition and walking performance in patients with Parkinson's disease (PD), which both decline with disease progression, are well known. There is lack of knowledge regarding the predictive value of cognition for changes in walking performance after individualized therapy. The aim of this study is to identify relevant predictive cognitive and affective parameters, measurable in daily clinical routines, for change in quantitative walking performance after early geriatric rehabilitation.

Methods

Forty-seven acutely hospitalized patients with advanced PD were assessed at baseline (T1) and at the end (T2) of a 2-week early rehabilitative geriatric complex treatment (ERGCT). Global cognitive performance (Montreal Cognitive Assessment, MoCA), EF and divided attention (Trail Making Test B minus A, delta TMT), depressive symptoms, and fear of falling were assessed at T1. Change in walking performance was determined by the difference in quantitative walking parameters extracted from a sensor-based movement analysis over 20 m straight walking in single (ST, fast and normal pace) and dual task (DT, with secondary cognitive, respectively, motor task) conditions between T1 and T2. Bayesian regression (using Bayes Factor BF₁₀) and multiple linear regression models were used to determine the association of non-motor characteristics for change in walking performance.

Results

Under ST, there was moderate evidence (BF₁₀ = 7.8, respectively, BF₁₀ = 4.4) that lower performance in the ∆TMT at baseline is associated with lower reduction of step time asymmetry after treatment (R ² _adj = 0.26, p ≤ 0.008, respectively, R ² _adj = 0.18, p ≤ 0.009). Under DT walking-cognitive, there was strong evidence (BF₁₀ = 29.9, respectively, BF₁₀ = 27.9) that lower performance in the ∆TMT is associated with more reduced stride time and double limb support (R ² _adj = 0.62, p ≤ 0.002, respectively, R ² _adj = 0.51, p ≤ 0.009). There was moderate evidence (BF₁₀ = 5.1) that a higher MoCA total score was associated with increased gait speed after treatment (R ² _adj = 0.30, p ≤ 0.02).

Discussion

Our results indicate that the effect of ERGT on change in walking performance is limited for patients with deficits in EF and divided attention. However, these patients also seem to walk more cautiously after treatment in walking situations with additional cognitive demand. Therefore, future development of individualized treatment algorithms is required, which address individual needs of these vulnerable patients.

Effect of Lower Limb vs. Abdominal Compression on Mobility in Orthostatic Hypotension: A Single-Blinded, Randomized, Controlled, Cross-Over Pilot Study in Parkinson's Disease

BACKGROUND

Orthostatic hypotension (OH) in Parkinson's disease (PD) is frequent and associated with impairments in quality of life and reduced activities of daily living. Abdominal binders (AB) and compression stockings (CS) have been shown to be effective non-pharmacological treatment options.

OBJECTIVE

Here, we investigate the effect of AB versus CS on physical activity using a digital mobility outcome (sit to stand [STS] frequency) collected in the usual environment as a primary endpoint.

METHODS

We enrolled 16 PD patients with at least moderate symptomatic OH. In a randomized, single-blinded, controlled, crossover design, participants were assessed without OH treatment over 1 week (baseline), then were given AB or CS for 1 week and subsequently switched to the other treatment arm. The primary outcome was the number of real-life STS movements per hour as assessed with a lower back sensor. Secondary outcomes included real-life STS duration, mean/systolic/diastolic blood pressure drop (BPD), orthostatic hypotension questionnaire (OHQ), PD quality of life (PDQ-39), autonomic symptoms (SCOPA-AUT), non-motor symptoms (NMSS), MDS-UPDRS, and activities of daily living (ADL/iADL).

RESULTS

Real-life STS frequency on CS was 4.4±4.1 per hour compared with 3.6±2.2 on AB and 3.6±1.8 without treatment (p = 1.0). Concerning the secondary outcomes, NMSS showed significant improvement with CS and AB. OHQ and SCOPA-AUT improved significantly with AB but not CS, and mean BPD drop worsened with CS but not AB. Mean STS duration, PDQ-39, MDS-UPDRS, ADL, and iADL did not significantly change.

CONCLUSION

Both AB and CS therapies do not lead to a significant change of physical activity in PD patients with at least moderate symptomatic OH. Secondary results speak for an effect of both therapies concerning non-motor symptoms, with superiority of AB therapy over CS therapy.

Association between heart failure severity and mobility in geriatric patients: an in-clinic study with wearable sensors

BACKGROUND

Individuals with heart failure (HF) frequently experience limitations in mobility, but specific aspects of these limitations are not well understood. This study investigated the association of HF severity, based on the New York Heart Association (NYHA) classes, with digital mobility outcomes (DMOs) and handgrip strength in older inpatients with HF.

METHODS

For this explorative analysis, hospital admission and discharge data from an ongoing, prospective cohort study were used. The sample included older participants with HF and a sub-sample of heart-healthy individuals. Participants were equipped with a wearable inertial measurement unit (IMU) system during mobility performance (balancing, sit-to-stand transfer, walking). We analyzed the association between 17 DMOs and HF severity with multiple linear regression models.

RESULTS

The total sample included 61 older participants (65-97 years of age, 55.7% female). Of all DMOs, only sway path in a semi-tandem stance position (m/s²) showed a relevant association with NYHA classes (admission: β = -0.28, P = 0.09; discharge: β = -0.39, P = 0.02). Handgrip strength showed a trend towards a significant association (admission: β = -0.15, P = 0.10; discharge: β = -0.15, P = 0.19).

CONCLUSIONS

This is to our best knowledge the first analysis on the association of HF severity and IMU-based DMOs. Sway path and handgrip strength may be the most promising parameters for monitoring mobility aspects in treatment of HF.

What contributes most to the SPPB and its subscores in hospitalized geriatric patients: an ICF model-based approach

Background

Mobility deficits are highly prevalent among geriatric patients and have serious impact on quality of life, hospitalizations, and mortality. This study aims to capture predictors of mobility deficits in hospitalized geriatric patients using the International Classification of Functioning, Disability and Health (ICF) model as a framework.

Methods

Data were obtained from n = 397 patients (78 ± 7 years, 15 ± 7 ICD-11 diagnoses) on a geriatric ward at time of admission. Mobility was assessed using the Short Physical Performance Battery (SPPB) total score and gait, static balance and transfer subscores. Parameters from an extensive assessment including medical history, neuropsychological and motor examination, and questionnaires were assigned to the five components of the ICF model. Spearman’s Correlation and multiple linear regression analyses were calculated to identify predictors for the SPPB total score and subscores.

Results

Use of walking aid, fear of falling (FOF, but not occurrence of previous falls), participation in society, ADL and grip strength were strongly associated with the SPPB total score and all subscores (p < .001). FOF and grip strength were significant predictors for the SPPB total score as well as for gait and transfer subscores. FOF also showed a strong association with the static balance subscore. The clinical parameters of the ICF model could only partially explain the variance in the SPPB total score (24%) and subscores (12–23%), with no parameter from the activities and participation component being significantly predictive.

Conclusions

FOF and reduced grip strength are associated with mobility deficits in a hospitalized geriatric cohort. Further research should focus on interventions to reduce FOF and increase muscle strength in geriatric patients. Moreover, there is a need for ICF-based assessments instruments (especially in the activities and participation components) that allow a holistic view on mobility and further daily life-relevant health aspects in geriatric patients.

Does Executive Function Influence Walking in Acutely Hospitalized Patients With Advanced Parkinson's Disease: A Quantitative Analysis

Introduction

It is well-known that, in Parkinson's disease (PD), executive function (EF) and motor deficits lead to reduced walking performance. As previous studies investigated mainly patients during the compensated phases of the disease, the aim of this study was to investigate the above associations in acutely hospitalized patients with PD.

Methods

A total of seventy-four acutely hospitalized patients with PD were assessed with the delta Trail Making Test (ΔTMT, TMT-B minus TMT-A) and the Movement Disorder Society-revised version of the motor part of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS III). Walking performance was assessed with wearable sensors under single (ST; fast and normal pace) and dual-task (DT; walking and checking boxes as the motor secondary task and walking and subtracting seven consecutively from a given three-digit number as the cognitive secondary task) conditions over 20 m. Multiple linear regression and Bayes factor BF10 were performed for each walking parameter and their dual-task costs while walking (DTC) as dependent variables and also included ΔTMT, MDS-UPDRS III, age, and gender.

Results

Under ST, significant negative effects of the use of a walking aid and MDS-UPDRS III on gait speed and at a fast pace on the number of steps were observed. Moreover, depending on the pace, the use of a walking aid, age, and gender affected step time variability. Under walking-cognitive DT, a resolved variance of 23% was observed in the overall model for step time variability DTC, driven mainly by age (β = 0.26, p = 0.09). Under DT, no other significant effects could be observed. ΔTMT showed no significant associations with any of the walking conditions.

Discussion

The results of this study suggest that, in acutely hospitalized patients with PD, reduced walking performance is mainly explained by the use of a walking aid, motor symptoms, age, and gender, and EF deficits surprisingly do not seem to play a significant role. However, these patients with PD should avoid walking-cognitive DT situations, as under this condition, especially step time variability, a parameter associated with the risk of falling in PD worsens.

Static Balance and Chair-Rise Performance in Neurogeriatric Patients: Promising Short Physical Performance Battery-Derived Predictors of Fear of Falling

Background

Fear of falling (FOF) negatively affects health-related quality of life and is common in neurogeriatric patients, however, related parameters are not well understood. This study investigated the relationship between FOF, physical performance (as assessed with the Short Physical Performance Battery and its subscores) and other aspects of sarcopenia in a sample of hospitalized neurogeriatric patients.

Methods

In 124 neurogeriatric patients, FOF was assessed with the Falls Efficacy Scale International (FES-I). Physical performance was measured using the Short Physical Performance Battery (SPPB) including walking duration, balance and five times sit-to-stand task (5xSST) subscores. Appendicular skeletal muscle mass (ASMM) was estimated with the cross-validated Sergi equation using Bioelectrical impedance analysis measures. The Depression im Alter-Skala (DIA-S) was used to assess depressive symptoms. Multiple regression models with FES-I score as outcome variable were computed using backward selection with AICc as selection criterion, including: (i) SPPB total score, ASMM/height2, grip strength, age, gender, positive fall history, number of medications, use of a walking aid, DIA-S score and Montreal Cognitive Assessment (MoCA) score; and (ii) SPPB subscores, ASMM/height2, grip strength, age, gender, positive fall history, number of medications, DIA-S score and MoCA score, once with and once without including use of a walking aid as independent variable.

Results

Lower SPPB total score, as well as lower SPPB balance and 5xSST subscores were associated with higher FES-I scores, but SPPB walking duration subscore was not. Moreover, DIA-S, number of medications and use of a walking aid were significantly associated with FOF.

Conclusion

Our preliminary results suggest that -if confirmed by subsequent studies- it may be worthwhile to screen patients with low SPPB balance and 5xSST subscores for FOF, and to treat especially these mobility deficits in neurogeriatric patients with FOF. Moreover, training neurogeriatric patients to use their walking aids correctly, critical evaluation of medication and treating depressive symptoms may further help reduce FOF in this highly vulnerable cohort.

2021 international consensus statement on optical coherence tomography for basal cell carcinoma: image characteristics, terminology and educational needs

BACKGROUND

Despite the widespread use of optical coherence tomography (OCT) for imaging of keratinocyte carcinoma, we lack an expert consensus on the characteristic OCT features of basal cell carcinoma (BCC), an internationally vetted set of OCT terms to describe various BCC subtypes, and an educational needs assessment.

OBJECTIVES

To identify relevant BCC features in OCT images, propose terminology based on inputs from an expert panel and identify content for a BCC-specific curriculum for OCT trainees.

METHODS

Over three rounds, we conducted a Delphi consensus study on BCC features and terminology between March and September 2020. In the first round, experts were asked to propose BCC subtypes discriminable by OCT, provide OCT image features for each proposed BCC subtypes and suggest content for a BCC-specific OCT training curriculum. If agreement on a BCC-OCT feature exceeded 67%, the feature was accepted and included in a final review. In the second round, experts had to re-evaluate features with less than 67% agreement and rank the ten most relevant BCC OCT image features for superficial BCC, nodular BCC and infiltrative and morpheaphorm BCC subtypes. In the final round, experts received the OCT-BCC consensus list for a final review, comments and confirmation.

RESULTS

The Delphi included six key opinion leaders and 22 experts. Consensus was found on terminology for three OCT BCC image features: (i) hyporeflective areas, (ii) hyperreflective areas and (iii) ovoid structures. Further, the participants ranked the ten most relevant image features for nodular, superficial, infiltrative and morpheaform BCC. The target group and the key components for a curriculum for OCT imaging of BCC have been defined.

CONCLUSION

We have established a set of OCT image features for BCC and preferred terminology. A comprehensive curriculum based on the expert suggestions will help implement OCT imaging of BCC in clinical and research settings.

Line-field confocal optical coherence tomography for the in vivo real-time diagnosis of different stages of keratinocyte skin cancer: a preliminary study

BACKGROUND

The treatment of keratinocyte cancers (KC) strictly depends on their differentiation and invasiveness. Non-invasive diagnostic techniques can support the diagnosis in real time, avoiding unnecessary biopsies. This study aimed to preliminarily define main imaging criteria and histological correlations of actinic keratosis (AK), Bowen's disease (BD) and squamous cell carcinoma (SCC) using the novel device line-field confocal optical coherence tomography (LC-OCT).

METHODS

Dermoscopy and LC-OCT images of 73 histopathologically confirmed lesions (46 AKs, 11 BD and 16 SCCs) were included in the study. Exemplary lesions (10 AKs, 5 BD and 5 SCCs) were additionally investigated with optical coherence tomography and reflectance confocal microscopy.

RESULTS

Most common LC-OCT findings of KC in the descriptive statistics were hyperkeratosis/parakeratosis, disruption of stratum corneum, broadened epidermis, basal and suprabasal keratinocyte atypia, dilated vessels/neoangiogenesis and elastosis/collagen alterations. In the univariate multinomial logistic regression, a preserved DEJ was less common in SCC compared with AK and BD, BD displayed marked keratinocyte atypia involving all epidermal layers (bowenoid pattern), while SCC showed ulceration, increased epidermal thickness, keratin plugs, acantholysis, not visible/interrupted DEJ and epidermal bright particles. LC-OCT increased the diagnostic confidence by 24.7% compared with dermoscopy alone.

CONCLUSIONS

Our study describes for the first time specific LC-OCT features of different stages of KC and their histopathological correlates, focusing on keratinocyte morphology and architecture of the epidermis and DEJ. LC-OCT may open new scenarios in the bedside diagnosis, treatment planning and follow-up of KC.

Line-field optical coherence tomography: In vivo diagnosis of basal cell carcinoma subtypes compared to histopathology

BACKGROUND

Basal cell carcinoma (BCC) is the most common skin cancer in the general population. Treatments vary from Mohs surgery to topical therapy, depending on the subtype. Dermoscopy, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) have gained a foothold in daily clinical practice to optimize diagnosis and subtype-oriented treatment. The new device Line-field confocal OCT (LC-OCT) allows imaging at high resolution and depth but its use is not yet been investigated in larger studies.

OBJECTIVES

To evaluate the main LC-OCT criteria for the diagnosis and subtyping of BCC in comparison to histopathology, OCT and RCM.

METHODS

Fifty-two histopathologically confirmed BCCs were evaluated for imaging criteria. Their frequency, predictive values and ROC curves were calculated. A multinominal regression with stepwise variables selection to distinguish BCC subtypes was performed.

RESULTS

Nodular BCCs were mainly characterized by atypical keratinocytes, altered DEJ, tumour nests in the dermis, dark clefting, prominent vascularisation and white hyperreflective stroma. Superficial BCCs showed a thickening of the epidermis due to a series of tumour lobules with clear connection to the DEJ (string of pearls pattern). Infiltrative BCCs were characterized by elongated hyporeflective tumour strands, surrounded by bright collagen (shoal of fish). The overall BCC subtype agreement between LC-OCT and conventional histology was 90.4 % (95% CI: 79.0, 96.8).

CONCLUSION

LC-OCT allows the non-invasive, real time identification of BCCs and their subtypes in vertical, horizontal and 3D mode compared to histology, RCM and OCT. Further larger studies are needed to better explore the clinical applications of this promising device.

Reliability of IMU-Derived Static Balance Parameters in Neurological Diseases

Static balance is a commonly used health measure in clinical practice. Usually, static balance parameters are assessed via force plates or, more recently, with inertial measurement units (IMUs). Multiple parameters have been developed over the years to compare patient groups and understand changes over time. However, the day-to-day variability of these parameters using IMUs has not yet been tested in a neurogeriatric cohort. The aim of the study was to examine day-to-day variability of static balance parameters of five experimental conditions in a cohort of neurogeriatric patients using data extracted from a lower back-worn IMU. A group of 41 neurogeriatric participants (age: 78 ± 5 years) underwent static balance assessment on two occasions 12-24 h apart. Participants performed a side-by-side stance, a semi-tandem stance, a tandem stance on hard ground with eyes open, and a semi-tandem assessment on a soft surface with eyes open and closed for 30 s each. The intra-class correlation coefficient (two-way random, average of the k raters' measurements, ICC2, k) and minimal detectable change at a 95% confidence level (MDC95%) were calculated for the sway area, velocity, acceleration, jerk, and frequency. Velocity, acceleration, and jerk were calculated in both anterior-posterior (AP) and medio-lateral (ML) directions. Nine to 41 participants could successfully perform the respective balance tasks. Considering all conditions, acceleration-related parameters in the AP and ML directions gave the highest ICC results. The MDC95% values for all parameters ranged from 39% to 220%, with frequency being the most consistent with values of 39-57%, followed by acceleration in the ML (43-55%) and AP direction (54-77%). The present results show moderate to poor ICC and MDC values for IMU-based static balance assessment in neurogeriatric patients. This suggests a limited reliability of these tasks and parameters, which should induce a careful selection of potential clinically relevant parameters.

Effect of speed and gradient on plantar force when running on an AlterG® treadmill

BACKGROUND

Anti-gravity treadmills are used to decrease musculoskeletal loading during treadmill running often in return to play rehabilitation programs. The effect different gradients (uphill/downhill running) have on kinetics and spatiotemporal parameters when using an AlterG® treadmill is unclear with previous research focused on level running only.

METHODS

Ten well-trained healthy male running athletes ran on the AlterG® treadmill at varying combinations of bodyweight support (60, 80, and 100% BW), speed (12 km/hr., 15 km/hr., 18 km/hr., 21 km/hr., and 24 km/hr), and gradients (- 15% decline, - 10, - 5, 0, + 5, + 10 + 15% incline), representing a total of 78 conditions performed in random order. Maximum plantar force and contact time were recorded using a wireless in-shoe force sensor insole system.

RESULTS

Regression analysis showed a linear relationship for maximum plantar force with bodyweight support and running speeds for level running (p < 0.0001, adj. R² = 0.604). The linear relationship, however, does not hold for negative gradients at speeds 12 & 15 km/h, with a relative 'dip' in maximum plantar force across all assisted bodyweight settings.

CONCLUSIONS

Maximum plantar force peaks are larger with faster running and smaller with more AlterG® assisted bodyweight support (athlete unweighing). Gradient made little difference except for a downhill grade of - 5% decreasing force peaks as compared to level or uphill running.

Step Length Is a Promising Progression Marker in Parkinson's Disease

Current research on Parkinson’s disease (PD) is increasingly concerned with the identification of objective and specific markers to make reliable statements about the effect of therapy and disease progression. Parameters from inertial measurement units (IMUs) are objective and accurate, and thus an interesting option to be included in the regular assessment of these patients. In this study, 68 patients with PD (PwP) in Hoehn and Yahr (H&Y) stages 1–4 were assessed with two gait tasks—20 m straight walk and circular walk—using IMUs. In an ANCOVA model, we found a significant and large effect of the H&Y scores on step length in both tasks, and only a minor effect on step time. This study provides evidence that from the two potentially most important gait parameters currently accessible with wearable technology under supervised assessment strategies, step length changes substantially over the course of PD, while step time shows surprisingly little change in the progression of PD. These results show the importance of carefully evaluating quantitative gait parameters to make assumptions about disease progression, and the potential of the granular evaluation of symptoms such as gait deficits when monitoring chronic progressive diseases such as PD.

Struktur der Hautkliniken und dermatologische Lehre in den neuen Universitäten in Deutschland

Im Zuge der Neugründung medizinischer Fakultäten in Deutschland muss auch die dermatologische Forschung und Lehre aufgebaut werden. Diese großen Zusatzaufgaben neben der Krankenversorgung stellen eine Herausforderung für die Klinikleitungen dar. In diesem Übersichtsbeitrag beschreiben exemplarisch Chefärztinnen und Chefärzte neuer Universitätshautkliniken und dermatologischer Fachabteilungen die Auswirkungen, die die Umwandlung in eine Universitätsklinik auf die Forschung und Lehre sowie den klinischen Alltag mit sich gebracht hat.

Validation of IMU-based gait event detection during curved walking and turning in older adults and Parkinson's Disease patients

Background

Identification of individual gait events is essential for clinical gait analysis, because it can be used for diagnostic purposes or tracking disease progression in neurological diseases such as Parkinson’s disease. Previous research has shown that gait events can be detected from a shank-mounted inertial measurement unit (IMU), however detection performance was often evaluated only from straight-line walking. For use in daily life, the detection performance needs to be evaluated in curved walking and turning as well as in single-task and dual-task conditions.

Methods

Participants (older adults, people with Parkinson’s disease, or people who had suffered from a stroke) performed three different walking trials: (1) straight-line walking, (2) slalom walking, (3) Stroop-and-walk trial. An optical motion capture system was used a reference system. Markers were attached to the heel and toe regions of the shoe, and participants wore IMUs on the lateral sides of both shanks. The angular velocity of the shank IMUs was used to detect instances of initial foot contact (IC) and final foot contact (FC), which were compared to reference values obtained from the marker trajectories.

Results

The detection method showed high recall, precision and F1 scores in different populations for both initial contacts and final contacts during straight-line walking (IC: recall \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}= 100%, precision \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}= 100%, F1 score \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}= 100%; FC: recall \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}= 100%, precision \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}= 100%, F1 score \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}= 100%), slalom walking (IC: recall \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}= 100%, precision \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 99%, F1 score \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}=100%; FC: recall \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}= 100%, precision \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 99%, F1 score \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$=$$\end{document}=100%), and turning (IC: recall \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 85%, precision \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 95%, F1 score \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥91%; FC: recall \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 84%, precision \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 95%, F1 score \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥89%).

Conclusions

Shank-mounted IMUs can be used to detect gait events during straight-line walking, slalom walking and turning. However, more false events were observed during turning and more events were missed during turning. For use in daily life we recommend identifying turning before extracting temporal gait parameters from identified gait events.

Wie wird man Uniklinikum? Neue Wege des Medizinstudiums in Deutschland

Die Nachfrage nach Studienplätzen der Humanmedizin übersteigt seit vielen Jahren deutlich das Angebot der staatlichen Medizinfakultäten in Deutschland. Durch den zunehmenden Ärztemangel steigt auf der anderen Seite der Bedarf an ausgebildeten Medizinerinnen und Medizinern. Um diese Lücke zu schließen, wurden in den letzten Jahren zahlreiche Möglichkeiten neu eröffnet, in Deutschland Humanmedizin zu studieren. Neben Neugründungen von Fakultäten sind insbesondere Kooperationen von Kliniken mit europäischen Universitäten und Privatuniversitäten zu nennen. Dieser Beitrag gibt eine Übersicht über die Optionen und Rahmenbedingungen.

[Noninvasive diagnostic imaging in pediatric skin lesions]

Optical coherence tomography (OCT) and reflectance confocal laser microscopy (RCM) allow noninvasive imaging diagnostics of the skin. Since the indication for a biopsy in children is generally made cautiously, OCT and KLM can be helpful in the clarification of pediatric skin lesions. In addition, biopsies only represent a snapshot of a small area of the skin, while noninvasive methods allow several locations to be examined over time, so that dynamic changes and the course of therapy can also be determined. In pediatric dermatology, these diagnostic methods are particularly suitable for the clarification of atypical pigment lesions, for infectious dermatoses such as scabies or tinea, and for the diagnosis of inflammatory and degenerative dermatoses.

Dynamic optical coherence tomography shows characteristic alterations of blood vessels in malignant melanoma

BACKGROUND

Dynamic optical coherence tomography (D-OCT) allows in vivo visualization of blood vessels in the skin and in malignant tumours. Vessel patterns in malignant melanoma may be associated with tumour stage.

OBJECTIVE

The aim of this study was to describe blood vessel patterns in melanomas and to correlate them with stage.

METHODS

One hundred fifty-nine malignant melanomas were assessed in a multicentre study. Every tumour was imaged using D-OCT prior to surgery and histologic evaluation. The tumour data such as thickness and ulceration as well as the staging at primary diagnosis and a follow-up of at least 40 months resulted in a stage classification. The vessel patterns were assessed according to predefined categories, compared with healthy adjacent skin, and correlated to stage.

RESULTS

Melanomas contained more blood vessels in different patterns compared with healthy adjacent skin. In particular, irregular vascular shapes such as blobs, coils, curves and serpiginous vessels were more common in melanomas. In addition, these patterns were significantly more often found in high-risk and metastatic melanomas than in low-risk lesions.

CONCLUSION

In melanomas, the density of the blood vessels is increased, and irregular vascular patterns are more frequent. At higher stages, especially in metastatic melanomas, these atypical vessels are significantly more common.

Quantitative ion determination in eccrine sweat gland cells correlates to sweat reduction of antiperspirant actives

OBJECTIVE

Axillary wetness represents an unwanted effect of the physiologically vital sweating mechanism, especially when it becomes excessive. Cosmetic products reducing sweat secretion rely on aluminium salts as the active ingredient acting by physically blocking the sweat gland. Driven by the interest to better understand the sweat mechanism and to develop alternative technologies against excessive sweating a search for an effective testing approach started as up to now, cost- and time-consuming in vivo studies represent the standard procedure for testing and identifying these alternatives.

MATERIAL AND METHODS

The herein described in vitro test system is based on the measurement of intracellular changes of the ion equilibrium in cultured eccrine sweat gland cells. Subsequently, in vivo studies on the back of volunteers were conducted to verify the sweat-reducing effect of in vitro newly discovered substance.

RESULTS

In this study, we describe an effective cell-based in vitro method as a potent tool for a more targeted screening of alternatives to aluminium salts. Testing the commonly used aluminium chlorohydrate as one example of an aluminium-based active in this screening procedure, we discovered a distinct influence on the ion equilibrium: Intracellular levels of sodium ions were decreased while those of chloride increased. Screening of various substances revealed a polyethyleneimine, adjusted to pH 3.5 with hydrochloric acid, to evoke the same alterations in the ion equilibrium as aluminium chlorohydrate. Subsequent in vivo studies showed its substantial antiperspirant action and confirmed the high efficiency of the polyethyleneimine solution in vivo. Further, specific investigations connecting the chloride content of the tested substances with the resulting sweat reduction pointed towards a substantial impact of the chloride ions on sweating.

CONCLUSION

The newly described in vitro cell-based screening method represents an effective means for identifying new antiperspirant actives and suggests an additional biological mechanism of action of sweat-reducing ingredients which is directed towards unbalancing of the ion equilibrium inside eccrine sweat gland cells.

„Pilze suchen – was hilft?“

Pilzinfektionen verursachen häufig eine Entzündung der Haut, die je nach Erreger und Lokalisation unterschiedlich stark ist. Diese Beobachtung kann bei der Auswahl der antimykotischen Therapie eine Hilfe sein.

Durch den Einsatz nichtinvasiver Geräte wie der Dermatoskopie, konfokalen Lasermikroskopie (KLM), optischen Kohärenztomografie (OCT) und dynamischen optischen Kohärenztomografie (D-OCT) gelingt eine Darstellung der Haut und auch ihrer Veränderungen bei entzündlichen Mykosen.

Dynamische OCT − was verraten uns die Gefäße?

Die Weiterentwicklung der optischen Kohärenztomografie (OCT) zur dynamischen OCT (D-OCT) erlaubt die gleichzeitige Darstellung der oberflächlichen Blutgefäße. Blut ist das wichtigste Transportsystem unseres Körpers, und sowohl durch äußere als auch durch innere Einflüsse können physiologische Prozesse beeinträchtigt werden. Die D-OCT ermöglicht erstmals die Darstellung dieser Veränderungen anhand der Gefäßdichte und Durchblutung. Durch wiederholtes schnelles Messen der gleichen untersuchten Region können mithilfe einer speziellen Software Unterschiede in einer Bildserie erfasst werden und so sich bewegende Teilchen, die den Blutbestandteilen entsprechen, bis zu einer Tiefe von 0,5 mm vom statischen Hautgewebe differenziert werden. Die Software bildet den Blutfluss im D-OCT-Bild in roter Farbe als Überlagerung über das grau-weiß strukturelle Gewebe ab. Mithilfe der D-OCT konnten physiologische Einflüsse auf die Durchblutung, wie Vasokonstriktion und Positionsänderung, Unterschiede aufgrund der anatomischen Körperregionen, aber auch therapeutische Effekte, wie z. B. durch die lokale Behandlung mit vasokonstringierendem Brimonidin-Gel (einem selektiven α2-Adrenorezeptor-Agonisten) oder bei der Lasertherapie nachgewiesen werden. Weiterhin fanden sich bestimmte Blutgefäßformen nur bei chronisch venösen Ulzera (wie Knäuel am Wundrand oder geschlängelte Gefäße bei Dermatosklerose), während die Blutgefäße bei akuten Wunden eine Häufung von anderen Gefäßformen und Verteilungsmustern zeigten. Bei ausgewählten entzündlichen und autoimmunbedingten Erkrankungen konnten die damit einhergehenden vaskulären Prozesse exemplarisch dargestellt werden. Auch ließ sich mit der D-OCT feststellen, dass eine erhöhte Blutgefäßdichte und gewisse Formen erst mit einer größeren Tumordicke von Melanomen (Breslow-Index) einhergehen. Außerdem können die Blutgefäße zur Differenzierung sowie zur Therapieauswahl von nicht-melanozytärem Hautkrebs beitragen. Die D-OCT ist jedoch nicht nur ein diagnostisches Gerät, sondern eignet sich auch zur bildgeführten Therapie wie der D-OCT-geführten Lasertherapie.

Die D-OCT bietet durch die Darstellung von Blutgefäßen zahlreiche diagnostische und therapeutische Einsatzmöglichkeiten. Die Blutgefäße verraten uns so viel über physiologische und pathologische Prozesse in unserer Haut, und ihre Darstellung wird in Zukunft eine individuellere, patienten-orientiertere Therapie erlauben, als es bisher möglich ist. So könnten z. B. Ulzera verschiedener Genese mittels D-OCT differenziert werden oder Melanome anhand der Gefäßmuster bereits präoperativ risikostratifiziert werden.

„Ein Unglück kommt selten allein …“

Die nichtinvasiven Geräte wie die optische Kohärenztomografie (OCT) und die konfokale Lasermikroskopie (KLM) sind bei der Diagnostik und Therapieauswahl vieler Erkrankungen z. B. von nichtmelanozytärem Hautkrebs sehr hilfreich. Ihr Einsatz eignet sich insbesondere dann, wenn differenzialdiagnostisch mehrere Diagnosen infrage kommen, die eine die andere Erkrankung verschleiert oder ein tieferer nichtinvasiver Blick in die Haut nötig wird.

Wir berichten über den Fall einer 89-jährigen Patientin mit Stevens-Johnson-Syndrom (SJS) nach Einnahme von Allopurinol aufgrund von Hyperurikämie und Gicht. Mit der OCT und KLM können erstmals die Charakteristika beider gemeinsam vorliegender Erkrankungen in vivo dargestellt werden.

Motor, cognitive and mobility deficits in 1000 geriatric patients: protocol of a quantitative observational study before and after routine clinical geriatric treatment - the ComOn-study

BACKGROUND

Motor and cognitive deficits and consequently mobility problems are common in geriatric patients. The currently available methods for diagnosis and for the evaluation of treatment in this vulnerable cohort are limited. The aims of the ComOn (COgnitive and Motor interactions in the Older populatioN) study are (i) to define quantitative markers with clinical relevance for motor and cognitive deficits, (ii) to investigate the interaction between both motor and cognitive deficits and (iii) to assess health status as well as treatment outcome of 1000 geriatric inpatients in hospitals of Kiel (Germany), Brescia (Italy), Porto (Portugal), Curitiba (Brazil) and Bochum (Germany).

METHODS

This is a prospective, explorative observational multi-center study. In addition to the comprehensive geriatric assessment, quantitative measures of reduced mobility and motor and cognitive deficits are performed before and after a two week's inpatient stay. Components of the assessment are mobile technology-based assessments of gait, balance and transfer performance, neuropsychological tests, frailty, sarcopenia, autonomic dysfunction and sensation, and questionnaires to assess behavioral deficits, activities of daily living, quality of life, fear of falling and dysphagia. Structural MRI and an unsupervised 24/7 home assessment of mobility are performed in a subgroup of participants. The study will also investigate the minimal clinically relevant change of the investigated parameters.

DISCUSSION

This study will help form a better understanding of symptoms and their complex interactions and treatment effects in a large geriatric cohort.

Investigating Priming Effects of Physical Practice on Motor Imagery-Induced Event-Related Desynchronization

For motor imagery (MI) to be effective, an internal representation of the to-be-imagined movement may be required. A representation can be achieved through prior motor execution (ME), but the neural correlates of MI that are primed by ME practice are currently unknown. In this study, young healthy adults performed MI practice of a unimanual visuo-motor task (Group MI, n = 19) or ME practice combined with subsequent MI practice (Group ME&MI, n = 18) while electroencephalography (EEG) was recorded. Data analysis focused on the MI-induced event-related desynchronization (ERD). Specifically, changes in the ERD and movement times (MT) between a short familiarization block of ME (Block pre-ME), conducted before the MI or the ME combined with MI practice phase, and a short block of ME conducted after the practice phase (Block post-ME) were analyzed. Neither priming effects of ME practice on MI-induced ERD were found nor performance-enhancing effects of MI practice in general. We found enhancements of the ERD and MT in Block post-ME compared to Block pre-ME, but only for Group ME&MI. A comparison of ME performance measures before and after the MI phase indicated however that these changes could not be attributed to the combination of ME and MI practice. The mixed results of this study may be a consequence of the considerable intra- and inter-individual differences in the ERD, introduced by specifics of the experimental setup, in particular the individual and variable task duration, and suggest that task and experimental setup can affect the interplay of ME and MI.

Evaluation of two histological classifications for actinic keratoses - PRO classification scored highest inter-rater reliability

BACKGROUND

Actinic keratoses (AKs) can histologically be classified by the extent of atypical keratinocytes throughout the epidermis or their pattern of basal proliferation. Currently, no data on the inter-rater reliability of both scores is available.

OBJECTIVE

To evaluate the inter-rater reliability of the two classification schemes; histological grade (AK I-III) and basal proliferation (PRO I-III).

METHODS

Histological images of 54 AKs were classified by 21 independent dermatopathologists with regard to basal proliferation (PRO I-III), histological grade (AK I-III) and assumed risk of progression into invasive carcinoma.

RESULTS

Overall, of the 54 AKs 16.7% (9/54) were classified as AK I, 66.7% (36/54) as AK II, and 16.7% (9/54) as AK III. With regards to basal growth pattern, 25.9% (14/54) were classified as PRO I, 42.6% (23/54) as PRO II, and 31.5% (17/54) as PRO III. We observed a highly significant inter-rater reliability for PRO-grading (P < 0.001) which was higher than for AK-grading (Kendall's W coefficient: AK = 0.488 vs. PRO = 0.793). We found substantial agreement for assumed progression risk for AKs with worsening basal proliferation (k = 0.759) compared to moderate agreement (k = 0.563) for different AK-gradings.

CONCLUSIONS

Histological classification of basal growth pattern (PRO) showed higher inter-rater reliability compared to the established classification of atypical keratinocytes throughout epidermal layers. Moreover, experienced dermatopathologists considered basal proliferation to be more important in terms of progression risk than upwards directed growth patterns. It should be considered to classify AKs according to their basal proliferation pattern (PRO I-III).

Langerhanszell-Histiozytose unter dem Bild einer Folliculitis decalvans und Intertrigo

Die Langerhanszell-Histiozytose ist eine seltene Erkrankung unklarer Ätiologie, die durch eine Proliferation histiozytärer Zellen in verschiedenen Geweben gekennzeichnet ist. Vor wenigen Jahren wurde entdeckt, dass ein Großteil der LCH-Zellen eine BRAF-Mutation aufweist. Eine neoplastische Genese ist demnach denkbar. Da mehrere Organe durch die proliferierende Zellen betroffen sein können, sind die Beschwerden der Langerhanszell-Histiozytose vielgestaltig. Das am häufigsten betroffene Organ bei der erwachsenen Langerhanszell-Histiozytose ist die Lunge, gefolgt von den Knochen. In ⅓ der Fälle ist die Haut betroffen, sodass dem Dermatologen bei der Diagnosefindung eine ausgesprochen wichtige Rolle zukommt. Wegweisende Befunde sind die Trias erosive, ekzemartige Hautveränderungen am Kapillitium sowie in den Intertrigines in Kombination mit einem Diabetes insipidus. Die Diagnose wird letztlich histologisch gestellt. Typisch sind dichte Infiltrate, bestehend aus großen Zellen mit bohnenförmigem Zellkern, die immunhistochemisch durch Nachweis von CD1a-Antigen auf der Zelloberfläche charakterisiert sind.

Therapeutisch werden neben topischen Steroiden, PUVA, systemischen Immunsuppressiva auch teilweise Polychemotherapien sowie chirurgische und auch strahlentherapeutische Maßnahmen angewandt. Aufgrund der neuesten Erkenntnisse der bestehenden BRAF-Mutation wird derzeit auch der Einsatz von BRAF-Inhibitoren diskutiert.

Bei lokalisierten Formen der LCH ist die Prognose günstig. Der Ausgang der disseminierten Form ist abhängig vom Ausmaß des Organbefalls sowie vom Alter der Patienten. In seltenen Fällen wurden Entwicklungen zu akuten myeloischen Leukämien beobachtet. Aufgrund der Seltenheit der Erkrankungen hat sich bisher kein systematischer und interdisziplinärer Ansatz zur Diagnosestellung und Therapie ebenso wie kein langfristiges Nachsorgekonzept etabliert.

Optical coherence tomography for margin definition of basal cell carcinoma before micrographic surgery-recommendations regarding the marking and scanning technique

BACKGROUND/PURPOSE

Mohs Micrographic Surgery (MMS) is the preferred therapeutic treatment for high-risk basal cell carcinoma (BCC). Optical Coherence Tomography (OCT) is a non-invasive imaging technique that enables the diagnosis of BCC. We thought to determine the margins of BCCs with OCT, prior to MMS, to reduce the number of surgical steps.

METHODS

Different permanent markers were tested on the skin regarding line width, resistance against disinfection and brightness in the OCT image. The visible tumor margins of BCCs were defined by dermoscopy, adding a safety margin of 2 mm and labeled using the selected pen, causing a signal shadow in OCT. Scans of the center and of entire margin were performed. If parts of the BCC were visible outside the margin, another 2 mm were added and the scan was repeated until the tissue outside the labeling looked tumor free.

RESULTS

Eight out of ten BCCs were totally excised in a single stage when margin delineation was done by OCT. Macroscopic margins were enlarged after OCT scanning in four patients, saving further stages of MMS.

CONCLUSION

OCT may help to better define the microscopic dimensions of BCCs and therefore reduce the number of stages of MMS.

Fluorescence (Multiwave) Confocal Microscopy

In addition to reflectance confocal microscopy, multiwave confocal microscopes with different laser wavelengths in combination with exogenous fluorophores allow fluorescence mode confocal microscopy in vivo and ex vivo. Fluorescence mode confocal microscopy improves the contrast between the epithelium and the surrounding soft tissue and allows the depiction of certain structures, like epithelial tumors, nerves, and glands.