[Psychometric Evaluation of the 'German Neurological Fatigue Index for Multiple Sclerosis (NFI-MS-G)' in a Sample of Rehabilitation Patients with Multiple Sclerosis]. / Psychometrische Prüfung des deutschsprachigen "Neurologischen Fragebogens zur Müdigkeit bei Multipler Sklerose (NFI-MS-G)" bei Rehabilitanden mit Multipler Sklerose.

PURPOSE: The purpose of this study was to provide a patient-reported outcome measure for people with multiple sclerosis (MS) comprehensively reflecting the construct of fatigue and developed upon the assumptions of the Rasch model. The Neurological Fatigue Index - Multiple Sclerosis (NFI-MS) is based on both a medical and patient-described symptom framework of fatigue and has been validated. Therefore, in this study the German version of the NFI-MS (NFI-MS-G) consisting of a physical and cognitive subscale and a summary scale was validated. METHOD: In this bi-centre-study, 309 people with MS undergoing outpatient rehabilitation or being≥2 months before or after their inpatient rehabilitation completed the German NFI-MS-G twice within 14-21 days together with other questionnaires. Correlation with established questionnaires and Rasch analysis were used for its validation. Additionally, psychometric properties of known-groups validity, internal consistency, test-retest reliability, measurement precision and readability were tested. Finally, the English NFI-MS and German NFI-MS-G were compared with each other to equate the language versions. RESULTS: The NFI-MS-G showed good internal construct validity, convergent and known-groups validity and internal consistency (Cronbach's alpha 0.84-0.93). The physical subscale showed minor local dependencies between items 1 and 7, 2 and 3 and 4 to 6, that could be treated by combining the respective items to testlets. Unidimensionality was found for the physical and cognitive subscales but not for the summary scale. Replacing the summary scale, a 2-domains subtest measuring the higher-order construct of fatigue was created. Good test-retest reliability (Lin's concordance correlation coefficient of 0.86-0.90) and low floor and ceiling effects were demonstrated. The NFI-MS-G was found easily readable and invariant across groups of gender, age, disease duration, timepoint and centre. CONCLUSION: The German version of the NFI-MS comprehensively represents the construct of fatigue and has adequate psychometric properties. The German version differs from the English original version with respect to a lack of unidimensionality of the summary scale and minor local dependencies of the physical subscale that could be canceled out using a testlet analysis.

Systematic analysis reveals that colony housing aligns gait profiles and strengthens link between histological and micro-CT bone markers in rat models of osteoarthritis.

Osteoarthritis (OA) etiopathogenesis is complex with strong environmental/lifestyle determinants that, in laboratory animals, extend to social context and stress levels. This study seeks to identify whether colony housing of rats exerts a social impact on locomotion behaviors to influence alignment between symptomatic (gait) and structural (bone micro-CT measures, cartilage morphometry, and histology) OA outcome measures. Rats were randomly allocated to conventional (type IV; n = 48) or rat colony cage (RCC; n = 30) housing, further randomized to OA surgical models (ACLT + tMx, MMT or DMM) or no surgery (control), and maintained for 19 weeks during which multiple gait recordings were made. Standard histological grading and bone micro-CT data were collected at necropsy. Principal component analysis was used to summarize the variation in gait, micro-CT or histology. Linear mixed effects model or two-way ANOVA was employed to evaluate the impact of the housing system, surgery and time on gait, or micro-CT and histology components Analyses reveal that RCC exaggerates trends in gait change via a combined effect of the housing system and surgery. Intriguingly, RCC-housed nonoperated control rats showed similar gait changes to rats subjected to surgery; the latter exhibited significant structural joint changes in both systems. Stronger correlation between histological and micro-CT bone changes were found in medial and lateral tibia joint compartments of rats housed in RCC system. This study has established that rat social housing exaggerates outcomes in traditional histological measures of OA, generates stronger links between histology and micro-CT bone changes and removes gait differences as a variable in their etiology.

Successful long-term management of spasticity in people with multiple sclerosis using a software application: Results from a randomized, controlled, multicenter study.

BACKGROUND AND PURPOSE: Successful long-term treatment of spasticity in people with multiple sclerosis (pwMS) is challenging. We investigated the effects of multidisciplinary inpatient rehabilitation (MIR) and an individualized self-training program delivered by an app on spasticity in pwMS. METHODS: First, we assessed the efficacy of 4-week MIR in ambulatory pwMS (Expanded Disability Status Scale < 7.0) with moderate to severe lower limb spasticity (defined by ≥4 points on the Numeric Rating Scale for spasticity [NRSs]) in a cohort of 115 pwMS at seven rehabilitation centers in Austria. In the case of a clinically relevant improvement in spasticity of ≥20% on the NRSs following MIR (n = 94), pwMS were randomly allocated in a 1:1 ratio to either the newly designed MS-Spasticity App or to a paper-based self-training program for 12 weeks. The primary outcome was change in NRSs (German Clinical Trials Registry DRKS00023960). RESULTS: MIR led to a significant reduction of 2.0 points on the NRSs (95% confidence interval [CI] = 2.5-2.0, p < 0.000). MIR was further associated with a statistically significant improvement in spasticity on the Modified Ashworth Scale, strength, and all mobility outcomes. Following MIR, self-training with the MS-Spasticity App was associated with a sustained positive effect on the NRSs, whereas paper-based self-training led to a worsening in spasticity (median NRSs difference = 1.0, 95% CI = 1.7-0.3, p = 0.009). The MS-Spasticity App was also associated with a significantly better adherence to self-training (95% vs. 72% completion rate, p < 0.001). CONCLUSIONS: In pwMS, MIR is able to significantly improve lower limb spasticity, strength, and mobility. Following MIR, an individually tailored antispasticity program delivered by an app leads to sustained positive long-term management.

ExerG: adapting an exergame training solution to the needs of older adults using focus group and expert interviews.

BACKGROUND: Exergames are playful technology-based exercise programs. They train physical and cognitive functions to preserve independence in older adults (OAs) with disabilities in daily activities and may reduce their risk of falling. This study gathered in-depth knowledge and understanding of three different user groups' experiences in and relevant needs, worries, preferences, and expectations of technology-based training, to develop an exergame training device for OAs. METHODS: We conducted a qualitative study using semi-structured focus group interviews of primary (OAs in geriatric or neurological rehabilitation) and secondary (health professionals) end users, as well as expert interviews of tertiary end users (health insurance experts or similar), exploring user perspectives on adjusting an existing exergame to OAs' needs. Voice-recorded interviews were transcribed by researchers and analyzed using thematic analysis (TA) following an inductive, data-driven, iterative approach. RESULTS: We interviewed 24 primary, 18 secondary, and 9 tertiary end users at two rehabilitation centers in Austria and Switzerland. Our TA approach identified five to six themes per user group. Themes in the primary end user group reflected aspects of safety, training goals, individuality, game environment, social interactions, and physical and technical overload. Themes in the secondary end user group comprised facets of meaningfulness, distraction through the game environment, safety, gamification elements, the availability and accessibility of the exergame. Tertiary end users' themes addressed aspects of financial reimbursement, suitable target populations, professional training for the handling of exergame devices, training goals, and concerns about the use of exergames in geriatric rehabilitation. CONCLUSIONS: In conclusion, an exergame for OAs must be safe, motivating and fully adaptable to the target group while promoting the return to or preservation of autonomy and independence in daily life. Our findings contribute to developing hard- and software extensions for the ExerG training device. Further research is needed to expand the validity of our findings to larger populations.

German translation, cultural adaptation and validation of the unidimensional self-efficacy scale for multiple sclerosis.

BACKGROUND: Self-efficacy concerns individuals' beliefs in their capability to exercise control in specific situations and complete tasks successfully. In people with multiple sclerosis (PwMS), self-efficacy has been associated with physical activity levels and quality of life. As a validated German language self-efficacy scale for PwMS is missing the aims of this study were to translate the Unidimensional Self-Efficacy Scale for Multiple Sclerosis (USE-MS) into German, establish face and content validity and cultural adaptation of the German version for PwMS in Austria. A further aim was to validate the German USE-MS (USE-MS-G) in PwMS. METHODS: Permission to translate and validate the USE-MS was received from the scale developers. Following guidelines for translation and validation of questionnaires and applying Bandura's concept of self-efficacy, the USE-MS was forward-backward translated with content and face validity established. Cultural adaptation for Austria was performed using cognitive patient interviews. Reliability was assessed using Cronbach's alpha, Person separation index and Lin's concordance correlation coefficient. Rasch analysis was employed to assess construct validity. Comparison was made to scales for resilience, general self-efficacy, anxiety and depression, multiple sclerosis fatigue and health-related quality of life. Data were also pooled with an historic English dataset to compare the English and German language versions. RESULTS: The translation and cultural adaptation were successfully performed in the adaptation process of the USE-MS-G. Pretesting was conducted in 30 PwMS, the validation of the final USE-MS-G involved 309 PwMS with minimal to severe disability. The USE-MS-G was found to be valid against the Rasch model when fitting scale data using a bifactor solution of two super-items. It was shown to be unidimensional, free from differential item functioning and well targeted to the study population. Excellent convergent and known-groups validity, internal consistency, person separation reliability and test-retest reliability were shown for the USE-MS-G. Pooling of the English and German datasets confirmed invariance of item difficulties between languages. CONCLUSION: The USE-MS-G is a robust, valid and reliable scale to assess self-efficacy in PwMS and can generate interval level data on an equivalent metric to the UK version. TRIAL REGISTRATION: ISRCTN Registry; ISRCTN14843579 ; prospectively registered on 02. 01. 2019.

Phenotyping the function of TRPV1-expressing sensory neurons by targeted axonal silencing.

Specific somatosensations may be processed by different subsets of primary afferents. C-fibers expressing heat-sensitive TRPV1 channels are proposed, for example, to be heat but not mechanical pain detectors. To phenotype in rats the sensory function of TRPV1(+) afferents, we rapidly and selectively silenced only their activity, by introducing the membrane-impermeant sodium channel blocker QX-314 into these axons via the TRPV1 channel pore. Using tandem mass spectrometry we show that upon activation with capsaicin, QX-314 selectively accumulates in the cytosol only of TRPV1-expressing cells, and not in control cells. Exposure to QX-314 and capsaicin induces in small DRG neurons a robust sodium current block within 30 s. In sciatic nerves, application of extracellular QX-314 with capsaicin persistently reduces C-fiber but not A-fiber compound action potentials and this effect does not occur in TRPV1(-/-) mice. Behavioral phenotyping after selectively silencing TRPV1(+) sciatic nerve axons by perineural injections of QX-314 and capsaicin reveals deficits in heat and mechanical pressure but not pinprick or light touch perception. The response to intraplantar capsaicin is substantially reduced, as expected. During inflammation, silencing TRPV1(+) axons abolishes heat, mechanical, and cold hyperalgesia but tactile and cold allodynia remain following peripheral nerve injury. These results indicate that TRPV1-expressing sensory neurons process particular thermal and mechanical somatosensations, and that the sensory channels activated by mechanical and cold stimuli to produce pain in naive/inflamed rats differ from those in animals after peripheral nerve injury.

Prostacyclin regulates spinal nociceptive processing through cyclic adenosine monophosphate-induced translocation of glutamate receptors.

BACKGROUND: Prostacyclin (PGI2) is known to be an important mediator of peripheral pain sensation (nociception) whereas little is known about its role in central sensitization. METHODS: The levels of the stable PGI2-metabolite 6-keto-prostaglandin F1α (6-keto-PGF1α) and of prostaglandin E2 (PGE2) were measured in the dorsal horn with the use of mass spectrometry after peripheral inflammation. Expression of the prostanoid receptors was determined by immunohistology. Effects of prostacyclin receptor (IP) activation on spinal neurons were investigated with biochemical assays (cyclic adenosine monophosphate-, glutamate release-measurement, Western blot analysis) in embryonic cultures and adult spinal cord. The specific IP antagonist Cay10441 was applied intrathecally after zymosan-induced mechanical hyperalgesia in vivo. RESULTS: Peripheral inflammation caused a significant increase of the stable PGI2 metabolite 6-keto-PGF1α in the dorsal horn of wild-type mice (n = 5). IP was located on spinal neurons and did not colocalize with the prostaglandin E2 receptors EP2 or EP4. The selective IP-agonist cicaprost increased cyclic adenosine monophosphate synthesis in spinal cultures from wild-type but not from IP-deficient mice (n = 5-10). The combination of fluorescence-resonance-energy transfer-based cyclic adenosine monophosphate imaging and calcium imaging showed a cicaprost-induced cyclic adenosine monophosphate synthesis in spinal cord neurons (n = 5-6). Fittingly, IP activation increased glutamate release from acute spinal cord sections of adult mice (n = 13-58). Cicaprost, but not agonists for EP2 and EP4, induced protein kinase A-dependent phosphorylation of the GluR1 subunit and its translocation to the membrane. Accordingly, intrathecal administration of the IP receptor antagonist Cay10441 had an antinociceptive effect (n = 8-11). CONCLUSION: Spinal prostacyclin synthesis during early inflammation causes the recruitment of GluR1 receptors to membrane fractions, thereby augmenting the onset of central sensitization.

Comparison of patient-reported outcomes of physical activity and accelerometry in people with multiple sclerosis and ambulatory impairment: A cross-sectional study.

BACKGROUND: Accelerometers and patient-reported outcomes (PRO) are used to assess physical activity (PA) in people with multiple sclerosis (pwMS). So far it is unknown, however, whether these assessments represent mobility limitations in pwMS with mild and moderate to severe disability alike. The primary aim of the study was to assess the correlation between accelerometry and International Physical Activity Questionnaire (IPAQ) scores in pwMS with different degrees of ambulatory impairment. Taken its frequent use into account, the Godin Leisure Time Exercise Questionnaire (GLTEQ) was investigated as additional PRO. METHODS: In a prospective cohort of pwMS, correlational analyses were performed between the number of daily steps, time spent in light, moderate to vigorous PA (MVPA) and time spent sitting as assessed using accelerometry (ActiGraph®-GT3X), and the respective IPAQ and GLTEQ scores. Additionally, associations of PA with disease-specific characteristics, aerobic capacity (VO2peak), walking assessments (Timed 25-Foot Walk, T25FW; 2-Minute Walk Test, 2MWT) and walking perception (Multiple Sclerosis Walking Scale-12; MSWS-12) were explored. Patient subgroups with mild (Expanded Disability Status Scale; EDSS score <4.0) and moderate to severe disability (EDSS ≥4.0) were analysed for the impact of ambulatory impairment on PA. Multiple linear regression was used to determine predictors of PA. RESULTS: A total of 56 pwMS completed the study, with a mean (standard deviation, SD) age of 48.4 (10.3) years, disease duration of 14.8 (9.6) years and median (interquartile range) EDSS score of 3.5 (2.0 - 4.4). Moderate to weak correlations were found between daily step count and IPAQ total metabolic equivalent (MET) minutes/week (p < 0.001; r = 0.506), MVPA MET-minutes/week (p < 0.01; r = 0.479) and walking MET-minutes/week (p < 0.05; r = 0.372) in the total cohort. Time spent sitting was inversely correlated with total MET-minutes/week and MVPA MET-minutes/week (p < 0.05; r = -0.358 and r = -0.365). Subgroup analysis revealed, that daily step count was significantly correlated with total MET-minutes/week, MVPA MET-minutes/week and walking MET-minutes/week (p < 0.01, r = 0.569; p < 0.01, r = 0.531 and p < 0.05, r = 0.480, respectively) in the "mild disability" subgroup only, whereas time spent sitting was inversely correlated with total MET-minutes/week (p < 0.05; r = -0.582) in the "moderate to severe disability" subgroup. There was no association between objectively assessed PA and GLTEQ scores in any group. In the total cohort, moderate to weak correlations were found between daily step count and walking assessments (T25FW: p < 0.01, ρ = -0.508; 2MWT: p < 0.01, ρ=0.463) and MSWS-12 (p < 0.001; ρ = -0.609). Moderate to weak correlations were also observed between VO2peak and walking assessments (T25FW: p < 0.01; ρ = -0.516; 2MWT: p < 0.01, ρ=0.480). Multiple linear regression analysis identified disability and VO2peak as predictors of PA (p = 0.045; ß=0.25 and p < 0.001; ß=0.49). CONCLUSION: Significant associations of objective PA measurements using accelerometry with IPAQ were found only in pwMS with "mild disability". In pwMS with "moderate to severe disability", IPAQ did not reflect the objectively assessed amount of PA. In our cohort, GLTEQ showed no association with objectively assessed PA. Thus, an MS-specific self-reported questionnaire for assessing PA is warranted.

Actual and imagined music-cued gait training for people with multiple sclerosis: a multicentre qualitative study.

OBJECTIVES: To explore the experiences and acceptability of music-cued motor imagery (MCMI), music-cued gait training (MCGT), and combined MCMI and MCGT (MCMI-MCGT) in people with multiple sclerosis (pwMS). We also aimed to explore participants' self-rated health status postintervention and gather recommendations for further programme development. DESIGN: Qualitative study alongside the double-blind randomised controlled real and imagined gait training with music-cueing (RIGMUC) multicentre trial of MCMI, MCGT and MCMI-MCGT. SETTING: PwMS recruited for the RIGMUC trial from Departments of Neurology at Medical Universities of Innsbruck and Graz and Clinic for Rehabilitation Muenster, Austria. PARTICIPANTS: All 132 pwMS with mild to moderate disability randomised into the trial were included in the analysis. METHODS: Participants practised home-based MCMI, MCGT or MCMI-MCGT for 30 min, 4×/week, for 4 weeks. Three trained researchers conducted weekly semistructured telephone interviews during the intervention period, supporting adherence, addressing problems, sharing experiences and assessing intervention acceptability. Follow-up interviews at 4-week postintervention aimed to understand participants' self-rated changes in walking, fatigue and overall health compared with their prestudy condition. Investigator triangulation was employed among the researchers to enhance trustworthiness and credibility. RESULTS: Using thematic analysis, we identified five themes: (1) empowerment, (2) remaining in sync, (3) interconnection between imagined and actual walking, (4) sustaining focus and (5) real-world transfer. Participants appreciated and found the imagined and actual MCGT innovative. Problems included concentration issues, early fatigue in advanced disability and difficulty synchronising with music cues. Positive changes in walking, fatigue and overall health postinterventions were reported offering valuable insights for programme development. CONCLUSIONS: A participatory study to codevelop a music-cued exercise programme for pwMS seems appropriate as participants appreciated the innovation and effectiveness of both imagined and actual MCGT. Future studies should also investigate pwMS' potential and limitations in enhancing their MCMI abilities with intensive therapist-supported practice. TRIAL REGISTRATION NUMBER: DRKS00023978.

Effects of activity-oriented physiotherapy with and without eye movement training on dynamic balance, functional mobility, and eye movements in patients with Parkinson's disease: An assessor-blinded randomised controlled pilot trial.

OBJECTIVES: To describe changes in balance, walking speed, functional mobility, and eye movements following an activity-oriented physiotherapy (AOPT) or its combination with eye movement training (AOPT-E) in patients with Parkinson's disease (PD). To explore the feasibility of a full-scale randomised controlled trial (RCT). METHODS: Using an assessor-blinded pilot RCT, 25 patients with PD were allocated to either AOPT or AOPT-E. Supervised interventions were performed 30 minutes, 4x/weekly, for 4 weeks, alongside inpatient rehabilitation. Outcomes were assessed at baseline and post-intervention, including dynamic balance, walking speed, functional and dual-task mobility, ability to safely balance, health-related quality of life (HRQoL), depression, and eye movements (number/duration of fixations) using a mobile eye tracker. Freezing of gait (FOG), and falls-related self-efficacy were assessed at baseline, post-intervention, and 4-week follow-up. Effect sizes of 0.10 were considered weak, 0.30 moderate, and ≥0.50 strong. Feasibility was assessed using predefined criteria: recruitment, retention and adherence rates, adverse events, falls, and post-intervention acceptability using qualitative interviews. RESULTS: Improvements were observed in dynamic balance (effect size r = 0.216-0.427), walking speed (r = 0.165), functional and dual-task mobility (r = 0.306-0.413), ability to safely balance (r = 0.247), HRQoL (r = 0.024-0.650), and depression (r = 0.403). Falls-related self-efficacy (r = 0.621) and FOG (r = 0.248) showed varied improvements, partly sustained at follow-up. Eye movement improvements were observed after AOPT-E only. Feasibility analysis revealed that recruitment was below target, with less than two patients recruited per month due to COVID-19 restrictions. Feasibility targets were met, with a retention rate of 96% (95% confidence interval [CI]: 77.68-99.79) and a 98.18% (95% CI: 96.12-99.20) adherence rate, exceeding the targets of 80% and 75%, respectively. One adverse event unrelated to the study intervention confirmed intervention safety, and interview data indicated high intervention acceptability. CONCLUSIONS: AOPT-E and AOPT appeared to be effective in patients with PD. Feasibility of a larger RCT was confirmed and is needed to validate results.

5,6-EET is released upon neuronal activity and induces mechanical pain hypersensitivity via TRPA1 on central afferent terminals.

Epoxyeicosatrienoic acids (EETs) are cytochrome P450-epoxygenase-derived metabolites of arachidonic acid that act as endogenous signaling molecules in multiple biological systems. Here we have investigated the specific contribution of 5,6-EET to transient receptor potential (TRP) channel activation in nociceptor neurons and its consequence for nociceptive processing. We found that, during capsaicin-induced nociception, 5,6-EET levels increased in dorsal root ganglia (DRGs) and the dorsal spinal cord, and 5,6-EET is released from activated sensory neurons in vitro. 5,6-EET potently induced a calcium flux (100 nm) in cultured DRG neurons that was completely abolished when TRPA1 was deleted or inhibited. In spinal cord slices, 5,6-EET dose dependently enhanced the frequency, but not the amplitude, of spontaneous EPSCs (sEPSCs) in lamina II neurons that also responded to mustard oil (allyl isothiocyanate), indicating a presynaptic action. Furthermore, 5,6-EET-induced enhancement of sEPSC frequency was abolished in TRPA1-null mice, suggesting that 5,6-EET presynaptically facilitated spinal cord synaptic transmission by TRPA1. Finally, in vivo intrathecal injection of 5,6-EET caused mechanical allodynia in wild-type but not TRPA1-null mice. We conclude that 5,6-EET is synthesized on the acute activation of nociceptors and can produce mechanical hypersensitivity via TRPA1 at central afferent terminals in the spinal cord.

Impaired glutamate recycling and GluN2B-mediated neuronal calcium overload in mice lacking TGF-ß1 in the CNS.

Transforming growth factor ß1 (TGF-ß1) is a pleiotropic cytokine expressed throughout the CNS. Previous studies demonstrated that TGF-ß1 contributes to maintain neuronal survival, but mechanistically this effect is not well understood. We generated a CNS-specific TGF-ß1-deficient mouse model to investigate the functional consequences of TGF-ß1-deficiency in the adult mouse brain. We found that depletion of TGF-ß1 in the CNS resulted in a loss of the astrocyte glutamate transporter (GluT) proteins GLT-1 (EAAT2) and GLAST (EAAT1) and decreased glutamate uptake in the mouse hippocampus. Treatment with TGF-ß1 induced the expression of GLAST and GLT-1 in cultured astrocytes and enhanced astroglial glutamate uptake. Similar to GLT-1-deficient mice, CNS-TGF-ß1-deficient mice had reduced brain weight and neuronal loss in the CA1 hippocampal region. CNS-TGF-ß1-deficient mice showed GluN2B-dependent aberrant synaptic plasticity in the CA1 area of the hippocampus similar to the glutamate transport inhibitor DL-TBOA and these mice were highly sensitive to excitotoxic injury. In addition, hippocampal neurons from TGF-ß1-deficient mice had elevated GluN2B-mediated calcium signals in response to extrasynaptic glutamate receptor stimulation, whereas cells treated with TGF-ß1 exhibited reduced GluN2B-mediated calcium signals. In summary, our study demonstrates a previously unrecognized function of TGF-ß1 in the CNS to control extracellular glutamate homeostasis and GluN2B-mediated calcium responses in the mouse hippocampus.

Enlarged colony housing promotes linear progression of subchondral bone remodeling in joint instability rat models.

Objective: Osteoarthritis (OA) is a disease with high prevalence and an unmet medical need for disease modifying treatments. In rat models, OA-like subchondral bone and cartilage changes can be induced by instability surgery with different severity levels. Factors which determine structural changes additionally comprise the study duration and activity-impacted joint loading. Methods: A medial meniscal tear (MMT) or anterior cruciate ligament transection with partial meniscectomy (ACLT+pMx) was induced unilaterally in rats housed in a rat colony cage (RCC), allowing high activity levels including jumping and stair climbing. In parallel, ACLT+pMx rats were housed in Type IV cages. The time course of OA-related changes was investigated at 4, 8, 12, and 16 weeks after surgery by micro-CT, gait analysis and joint diameter measurements. Results: Gait disturbance was observed after 2 weeks and to a similar extend in all models. The increase in ipsilateral joint diameters peaked after 2 weeks and were more pronounced after ACLT+pMx compared to MMT-surgery, but independent of housing. Micro-CT analysis revealed that increases in osseous tibial width were most distinct after ACLT+pMx in RCC and progressed continuously until week sixteen. In contrast, osseous tibial width of ipsilateral joints in MMT RCC and ACLT+pMx Type IV groups did not increase further after week twelve. In contralateral joints, this parameter was not affected, regardless of the model or caging. However, a significant increase in bone volume fraction and trabecular thickness was observed over time in the femur and tibia of both ipsilateral and contralateral knees. Here, the medial tibial compartment of the operated joint was most affected and linear changes were most pronounced in the ACLT+pMx RCC group. Conclusion: Increased movement of animals in colony cages leads to robust structural changes in subchondral bone after surgically induced joint instability over time, while in regular Type IV housing maximal changes are reached in week twelve. The new insights into the differentiation of the models, particularly with respect to the linear progression of bone changes in ACLT+pMx in the RCC, may be useful for the design of chronic OA-studies within a longer lifespan and therefore supporting the development of novel therapies.

R399E, A Mutated Form of Growth and Differentiation Factor 5, for Disease Modification of Osteoarthritis.

OBJECTIVE: To preclinically characterize a mutant form of growth and differentiation factor 5, R399E, with reduced osteogenic properties as a potential disease-modifying osteoarthritis (OA) drug. METHODS: Cartilage, synovium, and meniscus samples from patients with OA were used to evaluate anabolic and antiinflammatory properties of R399E. In the rabbit joint instability model, 65 rabbits underwent transection of the anterior cruciate ligament plus partial meniscectomy. Three intraarticular (IA) R399E doses were administered biweekly 6 times, and static incapacitance was determined to assess joint pain. OA was evaluated 13 weeks after surgery. In sheep, medial meniscus transection was performed to induce OA, dynamic weight bearing was measured in-life, and OA was assessed after 13 weeks. RESULTS: Intermittent exposure to R399E (1 week per month) was sufficient to induce cell proliferation and release of anabolic markers in 3-dimensional chondrocyte cultures. R399E also inhibited the release of interleukin-1ß (IL-1ß), IL-6, and prostaglandin E2 from cartilage with synovium, meniscal cell, and synoviocyte cultures. In rabbits, the mean difference (95% confidence interval [95% CI]) in weight bearing for R399E compared to vehicle was -5.8 (95% confidence interval [95% CI] -9.54, -2.15), -7.2 (95% CI -10.93, -3.54), and -7.7 (95% CI -11.49, -3.84) for the 0.6, 6, and 60 µg doses, respectively, 6 hours after the first IA injection, and was statistically significant through the entire study for all doses. Cartilage surface structure improved with the 6-µg dose. Structural and symptomatic improvement with the same dose was confirmed in the sheep model of OA. CONCLUSION: R399E influences several pathologic processes contributing to OA, highlighting its potential as a disease-modifying therapy.

Anti-inflammatory role of microsomal prostaglandin E synthase-1 in a model of neuroinflammation.

A major immunological response during neuroinflammation is the activation of microglia, which subsequently release proinflammatory mediators such as prostaglandin E(2) (PGE(2)). Besides its proinflammatory properties, cyclooxygenase-2 (COX-2)-derived PGE(2) has been shown to exhibit anti-inflammatory effects on innate immune responses. Here, we investigated the role of microsomal PGE(2) synthase-1 (mPGES-1), which is functionally coupled to COX-2, in immune responses using a model of lipopolysaccharide (LPS)-induced spinal neuroinflammation. Interestingly, we found that activation of E-prostanoid (EP)2 and EP4 receptors, but not EP1, EP3, PGI(2) receptor (IP), thromboxane A(2) receptor (TP), PGD(2) receptor (DP), and PGF(2) receptor (FP), efficiently blocked LPS-induced tumor necrosis factor α (TNFα) synthesis and COX-2 and mPGES-1 induction as well as prostaglandin synthesis in spinal cultures. In vivo, spinal EP2 receptors were up-regulated in microglia in response to intrathecally injected LPS. Accordingly, LPS priming reduced spinal synthesis of TNFα, interleukin 1ß (IL-1ß), and prostaglandins in response to a second intrathecal LPS injection. Importantly, this reduction was only seen in wild-type but not in mPGES-1-deficient mice. Furthermore, intrathecal application of EP2 and EP4 agonists as well as genetic deletion of EP2 significantly reduced spinal TNFα and IL-1ß synthesis in mPGES-1 knock-out mice after LPS priming. These data suggest that initial inflammation prepares the spinal cord for a negative feedback regulation by mPGES-1-derived PGE(2) followed by EP2 activation, which limits the synthesis of inflammatory mediators during chronic inflammation. Thus, our data suggest a role of mPGES-1-derived PGE(2) in resolution of neuroinflammation.

Magnetic resonance velocity mapping of 3D cerebrospinal fluid flow dynamics in hydrocephalus: preliminary results.

OBJECTIVES: To investigate the detectability of CSF flow alterations in the ventricular system of patients with hydrocephalus using time-resolved 3D MR velocity mapping. METHODS: MR velocity mapping was performed in 21 consecutive hydrocephalus patients and 21 age-matched volunteers using a 3D phase-contrast (PC) sequence. Velocity vectors and particle path lines were calculated for visualisation of flow dynamics. CSF flow was classified as "hypomotile flow" if it showed attenuated dynamics and as "hypermotile flow" if it showed increased dynamics compared with volunteers. Diagnostic efficacy was compared with routine 2D cine PC-MRI. RESULTS: Seven patients showed hypomotile CSF flow: six had non-communicating hydrocephalus due to aqueductal stenosis. One showed oscillating flow between the lateral ventricles after craniotomy for intracranial haemorrhage. Seven patients showed normal flow: six had hydrocephalus ex vacuo due to brain atrophy. One patient who underwent ventriculostomy 10 years ago showed a flow path through the opening. Seven patients showed hypermotile flow: three had normal pressure hydrocephalus, three had dementia, and in one the diagnosis remained unclear. The diagnostic efficacy of velocity mapping was significantly higher except for that of aqueductal stenosis. CONCLUSIONS: Our approach may be useful for diagnosis, therapy planning, and follow-up of different kinds of hydrocephalus.

Effects of actual and imagined music-cued gait training on motor functioning and brain activity in people with multiple sclerosis: protocol of a randomised parallel multicentre trial.

INTRODUCTION: Motor imagery (MI) refers to the mental rehearsal of a physical action without muscular activity. Our previous studies showed that MI combined with rhythmic-auditory cues improved walking, fatigue and quality of life (QoL) in people with multiple sclerosis (pwMS). Largest improvements were seen after music and verbally cued MI. It is unclear whether actual cued gait training achieves similar effects on walking as cued MI in pwMS. Furthermore, in pwMS it is unknown whether any of these interventions leads to changes in brain activation. The purpose of this study is therefore to compare the effects of imagined and actual cued gait training and a combination thereof on walking, brain activation patterns, fatigue, cognitive and emotional functioning in pwMS. METHODS AND ANALYSIS: A prospective double-blind randomised parallel multicentre trial will be conducted in 132 pwMS with mild to moderate disability. Randomised into three groups, participants will receive music, metronome and verbal cueing, plus MI of walking (1), MI combined with actual gait training (2) or actual gait training (3) for 30 min, 4× per week for 4 weeks. Supported by weekly phone calls, participants will practise at home, guided by recorded instructions. Primary endpoints will be walking speed (Timed 25-Foot Walk) and distance (2 min Walk Test). Secondary endpoints will be brain activation patterns, fatigue, QoL, MI ability, anxiety, depression, cognitive functioning, music-induced motivation-to-move, pleasure, arousal and self-efficacy. Data will be collected at baseline, postintervention and 3-month follow-up. MRI reference values will be generated using 15 matched healthy controls. ETHICS AND DISSEMINATION: This study follows the Standard Protocol Items: Recommendations for Interventional Trials-PRO Extension. Ethical approval was received from the Ethics Committees of the Medical Universities of Innsbruck (1347/2020) and Graz (33-056 ex 20/21), Austria. Results will be disseminated via national and international conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: DRKS00023978.

Phenotypic drug screen uncovers the metabolic GCH1/BH4 pathway as key regulator of EGFR/KRAS-mediated neuropathic pain and lung cancer.

Increased tetrahydrobiopterin (BH4) generated in injured sensory neurons contributes to increased pain sensitivity and its persistence. GTP cyclohydrolase 1 (GCH1) is the rate-limiting enzyme in the de novo BH4 synthetic pathway, and human single-nucleotide polymorphism studies, together with mouse genetic modeling, have demonstrated that decreased GCH1 leads to both reduced BH4 and pain. However, little is known about the regulation of Gch1 expression upon nerve injury and whether this could be modulated as an analgesic therapeutic intervention. We performed a phenotypic screen using about 1000 bioactive compounds, many of which are target-annotated FDA-approved drugs, for their effect on regulating Gch1 expression in rodent injured dorsal root ganglion neurons. From this approach, we uncovered relevant pathways that regulate Gch1 expression in sensory neurons. We report that EGFR/KRAS signaling triggers increased Gch1 expression and contributes to neuropathic pain; conversely, inhibiting EGFR suppressed GCH1 and BH4 and exerted analgesic effects, suggesting a molecular link between EGFR/KRAS and pain perception. We also show that GCH1/BH4 acts downstream of KRAS to drive lung cancer, identifying a potentially druggable pathway. Our screen shows that pharmacologic modulation of GCH1 expression and BH4 could be used to develop pharmacological treatments to alleviate pain and identified a critical role for EGFR-regulated GCH1/BH4 expression in neuropathic pain and cancer in rodents.

Soluble epoxide hydrolase limits mechanical hyperalgesia during inflammation.

BACKGROUND: Cytochrome-P450 (CYP450) epoxygenases metabolise arachidonic acid (AA) into four different biologically active epoxyeicosatrienoic acid (EET) regioisomers. Three of the EETs (i.e., 8,9-, 11,12- and 14,15-EET) are rapidly hydrolysed by the enzyme soluble epoxide hydrolase (sEH). Here, we investigated the role of sEH in nociceptive processing during peripheral inflammation. RESULTS: In dorsal root ganglia (DRG), we found that sEH is expressed in medium and large diameter neurofilament 200-positive neurons. Isolated DRG-neurons from sEH(-/-) mice showed higher EET and lower DHET levels. Upon AA stimulation, the largest changes in EET levels occurred in culture media, indicating both that cell associated EET concentrations quickly reach saturation and EET-hydrolyzing activity mostly effects extracellular EET signaling. In vivo, DRGs from sEH-deficient mice exhibited elevated 8,9-, 11,12- and 14,15-EET-levels. Interestingly, EET levels did not increase at the site of zymosan-induced inflammation. Cellular imaging experiments revealed direct calcium flux responses to 8,9-EET in a subpopulation of nociceptors. In addition, 8,9-EET sensitized AITC-induced calcium increases in DRG neurons and AITC-induced calcitonin gene related peptide (CGRP) release from sciatic nerve axons, indicating that 8,9-EET sensitizes TRPA1-expressing neurons, which are known to contribute to mechanical hyperalgesia. Supporting this, sEH(-/-) mice showed increased nociceptive responses to mechanical stimulation during zymosan-induced inflammation and 8,9-EET injection reduced mechanical thresholds in naive mice. CONCLUSION: Our results show that the sEH can regulate mechanical hyperalgesia during inflammation by inactivating 8,9-EET, which sensitizes TRPA1-expressing nociceptors. Therefore we suggest that influencing the CYP450 pathway, which is actually highly considered to treat cardiovascular diseases, may cause pain side effects.