Isokinetic and electromyographic characterization of ankle plantarflexors' hypertonia in people with multiple sclerosis.

BACKGROUND: This study aimed at quantifying ankle plantarflexors' resistance to passive motion (RPM) by isokinetic dynamometry and muscle activity through surface electromyography (sEMG) in persons with multiple sclerosis (PwMS) with limb stiffness and spasticity. METHODS: Slow and fast ankle dorsiflexions (from 5°/s to 210°/s) were imparted passively by an isokinetic dynamometer, and sEMG activity of plantarflexors was recorded at the same time as the square root of the moving average. Based on RPM evaluated at 5°/s, ankles were classified as more- and less-resistant as measured by average peak torque (APT). RESULTS: Measurements were obtained bilaterally from 24 PwMS (median EDSS: 5.5) with median Modified Ashworth Scale (MAS) score of 1.75. Compared to the lowest velocity inducing EMG-evident responses (120°/s), RPM increased significantly at 180°/s (+137.8 %; p < 0.0005) and 210°/s (+85.3 %; p < 0.0005) in the less-resistant side, and only at 210°/s (+113.8 %; p < 0.0005) in the more-resistant side. sEMG activity increased significantly and similarly between limbs at increasing velocities. Significant velocity-dependent increases were detected in both limbs, with no difference by side, at 180°/s (+34.5 %; p = 0.005) and 210°/s (+48.4 %; p = 0.004). Regression analyses confirmed side (ß=0.542; p < 0.0001) and speed (ß=0.238; p < 0.0001) as significant predictors of APT change, but only speed for sEMG (speed: ß=0.215; p = 0.019; side: ß=0.012; p = 0.893). Bivariate correlations revealed that RPM was associated negatively with MAS and positively with sEMG. CONCLUSION: Spasticity presented bilaterally in PwMS, with different mixed pictures of passive and reflex stiffness, both requiring attention. Combining isokinetics and sEMG allows detecting even subtle, subclinical alterations that can prompt and drive early tailored management.

A set of circulating microRNAs belonging to the 14q32 chromosome locus identifies two subgroups of individuals with recent-onset type 1 diabetes.

Circulating microRNAs (miRNAs) are linked to the onset and progression of type 1 diabetes mellitus (T1DM), thus representing potential disease biomarkers. In this study, we employed a multiplatform sequencing approach to analyze circulating miRNAs in an extended cohort of prospectively evaluated recent-onset T1DM individuals from the INNODIA consortium. Our findings reveal that a set of miRNAs located within T1DM susceptibility chromosomal locus 14q32 distinguishes two subgroups of individuals. To validate our results, we conducted additional analyses on a second cohort of T1DM individuals, confirming the identification of these subgroups, which we have named cluster A and cluster B. Remarkably, cluster B T1DM individuals, who exhibit increased expression of a set of 14q32 miRNAs, show better glycemic control and display a different blood immunomics profile. Our findings suggest that this set of circulating miRNAs can identify two different T1DM subgroups with distinct blood immunomics at baseline and clinical outcomes during follow-up.

Pancreatic beta-cell IL-22 receptor deficiency induces age-dependent dysregulation of insulin biosynthesis and systemic glucose homeostasis.

The IL-22RA1 receptor is highly expressed in the pancreas, and exogenous IL-22 has been shown to reduce endoplasmic reticulum and oxidative stress in human pancreatic islets and promote secretion of high-quality insulin from beta-cells. However, the endogenous role of IL-22RA1 signaling on these cells remains unclear. Here, we show that antibody neutralisation of IL-22RA1 in cultured human islets leads to impaired insulin quality and increased cellular stress. Through the generation of mice lacking IL-22ra1 specifically on pancreatic alpha- or beta-cells, we demonstrate that ablation of murine beta-cell IL-22ra1 leads to similar decreases in insulin secretion, quality and islet regeneration, whilst increasing islet cellular stress, inflammation and MHC II expression. These changes in insulin secretion led to impaired glucose tolerance, a finding more pronounced in female animals compared to males. Our findings attribute a regulatory role for endogenous pancreatic beta-cell IL-22ra1 in insulin secretion, islet regeneration, inflammation/cellular stress and appropriate systemic metabolic regulation.

Angiotensin I-converting enzyme type 2 expression is increased in pancreatic islets of type 2 diabetic donors.

AIMS: Angiotensin I-converting enzyme type 2 (ACE2), a pivotal SARS-CoV-2 receptor, has been shown to be expressed in multiple cells, including human pancreatic beta-cells. A putative bidirectional relationship between SARS-CoV-2 infection and diabetes has been suggested, confirming the hypothesis that viral infection in beta-cells may lead to new-onset diabetes or worse glycometabolic control in diabetic patients. However, whether ACE2 expression levels are altered in beta-cells of diabetic patients has not yet been investigated. Here, we aimed to elucidate the in situ expression pattern of ACE2 in Type 2 diabetes (T2D) with respect to non-diabetic donors which may account for a higher susceptibility to SARS-CoV-2 infection in beta-cells. MATERIAL AND METHODS: Angiotensin I-converting enzyme type 2 immunofluorescence analysis using two antibodies alongside insulin staining was performed on formalin-fixed paraffin embedded pancreatic sections obtained from n = 20 T2D and n = 20 non-diabetic (ND) multiorgan donors. Intensity and colocalisation analyses were performed on a total of 1082 pancreatic islets. Macrophage detection was performed using anti-CD68 immunohistochemistry on serial sections from the same donors. RESULTS: Using two different antibodies, ACE2 expression was confirmed in beta-cells and in pancreas microvasculature. Angiotensin I-converting enzyme type 2 expression was increased in pancreatic islets of T2D donors in comparison to ND controls alongside with a higher colocalisation rate between ACE2 and insulin using both anti-ACE2 antibodies. CD68+ cells tended to be increased in T2D pancreata, in line with higher ACE2 expression observed in serial sections. CONCLUSIONS: Higher ACE2 expression in T2D islets might increase their susceptibility to SARS-CoV-2 infection during COVID-19 in T2D patients, thus worsening glycometabolic outcomes and disease severity.

Intra-islet insulin synthesis defects are associated with endoplasmic reticulum stress and loss of beta cell identity in human diabetes.

AIMS/HYPOTHESIS: Endoplasmic reticulum (ER) stress and beta cell dedifferentiation both play leading roles in impaired insulin secretion in overt type 2 diabetes. Whether and how these factors are related in the natural history of the disease remains, however, unclear. METHODS: In this study, we analysed pancreas biopsies from a cohort of metabolically characterised living donors to identify defects in in situ insulin synthesis and intra-islet expression of ER stress and beta cell phenotype markers. RESULTS: We provide evidence that in situ altered insulin processing is closely connected to in vivo worsening of beta cell function. Further, activation of ER stress genes reflects the alteration of insulin processing in situ. Using a combination of 17 different markers, we characterised individual pancreatic islets from normal glucose tolerant, impaired glucose tolerant and type 2 diabetic participants and reconstructed disease progression. CONCLUSIONS/INTERPRETATION: Our study suggests that increased beta cell workload is accompanied by a progressive increase in ER stress with defects in insulin synthesis and loss of beta cell identity.

Isokinetic Resistance Training for Ankle Plantarflexor Spasticity and Muscle Weakness in People With Multiple Sclerosis: A Proof-of-Concept Case Series.

OBJECTIVE: To the best of the authors' knowledge, no data are available about the use of isokinetic resistance training for managing ankle plantarflexor spastic hypertonia in people with multiple sclerosis (MS). The aim of this proof-of-concept study was to explore the feasibility and effects of concentric contractions on spasticity-related resistance to passive motion, strength, and mobility in people with MS and ankle plantarflexor spasticity. METHODS: In this pretest/posttest case series, 5 people with MS (mean age = 53.6 [SD = 8.8] years; median Expanded Disability Status Scale score = 5; Modified Ashworth Scale range = 1-4) received 6 weeks of isokinetic resistance training of the spastic plantarflexors. Before and after the intervention, the following outcomes were assessed: average peak torque during passive robotic mobilization, isometric strength, surface electromyography (sEMG) from the spastic muscles, time to complete the 10-m Walk Test, and the Timed "Up & Go" Test. The standardized effect size was used to test pretest and posttest effects at the individual level. Group-level analyses were also performed. RESULTS: Following the training, the average peak torque recorded from the plantarflexors during passive motion at a velocity of 150 degrees per second was found to be decreased by at least 1 SD in all participants but 1, with a significant reduction at the group level of 23.8%. Conversely, no changes in sEMG activity were detected. Group-level analyses revealed that the maximal strength of the trained plantarflexors increased significantly (31.4%). Fast walking speed increased and time to complete the Timed "Up & Go" Test decreased in 4 participants, although not significantly at the group level. CONCLUSION: Isokinetic resistance training proved safe and feasible in people who had MS and ankle plantarflexor spasticity. The observed reductions in resistance to passive motion from the spastic plantarflexors in the absence of sEMG changes might suggest a mechanical rather than a neural effect of the training. IMPACT: Based on these preliminary findings, isokinetic resistance training does not exacerbate hypertonia in people with MS and ankle plantarflexor spasticity and could be safely used to manage muscle weakness in this population.

Increased Expression of Viral Sensor MDA5 in Pancreatic Islets and in Hormone-Negative Endocrine Cells in Recent Onset Type 1 Diabetic Donors.

The interaction between genetic and environmental factors determines the development of type 1 diabetes (T1D). Some viruses are capable of infecting and damaging pancreatic ß-cells, whose antiviral response could be modulated by specific viral RNA receptors and sensors such as melanoma differentiation associated gene 5 (MDA5), encoded by the IFIH1 gene. MDA5 has been shown to be involved in pro-inflammatory and immunoregulatory outcomes, thus determining the response of pancreatic islets to viral infections. Although the function of MDA5 has been previously well explored, a detailed immunohistochemical characterization of MDA5 in pancreatic tissues of nondiabetic and T1D donors is still missing. In the present study, we used multiplex immunofluorescence imaging analysis to characterize MDA5 expression and distribution in pancreatic tissues obtained from 22 organ donors (10 nondiabetic autoantibody-negative, 2 nondiabetic autoantibody-positive, 8 recent-onset, and 2 long-standing T1D). In nondiabetic control donors, MDA5 was expressed both in α- and ß-cells. The colocalization rate imaging analysis showed that MDA5 was preferentially expressed in α-cells. In T1D donors, we observed an increased colocalization rate of MDA5-glucagon with respect to MDA5-insulin in comparison to nondiabetic controls; such increase was more pronounced in recent-onset with respect to long-standing T1D donors. Of note, an increased colocalization rate of MDA5-glucagon was found in insulin-deficient-islets (IDIs) with respect to insulin-containing-islets (ICIs). Strikingly, we detected the presence of MDA5-positive/hormone-negative endocrine islet-like clusters in T1D donors, presumably due to dedifferentiation or neogenesis phenomena. These clusters were identified exclusively in donors with recent disease onset and not in autoantibody-positive nondiabetic donors or donors with long-standing T1D. In conclusion, we showed that MDA5 is preferentially expressed in α-cells, and its expression is increased in recent-onset T1D donors. Finally, we observed that MDA5 may also characterize the phenotype of dedifferentiated or newly forming islet cells, thus opening to novel roles for MDA5 in pancreatic endocrine cells.

Energy Expenditure and Oxygen Consumption During Activities of Daily Living in People With Multiple Sclerosis and Healthy Subjects: An Ecological Approach to Estimate Real-Life Fatigue and Fatigability.

OBJECTIVE: To compare oxygen consumption and energy expenditure (EE) of the activities of daily living (ADL) in people with multiple sclerosis (PwMS) and healthy subjects. DESIGN: Cross-sectional observational study. SETTING: Outpatient care facilities. PARTICIPANTS: Twenty-four moderately impaired PwMS and 21 healthy controls (N=45). INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Oxygen consumption, EE rate, and total EE assessed by portable open-circuit spirometry during the accomplishment of a comprehensive set of 14 ADL. Body composition was also assessed with bioelectrical impedance analysis. Body cell mass was used to normalize metabolic rates between groups. RESULTS: PwMS exhibited significantly higher oxygen consumption than controls in transfer and mobility tasks (walking with stairs: +10.4%, P=.04; without stairs: +15.2%, P=.002; driving: +10.4%, P=.04) and higher EE rates for walking (+13.6%, P=.01). ADL completion took significantly longer in PwMS. Consequently, when total EE to complete each ADL was considered, PwMS used significantly more energy in 10 of the 14 ADL. Of these, "climb stairs" and walking with or without stairs showed the largest differences (+100%, +99.5%, +79.3%, respectively; all P values<.0005), followed by "dressing" (+48.8%; P=.002), "laundry" (+41.7%; P=.007), and "shopping" (+40.1%; P=.003). CONCLUSIONS: Moderately disabled PwMS display oxygen consumption and EE rates during ADL that are comparable to those of matched healthy subjects, except for the activities that involve walking. Although metabolic rates were not different for the majority of ADL, PwMS showed higher total EE to complete the same activities at a comparable work intensity, which may contribute to the burden of "real-life" tiredness and fatigue typically described in this population. Importantly, the subjective Modified Fatigue Impact Scale score significantly correlated to EE and oxygen consumption of selected ADL, such as "make a bed," "driving," "clean surfaces," and "climb stairs." The joint employment of open-circuit spirometry during ADL and body composition analysis allows an accurate metabolic characterization of PwMS, who frequently complain of fatigue.

Contralateral Strength Training as Preparation for Direct Strength Training in a Patient With Unilateral Foot-Drop Because of Multiple Sclerosis: A Case Report.

OBJECTIVE: Direct strength training (DST) is effective in managing unilateral weakness in people with multiple sclerosis (MS). Its feasibility, however, is considerably reduced if one limb is too compromised to train. In this case, contralateral strength training (CST) of the unaffected side to induce a strength transfer to the untrained homologous muscles can help to establish a strength baseline in the weaker limb, eventually allowing direct training. Limited effects for CST, however, have been reported on patient functioning. We tested the effects on dynamometric, electromyographic, and functional outcomes of a sequential combination of CST and DST of the ankle dorsiflexors in a case of MS-related foot-drop. METHODS: A 56-year-old man diagnosed with relapsing-remitting MS exhibited severe weakness of the right dorsiflexors impairing functional dorsiflexion. The intervention consisted of a 6-week CST of the unaffected dorsiflexors followed by 2 consecutive 6-week DST cycles targeting the weaker dorsiflexors. RESULTS: At baseline, the participant could not dorsiflex his right ankle but could do so after CST. Maximal strength of the affected dorsiflexors increased by 80% following CST, by 31.1% following DST-1, and by a further 44.6% after DST-2. Neuromuscular recruitment was found progressively increased, with the largest changes occurring after DST-1. Improvements in mobility and walking speed were also detected, although plantar flexors' spasticity on the Modified Ashworth Scale increased from 1+ to 2. CONCLUSION: In this case, the sequential combination of CST and DST proved a feasible approach to manage severe unilateral weakness in a patient who was not able, at least initially, to dorsiflex his weaker ankle. In this perspective, CST may prime a minimum gain in strength necessary to allow subsequent direct training.

Effect of Eccentric Strength Training on Elbow Flexor Spasticity and Muscle Weakness in People With Multiple Sclerosis: Proof-of-Concept Single-System Case Series.

OBJECTIVE: To date, no attention has been devoted to the employment of eccentric contractions to manage spasticity in multiple sclerosis. This single-system case series aimed to explore the effects of eccentric training on spasticity-related resistance to passive motion in people with multiple sclerosis with elbow flexor spasticity. METHODS: Six people with multiple sclerosis (median Expanded Disability Status Scale score = 4.8, range = 2.0-5.5; Modified Ashworth Scale [MAS] score ≤ 3) underwent a 6-week eccentric strength training of the spastic muscles. Before and after the intervention, the following outcomes were assessed: resistive peak torque (RPT), isometric strength, resting limb position, passive range of motion and active range of motion, severity of hypertonia by MAS, and numerical rating scale. At baseline, the primary outcome (RPT) was tested over 3 time points to ensure a stable measurement. The 2-SD method was used to test pre-post training effects at individual level. Group-level analyses were also performed. RESULTS: Following the intervention RPT decreased by at least 2 SDs in all participants but 1, with a significant reduction at group level of 41.6 (29.6)%. Four people with multiple sclerosis reported a reduction in perceived spasticity severity. No changes in MAS score were detected. Group-level analyses revealed that maximal strength increased significantly in the trained elbow flexors (+30.9 [9.1]%). Elbow flexion at rest was found to be significantly reduced (-35.5 [12.4]%), whereas passive range of motion (+4.6%) and active range of motion (+11.8%) significantly increased. CONCLUSION: Eccentric training is feasible and safe to manage spasticity in people with multiple sclerosis. Preliminary data showed that this protocol can reduce resistance to passive motion, also improving strength, spasticity-free range of motion, and limb positioning. IMPACT: Patients with multiple sclerosis-related spasticity and moderate-to-severe disability can benefit from adding slow submaximal eccentric contractions to the conventional management of spasticity.

SCORS-G and Card Pull Effect of TAT Stories: A Study With a Nonclinical Sample of Children.

Previous research has shown that stimulus pull is one of the contributory factors influencing Thematic Apperception Test (TAT) responses. In recent years, there has been a resurgence of studies examining this. In particular, the Social Cognition and Object Relations Scale-Global Rating Method (SCORS-G) has been employed to examine stimulus pull in adult clinical and nonclinical samples. The present study is the first attempt to examine this issue in a nonclinical sample of children. Ninety-eight children from Italian elementary (1st to 5th grade) and middle (6th to 8th grade) schools provided narratives to six TAT cards (1, 2, 3BM, 4, 8BM, and 16). Some important findings with regard to variance within scales replicate prior findings from other studies. Furthermore, some findings regarding the specific nature of pull for particular TAT cards (1, 2, 3BM, and 4) replicate prior work. Given that Cards 8BM and 16's SCORS-G stimulus properties have not been previously studied, the pull of these cards is explored. Last, SCORS-G differences/similarities across these two age groups are highlighted. Suggestions for further research in this field are also provided, particularly concerning the use of SCORS-G and TAT for clinical assessment.

Dance therapy improves motor and cognitive functions in patients with Parkinson's disease.

OBJECTIVE: To explore the effects of Dance Therapy (DT) and Traditional Rehabilitation (TR) on both motor and cognitive domains in Parkinson's Disease patients (PD) with postural instability. METHODS: Sixteen PD patients with recent history of falls were divided in two groups (Dance Therapy, DT and Traditional Rehabilitation, TR); nine patients received 1-hour DT classes twice per week, completing 20 lessons within 10 weeks; seven patients received a similar cycle of 20 group sessions of 60 minutes TR. Motor (Berg Balance Scale - BBS, Gait Dynamic Index - GDI, Timed Up and Go Test - TUG, 4 Square-Step Test - 4SST, 6-Minute Walking Test - 6MWT) and cognitive measures (Frontal Assessment Battery - FAB, Trail Making Test A & B - TMT A&B, Stroop Test) were tested at baseline, after the treatment completion and after 8-week follow-up. RESULTS: In the DT group, but not in the TR group, motor and cognitive outcomes significantly improved after treatment and retained after follow-up. Significant changes were found for 6MWT (p = 0.028), TUG (p = 0.007), TMT-A (p = 0.014) and TMT-B (p = 0.036). CONCLUSIONS: DT is an unconventional physical therapy for PD patients which effectively impacts on motor (endurance and risk of falls) and non-motor functions (executive functions).

Origin of sound-evoked EMG responses in human masseter muscles.

Sound is a natural stimulus for both cochlear and saccular receptors. At high intensities it evokes in active masseter muscles of healthy subjects two overlapping reflexes: p11/n15 and p16/n21 waves, whose origin has not yet been demonstrated. Our purpose was to test which receptor in the inner ear is responsible for these reflexes. We compared masseter EMG responses induced in normal subjects (n = 9) by loud clicks (70-100 dB normal hearing level (NHL), 0.1 ms, 3 Hz) to those evoked in subjects with a selective lesion of the cochlea (n = 5), of the vestibule (n = 1) or with mixed cochlear-vestibular failure (n = 5). In controls, 100 dB clicks induced bilaterally, in the unrectified mean EMG (unrEMG), a clear p11 wave followed by a less clear n15 wave and a subsequent n21 wave. Lowering the intensity to 70 dB clicks abolished the p11/n15 wave, while a p16 wave appeared. Rectified mean EMG (rectEMG) showed, at all intensities, an inhibitory deflection corresponding to the p16/n21 wave in the unrEMG. Compared to controls, all deaf subjects had a normal p11 wave, together with more prominent n15 wave; however, the p16/n21 waves, and their corresponding inhibition in the rectEMG, were absent. The vestibular patient had bilaterally clear p11 waves only when 100 dB clicks were delivered bilaterally or to the unaffected ear. Stimulation of the affected ear induced only p16/n21 waves. Data from mixed patients were consistent with those of deaf and vestibular patients. We conclude that click-induced masseter p11/n15 waves are vestibular dependent, while p16/n21 waves depend on cochlear integrity.

Long lasting effects of transcranial direct current stimulation on motor imagery.

Transcranial magnetic stimulation (TMS) was employed to probe the modulatory effects of transcranial direct current stimulation of motor cortex on motor evoked responses (MEPs) produced during motor imagery. MEP amplitudes at rest and during motor imagery were assessed before and for a period of 60 min after transcranial direct current stimulation (tDCS) applied over the primary motor cortex at 1 mA for 5 min. Cathodal stimulation induced a decrease of about 30% of MEP amplitude at rest and a 50% reduction of MEP size during imagery. Ten minutes after tDCS, MEPs at rest returned to baseline values while MEPs during motor imagery were suppressed for up to 30 min. No changes in MEP amplitude during imagery were found after anodal stimulation. tDCS could represent a powerful tool to modulate the excitability of motor areas involved in mental practice and motor imagery.