Within-person fluctuations of fatigue in patients with a clinical diagnosis of systemic sclerosis and its relationship with mood, pain, sleep and physical activity.

Objectives: To explore the within-person fluctuations of fatigue in systemic sclerosis and its association with negative affect, positive affect, pain, perceived exertion of physical activity and quality of sleep. Methods: We performed an ecological momentary assessment study in adult patients with a clinical diagnosis of systemic sclerosis. During 14 days, patients completed daily assessments of fatigue severity, negative affect, positive affect, pain, quality of sleep and perceived exertion of physical activity at four fixed time points. The day-to-day fluctuations in fatigue were quantified by the intra-individual variance and probability of acute change, capturing the magnitude and frequency of clinical relevant within-person day-to-day fluctuations, respectively. Using multilevel models, the within-person association between fatigue and the daily assessments were analysed. Results: Fifty-seven patients with systemic sclerosis participated. The mean (standard deviation) intra-individual variance was 1.08 (0.42) and the probability of acute change was mean (standard deviation) 0.40 (0.14), ranging from 0.08 to 0.77. For fatigue, a within-person variation of 51% was observed. Multilevel analyses showed that higher average levels and daily increases in negative affect, pain and perceived exertion of physical activity were associated with more fatigue, while the opposite was observed for positive affect and quality of sleep. Positive affect demonstrated the strongest association with fatigue fluctuations. Conclusion: This is the first quantitative study showing that fatigue in systemic sclerosis is characterized by a dynamic course and that approximately half of the day-to-day fluctuations within persons are clinically meaningful. Furthermore, our results indicate that integrating activities with positive impact on mood into fatigue treatment strategies might reduce the frequency of fatigue fluctuations.

Experiences of systemic sclerosis patients with home monitoring of their pulmonary function: a qualitative study.

Objective: To evaluate the experiences, perceived benefits and disadvantages of home monitoring of pulmonary function in SSc patients with interstitial lung disease (ILD). Methods: Semistructured interviews were conducted among SSc-ILD patients who used the home monitoring application of pulmonary function for at least 3 months. In our program, patients are instructed to perform home spirometry weekly at fixed time points using a mobile application with results being directly visible for patients and physicians. Audiotapes of the interviews were transcribed verbatim and analysed using inductive thematic analysis after performing a member check. Results: A total of 13 patients were interviewed, with a median age of 58 years (range 36-75) and a median experience with home monitoring of 12 months (range 3-12). We identified four major themes, including routine of telemonitoring, impact of telemonitoring, trust in telemonitoring and implementation in regular healthcare. Overall, patients found performing home spirometry to be feasible. Major perceived benefits of performing home spirometry are an increase in patient empowerment, better understanding of the disease course and a reduction in hospital visits, whereas identified disadvantages are an emotional burden of telemonitoring, heightened awareness of illness, doubts about its validity and the need for digital competencies. All patients expressed their willingness to continue, although some patients emphasized the need for face-to-face visits. Conclusion: Telemonitoring of pulmonary function is accepted by SSc-ILD patients with the perceived benefits outweighing the disadvantages. Adopting a patient-centred strategy that considers individual factors and addresses concerns proactively is warranted to successfully implement home spirometry.

Efficacy of methylprednisolone in very early systemic sclerosis: results of the "Hit hard and early'' randomized controlled trial.

OBJECTIVE: We hypothesized that glucocorticoids would induce remission in very early Systemic Sclerosis patients by inhibition of inflammation driving the disease. We examined the efficacy and safety of methylprednisolone in very early Systemic Sclerosis. METHODS: In this trial adults with puffy fingers for less than three years, specific auto-antibodies and meeting the Very Early Diagnosis of Systemic Sclerosis criteria were randomly assigned (2:1) to methylprednisolone 1000 mg intravenously or placebo for 3 consecutive days 3 times with monthly intervals. The primary end point was nailfold capillary density at week 12. Capillary density at 52 weeks, number of megacapillaries, and patient-reported outcomes were secondary outcomes. In addition, we assessed disease progression and lung function decline over 52 weeks. We used linear regression analyses adjusted for baseline values and stratification variables to estimate differences between groups. RESULTS: Between February 2017 and February 2021, 87 patients were screened, of whom 30 (70% female, median (IQR) age 52·9 (40·8-60·8) years, median (IQR) disease duration 11.4 (4.6-18.6) months) were randomly assigned to methylprednisolone (n = 21) or placebo (n = 9). We found no difference in nailfold capillary density at 12 weeks: -0.5 (95% CI 1.1, 0.2) nor in any of the secondary outcomes. Eleven (37%) patients showed disease progression during 1 year follow up, 7 (23%) patients had a relevant pulmonary function decline. No serious adverse events were reported. CONCLUSIONS: No clinically relevant effect of short-term methylprednisolone in patients with very early Systemic Sclerosis was observed. A substantial proportion of patients showed disease progression.

Neurons of the inferior olive respond to broad classes of sensory input while subject to homeostatic control.

KEY POINTS: Purkinje cells in the cerebellum integrate input from sensory organs with that from premotor centres. Purkinje cells use a variety of sensory inputs relaying information from the environment to modify motor control. Here we investigated to what extent the climbing fibre inputs to Purkinje cells signal mono- or multi-sensory information, and to what extent this signalling is subject to recent history of activity. We show that individual climbing fibres convey multiple types of sensory information, together providing a rich mosaic projection pattern of sensory signals across the cerebellar cortex. Moreover, firing probability of climbing fibres following sensory stimulation depends strongly on the recent history of activity, showing a tendency to homeostatic dampening. ABSTRACT: Cerebellar Purkinje cells integrate sensory information with motor efference copies to adapt movements to behavioural and environmental requirements. They produce complex spikes that are triggered by the activity of climbing fibres originating in neurons of the inferior olive. These complex spikes can shape the onset, amplitude and direction of movements and the adaptation of such movements to sensory feedback. Clusters of nearby inferior olive neurons project to parasagittally aligned stripes of Purkinje cells, referred to as 'microzones'. It is currently unclear to what extent individual Purkinje cells within a single microzone integrate climbing fibre inputs from multiple sources of different sensory origins, and to what extent sensory-evoked climbing fibre responses depend on the strength and recent history of activation. Here we imaged complex spike responses in cerebellar lobule crus 1 to various types of sensory stimulation in awake mice. We find that different sensory modalities and receptive fields have a mild, but consistent, tendency to converge on individual Purkinje cells, with climbing fibres showing some degree of input-specificity. Purkinje cells encoding the same stimulus show increased events with coherent complex spike firing and tend to lie close together. Moreover, whereas complex spike firing is only mildly affected by variations in stimulus strength, it depends strongly on the recent history of climbing fibre activity. Our data point towards a mechanism in the olivo-cerebellar system that regulates complex spike firing during mono- or multi-sensory stimulation around a relatively low set-point, highlighting an integrative coding scheme of complex spike firing under homeostatic control.

Potentiation of cerebellar Purkinje cells facilitates whisker reflex adaptation through increased simple spike activity.

Cerebellar plasticity underlies motor learning. However, how the cerebellum operates to enable learned changes in motor output is largely unknown. We developed a sensory-driven adaptation protocol for reflexive whisker protraction and recorded Purkinje cell activity from crus 1 and 2 of awake mice. Before training, simple spikes of individual Purkinje cells correlated during reflexive protraction with the whisker position without lead or lag. After training, simple spikes and whisker protractions were both enhanced with the spiking activity now leading behavioral responses. Neuronal and behavioral changes did not occur in two cell-specific mouse models with impaired long-term potentiation at their parallel fiber to Purkinje cell synapses. Consistent with cerebellar plasticity rules, increased simple spike activity was prominent in cells with low complex spike response probability. Thus, potentiation at parallel fiber to Purkinje cell synapses may contribute to reflex adaptation and enable expression of cerebellar learning through increases in simple spike activity.