Fatigue in patients with primary Sjogren’s syndrome

Fatigue in patients with primary Sjögren's syndrome can be explained by force decline during a fatiguing task, muscle activation, mood, and the serum levels of proinflammatory cytokines.

Patients with primary Sjögren's syndrome will show attenuated task-related cortical activation compared to control subjects and/or an attenuated increase in activation of effort-related areas.

The study comprises two sessions lasting approximately two hours. The first session takes place at the department of neuroscience. Subjects perform 3 motor tasks during which they have to produce force with their index fingers (FDI muscle). The ulnar nerve is activated using electrical stimulation to determine the muscle activation.



The second session takes place at the neuroimaging center to repeat the motor tasks in the MR-scanner. Changes in cortical activation during the tasks are measured using a 3T MR-scanner. Muscle force is measured using MR-compatible force transducers, and muscle activation is measured by stimulating the ulnar nerve with MR-compatible surface electrodes.



During the study, subjects are asked to fill out six questionnaires*. For the serum levels of proinflammatory cytokines, data from a cohort study will be used and no additional material needs to be collected from pSS patients.



* Fatigue: Fatigue Severity Scale, Modified Fatigue Impact Scale, Multidimensional Fatigue Inventory. Mood: Hospital Anxiety and Depression Scale. Disease activity: EULAR Sjögren’s Syndrome Patient Reported Index, patient acceptable symptom state.

Fatigue protocol