Abstract / Summary
Abstract Background Fatigue and fatigability are common symptoms in people with neurological conditions, but their real-time assessment remains methodologically challenging. This systematic review aims to summarize definitions, assessment methods, and reported associations with other factors for state fatigue and fatigability in neurological conditions, with a focus on real-time assessment. Methods A systematic literature search was conducted from five databases for studies published from inception to 21 January 2025. The included studies involved adults with neurological conditions and real-time assessments of state fatigue or fatigability. Results A total of 41 studies met the inclusion criteria, comprising 1,610 participants with multiple sclerosis (MS), stroke, Parkinson’s disease, spinal cord injury, and neuropathy. The majority of the studies included participants with MS (70%) and stroke (13%). Thirty-five studies reported state fatigue, four reported fatigability, and two reported both. State fatigue was assessed using an ecological momentary assessment or a simple fatigue diary, typically over 7- or 14-day periods with six measurements per day at random intervals delivered via smartphone applications. Fatigue questions were mostly aligned using a single item on a numeric rating scale (0–10). State fatigue showed within-day variation, generally worsening toward the afternoon or evening compared with the morning. State fatigue was associated with increased pain, stress, cognitive deficits, negative mood, and reduced social interactions. The overall compliance rate was 81%, and the retention rate was 90% in state fatigue studies. Fatigability was assessed less frequently, primarily through declines in motor performance for upper extremity function using tapping or pinching tasks. Conclusions Real-time assessments seem to be a promising complementary approach for assessing state fatigue, with the most robust finding relating to within-day variations in MS and stroke. Real-time assessments are still a relatively new method for capturing fatigability in the context of participants’ daily lives. Future studies are encouraged to build more evidence on real-time assessments, especially in fatigability.