Individuals with multiple sclerosis (MS) commonly experience cognitive fatigue (CF), defined as a decrease in cognitive performance with sustained activity. Despite its known occurrence, CF in MS remains understudied. A study aimed to elucidate the extent to which depression, anxiety, information processing speed, and sleep quality predict subjective and objective CF in patients with MS. The results were published in Multiple Sclerosis and Related Disorders.

To conduct this study, researchers analyzed 53 patients with MS (approximately 70% women; mean age, 44). In the population of interest, the majority (88.7%) had relapsing MS. Objective CF was measured by the Paced Auditory Serial Addition Test (PASAT). Performance on the last third of the PASAT was compared to performance on the first third, a validated measurement of objective CF. The researchers measured subjective CF by the cognitive component of the Modified Fatigue Impact Scale (MFIS). Depression, anxiety, information processing speed, and sleep quality data was collected. All assessments took place on the same day. Pearson’s r was calculated to examine the relationship among all continuous outcome measures while linear regression analyses were used to examine predictors of subjective and objective CF.

The study did find a clinically significant evidence that objective CF and subjective CF were not significantly related (r=-0.16). Moreover, there was no statistically significant predictors of objective CF noted. In contrast, subjective CF demonstrated a statistically significant relationship with the Symbol Digit Modalities Test (r=- 0.29, P=0.05), Hospital Anxiety and Depression Scale (HADS) depression subscale (r=0.61, P<0.001), HADS anxiety subscale (r=0.54, P<0.001), and sleep quality (r=0.33, P=0.02). Additionally, all variables predicted subjective CF (P=0.0002). In particular, anxiety significantly predicted subjective CF when controlling for depression, information speed, and sleep quality.

“This study demonstrated that subjective CF is significantly predicted by anxiety, and strongly influenced by information processing impairment and depression,” the researchers concluded. “Addressing underlying affective factors, such as anxiety or depression, may help alleviate perceived or subjective CF among persons with MS, thus improving their function and quality of life.”



Keywords: echocardiography, pericardiectomy, pericarditis, constrictive, tricuspid valve