The Role of Fatigue, Depression, and Other Clinical Factors in Determining Cognitive Status in Pediatric Multiple Sclerosis and Transverse Myelitis

Multiple sclerosis (MS) and transverse myelitis (TM) are immune-mediated demyelinating diseases of the central nervous system (CNS). MS is a chronic inflammatory disease that impacts both the brain and spinal cord; whereas, TM is a monophasic condition impacting only the spinal cord. Not surprisingly, cerebral involvement present in MS has precipitated research documenting deficits in cognition and problems related to fatigue and depression. Few studies have examined the prevalence of cognitive impairment or the role of fatigue and depression in cognitive functioning in pediatric patients with TM. Limited evidence suggests that both youth with MS and TM are at risk for adverse neuropsychological outcomes, less is known about underlying clinical factors that may influence cognitive functioning. Consequently, the objective of the present study was to explore the role of fatigue, depression, and disease-related clinical variables (physical functioning, age at onset, time since onset) in determining the cognitive status (i.e., impaired or not impaired) in youth with MS and TM. Sixty-seven pediatric MS and 53 pediatric idiopathic TM participants were administered a brief neuropsychological screening evaluation as part of routine clinical care. Analyses examining parent-proxy rating of fatigue and depression revealed no significant differences between MS and TM groups. Additionally, a logistic regression was conducted to evaluate the impact of a proposed linear combination of predictor variables in determining cognitive status (i.e., impaired or not impaired). Results revealed that none of the predictor variables were significant contributors to cognitive status. However, a stepwise logistic regression revealed that increased parent-proxy ratings of depression symptoms contributed to the likelihood that MS and TM participants were defined as cognitively impaired. Additionally, exploratory analyses revealed that youth with MS (42%) experience a significantly higher rate of cognitive impairment than youth with TM (21%). Analyses found that both youth with MS and TM were rated as having a greater number of fatigue symptoms than would be expected in healthy controls, though they were not more likely to be rated as having depression symptoms. Findings of the present study suggest that youth with MS and youth with TM should undergo routine screening of cognitive functioning, as well as fatigue and depression symptoms. Such routine screenings would not only assist with identification of problems, but also facilitate the creation and implementation of interventions to address them. Research would likely benefit from additional studies examining the influence of fatigue and depression symptoms on cognitive functioning in MS and TM, albeit with larger sample sizes and additional metrics for assessing cognition, fatigue, and depression symptoms.