Cognitive impairment is highly prevalent in patients with systemic lupus erythematosus (SLE), a study from Canada finds. The research also addressed the validity of different screening tools for this difficulty in lupus, and found the Montreal Cognitive Assessment (MoCA) may be more suitable that others.
The study, “Performance of Screening Tests for Cognitive Impairment in Systemic Lupus Erythematosus,” appeared in the Journal of Rheumatology.
Zahi Touma,with the Lupus Clinic, Centre for Prognosis Studies in the Rheumatic Diseases, Toronto Western Hospital, was the study’s senior author. The team also included scientists from the University of Toronto and York University, also in Toronto.
Cognitive impairment is a common complication in lupus, affecting between 20 and 80 percent of patients. Early detection of may help patients adapt, and reduce its impact on their quality of life. However, no appropriate screening tools now exist to assess cognition in lupus patients, which delays diagnosis.
The gold standard recommended by the American College of Rheumatology to assess cognitive impairment in lupus — the ACR-SLE battery — represents a cost burden and is time-consuming. Among the cognitive deficits shown in lupus patients using this test, clinicians reported impairments in attention, learning and recall, verbal and nonverbal fluency, and psychomotor functions.
Other cognitive assessment tools have been used, like the Hopkins Verbal Learning Test-Revised (HVLT-R), a learning and memory test that assesses verbal learning, ability to access newly learned information, and retention. HVLT-R also evaluates delayed recall, which is further addressed by the Montreal Cognitive Assessment (MoCA), and the Mini Mental State Examination (MMSE). These two tests are used to detect mild cognitive impairment. In addition, the Perceived Deficits Questionnaire 5-Item (PDQ-5) assesses perceived faults in cognition from the patient’s perspective.
The study enrolled 98 adults to determine how common cognitive impairment was among lupus patients, using the MoCA, the MMSE, the HVLT-R and the PDQ-5. The researchers also aimed to define the link between patients’ cognitive function and their demographic, psychosocial, and clinical data.
The MoCA and MMSE tests were compared with the HVLT-R, with respect to sensitivity/specificity and predictive value. All participants underwent a test of intellectual ability and completed questionnaires regarding anxiety, depression, and perceived cognitive deficits.
Results showed that MoCA and HVLT-R detected cognitive impairment in 48% and 31% of lupus patients, respectively. MoCA was also seen to show greater sensitivity, but decreased specificity than the MMSE.
MoCA revealed that lupus patients had important difficulties in attention, language, and recall, which may substantially lower patients’ quality of life. “Objective evidence of such deficits with further diagnostic testing in patients with SLE may help treating physicians and other healthcare providers focus their efforts into these specific areas of CI [cognitive impairment],” the authors wrote.
While further tests are needed, the authors conclude that “MoCA can be the preferential screening test for an ambulatory clinic setting because it is available free in university settings.”
The analysis further showed that PDQ-5 was predictive of objective cognitive impairment. As perceived deficits can be disabling functionally, the authors advise that regardless of potential discrepancies with objective impairment, “PDQ-5 should be administered alongside cognitive screening assessment tools.”
Mild association with depression was also found. Longer disease duration and a higher level of education were inversely correlated with cognitive impairment. Specifically, a one-year increase in years of education decreased the probability of such impairment by 19%.
Future studies will focus on patients “who should be considered for further diagnostic cognitive testing,” the researchers said.