Association between Cognitive Impairment and Olfactory Deficits in Systemic Lupus Erythematosus Without Major Neuropsychiatric Syndromes

Objective Cognitive impairment is a common neuropsychiatric manifestation of systemic lupus erythematosus (SLE). However, it is not routinely assessed despite its high morbidity and mortality. The aim of the study was to investigate the utility of a brief neuropsychological battery, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), to evaluate cognitive deficits in patients with SLE and to examine the relationship between cognitive and olfactory function. Methods Fifty-five SLE patients and 50 age- and sex-matched healthy control subjects were administered the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), a cognitive screening battery that evaluated five index of cognition including immediate memory (IMME), visuospatial/constructional (Vis/Con), language (LANG), attention (ATT), delayed memory (DEME). Olfactory functions were evaluated using olfactory function assessment by computerized testing including the three stages of smell: threshold (THR), identification (ID) and memory (ME) of the different odors. The disease activity and cumulative damage were assessed by the SLE Disease Activity Index 2000 (SLEDAI-2K) and the Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology(ACR) Damage Index (SDI). Results Patients with SLE exhibited significant lower total RBANS score, IMME, Vis/Con, ATT and DEME index scores than normal controls (P < 0.01 for all and P = 0.027 for attention). Performances on RBANS immediate memory, language, attention and total scores were correlated with education level of SLE patients. Reduced RBANS index and total scores were associated with several organ involvement and autoantibodies. SLE patients with higher SLEDAI-2K scores or with accumulated damage (SDI≥1) showed decreased RBANS scores than patients with lower SLEDAI-2K scores or without accumulated damage. All the olfactory scores (THR, ID and ME) in patients with SLE were significantly decreased than the control group (all P = 0.001). Patients had higher proportion of anosmia (8.57% vs 0%) and hyposmia (28.58% vs 5.72%) than controls (χ2 = 10.533, P = 0.015). Multivariable regression analysis revealed that olfactory threshold, identification and memory had a positive effect on RBANS index score. Olfactory memory and total score were significantly correlated with the RBANS delayed memory (r = 0.393, P = 0.021) and total scores (r = 0.429, P = 0.011).Conclusion The results of this study indicate that significantly correlated cognitive and olfactory functions are impaired in SLE patients. The RBANS is a potentially useful instrument for evaluating neuropsychological status in SLE. Physicians are encouraged to perform routine screening in patients with SLE to detect subtle cognitive dysfunction and strategize early treatment options.

Assessment of cognitive functions in patients with multiple sclerosis applying the normative values of the Rao’s brief repeatable battery in the Portuguese population

Background The Brief Repeatable Battery of Neuropsychological Tests (BRBN-T) is one of the most sensitive and used measures for detecting cognitive impairment in Multiple Sclerosis (MS). Objective The aim of this study was to adapt and validate this battery to the Portuguese population of MS patients. Methods The Portuguese version of the BRBN-T was applied to a stratified control national sample of 326 individuals considering sex, age, educational level and geographic location and also a clinical sample of 115 MS patients from several national hospitals. Through the exploration of its psychometrics properties, the Portuguese BRBN-T norms were produced. Results The normative data is presented as a regression-based formula to adjust test scores for gender, education and age, and the results reveal the BRBN-T has the ability to differentiate between MS patients and healthy participant’s cognitive performance. Conclusion This study demonstrated in our clinical population a good ability to detect cognitive impairment. Its clearly contributed to reinforcing the neuropsychological assessment in Portugal in patients with MS, by providing a new set of instruments, which can be used in the clinical practice, and in future studies. Moreover, it will allow a rigorous and precise support in relation to neuropsychological assessment for future longitudinal studies and clinical trials.