Cognitive Impairments in Systemic Lupus Erythematosus

Abstract

Recent years have seen significant changes in our concepts of cognitive impairments (CI) and dementia. The older view was that these disorders were the inevitable fate of elderly and old people, though many studies have now been reported on the frequencies, types, and mechanisms of development of cognitive impairments at younger ages, which are usually associated with one disease or another, especially those affecting the CNS. These latter include cerebrovascular impairments (CVI). While most attention in this area used to be paid to stroke, more attention is now focused on non-stroke forms of acute CVI (aCVI). Furthermore, studies in this field have addressed autoimmune demyelinating diseases.One such autoimmune disease is systemic lupus erythematosus (SLE). This is one of the most widespread autoimmune diseases and has an incidence of 10-60 per 100,000 members of the population, with more women affected than men. Disease onset is generally at age 15-30 years, the course is chronic, and many organs and systems are affected (skin, joints, lungs, heart, etc.) [1,2]. More than two thirds of SLE patients have symptoms of nervous system lesions. The American College of Rheumatologists [40] has identified 19 syndromes of nervous system lesions. The neurological manifestations include aseptic meningitis, cerebrovascular disorders, demyelinating syndromes, headache, extrapyramidal disorders, epileptic seizures, and syndromes involving the peripheral nervous system.Changes in the mental domain consist primarily of cognitive dysfunctions. One-hour neuropsychological testing is recommended for detection of this condition, including assessment of verbal ability, attention, various types of memory, information processing speed, and psychomotor function. Ainiala et al.[3] performed a population study to detect mental disorders in SLE patients aged 16-65 years using enhanced neuropsychological testing. CI was detected in 81% of patients, which were quite severe in 38% of cases. In one recent study [32], the incidence of these impairments in SLE was 37-95%.However, the rather large spread in results should be noted -from 12% to 87% (see Table 1) [7,9,13,15,21,28]. The significant variation in the incidence of CI depends on the gender/age composition of the groups of SLE patients studied, the methods used, the patient cohort size, and the absence of a unified approach to diagnosis, especially in the earlier studies (some of these are included in Table 1).The severity of CI is very variable -from minimal dysfunction through to dementia [6,13,21,31,32,36]. Monastero et al. [34] noted significant deterioration of long-term and visual memory in 52.2% of cases and mild CI in half of all patients with SLE and CNS lesions as compared with 26.9% of SLE patients without these. Brey et al. [6] investigated 67 patients and found that 21% had no impairments, 43% had mild cognitive disorders, 30% had moderate cognitive disorders, and 6% had dementia, the most severe impairments affecting verbal and visual memory. It should be noted that mo...