Neuropsychological impairment in auto-immune disease

Estimations of the prevalence of central nervous system involvement in patients with systemic lupus erythematosus (SLE) vary from 25 to 75%. In order to assess possible deficits in memory, attention, and/or reaction time, a battery of neuropsychological tests was administered to 15 patients with SLE and to two matched groups of control subjects; eight patients on corticosteroids and 15 healthy controls. The test battery included the Multiple Choice Word Fluency Test (MWT-B), Benton Visual Memory Scale, Syndrome Short Test (SKT; attention and memory), Attention and Concentration Test (d2), Wechsler Adult Intelligence Scale (WAIS) subtests for Comprehension, Digit Span, Block Design, a Computer Controlled Reaction Time task (CCRT), and a Learning and Memory Test (LGT-3). Results revealed a statistically significant short-term memory deficit (for all six relevant subtests used) and a marked delayed simple reaction time in SLE patients as compared with scores in healthy subjects. An attention deficit as well as the expected difference between the estimated premorbid and actual level of intelligence could not be demonstrated. With three exceptions (SKT-9 figural recognition, Benton Visual Memory, and LGT-3 figural recognition), patients treated with corticosteroids did not differ from healthy controls. They also did not differ from SLE patients in any of the parameters tested. It therefore appears that the demonstrated deficit in short-term memory and reaction time in SLE patients may not only be due to the neuropsychiatric manifestation of SLE but possibly also result from medication side-effects.