Multimodal electroneurophysiological studies of systemic lupus erythematosus

The purpose of this study was to obtain electrophysiological documentation of possible involvement of central and peripheral nervous system (CNS and PNS) in systemic lupus erythematosus (SLE) patients even in the absence of neurological manifestations. The study included 30 consecutive patients with SLE and 25 age- and sex-matched volunteers as a control group. They were subjected to neurological and rheumatological tests and an extensive battery of neurophysiological tests, besides Wechsler adult intelligence scale. Overt neurological manifestations were observed in 14 patients (46.7%). Neurophysiological data revealed that 25 patients (83%) had at least 2 abnormal tests; 11 (68.8%) patients of the asymptomatic group and 14 patients (100%) of the symptomatic group with no significant differences between them. Seventeen patients (56.7%) had evidence of PNS dysfunction either in nerves (46.7%) or muscles (10%); 7 of them in the asymptomatic group. Twenty-four patients (80%) had evidence of CNS dysfunction. Twenty-two patients (73%) had abnormalities recorded on electroencephalography; 9 patients in the asymptomatic group and 13 patients in the symptomatic group. Eleven patients (37%) had abnormal values of P100 of visual evoked potential; 5 patients in the asymptomatic group and 6 in the symptomatic group. Eight patients (26.7%) had abnormal latency of wave I of brain stem response; 3 of them in the asymptomatic group. Abnormal prolongation of the P300 component of event-related potentials was recorded in 2 patients (12.5%) of the asymptomatic group, while low IQ was observed in 8 patients of each group. Neurophysiological abnormalities are fairly common in SLE patients whether symptomatic or asymptomatic. The use of such tests favors a true incidence of nervous system involvement, more accurate diagnosis, and may lead to better clinical care before the development of debilitating CNS and PNS changes.