Clinical neurophysiology in the assessment of neurological symptoms in systemic lupus erythematosus.

Neurophysiological studies were performed on 22 randomly selected patients with systemic lupus erythematosus in order to determine whether this form of assessment might be of value in the diagnosis and management of neurological lupus. Sixteen patients described neurological lupus. In eight, neurological symptoms were present at the time of neurophysiological testing. All eight had neurophysiological abnormalities. In six the abnormality was of central origin manifesting as a disorder of either visual evoked response (VER) or brain-stem auditory evoked response (BAER). In the remaining two, an isolated disorder of peripheral nerve conduction (PNC) was present. In the eight patients with previous neurological symptoms five (63%) had neurophysiological abnormalities, but a central disorder was observed in only one and abnormal PNC was present in all. Of the six patients with no neurological symptoms, three (50%) had central neurophysiological disorders. No correlation between individual neurophysiological disorders and specific neurological symptoms was observed. However, all four patients with active vasculitis and all seven with lymphopenia had a neurophysiological disorder. If these observations are extended and confirmed, neurophysiological studies may provide a useful test to the clinician in the evaluation and management of neurological lupus.