Diagnosing and attributing neuropsychiatric events to systemic lupus erythematosus: time to untie the Gordian knot?

Neurological and psychiatric syndromes, collectively referred to as NPSLE, occur frequently in SLE. The frequency of NPSLE varies from 21 to 95%; however, only 13-38% of neuropsychiatric (NP) events could be attributable to SLE in the NPSLE SLICC inception cohort. This variability in the frequency of NPSLE is attributable to the low specificity of the ACR case definitions for SLE-attributed NP syndromes, inclusion of minor NP events in the ACR nomenclature, difficulty in ascertainment of NP events and diverse experience of rheumatologists in the clinical assessment of NP events. Making the correct and early attribution of NP events to SLE is important to institute appropriate immunosuppressive treatment for favourable outcomes. Various attribution models using composite decision rules have been developed and used to ascribe NP events to SLE. This review will focus on the various clinical presentations, diagnostic work-up and attributions of the common NPSLE syndromes, including other NP events not included in the ACR nomenclature but which have come to attention in recent years.