How "Soft" Are Soft Neurological Signs? The Relationship of Subjective Neuropsychiatric Complaints to Cognitive Function in Systemic Lupus Erythematosus

SUSAN D. DENBURG, KATHERYNE E. STEWART, LAWRENCE E. HART, and JUDAH A. DENBURG

ABSTRACT.

Objective. As part of a longitudinal study of cognitive function in systemic lupus erythematosus (SLE), we documented the range and frequency of subjective neurologic and/or psychiatric (NP) complaints in Never-NP-SLE patients, and related these to cognitive function, using the latter as a primary indicator of nervous system involvement.

Methods. Thirty patients with SLE who did not have major neurologic and psychiatric involvement underwent baseline and followup neuropsychological testing roughly 5 years apart. Within 0–13 months prior to retesting, each patient completed a 42 item questionnaire recording NP symptoms.

Results. The group as a whole endorsed 26% of symptoms. Fourteen patients labelled high endorsers (> 35% of items) endorsed, on average, 42% of symptoms. There was a significant association between higher item endorsement and lower cognitive function (r = –0.46, p < 0.02) and significantly poorer cognitive performance in the high compared to low endorser groups (t = –3.07, p < 0.005). In addition, a subset of 8 items was endorsed at least twice as often by SLE patients as by patients with rheumatoid arthritis (n = 12) or healthy controls (n = 10).

Conclusion. These results suggest that "minor" NP symptoms and, in particular, a small subset of subjective complaints may be sufficient to raise suspicion of subclinical nervous system involvement in the absence of clinically evident NP-SLE. (J Rheumatol 2003;30:1006-10)

Key Indexing Terms:

SYSTEMIC LUPUS ERYTHEMATOSUS
NEUROPSYCHOLOGICAL TESTING
FOLLOWUP STUDY
COGNITION DISORDERS
QUESTIONNAIRE

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From the Department of Psychiatry and Behavioural Neurosciences and Department of Medicine, McMaster University, Hamilton, Ontario, Canada.

Supported by The Arthritis Society, the Ontario Mental Health Foundation, the Ontario Lupus Association, the Lupus Foundation of Ontario, and the Lupus Society of Hamilton.

S.D. Denburg, PhD, Professor; K.E. Stewart, BSc, Department of Psychiatry and Behavioural Neurosciences; L.E. Hart, MB BCh, Associate Professor; J.A. Denburg, MD, Professor, Department of Medicine.

Address reprint requests to Dr. S.D. Denburg, HSC-2E17, McMaster University, 1200 Main Street West, Hamilton, Ontario L8N 3Z5, Canada.

Submitted January 22, 2002; revision accepted November 25, 2002.

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