- Objective. To characterize sleep patterns of patients with juvenile rheumatoid arthritis (JRA). Methods. Sixteen patients with JRA aged 12 ± 4 years and 9 controls aged 11 ± 3 years underwent a comprehensive evaluation by self-report questionnaire and formal all night polysomnographic recordings. Multiple sleep latency test was performed in 7 patients. Results. Patients had 90% more arousals and awakenings (p < 0.01) and the median length of occurrences of uninterrupted sleep in stages 2 and 3 and rapid eye movement (REM) sleep was 60% shorter than in controls (p < 0.01). The overall amount of sleep stage shift from deeper to lighter sleep was 23.5 ± 10.8 events in patients compared to 14.9 ± 4.0 in controls (p<0.05). In 15 of 16 patients 15% of non-REM sleep consisted of alpha-delta (alpha-rating) sleep, compared with less than 1% in controls (p<0.001). Multiple sleep latency test for patients was 10.3 ± 2.6 min. There were no differences between JRA and controls in self-reported questions. However, patients reported longer afternoon naps, 1.8 ± 1.3 h compared to 0.3 ± 0.8 h in controls (p<0.05). Conclusion. Objective polysomnographic evidence of abnormal sleep has been confirmed in patients with JRA. Sleep disturbance was associated with daytime sleepiness as evidenced by abnormal multiple sleep latency test and longer afternoon naptime.