OBJECTIVES: Hypersomnolence of narcolepsy is commonly treated with modafinil, but its impacts on circadian rhythm remain unclear. Compared with standard parametric analyses, the non-parametric analysis of actigraphy offers more details to observe sleep-wake patterns. This study monitored narcolepsy patients' rest-activity patterns before and after modafinil treatment by actigraphy. Data were analyzed with non-parametric methods to evaluate outcomes and investigate the potential predictive markers for treatment response.
METHODS: We prospectively recruited participants with type 1 and 2 narcolepsy. Participants received 200-400 mg of modafinil daily for six months and actigraphy was worn for 7-14 days before and after treatment. We used paired sample t-tests for pre- and post-treatment comparisons and independent sample t-tests and chi-square tests to assess group differences. Correlation analyses were conducted using Pearson's correlation test.
RESULTS: A total of 103 participants (mean age: 23.95 ± 10.14 years; 53.4 % male) were recruited, including 64 with NT1 and 39 with NT2. After modafinil treatment, significant increases in daytime activity were observed, along with an earlier shift in the midpoint time of daytime activity. Patients with NT1 showed more improvements than those with NT2. Correlation analysis showed that subjective sleepiness and quality of life were associated with circadian parameters, and patients with a higher REM percentage and those with nocturnal sleep onset REM period demonstrated greater improvements in circadian parameters.
CONCLUSION: Modafinil improves circadian rest-activity rhythms in narcolepsy patients, especially those with NT1. The role of REM percentage and nocturnal SOREMP as predictive markers for treatment outcomes warrant further investigation.
