A retrospective study in Neurology demonstrates that intravenous methylprednisolone (IV-MP) reduces the duration of Kleine-Levin syndrome (KLS) episodes, but the evidence for these findings is subjected to potential biases and confounding and may be unrepresentative of the entire KLS patient population at large.
Investigators administered IV-MP 1 g/d for a total of 3 days to 26 patients with KLS, with a total of 43 IV-MP sessions. Additionally, the investigators compared these patients with 48 steroid-naive patients with KLS who were matched for age, sex, age at KLS onset, and number of KLS episodes.
In the untreated population, the investigators measured changes between 2 successive episodes. During each episode, patients rated IV-MP treatment as either deleterious, inefficacious, efficacious, or very efficacious and completed a questionnaire on side effects associated with the therapy. The primary outcome was the proportion of patients with a treated episode ≥1 week shorter than the prior episode.
Compared with the untreated group, a significantly higher percentage of patients treated with the first IV-MP session experienced a >6-day reduction in KLS episodes (10.4% vs 42.3%, respectively; P =.002). When IV-MP was infused within the first 10 days of a KLS episode, a higher proportion of patients receiving IV-MP experienced the primary outcome when compared with untreated patients (65.5% vs 10.5%, respectively; P <.0001). While 61.3% of patients reported at least 1 adverse event, these were mild in severity and mostly transient. Only 6.5% of patients reported worsening of KLS symptoms following treatment; however, these patients did report that their episodes were shorter.
A limitation of this study is potential selection bias of good responders, which may have explained the increasing benefit with recurrent IV-MP use.
According to the investigators, the benefit of steroids during KLS episodes may be partially explained by KLS having “an inflammatory root, although no abnormal immunoglobulin, cytokines, or immune cells have yet been identified.”
Léotard A, Groos E, Chaumereuil C, et al. IV steroids during long episodes of Kleine-Levin syndrome [published online March 23, 2018]. Neurology. doi:10.1212/WNL.0000000000005349