Lithium therapy in Kleine-Levin syndrome: An open-label, controlled study in 130 patients.

To compare the benefits and risks of lithium therapy vs abstention/other treatments in Kleine-Levin syndrome (KLS). In a KLS cohort followed in a single center, 130 patients regularly took lithium carbonate (median dose 1,000 mg/day; n = 71; 40 children), valproate (n = 5), contraceptive pill (n = 5), or no treatment (n = 49). The disease characteristics (frequency, mean, and longest durations of episodes, time incapacitated per year) were compared before and after follow-up in the lithium vs abstention groups. The time between KLS onset and therapeutic onset was 69 ± 92 months. The patients were then followed up for a mean of 21.5 ± 17.8 months. Before treatment, the 71 patients treated with lithium tended to have a higher frequency of episodes per year (3.8 ± 2.9 vs 2.9 ± 2.6) and had a longer time spent incapacitated (57 ± 51 vs 37 ± 35 days) than the untreated patients. The mean (-8 ± 20 vs 2 ± 13 days) and longest (-18 ± 35 vs -5 ± 13) episode duration, the time spent incapacitated (-37 ± 65 days vs -10 ± 38), as well as the frequency of episodes per year (-2.6 ± 2.9 vs 1.3 ± 2.78) decreased significantly more in the treated than in the untreated patients. Side effects (reported by 50% of the patients) were mild and classical with lithium (tremor, increased drinking, diarrhea, and subclinical hypothyroidism). In this large, prospective, open-label, controlled study, the benefit/risk ratio of lithium therapy is superior to that of abstention, supporting the concept that lithium has anti-inflammatory/neuroprotective effects. This study provides Class IV evidence that for patients with KLS, lithium decreases the frequency and duration of KLS episodes.