Case series of three children and adolescents with periodic hypersomnia

Background: Periodic hypersomnias in children and adolescents are described according to etiological groups like: 1) idiopathic - the Kleine Levin syndrome (KLS) and its clinical variants 2) organic and 3) other psychiatric conditons. KLS is described as a triad of recurrent hypersomnolence, hyperphagia, and hypersexuality. However, an incomplete presentation characterized by hypersomnia without other features has also been described. Aim: To report and compare three cases of children and adolescents, who presented as periodic hypersomnias with variable clinical picture and subsequently diagnosed to have KLS. Methods: Chart review of cases and selective review of literature pertinent to periodic hypersomnias with special reference to Kleine Levin syndrome was done. Results: Out of the three cases, one male who had impaired thyroid function tests was given thyroxine supplements along with lithium prophylaxis. The other male was given modafinil during episodes apart from continuous lithium prophylaxis. The female who had less severe episodes was given only modafinil during episodes. The polysomnographic findings though altered were not specific. All the three cases had reduced frequency, duration and severity of episodes following treatment. Conclusions: There is considerable evidence for lithium in preventing further episodes when compared to medical abstention in patients with KLS. Our case series also highlights the role of lithium in KLS. However, stimulants like modafinil can be adjunctively used during episodes or as monotherapy in episodes of lesser severity. Therapeutic trials of drugs able to prevent KLS are warranted. Because of rarity of the condition these trials should have a multicenter design.