Ramelteonにより幻視が消失したレビー小体型認知症の2症例

Abstract

Herein, I report the improvement of visual hallucinations (VHs) in 2 patients with a clinical diagnosis of probable dementia with Lewy bodies (DLB) through the use of ramelteon, a selective MT1/MT2 melatonin receptor agonist. When first seen with complaints of VHs and insomnia in our memory clinic, their scores on the Mini-Mental State Examination were 25 and 20. One patient developed VHs at the age of 72 and could describe them in detail (e.g., a large crowd attending a midnight party). The other patient had dreamed of his deceased wife since the age of 78. He developed VHs at the age of 81 and could describe them in detail: his deceased wife was present and he tried to talk to her, but she did not respond. Both patients lived alone and telephoned their family with complaints of VHs in the middle of night, resulting in an increase in the burdens of care. Because cholinesterase inhibitors had been prescribed for both patients, further pharmacotherapeutic interventions targeted their insomnia rather than their VHs to avoid neuroleptic drug sensitivity, a recommendation of the DLB guidelines. Furthermore, ramelteon has few adverse effects. Within 8 weeks of initiating ramelteon, the VHs had disappeared and the insomnia had improved in both patients. Melatonin is recommended for the treatment of REM sleep behavior disorder (RBD), which is a frequent feature of DLB. The efficacy of ramelteon for VHs suggests a possible association of RBD with psychiatric symptoms in patients with DLB.