アルツハイマー病として経過した後にレビー小体型痴呆のAD型と診断された初老期女性例

A Presenile Female Patient Diagnosed as Having Dementia with Lewy Bodies of the AD form After the Clinical Course of Alzheimer's Disease

抄録

　54歳時，記憶障害と抑うつ状態で発症した後，認知機能障害が進行してアルツハイマー病(AD)として経過し，64歳時，急性の経過で認知機能の変動と幻視・誤認を伴う精神症状が出現し，パーキンソニズムが進行したことから，レビー小体型痴呆(DLB)と診断した65歳女性例を報告した。脳SPECT所見も後頭葉の血流が低下しDLBの診断を支持していた。本例をDLBのAD型ととらえることにより，臨床診断が困難とされるAD型DLBも臨床症状と経過を注意深く検討することから臨床診断が可能であることが示され，初老期発症のADの中にDLBのAD型が混在している可能性が示唆された。

Summary

　The patient was a 65-year-old Japanese woman. At the age of 54, she developed memory disturbance and depressive state. Thereafter, her cognitive impairment progressed, and she was diagnosed as having Alzheimer's disease (AD). At the age of 64, she revealed acutely fluctuating cognition and psychiatric symptoms including visual hallucinations and misidentification of persons as well as progressive parkinsonism, and was therefore diagnosed as having dementia with Lewy bodies (DLB). Brain SPECT examination exhibited hypoperfusion in the occipital lobe, supporting the diagnosis of DLB. If the present case is regarded as DLB of the AD form, this report indicates that although the clinical diagnosis of the AD form DLB has been difficult, it can be clinically diagnosed through the careful observation of clinical symptoms and course. In addition, it suggests the possibility that the AD form DLB is intermingled with early onset AD.