Cingulate Island Sign

Cingulate Island Sign

レヴィ小体型認知症（DLB）の新国際診断基準では支持的バイオマーカーの血流・代謝所見に，新たにcingulate island sign（CIS）が取り入れられた。アルツハイマー病では後部帯状回〜楔前部の血流が低下するのに対し，DLBでは後部帯状回の血流は相対的に保持されるという所見で，病理学的には神経原線維変化の進行と逆相関を示すとされている。糖代謝画像での所見とされているが，脳血流SPECT画像でも抽出することが可能であったので，この脳血流SPECT画像におけるCISを中心に述べる。

Abstract

The Dementia with Lewy Bodies (DLB) Consortium refined its recommendations for the clinical diagnosis of DLB last year. The generalized low uptake of single photon emission computed tomography (SPECT)/positron emission tomography (PET) perfusion/metabolism scan with reduced occipital activity with or without the cingulate island sign (CIS) in FDG-PET imaging was described as a supportive biomarker of DLB. CIS shows that brain metabolism in the posterior cingulate of patients with DLB is relatively preserved compared with Alzheimer's disease (AD). Metabolism in the posterior cingulate is known to be dicreased in patients with AD. CIS is also known to have negative correlation with the Braak neurofibrillary tangle stages. Recently, we studied CIS of brain perfusion SPECT and concluded that optimized CIS using brain perfusion SPECT is clinically useful for differentiating DLB from AD. This feasibility of studying CIS using brain perfusion SPECT when diagnosing DLB is described in this article.