Dementia with Lewy bodies

Abstract

Objectives: To investigate clinical, imaging, and pathologic associations of the cingulate island sign (CIS) in dementia with Lewy bodies (DLB).Methods: We retrospectively identified and compared patients with a clinical diagnosis of DLB (n 5 39); patients with Alzheimer disease (AD) matched by age, sex, and education (n 5 39); and cognitively normal controls (n 5 78) who underwent 18 F-fluorodeoxyglucose (FDG) and C11 Pittsburgh compound B (PiB)-PET scans. Among these patients, we studied those who came to autopsy and underwent Braak neurofibrillary tangle (NFT) staging (n 5 10). Dementia with Lewy bodies (DLB) is the second most common cause of dementia.1 Despite revised criteria, 2 clinically distinguishing DLB from other neurodegenerative diseases continues to be problematic. In fact, the National Alzheimer's Coordinating Center registry reported the sensitivity of clinical diagnoses of DLB compared with subsequent pathologic examination to be 32.1%. 3Complicating the inaccuracies of clinical diagnosis, the majority of dementia cases have multiple pathologies at autopsy. 4,5 Coexisting Alzheimer disease (AD) pathology occurs in 51% to 66% of those with pathologically confirmed DLB. 1,6 Accurate antemortem prediction of underlying causes of dementia is important for determining a prognosis, 7,8 predicting treatment response, 9 and planning for clinical trials. Additional biomarkers are required to better distinguish DLB from AD and to predict relative contributions of different underlying pathologies to DLB. By measuring b-amyloid (Ab) deposition with C11 Pittsburgh compound B (PiB) binding, investigators have demonstrated that more than half of patients with DLB have Ab deposition in the brain. 10,11From the Departments of Neurology

18F-FDG PET in Posterior Cortical Atrophy and Dementia with Lewy Bodies

“…In addition to a characteristic pattern of occipital hypometabolism, studies in DLB have noted that the posterior cingulate is relatively spared and that a ratio of hypometabolism of the posterior cingulate to the precuneus plus cuneus (i.e., the cingulate island sign [CIS]) can differentiate DLB from typical Alzheimer dementia with high accuracy (14)(15)(16). It is unclear, however, whether the CIS is also a feature of PCA.…”

“…It is unclear, however, whether the CIS is also a feature of PCA. The presence of the CIS is associated with lower Braak stages (14,17), and hence one could hypothesize that it may help differentiate DLB from PCA, because PCA is often associated with Alzheimer disease pathology and high Braak stage (1).…”

Nuclear Medicine Applications in Movement Disorders

“…LCD ile AH'nın ayırıcı tanısında beyin FDG PET görüntüleme bulgularından yararlanılabilir (56,59,60,61,62). LCD'da AH'nda gözlenen temporoparietal hipometabolizmaya ek olarak oksipital de hipometabolizma bulgusu olması (56,59,62) ve posterior singulat korteks metabolizmasının kuneus ile prekuneus metabolizmasına göre daha çok korunmuş olmasından kaynaklanan "singulat adası bulgusu" LCD'nin AH'sinden ayırt edilmesini sağlayan özelliklerdir (62). Beyin FDG PET görüntüleme ile AH ve LCD ayırıcı tanısının %90'nın üzerinde tanısal doğruluk ile yapılabileceği bildirilmiştir (59,62).…”

Is dopamine transporter invariably impaired at the time of diagnosis in dementia with Lewy bodies?

“…Indeed, 123 Imetaiodobenzylguanidine (MIBG) cardiac planar scintigraphy has shown high sensitivity in detecting norepinephrine transporter deficit at the cardiac level even in DLB patients without autonomic failure [9], and the likelihood that a patient with probable DLB has both a normal 123 I-ioflupane SPECT scan and a normal 123 I-MIBG scan should be exceedingly rare. Alternative tools are 18 F-FDG PET that often shows much more pronounced hypometabolism in the occipital cortex than in AD patients and patients with other dementias [10]. Moreover, as compared to AD, FD -PET shows relatively preserved uptake in the precuneus/posterior cingulate region in DLB, the so-called 'cingulate island' sign [10].…”

“…Alternative tools are 18 F-FDG PET that often shows much more pronounced hypometabolism in the occipital cortex than in AD patients and patients with other dementias [10]. Moreover, as compared to AD, FD -PET shows relatively preserved uptake in the precuneus/posterior cingulate region in DLB, the so-called 'cingulate island' sign [10]. Finally, quantitative electroencephalography (qEEG), a simple, noninvasive and cheap tool can show significantly higher variability of posterior dominance frequency in DLB patients than in AD patients [11].…”