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Background: Differential diagnosis between frontotemporal dementia (FTD) and Alzheimer's disease (AD) is often challenging. Autopsy series have identified AD pathology in a consistent percentage of patients clinically diagnosed with frontotemporal dementia (FTD). It has been demonstrated that the levels of tau and Aβ42 in cerebrospinal fluid (CSF) are a reliable marker for AD. Objective: To evaluate the presence of a CSF AD-like pattern in patients with FTD, and the related brain changes, to assess whether these patients had features resembling an AD pattern of hypoperfusion. Methods: Clinically-diagnosed non-monogenic FTD patients underwent an extensive neuropsychological assessment, 99mTc-ECD SPECT, and CSF analysis (tau and Aβ42 levels). FTD AD-like and FTD non-AD-like patterns were identified, and neuropsychological and neuroimaging features compared. Results: CSF AD-like pattern was reported in 9 cases out of 43 (21%). FTD AD-like and non-AD-like patients did not differ in demographic characteristics, cognitive deficits, or behavioral changes. Both groups had greater hypoperfusion in frontotemporal lobes as compared to age-matched controls. When FTD AD-like patients were compared to the FTD non-AD-like group, the former had greater hypoperfusion in brain areas typically affected by AD, namely precuneus, temporal, and parietal areas. Conclusions: CSF AD-like profile in FTD is associated with brain abnormalities typically found in classical AD, confirming the usefulness of CSF testing. Detecting an ongoing AD pathological process in FTD has several implications for defining distinctive treatment approaches, guiding genetic screening, and helping in patient selection in future clinical trials in both FTLD and AD therapeutics. [ABSTRACT FROM AUTHOR]

Prediction of survival in frontotemporal lobar degeneration (FTLD) is guesswork. The aim of the present study was to evaluate whether SPECT scan may be useful to predict prognosis of long term survival in FTLD patients. A cohort of 125 patients with FTLD who underwent brain SPECT scan at the time of enrollment and who were further followed up for at least one year were considered. In each subject, volume of interests (VOIs) covering frontotemporal and parietal regions, bilaterally, were drawn. Principal component analysis (PCA) was applied on VOIs, and a Cox regression model was carried out to find out best predictors of survival. A two-pattern PCA solution was chosen, explaining more than 70% of variance, and 'frontal' PC1 and 'temporal' PC2 components were identified. The frontal PC1 was associated with higher rate of faster progression (HR = 2.06, 95% CI = 1.23-3.44, p = 0.006 for univariate model, and HR = 1.85, 95% CI = 1.04-3.28, p = 0.03 for multivariate model). In particular, right orbitofrontal cortex showed the higher loadings in PC1; the worse the scores of this region the shorter the survival was reported. We suggest that SPECT imaging, beyond a helpful tool in diagnostic assessment, may be an easily and accessible marker of disease outcome in FTLD. Further studies considering structural neuroimaging are warranted. [ABSTRACT FROM AUTHOR]