Optical coherence tomography is a simple, high-resolution technique to quantify the thickness of retinal nerve fiber layer (RNFL). Previous studies have shown that degenerative changes occur in optic nerve fibers and are manifested as thinning of RNLF in patients with Alzheimer's disease (AD). However, there are no studies on the thickness of the RNLF in other types of dementia, such as dementia with Lewy bodies and dementia associated with Parkinson's disease. In this study, patients fulfilling diagnostic for AD (n = 10), dementia with Lewy bodies (n = 10), dementia associated with Parkinson's disease (n = 10), and cognitively normal age-matched controls (n = 10) underwent optical coherence tomography examinations to measure RNLF thickness. There was a significant decrease in RNLF thickness in each type of dementia compared to the control group (Mann-Whitney test, all p < 0.001). Although patients with dementia with Lewy bodies may have a greater thinning than both patients with AD and dementia associated with Parkinson's disease, the differences were statistically nonsignificant (Kruskal-Wallis test, p = 0.525). The thickness of the RNLF correlated significantly (p < 0.001) with both the Mini-Mental State Examination and the Mattis Dementia Rating Scale scores in all types of dementia; that is to say, the greater the cognitive deterioration, the greater the reduction of thickness of the RNLF. The findings from this study show that retinal involvement measured by optical coherence tomography may also be present in non-AD dementias.

Background: Our aim was to evaluate and compare the diagnostic properties of 5 screening tests for the diagnosis of mild Alzheimer disease (AD). Methods: We conducted a prospective and cross-sectional study of 92 patients with mild AD and of 68 healthy controls from our Department of Neurology. The diagnostic properties of the following tests were compared: Mini-Mental State Examination (MMSE), Addenbrooke's Cognitive Examination III (ACE-III), Memory Impairment Screen (MIS), Montreal Cognitive Assessment (MoCA), and Rowland Universal Dementia Assessment Scale (RUDAS). Results: All tests yielded high diagnostic accuracy, with the ACE-III achieving the best diagnostic properties. The area under the curve was 0.897 for the ACE-III, 0.889 for the RUDAS, 0.874 for the MMSE, 0.866 for the MIS, and 0.856 for the MoCA. The Mini-ACE score from the ACE-III showed the highest diagnostic capacity (area under the curve 0.939). Memory scores of the ACE-III and of the RUDAS showed a better diagnostic accuracy than those of the MMSE and of the MoCA. All tests, especially the ACE-III, conveyed a higher diagnostic accuracy in patients with full primary education than in the less educated group. Implementing normative data improved the diagnostic accuracy of the ACE-III but not that of the other tests. Conclusions: The ACE-III achieved the highest diagnostic accuracy. This better discrimination was more evident in the more educated group.

Our results suggest that ACE-III is a useful neuropsychological test for assessing the cognitive domains of attention, language, memory, and visuospatial function. It also enables detection of Alzheimer's disease in early stages.

BackgroundPositron emission tomography (PET) images with amyloid tracers show normal uptake in healthy white matter, which suggests that amyloid tracers are potentially useful for studying such white matter diseases as multiple sclerosis (MS).MethodsTwelve patients diagnosed with MS (5 with RRMS, 5 with SPMS, and 2 with PPMS) and 3 healthy controls underwent studies with MRI and 18F-florbetaben-PET imaging. Images were preprocessed using Statistical Parametric Mapping software. We analysed 18F-florbetaben uptake in demyelinating plaques (appearing as hyperintense lesions in FLAIR sequences), in normal-appearing white matter, and in grey matter.ResultsMean standardized uptake value relative to cerebellum was higher in normally appearing white matter (NAWM) (1.51 ± 0.12) than in damaged white matter (DWM) (1.24 ± 0.12; P = .002). Mean percentage of change between NAWM and DWM was −17.56 % ± 6.22 %. This percentage of change correlated negatively with EDSS scores (r = −0.61, p < .05) and with age (r = −0.83, p < 0.01). Progressive forms of MS showed a more pronounced reduction of the uptake in DWM in comparison to relapsing-remitting form.ConclusionsUptake of 18F-florbetaben in damaged white matter is lower than that occurring in normally-appearing white matter. These findings indicate that amyloid tracers may be useful in studies of MS, although further research is needed to evaluate the utility of amyloid-PET in monitoring MS progression.Electronic supplementary materialThe online version of this article (doi:10.1186/s12883-015-0502-2) contains supplementary material, which is available to authorized users.

The Spanish version of the ACE-III is a reliable and valid test for diagnosing dementia. Its diagnostic accuracy is high, especially in patients with a higher level of education.

BackgroundCognitive impairment is frequent and disabling in multiple sclerosis (MS). Changes in information processing speed constitute the most important cognitive deficit in MS. However, given the clinical and topographical variability of the disease, cognitive impairment may vary greatly and appear in other forms in addition to slower information processing speed. Our aim was to determine the frequency of cognitive impairment, the principal cognitive domains, and components involved in MS and to identify factors associated with presence of cognitive impairment in these patients in a large series of patients.MethodsCross-sectional study of 311 patients with MS [236 with relapsing-remitting MS (RRMS), 52 with secondary progressive MS (SPMS), and 23 with primary progressive MS (PPMS)]. Patients’ cognitive function was assessed with a comprehensive neuropsychological assessment protocol. Patients displaying deficits in 2 or more cognitive domains were considered to have cognitive impairment associated with MS. We conducted a principal component analysis to detect different cognitive patterns by identifying clusters of tests highly correlated to one another.ResultsCognitive impairment was detected in 41.5% of the sample, and it was more frequent in patients with SPMS and PPMS (P = 0.002). Expanded Disability Status Scale scores and education were independent predictors of cognitive impairment. Principal component analysis identified seven clusters: attention and basic executive function (including information processing speed), planning and high-level executive function, verbal memory and language, executive and visuospatial performance time, fatigue-depression, visuospatial function, and basic attention and verbal/visual working memory. Mean scoring of components 2 (high-order executive functioning) and 3 (verbal memory-language) was higher in patients with RRMS than in those with PPMS (component 2) and SPMS (component 3).ConclusionMS is linked to multiple cognitive profiles and disturbances in different domains. This suggests that cognitive alterations in MS are heterogeneous and affect other domains in addition to information processing speed.

The logopenic variant of primary progressive aphasia (lvPPA) has been associated with Alzheimer disease, although this relationship is still subject to debate. The purpose of this study is to determine the frequency of amyloid biomarkers in patients with lvPPA, and record any potential clinical or topographic differences between patients with and without amyloid deposits. We conducted cognitive examination and positron-emission tomography studies with fluorodeoxyglucose ((18)F) and florbetapir ((18)F) in a cohort of 16 patients diagnosed with lvPPA. We evaluated the prevalence of amyloid deposits as well as any clinical and metabolic differences between the groups with and without significant presence of amyloid deposits. Eleven patients (69 %) were considered amyloid-positive. The amyloid-positive group displayed less metabolic activity in the left temporoparietal region than the control group, while the amyloid-negative group showed lower metabolism in the left temporoparietal region extending to the anterior temporal and basal frontal regions. The percentage of change in patients with clinical and FDG-PET follow-up did not differ between the amyloid-positive and amyloid-negative subgroups. The frequency of amyloid-positive cases confirms that lvPPA is frequently associated with Alzheimer disease. Amyloid-negative patients show a different cerebral metabolic pattern. These findings show the relevance of using amyloid PET to study lvPPA, and also suggest that the logopenic variant may not be specific to Alzheimer disease in certain cases.

Background: The Loewenstein-Acevedo Scale for Semantic Interference and Learning (LASSI-L) is a novel cognitive test that measures recovery from proactive semantic interference, which may be an early cognitive marker of Alzheimer’s disease (AD). Objective: To generate normative data for a Spaniard population and to validate the LASSI-L for the diagnosis of amnestic mild cognitive impairment (aMCI) and mild AD. Methods: We performed a cross-sectional study in which 97 healthy participants, 34 with aMCI, and 33 with mild AD were studied with LASSI-L and a comprehensive neuropsychological protocol. The overlapping strategy analysis was used to maximize the sample size and to provide age- and education-adjusted normative data using a logistic regression analysis. Results: Internal consistency was 0.932. Convergent validity with the Free and Cued Selective Reminding Test was moderate. LASSI-L raw scores were correlated with age and years of education, but not gender. The area under the curve for discriminating between healthy controls and aMCI was 0.909, and between healthy controls and mild AD was 0.986. LASSI-L sub-scores representing maximum storage capacity, recovery from proactive interference, and delayed recall yielded the highest diagnostic accuracy. Conclusions: The LASSI-L is a reliable and valid test for the diagnosis of aMCI and mild AD. The age and education influences on the performance of the test and normative data are provided. LASSI-L merits further studies to evaluate its ability to detect preclinical AD and predict progression to aMCI and early dementia.