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Background: This study aimed at comparing, within the 2018 NIA-AA amyloidosis/tauopathy/neurodegeneration (ATN) framework, the distribution of T ± profiles across A + patients with MCI and dementia in a retrospective, single-center, clinic-based cohort. Methods: We retrospectively collected data on N = 168 A + patients with either MCI due to AD (N = 50) or probable AD dementia (ADD; N = 118). ATN status was assigned, according to the 2018 NIA-AA framework, based on cerebrospinal fluid (CSF) biomarker concentrations. A χ2-test for independent samples was run to compare the distribution of A + T + vs. A + T- profiles, regardless of N status, across MCI and dementia patients. Results: The most represented ATN profile in both groups was A + T + N + (MCI: 54%; dementia: 70.3%); 3.4% of dementia patients and none within the MCI cohort presented with an A + T-N + profile. When grouping ATN profiles solely based on A and T dimensions, the prevalence of A + T + was of 76.3% and 66% in dementia and MCI patients, respectively. No association between clinical diagnoses (i.e., MCI vs. dementia status) and AT profiles (i.e., A + T + vs. A + T-) was detected. Discussion: The distribution of A + T + vs. A + T- does not differ between MCI and ADD, with A + T + profiles being predominant in both clinical categories. This does not support the common notion of A + T- profiles being relatively more prevalent in MCI patients, as indexing an earlier and/or less severe disease. Hence, caution should be exerted in attributing a case of MCI to prodromal AD solely based on A-positivity in the presence of a T-negative profile.

Background Olfactory dysfunction in coronavirus disease 2019 (COVID-19) is common during acute illness and appears to last longer than other symptoms. The aim of this study was to objectively investigate olfactory dysfunction in two cohorts of patients at two different stages: during acute illness and after a median recovery of 4 months. Methods Twenty-five acutely ill patients and 26 recovered subjects were investigated. Acute patients had a molecular diagnosis of COVID-19; recovered subjects had a positive antibody assay and a negative molecular test. A 33-item psychophysical olfactory identification test tailored for the Italian population was performed. Results Median time from symptoms onset to olfactory test was 33 days in acute patients and 122 days in recovered subjects. The former scored a significantly higher number of errors at psychophysical testing (median [IQR]: 8 [13] vs 3 [2], p < 0.001) and were more frequently hyposmic (64% vs 19%, p = 0.002). Recovered subjects reported a variable time to subjective olfactory recovery, from days up to 4 months. Participants included in the study reported no significant nasal symptoms at olfactory testing. Among recovered subject who reported olfactory loss during acute COVID-19, four (27%) were still hyposmic. Demographic and clinical characteristics did not show significant associations with olfactory dysfunction. Conclusion Moderate-to-severe hospitalized patients showed a high level and frequency of olfactory dysfunction compared to recovered subjects. In the latter group, subjects who reported persisting olfactory dysfunction showed abnormal scores on psychophysical testing, indicating that, at least in some subjects, persistent hyposmia may represent a long-term sequela of COVID-19.

Traditional cognitive assessment in neurological conditions involving physical disability is often prevented by the presence of verbal-motor impairment; to date, an extensive motor-verbal-free neuropsychological battery is not available for such purposes. We adapted a set of neuropsychological tests, assessing language, attentional abilities, executive functions and social cognition, for eye-tracking (ET) control, and explored its feasibility in a sample of healthy participants. Thirty healthy subjects performed a neuropsychological assessment, using an ET-based neuropsychological battery, together with standard "paper and pencil" cognitive measures for frontal (Frontal Assessment Battery-FAB) and working memory abilities (Digit Sequencing Task) and for global cognitive efficiency (Montreal Cognitive Assessment-MoCA). Psychological measures of anxiety (State-Trait Anxiety Inventory-Y-STAI-Y) and depression (Beck Depression Inventory-BDI) were also collected, and a usability questionnaire was administered. Significant correlations were observed between the "paper and pencil" screening of working memory abilities and the ET-based neuropsychological measures. The ET-based battery also correlated with the MoCA, while poor correlations were observed with the FAB. Usability aspects were found to be influenced by both working memory abilities and psychological components. The ET-based neuropsychological battery developed could provide an extensive assessment of cognitive functions, allowing participants to perform tasks independently from the integrity of motor or verbal channels. Further studies will be aimed at investigating validity and usability components in neurological populations with motor-verbal impairments.