Unraveling Moral Reasoning in Amyotrophic Lateral Sclerosis: How Emotional Detachment Modifies Moral Judgment.

In the last decade, scientific literature provided solid evidence of cognitive deficits in amyotrophic lateral sclerosis (ALS) patients and their effects on end-life choices. However, moral cognition and judgment are still poorly investigated in this population. Here we aimed at evaluating both socio-cognitive and socio-affective components of moral reasoning in a sample of 28 ALS patients. Patients underwent clinical and neuropsychological evaluation including basic cognitive and social cognition measures. Additionally, we administered an experimental task including moral dilemmas, with instrumental and incidental conditions. Patients' performances were compared with a control group [healthy control (HC)], including 36 age-, gender-, and education-matched healthy subjects. Despite that the judgment pattern was comparable in ALS and HC, patients resulted less prone to carry out a moral transgression compared to HC. Additionally, ALS patients displayed higher levels of moral permissibility and lower emotional arousal, with similar levels of engagement in both instrumental and incidental conditions. Our findings expanded the current literature about cognitive deficits in ALS, showing that in judging moral actions, patients may present non-utilitarian choices and emotion flattening. Such a decision-making profile may have relevant implications in applying moral principles in real-life situations and for the judgment of end-of-life treatments and care in clinical settings.

Diagnostic accuracy of cerebrospinal fluid biomarkers measured by chemiluminescent enzyme immunoassay for Alzheimer disease diagnosis.

In the last decades, an important role of cerebrospinal fluid (CSF) biomarkers for Alzheimer disease (AD) diagnosis has emerged. The evaluation of the triad consisting of 42 aminoacid-long amyloid-beta peptide (Aß42), total Tau (tTau) and Tau phosphorylated at threonine 181 (pTau) have been recently integrated into the research diagnostic criteria of AD. For a long time, the enzyme-linked immunosorbent assay (ELISA) has represented the most commonly used method for the measurement of CSF biomarkers levels. This study aimed to assess the diagnostic accuracy of CSF biomarkers, namely Aß42, tTau and pTau and their ratio, measured by fully automated CLEIA assay (Lumipulse). We included 96 patients clinically diagnosed as AD (48) and non-AD (48). All CSF biomarkers levels were measured on Lumipulse G1200 fully automated platform (Fujirebio Inc. Europe, Gent, Belgium). Aß42 levels, 42/40 ratio, 42/tTau ratio, 42/PTau ratio were significantly reduced, and tTau and PTau levels were significantly increased in AD patients in comparison with non-AD patients. The receiving operator curve (ROC) analysis showed good diagnostic accuracy of all CSF biomarkers and their ratios for discriminating AD patients from non-AD patients, with 42/40 ratio having the best AUC (0.724, 95%CI 0.619-0.828; p < 0.001). Our findings support the use of CSF biomarkers measured by CLEIA method on a fully automated platform for AD diagnosis.

Altered parietal-motor connections in Alzheimer's disease patients.

Alzheimer's disease (AD) is characterized by altered functional cortico-cortical connectivity likely due to loss of afferent and efferent connections between different cortical areas. Here we explored parieto-frontal functional connectivity in 15 AD patients and 12 healthy control subjects by means of bifocal transcranial magnetic stimulation (TMS). Conditioning stimuli were applied over the right posterior parietal cortex (PPC) at different intensities (90% and 110% of resting motor threshold, RMT). Motor evoked potentials (MEPs) were then recorded from the ipsilateral primary motor cortex at different interstimulus intervals (ISIs) ranging between 2 and 15 ms. Results showed that in healthy subjects, a conditioning TMS pulse applied over the ipsilateral PPC at 90%, but not at 110%, of RMT intensity was able to increase the excitability of the right M1. This functional interaction peaked at ISI = 6 ms. Conversely, in AD patients the facilitatory pattern of parieto-motor connections was evident only when TMS was delivered at an intensity of 110% of RMT with a peak at ISI = 8 ms. Moreover in AD patients, treatment with cholinesterase inhibitors did not induce any significant modification in the strength of the connection. In subsequent analyses, we found that, in AD patients, the effects induced by PPC conditioning at 110% RMT correlated with neuropsychological measures of episodic memory and executive functions, implying that patients with better cognitive performance had less impaired connectivity. Our findings reveal that parieto-frontal cortico-cortical functional connectivity is altered in AD patients, providing further evidence for a disconnection-based interpretation of AD symptoms.

Predicting disease progression in Alzheimer's disease: the role of neuropsychiatric syndromes on functional and cognitive decline.

Patients with Alzheimer's disease (AD) have heterogeneous rates of disease progression. The aim of the current study is to investigate whether neuropsychiatric disturbances predict cognitive and functional disease progression in AD, according to failure theory. We longitudinally examined 177 memory-clinic AD outpatients (mean age = 73.1, SD = 8.1; 70.6% women). Neuropsychiatric disturbances at baseline were categorized into five syndromes. Patients were followed for up to two years to detect rapid disease progression defined as a loss of ≥ 1 abilities in Activities of Daily living (ADL) or a drop of ≥ 5 points on Mini-Mental State Examination (MMSE). Hazard ratios (HR) were calculated with Gompertz regression, adjusting for sociodemographics, baseline cognitive and functional status, and somatic comorbidities. Most patients (74.6%) exhibited one or more neuropsychiatric syndromes at baseline. The most common neuropsychiatric syndrome was Apathy (63.8%), followed by Affective (37.3%), Psychomotor (8.5%), Manic (7.9%), and Psychotic (5.6%) syndromes. The variance between the observed (Kaplen Meier) and predicted (Gompertz) decline for disease progression in cognition (0.30, CI = 0.26-0.35), was higher than the variance seen for functional decline (0.22, CI = 0.18-0.26). After multiple adjustment, patients with the Affective syndrome had an increased risk of functional decline (HR = 2.0; CI = 1.1-3.6), whereas the risk of cognitive decline was associated with the Manic (HR = 3.2, CI = 1.3-7.5) syndrome. In conclusion, specific neuropsychiatric syndromes are associated with functional and cognitive decline during the progression of AD, which may help with the long-term planning of care and treatment. These results highlight the importance of incorporating a thorough psychiatric examination in the evaluation of AD patients.

Neuropsychological predictors of rapidly progressing patients with Alzheimer's disease.

BACKGROUND: Alzheimer disease (AD) has heterogeneous clinical manifestations. Different neuropsychological profiles in AD patients might be indicative of the diffusion of the pathological process and might be associated with differences in rates of disease progression. METHODS: We studied 154 newly diagnosed AD patients (65.6% women; mean age: 73 years). Performance in memory, executive functions, praxis and language domains was categorized into mild, moderate and severe impairment. The time-dependent probability of losing 5 points on the Mini-Mental State Examination (MMSE) over 2 years was considered as disease progression and evaluated by survival analysis. RESULTS: One fourth of the patients decreased by ≥ 5 MMSE points over the 2-year follow-up. Rapid disease progression was more frequent in more educated patients and in those with moderate severity of global cognitive impairment. In univariate analysis, more severe memory and executive functioning impairment were associated with higher probabilities of progression. The association with memory was explained by differences in executive function impairment that remained statistically significant in multivariate analyses. CONCLUSIONS: Patients with more severe executive functioning impairment have a worse prognosis over 2 years. This might be due to involvement of the prefrontal cortex by the pathological process of AD in patients with severe executive deficits.

Resonance of cortico-cortical connections of the motor system with the observation of goal directed grasping movements.

Goal directed movements require the activation of parietal, premotor and primary motor areas. In monkeys, neurons of these areas become active also during the observation of movements performed by others, especially for coding the goal of the action (mirror system). Using bifocal transcranial magnetic stimulation (TMS) in healthy subjects, we tested whether the observation of goal directed reach to grasp actions may lead to specific changes in the short-latency connections linking key areas of the mirror system, such as the anterior intraparietal cortex (AIP) and the ventral premotor cortex (PMv), with the primary motor cortex (M1). We found that AIP-M1 and PMv-M1 cortico-cortical interactions were specifically activated when observing successful reaching to grasp goal directed actions, in which the hand posture was congruent with the goal of the action performed by the actor. On the other hand they were not modified when the same goal directed actions were performed wrongly with an inappropriate grasping posture. A similar profile of excitability was observed when testing specific intracortical facilitatory circuits in M1 (I(2)-waves), known to reflect the activity in cortico-cortical pathways transmitting information from PMv. We conclude that the simple observation of others' goal directed actions is able to induce specific neurophysiological changes in some cortico-cortical circuits of the human motor system.

Color discrimination performance in patients with Alzheimer's disease.

BACKGROUND/AIMS: Visual deficits are frequent in Alzheimer's disease (AD), yet little is known about the nature of these disturbances. The aim of the present study was to investigate color discrimination in patients with AD to determine whether impairment of this visual function is a cognitive or perceptive/sensory disturbance. METHODS: A cross-sectional clinical study was conducted in a specialized dementia unit on 20 patients with mild/moderate AD and 21 age-matched normal controls. Color discrimination was measured by the Farnsworth-Munsell 100 hue test. Cognitive functioning was measured with the Mini-Mental State Examination (MMSE) and a comprehensive battery of neuropsychological tests. The scores obtained on the color discrimination test were compared between AD patients and controls adjusting for global and domain-specific cognitive performance. RESULTS: Color discrimination performance was inversely related to MMSE score. AD patients had a higher number of errors in color discrimination than controls (mean +/- SD total error score: 442.4 +/- 84.5 vs. 304.1 +/- 45.9). This trend persisted even after adjustment for MMSE score and cognitive performance on specific cognitive domains. CONCLUSIONS: A specific reduction of color discrimination capacity is present in AD patients. This deficit does not solely depend upon cognitive impairment, and involvement of the primary visual cortex and/or retinal ganglionar cells may be contributory.

Predictors of progression of cognitive decline in Alzheimer's disease: the role of vascular and sociodemographic factors.

Rates of disease progression differ among patients with Alzheimer's disease, but little is known about prognostic predictors. The aim of the study was to assess whether sociodemographic factors, disease severity and duration, and vascular factors are prognostic predictors of cognitive decline in Alzheimer's disease progression. We conducted a longitudinal clinical study in a specialized clinical unit for the diagnosis and treatment of dementia in Rome, Italy. A total of 154 persons with mild to moderate Alzheimer's disease consecutively admitted to the dementia unit were included. All patients underwent extensive clinical examination by a physician at admittance and all follow-ups. We evaluated the time-dependent probability of a worsening in cognitive performance corresponding to a 5-point decrease in Mini-Mental State Examination (MMSE) score. Survival analysis was used to analyze risk of faster disease progression in relation to age, education, severity and duration of the disease, family history of dementia, hypertension, hypercholesterolemia, and type 2 diabetes. Younger and more educated persons were more likely to have faster Alzheimer's disease progression. Vascular factors such as hypertension and hypercholesterolemia were not found to be significantly associated with disease progression. However, patients with diabetes had a 65% reduced risk of fast cognitive decline compared to Alzheimer patients without diabetes. Sociodemographic factors and diabetes predict disease progression in Alzheimer's disease. Our findings suggest a slower disease progression in Alzheimer's patients with diabetes. If confirmed, this result will contribute new insights into Alzheimer's disease pathogenesis and lead to relevant suggestions for disease treatment.