A radioisotopic method was used to evaluate the state and dynamics of the lymphatic system in 92 patients affected by chronic oedema of the limbs and in 12 control subjects. After interstitial injections of 99mTc-sulphur microcolloid, scans were obtained using a LFOV camera linked to a data processor. The quantitative indices of clearance and lymph node uptake obtained showed good correlation with lymphoedema etiology, controls and ostensibly healthy limbs of patients affected by monolateral disease. In conclusion, quantitative lymphoscintigraphy appears to be a feasible indicator of early changes in the lymph pathophysiology and supports the hypothesis that lymphoedema generally arises from a predisposing congenital pathology.

The amyloid hypothesis (AH) is still the most accepted model to explain the pathogenesis of inherited Alzheimer's disease (IAD). However, despite the neuropathological overlapping with the non-inherited form (NIAD), AH waver in explaining NIAD. Thus, 30 years after its first statement several questions are still open, mainly regarding the role of amyloid plaques (AP) and apolipoprotein E (APOE). Accordingly, a pathogenetic model including the role of AP and APOE unifying IAD and NIAD pathogenesis is still missing. In the present understanding of the AH, we suggested that amyloid-␤ (A␤) peptides production and AP formation is a physiological aging process resulting from a systemic age-related decrease in the efficiency of the proteins catabolism/clearance machinery. In this pathogenetic model A␤ peptides act as neurotoxic molecules, but only above a critical concentration [A␤] c . A threshold mechanism triggers IAD/NIAD onset only when [A␤] ≥ [A␤] c . In this process, APOE modifies [A␤] c threshold in an isoform-specific way. Consequently, all factors influencing A␤ anabolism, such as amyloid beta precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) gene mutations, and/or A␤ catabolism/clearance could contribute to exceed the threshold [A␤] c , being characteristic of each individual. In this model, AP formation does not depend on [A␤] c . The present interpretation of the AH, unifying the pathogenetic theories for IAD and NIAD, will explain why AP and APOE4 may be observed in healthy aging and why they are not the cause of AD. It is clear that further studies are needed to confirm our pathogenetic model. Nevertheless, our suggestion may be useful to better understand the pathogenesis of AD.

Psychosis (delusions or hallucinations) in Alzheimer’s disease (AD + P) occurs in up to 50% of individuals and is associated with significantly worse clinical outcomes. Atypical antipsychotics, first developed for schizophrenia, are commonly used in AD + P, suggesting shared mechanisms. Despite this implication, little empirical research has been conducted to examine whether there are mechanistic similarities between AD + P and schizophrenia. In this study, we tested whether polygenic risk score (PRS) for schizophrenia was associated with AD + P. Schizophrenia PRS was calculated using Psychiatric Genomics Consortium data at ten GWAS p value thresholds (PT) in 3111 AD cases from 11 cohort studies characterized for psychosis using validated, standardized tools. Association between PRS and AD + P status was tested by logistic regression in each cohort individually and the results meta-analyzed. The schizophrenia PRS was associated with AD + P at an optimum PT of 0.01. The strongest association was for delusions where a one standard deviation increase in PRS was associated with a 1.18-fold increased risk (95% CI: 1.06–1.3; p = 0.001). These new findings point towards psychosis in AD—and particularly delusions—sharing some genetic liability with schizophrenia and support a transdiagnostic view of psychotic symptoms across the lifespan.

Abnormalities of water homeostasis can be early expressions of neuronal dysfunction, brain atrophy, chronic cerebrovasculopathy and neurodegenerative disease. The aim of this study was to analyze the serum osmolality of subjects with cognitive impairment. One thousand and ninety-one consecutive patients attending the Alzheimer’s Evaluation Unit were evaluated with the Mini-Mental State Examination (MMSE), 21-Item Hamilton Depression Rating Scale (HDRS-21), Activities of Daily Living (ADL), Instrumental-ADL (IADL), Mini Nutritional Assessment (MNA), Exton-Smith Scale (ESS), and Cumulative Illness Rating Scale (CIRS). For each patient, the equation for serum osmolality developed by Khajuria and Krahn was applied. Five hundred and seventy-one patients had cognitive decline and/or depression mood (CD-DM) and 520 did not have CD-DM (control group). Patients with CD-DM were less likely to be male (p < 0.001), and were more likely to be older (p < 0.001), have a significant clear cognitive impairment (MMSE: p < 0.001), show the presence of a depressive mood (HDRS-21: p < 0.001) and have major impairments in ADL (p < 0.001), IADL (p < 0.001), MNA (p < 0.001), and ESS (p < 0.001), compared to the control group. CD-DM patients had a higher electrolyte concentration (Na+: p < 0.001; K+: p < 0.001; Cl−: p < 0.001), risk of dehydration (osmolality p < 0.001), and kidney damage (eGFR: p = 0.021), than the control group. Alzheimer’s disease (AD) patients showed a major risk for current dehydration (p ≤ 0.001), and dehydration was associated with the risk of developing a type of dementia, like AD or vascular dementia (VaD) (OR = 2.016, p < 0.001). In the multivariate analysis, the presence of dehydration state was associated with ADL (p < 0.001) and IADL (p < 0.001), but independently associated with age (r2 = 0.0046, p = 0.77), ESS (r2 = 0.0052, p = 0.54) and MNA (r2 = 0.0004, p = 0.48). Moreover, younger patients with dementia were significantly more dehydrated than patients without dementia (65–75 years, p = 0.001; 76–85 years, p = 0.001; ≥86 years, p = 0.293). The hydromolecular hypothesis intends to explain the relationship between dehydration and cognitive impairment in older patients as the result of protein misfolding and aggregation, in the presence of a low interstitial fluid volume, which is a defect of the microcirculation. Defective proteins were shown to impair the amount of information in brain biomolecular mechanisms, with consequent neuronal and synaptic damage.