Background/Objectives: Multiple system atrophy (MSA) presents a challenging diagnosis due to its clinical overlap with other neurodegenerative disorders, especially other α-synucleinopathies. The main purpose of this systematic review and meta-analysis was to assess neurofilament light chain (NfL) differences in the CSF and blood of patients with MSA versus the healthy control group (HC), patients with Parkinson’s disease (PD) and patients with Lewy body dementia (LBD). Secondarily, the diagnostic metrics of CSF and circulating NfL in MSA versus HC, PD, LBD, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) were discussed. Methods: MEDLINE and EMBASE were thoroughly searched for relevant case-control studies. Standardized mean differences (SMDs) were calculated separately for CSF and blood NfL per comparison. Statistical heterogeneity was assessed based on the Q and I^2 statistics. Results: Twenty-five relevant studies were retrieved. Quantitative syntheses revealed elevated CSF and circulating NfL levels in individuals with MSA versus HC [SMD = 1.80 (95%CI = 1.66, 1.94) and SMD = 2.00 (95%CI = 1.36, 2.63), respectively] versus PD [SMD = 1.65 (95%CI = 1.26, 2.03) and SMD = 1.63 (95%CI = 0.84, 2.43), respectively] as well as versus LBD [SMD = 1.17, (95%CI = 0.71, 1.63) and SMD = 0.65 (95%CI = 0.30, 1.00), respectively]. Diagnostic accuracy was outstanding for CSF and blood NfL in MSA versus HC and PD, and it was moderate in MSA versus LBD. On the other hand, it was suboptimal in MSA vs. PSP and CBD. Conclusions: Both CSF and circulating NfL levels are elevated in MSA compared to HC, PD and LBD. To achieve optimal diagnostic properties, further work is required in the standardization of processes and the establishment of reference NfL intervals and/or thresholds.

Background/Objectives: SARS-CoV-2 can affect the central nervous system directly or indirectly. AD shares several similarities with long COVID cognitive impairment on a molecular and imaging level, as well as common risk factors. The objective of this review is to evaluate the incidence of post-acute COVID-19 cognitive impairment. Secondarily, we aim to determine if neuroinflammation in COVID-19 survivors may be associated with the onset of neurological disease, with a focus on Alzheimer’s disease (AD). Methods: literature search up to March 2025 on the prevalence of cognitive deficits in COVID-19 survivors, underlying pathophysiology and associations with neurological disorders. Results: a wide array of neuropsychiatric manifestations is associated with COVID-19; executive function, memory, and attention are the most frequently reported neurocognitive deficits, regardless of COVID-19 severity. There are associations between the risks for cognitive deficits post-infection with the age of the patients and the severity of the disease. Increasing evidence suggests that neurocognitive deficits are associated with the onset of neurological and neuropsychiatric disease in COVID-19 survivors. Conclusions: clinicians caring for COVID-19 survivors should actively investigate neurocognitive sequelae, particularly for patients with increased risk for cognitive deficits.

Background/Objectives: Social cognition impairment is common in multiple sclerosis (MS) and could implicate the well-being of patients by promoting difficulties in social interactions. This study investigated the relationship between social cognition and quality of life (QoL) in patients with MS (PwMSs). Methods: In total, 100 PwMSs, enrolled as per distinct criteria, underwent neuropsychological assessment using validated questionnaires and scales. To assess QoL, Multiple Sclerosis Quality of Life-54 (MSQOL-54) questionnaires, both physical and mental, were utilized. The components of social cognition were evaluated using the Reading the Mind in the Eyes Test (RMET) and the Faux Pas task. The type of MS and years since diagnosis were also recorded. Results: The RMET score (β = 0.336; p = 0.001) and years since diagnosis (β = −0.225; p = 0.017) emerged as significant predictors of physical QoL, whereas the Faux Pas score did not significantly predict MSQOL-54_PHYSICAL scores (p = 0.451). Both Faux Pas (β = 0.247; p = 0.015) and RMET scores (β = 0.221; p = 0.028) showed a positive association with MSQOL-54_MENTAL scores. The years since diagnosis did not significantly predict the mental component of QoL (p = 0.635). Conclusions: Social cognition deficits are crucial for the social functioning of patients with MS, inevitably affecting both physical and mental aspects of QoL.