Detection of TDP-43 seeding activity in the olfactory mucosa from patients with frontotemporal dementia.

INTRODUCTION: We assessed TAR DNA-binding protein 43 (TDP-43) seeding activity and aggregates detection in olfactory mucosa of patients with frontotemporal lobar degeneration with TDP-43-immunoreactive pathology (FTLD-TDP) by TDP-43 seeding amplification assay (TDP43-SAA) and immunocytochemical analysis. METHODS: The TDP43-SAA was optimized using frontal cortex samples from 16 post mortem cases with FTLD-TDP, FTLD with tau inclusions, and controls. Subsequently, olfactory mucosa samples were collected from 17 patients with FTLD-TDP, 15 healthy controls, and three patients carrying MAPT variants. RESULTS: TDP43-SAA discriminated with 100% accuracy post mortem cases presenting or lacking TDP-43 neuropathology. TDP-43 seeding activity was detectable in the olfactory mucosa, and 82.4% of patients with FTLD-TDP tested positive, whereas 86.7% of controls tested negative (P < 0.001). Two out of three patients with MAPT mutations tested negative. In TDP43-SAA positive samples, cytoplasmatic deposits of phosphorylated TDP-43 in the olfactory neural cells were detected. DISCUSSION: TDP-43 aggregates can be detectable in olfactory mucosa, suggesting that TDP43-SAA might be useful for identifying and monitoring FTLD-TDP in living patients.

Clinical and pathology characterization of small nerve fiber neuro(no)pathy in cerebellar ataxia with neuropathy and vestibular areflexia syndrome.

BACKGROUND AND PURPOSE: Biallelic mutation/expansion of the gene RFC1 has been described in association with a spectrum of manifestations ranging from isolated sensory neuro(no)pathy to a complex presentation as cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS). Our aim was to define the frequency and characteristics of small fiber neuropathy (SFN) in RFC1 disease at different stages. METHODS: RFC1 cases were screened for SFN using the Neuropathic Pain Symptom Inventory and Composite Autonomic Symptom Score 31 questionnaires. Clinical data were retrospectively collected. If available, lower limb skin biopsy samples were evaluated for somatic epidermal and autonomic subepidermal structure innervation and compared to healthy controls (HCs). RESULTS: Forty patients, median age at onset 54 years (interquartile range [IQR] 49-61) and disease duration 10 years (IQR 6-16), were enrolled. Mild-to-moderate positive symptoms (median Neuropathic Pain Symptom Inventory score 12.1/50, IQR 5.5-22.3) and relevant autonomic disturbances (median Composite Autonomic Symptom Score 31 37.0/100, IQR 17.7-44.3) were frequently reported and showed scarce correlation with disease duration. A non-length-dependent impairment in nociception was evident in both clinical and paraclinical investigations. An extreme somatic denervation was observed in all patients at both proximal (fibers/mm, RFC1 cases 0.0 vs. HCs 20.5, p < 0.0001) and distal sites (fibers/mm, RFC1 cases 0.0 vs. HCs 13.1, p < 0.0001); instead only a slight decrease was observed in cholinergic and adrenergic innervation of autonomic structures. CONCLUSIONS: RFC1 disease is characterized by a severe and widespread somatic SFN. Skin denervation may potentially represent the earliest feature and drive towards the suspicion of this disorder.

CADUCEO: A Platform to Support Federated Healthcare Facilities through Artificial Intelligence.

Data-driven algorithms have proven to be effective for a variety of medical tasks, including disease categorization and prediction, personalized medicine design, and imaging diagnostics. Although their performance is frequently on par with that of clinicians, their widespread use is constrained by a number of obstacles, including the requirement for high-quality data that are typical of the population, the difficulty of explaining how they operate, and ethical and regulatory concerns. The use of data augmentation and synthetic data generation methodologies, such as federated learning and explainable artificial intelligence ones, could provide a viable solution to the current issues, facilitating the widespread application of artificial intelligence algorithms in the clinical application domain and reducing the time needed for prevention, diagnosis, and prognosis by up to 70%. To this end, a novel AI-based functional framework is conceived and presented in this paper.

SARS-CoV-2 antibodies in inflammatory neurological conditions: a multicentre retrospective comparative study.

It is well established that neurological and non-neurological autoimmune disorders can be triggered by viral infections. It remains unclear whether SARS-CoV-2 infection induces similar conditions and whether they show a distinctive phenotype. We retrospectively identified patients with acute inflammatory CNS conditions referred to our laboratory for antibody testing during the pandemic (March 1 to August 31, 2020). We screened SARS-COV-2 IgA/IgG in all sera by ELISA and confirmed the positivity with additional assays. Clinical and paraclinical data of SARS-COV-2-IgG seropositive patients were compared to those of seronegative cases matched for clinical phenotype, geographical zone, and timeframe. SARS-CoV-2-IgG positivity was detected in 16/339 (4%) sera, with paired CSF positivity in 3/16. 5 of these patients had atypical demyelinating disorders and 11 autoimmune encephalitis syndromes. 9/16 patients had a previous history of SARS-CoV-2 infection and 6 of them were symptomatic. In comparison with 32 consecutive seronegative controls, SARS-CoV-2-IgG-positive patients were older, frequently presented with encephalopathy, had lower rates of CSF pleocytosis and other neurological autoantibodies, and were less likely to receive immunotherapy. When SARS-CoV-2 seropositive versus seronegative cases with demyelinating disorders were compared no differences were seen. Whereas seropositive encephalitis patients less commonly showed increased CSF cells and protein, our data suggest that an antecedent symptomatic or asymptomatic SARS-CoV-2 infection can be detected in patients with autoimmune neurological conditions. These cases are rare, usually do not have specific neuroglial antibodies.

Invasive Assessment of Coronary Microcirculation: A State-of-the-Art Review.

A significant proportion of patients presenting with signs and symptoms of myocardial ischemia have no "significant" epicardial disease; thereby, the assessment of coronary microcirculation gained an important role in improving diagnosis and guiding therapy. In fact, coronary microvascular dysfunction (CMD) could be found in a large proportion of these patients, supporting both symptoms and signs of myocardial ischemia. However, CMD represents a diagnostic challenge for two main reasons: (1) the small dimension of the coronary microvasculature prevents direct angiographic visualization, and (2) despite the availability of specific diagnostic tools, they remain invasive and underused in the current clinical practice. For these reasons, CMD remains underdiagnosed, and most of the patients remain with no specific treatment and quality-of-life-limiting symptoms. Of note, recent evidence suggests that a "full physiology" approach for the assessment of the whole coronary vasculature may offer a significant benefit in terms of symptom improvement among patients presenting with ischemia and non-obstructive coronary artery disease. We analyze the pathophysiology of coronary microvascular dysfunction, providing the readers with a guide for the invasive assessment of coronary microcirculation, together with the available evidence supporting its use in clinical practice.

Olfactory swab sampling optimization for α-synuclein aggregate detection in patients with Parkinson's disease.

BACKGROUND: In patients with Parkinson's disease (PD), real-time quaking-induced conversion (RT-QuIC) detection of pathological α-synuclein (α-syn) in olfactory mucosa (OM) is not as accurate as in other α-synucleinopathies. It is unknown whether these variable results might be related to a different distribution of pathological α-syn in OM. Thus, we investigated whether nasal swab (NS) performed in areas with a different coverage by olfactory neuroepithelium, such as agger nasi (AN) and middle turbinate (MT), might affect the detection of pathological α-syn. METHODS: NS was performed in 66 patients with PD and 29 non-PD between September 2018 and April 2021. In 43 patients, cerebrospinal fluid (CSF) was also obtained and all samples were analyzed by RT-QuIC for α-syn. RESULTS: In the first round, 72 OM samples were collected by NS, from AN (NSAN) or from MT (NSMT), and 35 resulted positive for α-syn RT-QuIC, including 27/32 (84%) from AN, 5/11 (45%) from MT, and 3/29 (10%) belonging to the non-PD patients. Furthermore, 23 additional PD patients underwent NS at both AN and MT, and RT-QuIC revealed α-syn positive in 18/23 (78%) NSAN samples and in 10/23 (44%) NSMT samples. Immunocytochemistry of NS preparations showed a higher representation of olfactory neural cells in NSAN compared to NSMT. We also observed α-syn and phospho-α-syn deposits in NS from PD patients but not in controls. Finally, RT-QuIC was positive in 22/24 CSF samples from PD patients (92%) and in 1/19 non-PD. CONCLUSION: In PD patients, RT-QuIC sensitivity is significantly increased (from 45% to 84%) when NS is performed at AN, indicating that α-syn aggregates are preferentially detected in olfactory areas with higher concentration of olfactory neurons. Although RT-QuIC analysis of CSF showed a higher diagnostic accuracy compared to NS, due to the non-invasiveness, NS might be considered as an ancillary procedure for PD diagnosis.

"Ependymal-in" Gradient of Thalamic Damage in Progressive Multiple Sclerosis.

Leptomeningeal and perivenular infiltrates are important contributors to cortical grey matter damage and disease progression in multiple sclerosis (MS). Whereas perivenular inflammation induces vasculocentric lesions, leptomeningeal involvement follows a subpial "surface-in" gradient. To determine whether similar gradient of damage occurs in deep grey matter nuclei, we examined the dorsomedial thalamic nuclei and cerebrospinal fluid (CSF) samples from 41 postmortem secondary progressive MS cases compared with 5 non-neurological controls and 12 controls with other neurological diseases. CSF/ependyma-oriented gradient of reduction in NeuN+ neuron density was present in MS thalamic lesions compared to controls, greatest (26%) in subventricular locations at the ependyma/CSF boundary and least with increasing distance (12% at 10 mm). Concomitant graded reduction in SMI31+ axon density was observed, greatest (38%) at 2 mm from the ependyma/CSF boundary and least at 10 mm (13%). Conversely, gradient of major histocompatibility complex (MHC)-II+ microglia density increased by over 50% at 2 mm at the ependyma/CSF boundary and only by 15% at 10 mm and this gradient inversely correlated with the neuronal (R = -0.91, p < 0.0001) and axonal (R = -0.79, p < 0.0001) thalamic changes. Observed gradients were also detected in normal-appearing thalamus and were associated with rapid/severe disease progression; presence of leptomeningeal tertiary lymphoid-like structures; large subependymal infiltrates, enriched in CD20+ B cells and occasionally containing CXCL13+ CD35+ follicular dendritic cells; and high CSF protein expression of a complex pattern of soluble inflammatory/neurodegeneration factors, including chitinase-3-like-1, TNFR1, parvalbumin, neurofilament-light-chains and TNF. Substantial "ependymal-in" gradient of pathological cell alterations, accompanied by presence of intrathecal inflammation, compartmentalized either in subependymal lymphoid perivascular infiltrates or in CSF, may play a key role in MS progression. SUMMARY FOR SOCIAL MEDIA: Imaging and neuropathological evidences demonstrated the unique feature of "surface-in" gradient of damage in multiple sclerosis (MS) since early pediatric stages, often associated with more severe brain atrophy and disease progression. In particular, increased inflammation in the cerebral meninges has been shown to be strictly associated with an MS-specific gradient of neuronal, astrocyte, and oligodendrocyte loss accompanied by microglial activation in subpial cortical layers, which is not directly related to demyelination. To determine whether a similar gradient of damage occurs in deep grey matter nuclei, we examined the potential neuronal and microglia alterations in the dorsomedial thalamic nuclei from postmortem secondary progressive MS cases in combination with detailed neuropathological characterization of the inflammatory features and protein profiling of paired CSF samples. We observed a substantial "subependymal-in" gradient of neuro-axonal loss and microglia activation in active thalamic lesions of progressive MS cases, in particular in the presence of increased leptomeningeal and cerebrospinal fluid (CSF) inflammation. This altered graded pathology was found associated with more severe and rapid progressive MS and increased inflammatory degree either in large perivascular subependymal infiltrates, enriched in B cells, or within the paired CSF, in particular with elevated levels of a complex pattern of soluble inflammatory and neurodegeneration factors, including chitinase 3-like-1, TNFR1, parvalbumin, neurofilament light-chains and TNF. These data support a key role for chronic, intrathecally compartmentalized inflammation in specific disease endophenotypes. CSF biomarkers, together with advance imaging tools, may therefore help to improve not only the disease diagnosis but also the early identification of specific MS subgroups that would benefit of more personalized treatments. ANN NEUROL 2022;92:670-685.

Ischemic stroke due to sporadic and genetic pulmonary arteriovenous malformations: Case report.

Pulmonary arteriovenous malformations (PAVMs) encompass congenital and genetic vascular anomalies characterized by complex interlacing of arteries and veins connected by fistulas, which allow rapid and continuous extracardiac right-to-left shunting (RLS). Presenting neurologic manifestations of PAVM include brain abscess and stroke, as the consequence of paradoxical embolism. Although rare, PAVM represents an overlooked cause of cryptogenic ischemic stroke in young adults, being misdiagnosed as patent foramen ovale and a preventable trigger of silent cerebral ischemic changes. In the emergency clinical setting, the recommended ischemic stroke workup in patients with RLS should include the influence of postural changes and the effect of Valsalva maneuver on the entity of the RLS on contrast-enhanced transcranial color Doppler ultrasound and the delay in the right inferior pulmonary vein and left heart opacification on contrast-enhanced transthoracic echocardiography. This is in addition to the evaluation of chest X-rays or thoracic computed tomography. We here describe two patients with ischemic stroke due to sporadic and genetic PAVM-associated paradoxical embolism.

Persistent chemosensory dysfunction in a young patient with mild COVID-19 with partial recovery 15 months after the onset.

OBJECTIVE: It is reported that recovery from COVID-19 chemosensory deficit generally occurs in a few weeks, although olfactory dysfunction may persist longer. Here, we provide a detailed follow-up clinical investigation in a very young female patient (17-year-old) with a long-lasting anosmia after a mild infection, with partial recovery 15 months after the onset. METHODS: Neuroimaging and neurophysiologic assessments as well as olfactory mucosa swabbing for microbiological and immunocytochemical analyses were performed. Olfactory and gustatory evaluations were conducted through validated tests. RESULTS: Chemosensory evaluations were consistent with anosmia associated with parosmia phenomena and gustatory impairment, the latter less persistent. Brain MRI (3.0 T) showed no microvascular injury in olfactory bulbs and brain albeit we cannot rule out slight structural abnormalities during the acute phase, and a high-density EEG was negative. Immunocytochemistry of olfactory mucosa swabs showed high expression of ACE2 in sustentacular cells and lower dot-like cytoplasmic positivity in neuronal-shaped cells. DISCUSSION: The occurrence of long-term persistent olfactory deficit in spite of the absence of structural brain and olfactory bulb involvement supports the view of a possible persistent dysfunction of both sustentacular cells and olfactory neurons. The gustatory dysfunction even if less persisting for the described features could be related to a primary gustatory system involvement. Future longitudinal studies are needed to investigate the persistence of chemosensory impairment, which could have a relevant impact on the daily life.

Impact of direct acting antivirals (DAA) on neurologic disorders in chronic hepatitis C.

INTRODUCTION: Neurologic and neuropsychiatric manifestations sometimes provide the first evidence of an unknown HCV infection. These conditions develop with a variable ranging of morbidity, including: "brain fog," fatigue, subtle cognitive and attention impairment, but also with more severe complications or acute presentation, like encephalomyelitis, encephalopathy, stroke and peripheral nerves involvement. EVIDENCE ACQUISITION: We performed a systematic literature search on PubMed, Cochrane Library and Web of Science databases for articles only in English language, that assessed the relationship between "DAA treatment and neurologic disorders" and after the attainment of SVR in full reports of cases that received the DAA schedule from January 2015 to December 2019. The following terms were used: "chronic Hepatitis C," "HCV," "DAA," "direct-acting antiviral," "SVR," "sustained virologic response," peripheral neuropathy" and "neurologic diseases or disorders." EVIDENCE SYNTHESIS: HCV infection does not only involve the liver, causing cirrhosis and hepatocellular carcinoma (HCC), but also induces extrahepatic manifestations (EHM), mainly due to a complex immune disease, that damage small and medium vessels, called "mixed cryoglobulinemic vasculitis" (MCV). This kind of mechanism generates most of the HCV-induced neurological damages. Since 2015, the availability of direct-acting antiviral (DAA) oral molecules interfering with HCV replication has completely revolutionized therapeutic options and the target population, which now includes patients aged 12 to 80 years and with advanced liver disease. Relevant was the highlighted DAA effectiveness by achievement of a sustained virologic response (SVR) in about 95% of cases, showing a great tolerability. CONCLUSIONS: This favorable effect has arisen in a wide category of patients infected by HCV, including subjects with cirrhosis and complications and/or with EHM, who showed a significant improvement of their symptoms and the disease regression. In this concise review, we examine the clinical outcomes after the introduction of the DAA for the treatment of chronic hepatitis C (CHC), focusing on the neurologic disorders and concluding that there is a strong amelioration of neurologic conditions in several cases, particularly, after attaining the viral eradication with a favorable course in most treated cases.

The contribution of the Italian residents in neurology to the COVID-19 crisis: admirable generosity but neurological training remains their priority.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has severely impacted the Italian healthcare system, underscoring a dramatic shortage of specialized doctors in many disciplines. The situation affected the activity of the residents in neurology, who were also offered the possibility of being formally hired before their training completion. AIMS: (1) To showcase examples of clinical and research activity of residents in neurology during the COVID-19 pandemic in Italy and (2) to illustrate the point of view of Italian residents in neurology about the possibility of being hired before the completion of their residency program. RESULTS: Real-life reports from several areas in Lombardia-one of the Italian regions more affected by COVID-19-show that residents in neurology gave an outstanding demonstration of generosity, collaboration, reliability, and adaptation to the changing environment, while continuing their clinical training and research activities. A very small minority of the residents participated in the dedicated selections for being hired before completion of their training program. The large majority of them prioritized their training over the option of earlier employment. CONCLUSIONS: Italian residents in neurology generously contributed to the healthcare management of the COVID-19 pandemic in many ways, while remaining determined to pursue their training. Neurology is a rapidly evolving clinical field due to continuous diagnostic and therapeutic progress. Stakeholders need to listen to the strong message conveyed by our residents in neurology and endeavor to provide them with the most adequate training, to ensure high quality of care and excellence in research in the future.

Neurological symptoms and axonal damage in COVID-19 survivors: are there sequelae?

The persistence of neurological symptoms after SARS-CoV-2 infection, as well as the presence of late axonal damage, is still unknown. We performed extensive systemic and neurological follow-up evaluations in 107 out of 193 consecutive patients admitted to the COVID-19 medical unit, University Hospital of Verona, Italy between March and June 2020. We analysed serum neurofilament light chain (NfL) levels in all cases including a subgroup (n = 29) of patients with available onset samples. Comparisons between clinical and biomarker data were then performed. Neurological symptoms were still present in a significant number (n = 49) of patients over the follow-up. The most common reported symptoms were hyposmia (n = 11), fatigue (n = 28), myalgia (n = 14), and impaired memory (n = 11) and were more common in cases with severe acute COVID-19. Follow-up serum NfL values (15.2 pg/mL, range 2.4-62.4) were within normal range in all except 5 patients and did not differentiate patients with vs without persistent neurological symptoms. In patients with available onset and follow-up samples, a significant (p < 0.001) decrease of NfL levels was observed and was more evident in patients with a severe acute disease. Despite the common persistence of neurological symptoms, COVID-19 survivors do not show active axonal damage, which seems a peculiar feature of acute SARS-CoV-2 infection.

Comparison of MRI Lesion Evolution in Different Central Nervous System Demyelinating Disorders.

BACKGROUND AND OBJECTIVE: There are few studies comparing lesion evolution across different CNS demyelinating diseases, yet knowledge of this may be important for diagnosis and understanding differences in disease pathogenesis. We sought to compare MRI T2 lesion evolution in myelin oligodendrocyte glycoprotein immunoglobulin G (IgG)-associated disorder (MOGAD), aquaporin 4 IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG-NMOSD), and multiple sclerosis (MS). METHODS: In this descriptive study, we retrospectively identified Mayo Clinic patients with MOGAD, AQP4-IgG-NMOSD, or MS and (1) brain or myelitis attack; (2) available attack MRI within 6 weeks; and (3) follow-up MRI beyond 6 months without interval relapses in that region. Two neurologists identified the symptomatic or largest T2 lesion for each patient (index lesion). MRIs were then independently reviewed by 2 neuroradiologists blinded to diagnosis to determine resolution of T2 lesions by consensus. The index T2 lesion area was manually outlined acutely and at follow-up to assess variation in size. RESULTS: We included 156 patients (MOGAD, 38; AQP4-IgG-NMOSD, 51; MS, 67) with 172 attacks (brain, 81; myelitis, 91). The age (median [range]) differed between MOGAD (25 [2-74]), AQP4-IgG-NMOSD (53 [10-78]), and MS (37 [16-61]) (p < 0.01) and female sex predominated in the AQP4-IgG-NMOSD (41/51 [80%]) and MS (51/67 [76%]) groups but not among those with MOGAD (17/38 [45%]). Complete resolution of the index T2 lesion was more frequent in MOGAD (brain, 13/18 [72%]; spine, 22/28 [79%]) than AQP4-IgG-NMOSD (brain, 3/21 [14%]; spine, 0/34 [0%]) and MS (brain, 7/42 [17%]; spine, 0/29 [0%]) (p < 0.001). Resolution of all T2 lesions occurred most often in MOGAD (brain, 7/18 [39%]; spine, 22/28 [79%]) than AQP4-IgG-NMOSD (brain, 2/21 [10%]; spine, 0/34 [0%]) and MS (brain, 2/42 [5%]; spine, 0/29 [0%]) (p < 0.01). There was a larger median (range) reduction in T2 lesion area in mm2 on follow-up axial brain MRI with MOGAD (213 [55-873]) than AQP4-IgG-NMOSD (104 [0.7-597]) (p = 0.02) and MS (36 [0-506]) (p < 0.001) and the reductions in size on sagittal spine MRI follow-up in MOGAD (262 [0-888]) and AQP4-IgG-NMOSD (309 [0-1885]) were similar (p = 0.4) and greater than in MS (23 [0-152]) (p < 0.001). DISCUSSION: The MRI T2 lesions in MOGAD resolve completely more often than in AQP4-IgG-NMOSD and MS. This has implications for diagnosis, monitoring disease activity, and clinical trial design, while also providing insight into pathogenesis of CNS demyelinating diseases.

A 58-year-old man with B-cell chronic lymphocytic leukemia and multiple strokes.

A 58-year-old male with B-cell chronic lymphocytic leukemia presented with fever, chest pain, and acute-onset neurological deficits suggestive of multiple strokes (A). Brain autopsy revealed softening areas in the brain parenchyma (B, C) corresponding to extensive necrosis (D) caused by neuroinvasion by Aspergillus hyphae (E, F) necrosis (D) caused by neuroinvasion by Aspergillus hyphae (E, F).

Statin-associated necrotizing autoimmune myopathy with concurrent myasthenia gravis.

Statin treatment has been associated with necrotizing autoimmune myopathy and has been linked to myasthenia gravis. We present an unprecedented clinical challenge with both disorders occurring in a patient treated with statins few months earlier.

Alpha-synuclein seeds in olfactory mucosa of patients with isolated REM sleep behaviour disorder.

Isolated REM sleep behaviour disorder (RBD) is an early-stage α-synucleinopathy in most, if not all, affected subjects. Detection of pathological α-synuclein in peripheral tissues of patients with isolated RBD may identify those progressing to Parkinson's disease, dementia with Lewy bodies or multiple system atrophy, with the ultimate goal of testing preventive therapies. Real-time quaking-induced conversion (RT-QuIC) provided evidence of α-synuclein seeding activity in CSF and olfactory mucosa of patients with α-synucleinopathies. The aim of this study was to explore RT-QuIC detection of α-synuclein aggregates in olfactory mucosa of a large cohort of subjects with isolated RBD compared to patients with Parkinson's disease and control subjects. This cross-sectional case-control study was performed at the Medical University of Innsbruck, Austria, the Hospital Clinic de Barcelona, Spain, and the University of Verona, Italy. Olfactory mucosa samples obtained by nasal swab in 63 patients with isolated RBD, 41 matched Parkinson's disease patients and 59 matched control subjects were analysed by α-synuclein RT-QuIC in a blinded fashion at the University of Verona, Italy. Median age of patients with isolated RBD was 70 years, 85.7% were male. All participants were tested for smell, autonomic, cognitive and motor functions. Olfactory mucosa was α-synuclein RT-QuIC positive in 44.4% isolated RBD patients, 46.3% Parkinson's disease patients and 10.2% control subjects. While the sensitivity for isolated RBD plus Parkinson's disease versus controls was 45.2%, specificity was high (89.8%). Among isolated RBD patients with positive α-synuclein RT-QuIC, 78.6% had olfactory dysfunction compared to 21.4% with negative α-synuclein RT-QuIC (P < 0.001). The extent of olfactory dysfunction was more severe in isolated RBD patients positive than negative for olfactory mucosa a-synuclein RT-QuIC (P < 0.001). We provide evidence that the α-synuclein RT-QuIC assay enables the molecular detection of neuronal α-synuclein aggregates in olfactory mucosa of patients with isolated RBD and Parkinson's disease. Although the overall sensitivity was moderate in this study, nasal swabbing is attractive as a simple, non-invasive test and might be useful as part of a screening battery to identify subjects in the prodromal stages of α-synucleinopathies. Further studies are needed to enhance sensitivity, and better understand the temporal dynamics of α-synuclein seeding in the olfactory mucosa and spreading to other brain areas during the progression from isolated RBD to overt α-synucleinopathy, as well the impact of timing, disease subgroups and sampling technique on the overall sensitivity.

Alpha-synuclein seeds in olfactory mucosa and cerebrospinal fluid of patients with dementia with Lewy bodies.

In patients with suspected dementia with Lewy bodies, the detection of the disease-associated α-synuclein in easily accessible tissues amenable to be collected using minimally invasive procedures remains a major diagnostic challenge. This approach has the potential to take advantage of modern molecular assays for the diagnosis of α-synucleinopathy and, in turn, to optimize the recruitment and selection of patients in clinical trials, using drugs directed at counteracting α-synuclein aggregation. In this study, we explored the diagnostic accuracy of α-synuclein real-time quaking-induced conversion assay by testing olfactory mucosa and CSF in patients with a clinical diagnosis of probable (n = 32) or prodromal (n = 5) dementia with Lewy bodies or mixed degenerative dementia (dementia with Lewy bodies/Alzheimer's disease) (n = 6). Thirty-eight patients with non-α-synuclein-related neurodegenerative and non-neurodegenerative disorders, including Alzheimer's disease (n = 10), sporadic Creutzfeldt-Jakob disease (n = 10), progressive supranuclear palsy (n = 8), corticobasal syndrome (n = 1), fronto-temporal dementia (n = 3) and other neurological conditions (n = 6) were also included, as controls. All 81 patients underwent olfactory swabbing while CSF was obtained in 48 participants. At the initial blinded screening of olfactory mucosa samples, 38 out of 81 resulted positive while CSF was positive in 19 samples out of 48 analysed. After unblinding of the results, 27 positive olfactory mucosa were assigned to patients with probable dementia with Lewy bodies, five with prodromal dementia with Lewy bodies and three to patients with mixed dementia, as opposed to three out 38 controls. Corresponding results of CSF testing disclosed 10 out 10 positive samples in patients with probable dementia with Lewy bodies and six out of six with mixed dementia, in addition to three out of 32 for controls. The accuracy among results of real-time quaking-induced conversion assays and clinical diagnoses was 86.4% in the case of olfactory mucosa and 93.8% for CSF. For the first time, we showed that α-synuclein real-time quaking-induced conversion assay detects α-synuclein aggregates in olfactory mucosa of patients with dementia with Lewy bodies and with mixed dementia. Additionally, we provided preliminary evidence that the combined testing of olfactory mucosa and CSF raised the concordance with clinical diagnosis potentially to 100%. Our results suggest that nasal swabbing might be considered as a first-line screening procedure in patients with a diagnosis of suspected dementia with Lewy bodies followed by CSF analysis, as a confirmatory test, when the result in the olfactory mucosa is incongruent with the initial clinical diagnosis.

Algal blooms of Alexandrium spp. and Paralytic Shellfish Poisoning toxicity events in mussels farmed in Sicily.

Marine biotoxins can accumulate in filter- feeders bivalve molluscs, that may represent a source of potential health problems being vectors of toxins, that are transferred to humans through their consumption. Harmful Algal Blooms impact on aquaculture may give also economic losses due to temporary closures of contaminated shellfish harvest and marketing. The presence of toxic algae for Paralytic Shellfish Poisoning (PSP), with recurrent toxic blooms of dinoflagellates, such as several Alexandrium species, been known since 2000 in the waters of an Ionian bay of Sicily, the Syracuse harbour, where shellfish farms are located. Our previous works reported in this area the positivity for PSP toxin in mussels (Mytilus galloprovincialis) with saxitoxin concentrations above the limit of the law and the simultaneous presence of toxic species of the genus Alexandrium in the waters. This work reports new recent episodes of algal blooms of Alexandrium minutum in the waters of the Syracuse harbour and PSP toxin contamination in farmed mussels, with values beyond the limits established by law, with the consequent immediate closure of the production area. PSP toxicity was detected with the MBA (Mouse Bioassay) with the confirm carried out with Lawrence method to quantify the total saxitoxin equivalents and characterize the toxic profile. Regular application of the implemented health plan is very important in order to prevent any risk and protect consumer health.