Search

Blunt thoracic trauma (BTT) is a leading cause of emergency department (ED) trauma-related attendance. Risk prediction tools are commonly to predict patients' outcomes and assign them to the most appropriate care setting. The STUMBL score is a prognostic model for BTT, derived and validated in the United Kingdom; items comprising the score are age, number of rib fractures, use of pre-injury anticoagulants, chronic lung disease and oxygen saturation levels. This study's aim was to validate the STUMBL score in an Italian ED.This single-centre retrospective validation study was conducted in the ED of Santa Croce and Carle hub hospital in Cuneo, north-western Italy. All patients with an ED attendance for isolated BTT from 2018 to 2021 were included. Exclusion criteria were an age of under eighteen and the presence of any immediately life-threatening lesion. The primary outcome was the development of trauma-related complications, defined by the occurrence of one or more of the following: in-hospital mortality, pulmonary complications (infection, pleural effusion, haemothorax, pneumothorax, pleural empyema), need for intensive care unit admission, hospital length of stay equal to or greater than seven days. The performance of the STUMBL score was analysed in terms of discrimination with the evaluation of the receiver operating characteristic curve and calibration with the Hosmer-Lemeshow test and with the calibration belt.745 patients were enroled (median age 64 [25th;75th percentile: 50;78], male/female ratio 1:4, median Charlson comorbidity index 2 [1;4], median STUMBL score 11 [6;17]). 65.2% of patients were discharged home after ED evaluation. 203 patients (27.2%) developed the primary outcome. The STUMBL score was significantly different in patients with complications compared to those without complications (9 [5;13] vs 21 [17;25], p 0.001). The C index of the score for the primary outcome was 0.90 (95% CI 0.88-0.93), and the result of the Hosmer-Lemeshow test was 9.01 (p = 0.34). STUMBL score = 16 has a sensitivity of 0.80 (95% CI 0.75-0.85), specificity of 0.87 (95% CI 0.84-0.90), a positive predictive value of 0.70 (95% CI 0.64-0.76), and a negative predictive value of 0.92 (95% CI 0.90-0.94).In this validation study, the STUMBL score demonstrated excellent discrimination and calibration in predicting the outcome of patients attending the ED with a BTT.

Isolated exclusion of the non-coronary sinus (NCS) is an attractive strategy in valve-sparing aortic root surgery, which avoids the mobilisation and re-implantation of coronary ostia. However, the long-term durability of aortic valve repair and the fate of remnant sinuses of Valsalva remain unclear.From January 2006 to December 2013, 29 patients underwent replacement of the ascending aorta extending to the NCS (group NCS) and 56 patients underwent a modified Yacoub procedure (group MY) in our centre by a single surgeon. Significant difference of preoperative parameters was observed between two groups in the presence of bicuspid aortic valve (41.4% vs 12.5%, p=0.002) and the diameter of the sinus of Valsalva (47.3±4.7 mm vs 51.5±4.9 mm, p=0.01).The group NCS, as compared to the group MY, was associated with significantly shorter cardiopulmonary bypass time (106.6±40.5 min vs 138.4±37.5 min, p=0.001) and aortic cross clamping time (69.0±21.8 min vs 105.4±27.8 min, p0.01). The mean follow-up was 11.5±2.8 years. No surgical re-intervention was performed for aortopathies of the aortic root; the neo-sinus were not dilated in either groups (38.2±4.2 mm vs 34.0±4.0 mm, p0.01). The 10-year freedom from aortic valve-related re-operation was estimated to be 96.6±3.4% and 94.5±3.1% (p=0.58), and the cumulative 10-year survival rates were 95.2±4.6% and 85.6±4.7% (p=0.61) in the group NCS and the group MY, respectively.Aortic valve-sparing isolated NCS replacement can be safely performed in selected patients; its early outcomes, overall survival and long-term freedom from aortic valve-related or aortopathy-related re-intervention were comparable to those obtained with the Yacoub procedure.

Nerve conduction studies (NCS) are an essential aspect of the assessment of patients with peripheral neuropathies. However, conventional NCS do not reflect activation of small afferent fibers, including Aδ and C fibers. A definitive gold standard for laboratory evaluation of these fibers is still needed and therefore, clinical evaluation remains fundamental in patients with small fiber neuropathies (SFN). Several clinical and research techniques have been developed for the assessment of small fiber function, such as (i) microneurography, (ii) laser evoked potentials, (iii) contact heat evoked potentials, (iv) pain-related electrically evoked potentials, (v) quantitative thermal sensory testing, (vi) skin biopsy-intraepidermal nerve fiber density and (vii) corneal confocal microscopy. The first five are physiological techniques, while the last two are morphological. They all have advantages and limitations, but the combined use of an appropriate selection of each of them would lead to gathering invaluable information for the diagnosis of SFN. In this review, we present an update on techniques available for the study of small afferent fibers and their clinical applicability. A summary of the anatomy and important physiological aspects of these pathways, and the clinical manifestations of their dysfunction is also included, in order to have a minimal common background.

Mutations in DNAJB2 are associated with autosomal recessive hereditary motor neuropathies/ Charcot-Marie-Tooth disease type 2 (CMT2). We describe an Italian family with CMT2 due to a homozygous DNAJB2 mutation and provide insight into the pathomechanisms.Patients with DNAJB2 mutations were characterized clinically, electrophysiologically and by means of skin biopsy. mRNA and protein levels were studied in lymphoblastoid cells (LCLs) from patients and controls.Three affected siblings were found to carry a homozygous DNAJB2 null mutation segregating with the disease. The disease manifested in the second to third decade of life. Clinical examination showed severe weakness of the thigh muscles and complete loss of movement in the foot and leg muscles. Sensation was reduced in the lower limbs. All patients had severe hearing loss and the proband also had Parkinson's disease (PD). Nerve conduction studies showed an axonal motor and sensory length-dependent polyneuropathy. DNAJB2 expression studies revealed reduced mRNA levels and the absence of the protein in the homozygous subject in both LCLs and skin biopsy. Interestingly, we detected phospho-alpha-synuclein deposits in the proband, as already seen in PD patients, and demonstrated TDP-43 accumulation in patients' skin.Our results broaden the clinical spectrum of DNAJB2-related neuropathies and provide evidence that DNAJB2 mutations should be taken into account as another causative gene of CMT2 with hearing loss and parkinsonism. The mutation likely acts through a loss-of-function mechanism, leading to toxic protein aggregation such as TDP-43. The associated parkinsonism resembles the classic PD form with the addition of abnormal accumulation of phospho-alpha-synuclein.

Phosphorylated TDP-43 (pTDP-43) aggregates in the cytoplasm of motor neurons and neuroglia in the brain are one of the pathological hallmarks of amyotrophic lateral sclerosis. Although the axons exceed the total volume of motor neuron soma by several orders of magnitude, systematic studies investigating the presence and distribution of pTDP-43 aggregates within motor nerves are still lacking. The aim of this study is to define the TDP-43/pTDP-43 pathology in diagnostic motor nerve biopsies performed on a large cohort of patients presenting with a lower motor neuron syndrome and to assess whether this might be a discriminating tissue biomarker for amyotrophic lateral sclerosis and non-amyotrophic lateral sclerosis cases. We retrospectively evaluated 102 lower motor neuron syndrome patients referred to our centre for a diagnostic motor nerve biopsy. Histopathological criteria of motor neuron disease and motor neuropathy were applied by two independent evaluators, who were blind to clinical data. TDP-43 and pTDP-43 were evaluated by immunohistochemistry, and results compared to final clinical diagnosis. We detected significant differences between amyotrophic lateral sclerosis and non-amyotrophic lateral sclerosis cases in pTDP-43 expression in myelinated fibres: axonal accumulation was detected in 98.2% of patients with amyotrophic lateral sclerosis versus 30.4% of non-amyotrophic lateral sclerosis samples (P < 0.0001), while concomitant positive staining in Schwan cell cytoplasm was found in 70.2% of patients with amyotrophic lateral sclerosis versus 17.4% of patients who did not have amyotrophic lateral sclerosis (P < 0.001). Importantly, we were also able to detect pTDP-43 aggregates in amyotrophic lateral sclerosis cases displaying normal features at standard histopathological analysis. Our findings demonstrated that a specific pTDP-43 signature is present in the peripheral nervous system of patients with amyotrophic lateral sclerosis, and could be exploited as a specific, accessible tissue biomarker. The detection of pTDP-43 aggregates within motor nerves of living patients with amyotrophic lateral sclerosis, occurring before axonal degeneration, suggests that this is an early event that may contribute to amyotrophic lateral sclerosis pathogenesis.

Valve-sparing aortic root replacement (VSRR) techniques have several advantages such as preservation of physiological haemodynamics of the native aortic valve and avoidance of prosthetic valve-related complications. However, VSRR procedures are generally performed in young patients and the long-term results in elderly patients (≥65 years) are scarce.Fifty-six (56) consecutive patients underwent VSRR surgery by a single surgeon at the current centre between January 2006 and December 2013; a modified "remodelling technique" was typically performed. The mean age was 58.86±12.5 years; Marfan syndrome and bicuspid aortic valve were both present in six patients (10.7%); 38 patients (67.8%) presented with greater than moderate aortic regurgitation; and 17 patients (30.4%) were in New York Heart Association (NYHA) class III before surgery. They were divided into two groups according to their ages receiving VSRR surgery: Group E (elderly patients aged ≥65 years, n=24) and Group Y (young patients aged65 years, n=32). The primary outcomes were aortic valve-related reoperation, cardiovascular reoperation, all-cause mortality, and functional status.One (1) patient in Group E was converted to aortic valve replacement as a result of a failed aortic valve repair. No perioperative mortality was observed. The mean follow-up was 11.5±2.9 years. Aortic valve-related reoperation was noted in two patients of each group (one with endocarditis, one with severe aortic regurgitation). Cardiovascular reoperations were observed in three and six patients, and all-cause deaths in seven and two patients in Group E and Group Y, respectively. The 10-year freedom from aortic valve-related reoperation was estimated to be 91.7±5.6% and 92.7±5.0% (p=0.594), the 10-year freedom from cardiovascular reoperation was 86.4±7.3% and 81.1±7.7% (p=0.781), and the cumulative 10-year survival rates were 74.0±9.2% and 93.8±4.3% (p=0.018) in Group E and Group Y, respectively. During follow-up, 6.7% of patients were in NYHA class III and 6.4% of patients developed moderate-to-severe aortic regurgitation. Cox regression analysis failed to identify predictors for primary outcomes.Valve-sparing aortic root replacement can safely be performed in elderly patients with low early mortality and satisfactory long-term freedom from aortic valve-related and cardiovascular re-intervention.

Neuropathic pain is amongst the most common non-communicable disorders and the poor effectiveness of current treatment is an unmet need. Although pain is a universal experience, there are significant inter-individual phenotypic differences. Developing models that can accurately recapitulate the clinical pain features is crucial to better understand underlying pathophysiological mechanisms and find innovative treatments. Current data from heterologous expression systems that investigate properties of specific molecules involved in pain signaling, and from animal models, show limited success with their translation into the development of novel treatments for pain. This is in part because they do not recapitulate the native environment in which a particular molecule functions, and due to species-specific differences in the properties of several key molecules that are involved in pain signaling. The limited availability of post-mortem tissue, in particular dorsal root ganglia (DRG), has hampered research using human cells in pre-clinical studies. Human induced-pluripotent stem cells (iPSCs) have emerged as an exciting alternative platform to study patient-specific diseases. Sensory neurons that are derived from iPSCs (iPSC-SNs) have provided new avenues towards elucidating peripheral pathophysiological mechanisms, the potential for development of personalized treatments, and as a cell-based system for high-throughput screening for discovering novel analgesics. Nevertheless, reprogramming and differentiation protocols to obtain nociceptors have mostly yielded immature homogenous cell populations that do not recapitulate the heterogeneity of native sensory neurons. To close the gap between native human tissue and iPSCs, alternative strategies have been developed. We will review here recent developments in differentiating iPSC-SNs and their use in pre-clinical translational studies. Direct conversion of stem cells into the cells of interest has provided a more cost- and time-saving method to improve reproducibility and diversity of sensory cell types. Furthermore, multi-cellular strategies that mimic in vivo microenvironments for cell maturation, by improving cell contact and communication (co-cultures), reproducing the organ complexity and architecture (three-dimensional organoid), and providing iPSCs with the full spatiotemporal context and nutrients needed for acquiring a mature phenotype (xenotransplantation), have led to functional sensory neuron-like systems. Finally, this review touches on novel prospective strategies, including fluorescent-tracking to select the differentiated neurons of relevance, and dynamic clamp, an electrophysiological method that allows direct manipulation of ionic conductances that are missing in iPSC-SNs.

Familial periodic paralyses (PPs) are inherited disorders of skeletal muscle characterized by recurrent episodes of flaccid muscle weakness. PPs are classified as hypokalemic (HypoPP), normokalemic (NormoPP), or hyperkalemic (HyperPP) according to the potassium level during the paralytic attacks. HypoPP is an autosomal dominant disease caused by mutations in the CACNA1S gene, encoding for Cav1.1 channel (HypoPP-1), or SCN4A gene, encoding for Nav1.4 channel (HypoPP-2). In the present study, we included 60 patients with a clinical diagnosis of HypoPP. Fifty-one (85%) patients were tested using the direct sequencing (Sanger method) of all reported HypoPP mutations in CACNA1S and SCN4A genes; the remaining 9 (15%) patients were analyzed through a next-generation sequencing (NGS) panel, including the whole CACNA1S and SCN4A genes, plus other genes rarely associated to PPs. Fifty patients resulted mutated: 38 (76%) cases showed p.R528H and p.R1239G/H CACNA1S mutations and 12 (24%) displayed p.R669H, p.R672C/H, p.R1132G/Q, and p.R1135H SCN4A mutations. Forty-one mutated cases were identified among the 51 patients managed with Sanger sequencing, while all the 9 cases directly analyzed with the NGS panel showed mutations in the hotspot regions of SCN4A and CACNA1S. Ten out of the 51 patients unresolved through the Sanger sequencing were further analyzed with the NGS panel, without the detection of any mutation. Hence, our data suggest that in HypoPP patients, the extension of genetic analysis from the hotspot regions using the Sanger method to the NGS sequencing of the entire CACNA1S and SCN4A genes does not lead to the identification of new pathological mutations.

Small fiber neuropathy (SFN) is a common condition affecting thinly myelinated A delta and unmyelinated C fibers, often resulting in excruciating pain and dysautonomia. SFN has been associated with several conditions, but a significant number of cases have no discernible cause. Recent genetic studies have identified potentially pathogenic gain-of-function mutations in several poreforming voltage-gated sodium channel alpha subunits (Na-v) in a subset of patients with SFN, but the auxiliary sodium channel beta-subunits have been less implicated in the development of the disease. beta subunits modulate Na-v trafficking and gating, and several mutations have been linked to epilepsy and cardiac dysfunction. Recently, we provided the first evidence for the contribution of a mutation in the beta 2 subunit to pain in human painful diabetic neuropathy. Here, we provide the first evidence for the involvement of a sodium channel beta subunit mutation in the pathogenesis of SFN with no other known causes. We show, through current-clamp analysis, that the newly identified Y69H variant of the beta(2) subunit induces neuronal hyperexcitability in dorsal root ganglion neurons, lowering the threshold for action potential firing and allowing for increased repetitive action potential spiking. Underlying the hyperexcitability induced by the beta(2)-Y69H variant, we demonstrate an upregulation in tetrodotoxin-sensitive, but not tetrodotoxin-resistant sodium currents. This provides the first evidence for the involvement of beta(2) subunits in SFN and strengthens the link between sodium channel beta subunits and the development of neuropathic pain in humans.NEW & NOTEWORTHY Small fiber neuropathy (SFN) often has no discernible cause, although mutations in the voltage-gated sodium channel alpha subunits have been implicated in some cases. We identify a patient suffering from SFN with a mutation in the auxiliary beta 2 subunit and no other discernible causes for SFN. Functional assessment confirms this mutation renders dorsal root ganglion neurons hyperexcitable and upregulates tetrodotoxin-sensitive sodium currents. This study strengthens a newly emerging link between sodium channel beta 2 subunit mutations and human pain disorders.

Neuropathic pain is a characteristic feature of small fiber neuropathy (SFN), which in 18% of the cases is caused by genetic variants in voltage-gated sodium ion channels. In this study, we assessed the role of fifteen other ion channels in neuropathic pain. Patients with SFN (n = 414) were analyzed for ANO1, ANO3, HCN1, KCNA2, KCNA4, KCNK18, KCNN1, KCNQ3, KCNQ5, KCNS1, TRPA1, TRPM8, TRPV1, TRPV3 and TRPV4 variants by single-molecule molecular inversion probes–next-generation sequencing. These patients did not have genetic variants in SCN3A, SCN7A-SCN11A and SCN1B-SCN4B. In twenty patients (20/414, 4.8%), a potentially pathogenic heterozygous variant was identified in an ion-channel gene (ICG). Variants were present in seven genes, for two patients (0.5%) in ANO3, one (0.2%) in KCNK18, two (0.5%) in KCNQ3, seven (1.7%) in TRPA1, three (0.7%) in TRPM8, three (0.7%) in TRPV1 and two (0.5%) in TRPV3. Variants in the TRP genes were the most frequent (n = 15, 3.6%), partly in patients with high mean maximal pain scores VAS = 9.65 ± 0.7 (n = 4). Patients with ICG variants reported more severe pain compared to patients without such variants (VAS = 9.36 ± 0.72 vs. VAS = 7.47 ± 2.37). This cohort study identified ICG variants in neuropathic pain in SFN, complementing previous findings of ICG variants in diabetic neuropathy. These data show that ICG variants are central in neuropathic pain of different etiologies and provides promising gene candidates for future research.

In a context of high demand for hospital services among older people, we aimed to assess the rate and determinants of inappropriate hospitalizations of older patients, and to what extent they were associated with inappropriate hospital stay. This prospective observational multicentre study evaluated a random sample of consecutive patients aged ≥ 70 years accessing the Emergency Department (ED) of two Italian tertiary hospitals. A standardized comprehensive geriatric assessment was carried out in each patient, including the Blaylock Risk Assessment Screen Scale (BRASS) for identification of patients at risk of difficult discharge. Inappropriate hospitalization was defined by the ED physician when patients did not necessitate hospital-provided procedures but was due to social reasons or lack of an alternative care-setting. Among 1877 patients (median age 80.7 years, 50.1% male), with a high prevalence of functional dependence and social isolation (around 30% and 25%, respectively), 767 (40.9%) were hospitalized. Incidence of inappropriate hospitalization was 14.6% (95% CI 12.1%-17.1%) and was associated with moderate-high risk of difficult discharge at BRASS (OR = 1.98, 95% CI 1.16-3.39, p = 0.013) and the presence of dementia with behavioural disorders (OR = 1.79, 95% CI 1.10-2.91, p = 0.020). Compared with patients appropriately admitted, inappropriate hospitalizations had shorter length of hospital stay but accounted for 1059/9154 days of stay (11.6%). Inappropriate hospitalizations occurred in less than 15% of cases, mainly accounted for by patients no longer manageable at home, but contributed to the greatest proportion of inappropriate hospital stay. These findings highlight the need of implementing appropriate home-care services and ensuring rapid access to suitable care-facilities for community-dwelling frail older patients.

Introduction Electrophysiological diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) may be challenging. Thus, with the aim ofproviding some practical advice in electrophysiological approach to a patient with suspected CIDP, we analyzed electrophysiological data from 499 patients enrolled inthe Italian CIDP Database. Methods We calculated the rate of each demyelinating feature, the rate of demyelinating features per nerve, the diagnostic rate for upper andlower limb nerves, and, using a ROC curve analysis, the diagnostic accuracy of each couple of nerves and each demyelinating feature, for every CIDP subtype.Moreover, we compared the electrophysiological data of definite and probable CIDP patients with those of possible and not-fulfilling CIDP patients, and by a logisticregression analysis, we estimated the odds ratio (OR) to make an electrophysiological diagnosis of definite or probable CIDP. Results The ulnar nerve had the highestrate of demyelinating features and, when tested bilaterally, had the highest diagnostic accuracy except for DADS in which peroneal nerves were the most informative.In possible and not-fulfilling CIDP patients, a lower number of nerves and proximal temporal dispersion (TD) measurements had been performed compared to definiteand probable CIDP patients. Importantly, OR for each tested motor nerve and each TD measurement was 1.59 and 1.33, respectively. Conclusion Our findingsdemonstrated that the diagnosis of CIDP may be missed due to inadequate or incomplete electrophysiological examination or interpretation. At the same time, thesedata taken together could be useful to draw a thoughtful electrophysiological approach to patients suspected of CIDP.

ObjectiveTo present standardized diagnostic criteria for idiopathic distal sensory polyneuropathy (iDSP) and its subtypes: idiopathic mixed fiber sensory neuropathy (iMFN), idiopathic small fiber sensory neuropathy (iSFN), and idiopathic large fiber sensory neuropathy (iLFN) for use in research.MethodsThe Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities and Networks (ACTTION) public-private partnership with the Food and Drug Administration convened a meeting to develop consensus diagnostic criteria for iMFN, iSFN, and iLFN. After background presentations, a collaborative, iterative approach was used to develop expert consensus for new criteria.ResultsAn iDSP diagnosis requires at least 1 small fiber (SF) or large fiber (LF) symptom, at least 1 SF or LF sign, abnormalities in sensory nerve conduction studies (NCS) or distal intraepidermal nerve fiber density (IENFD), and exclusion of known etiologies. An iMFN diagnosis requires that at least 1 of the above clinical features is SF and 1 clinical feature is LF with abnormalities in sensory NCS or IENFD. Diagnostic criteria for iSFN require at least 1 SF symptom and at least 1 SF sign with abnormal IENFD, normal sensory NCS, and the absence of LF symptoms and signs. Diagnostic criteria for iLFN require at least 1 LF symptom and at least 1 LF sign with normal IENFD, abnormal sensory NCS, and absence of SF symptoms and signs.ConclusionAdoption of these standardized diagnostic criteria will advance research and clinical trials and spur development of novel therapies for iDSPs.

Introduction Subcutaneous sumatriptan, a 5HT1B/1D agonist, is the most effective drug in cluster headache acute treatment. About 25% of the patients do not respond to subcutaneous sumatriptan; the reasons for this are unknown. In this study, we compare clinical characteristics of cluster headache patients responding and non-responding to subcutaneous sumatriptan. Methods We retrospectively investigated the clinical records of 277 cluster headache patients. Patients reporting repeated satisfactory response to subcutaneous sumatriptan within 15 minutes were considered responders. Results Of 206 cluster headache patients who had used subcutaneous sumatriptan (mean age 45.6, 16% females, 48% chronic), 91% were responders, and 9% non-responders. Compared to responders, non-responders had longer and more frequent attacks: 60 (median; IQR 38–90) vs. 100 (60–120) minutes ( p = 0.028), 4 (2.5–5) vs. 3 (2–4) attacks/day ( p = 0.024). No other difference was found. Conclusions In cluster headache attacks with long duration and high frequency, pain mechanisms not involving 5HT1B/1D receptors may play a more relevant role.

Small fiber neuropathy (SFN) is a heterogeneous group of disorders affecting thin myelinated Aδ and unmyelinated C fibers. Common symptoms include neuropathic pain and autonomic disturbances, and the typical clinical presentation is that of a length-dependent polyneuropathy, although other distributions could be present.This review focuses on several aspects of SFN including etiology, clinical presentation, diagnostic criteria and tests, management, and future perspectives. Diagnostic challenges are discussed, encompassing the role of accurate and standardized assessment of symptoms and signs and providing clues for the clinical practice. The authors discuss the evidence in support of skin biopsy and quantitative sensory testing as diagnostic tests and present an overview of other diagnostic techniques to assess sensory and autonomic fibers dysfunction. The authors also suggest a systematic approach to the etiology including a set of laboratory tests and genetic examinations of sodium channelopathies and other rare conditions that might drive the therapeutic approach based on underlying cause or symptoms treatment.SFN provides a useful model for neuropathic pain whose known mechanisms and cause could pave the way toward personalized treatments.

Increasing literature has linked COVID-19 to peripheral nervous system (PNS) diseases. In addition, as we move from the pandemic to the vaccination era, literature interest is shifting towards the potential association between COVID-19 vaccines and PNS manifestations. We reviewed published literature on COVID-19, COVID-19 vaccines and PNS manifestations between 1 January 2020 and 1 December 2021. For Guillain-Barré syndrome (GBS), isolated cranial neuropathy (ICN) and myositis associated with COVID-19, the demographic, clinical, laboratory, electrophysiological and imaging features were included in a narrative synthesis. We identified 169 studies on COVID-19-associated complications, including 63 papers (92 patients) on GBS, 29 papers (37 patients) on ICN and 11 papers (18 patients) on myositis. Additional clinical phenotypes included chronic inflammatory demyelinating polyneuropathy, vasculitic neuropathies, neuralgic amyotrophy, critical care-related complications, and myasthenia gravis. PNS complications secondary to COVID-19 vaccines have been reported during randomized clinical trials, in real-world case reports, and during large-scale surveillance programs. These mainly include cases of GBS, Bell's palsy, and cases of neuralgic amyotrophy. Based on our extensive review of the literature, any conclusion about a pathophysiological correlation between COVID-19 and PNS disorders remains premature, and solely supported by their temporal association, while epidemiological and pathological data are insufficient. The occurrence of PNS complications after COVID-19 vaccines seems limited to a possible higher risk of facial nerve palsy and GBS, to a degree that widespread access to the ongoing vaccination campaign should not be discouraged, while awaiting for more definitive data from large-scale surveillance studies.

The SARS-CoV-2 Omicron variant emerged in South Africa in November 2021, and has later been identified worldwide, raising serious concerns. A real-time RT-PCR assay was designed for the rapid screening of the Omicron variant, targeting characteristic mutations of the spike gene. The assay was used to test 737 sewage samples collected throughout Italy (19/21 Regions) between 11 November and 25 December 2021, with the aim of assessing the spread of the Omicron variant in the country. Positive samples were also tested with a real-time RT-PCR developed by the European Commission, Joint Research Centre (JRC), and through nested RT-PCR followed by Sanger sequencing. Overall, 115 samples tested positive for Omicron SARS-CoV-2 variant. The first occurrence was detected on 7 December, in Veneto, North Italy. Later on, the variant spread extremely fast in three weeks, with prevalence of positive wastewater samples rising from 1.0% (1/104 samples) in the week 5-11 December, to 17.5% (25/143 samples) in the week 12-18, to 65.9% (89/135 samples) in the week 19-25, in line with the increase in cases of infection with the Omicron variant observed during December in Italy. Similarly, the number of Regions/Autonomous Provinces in which the variant was detected increased from one in the first week, to 11 in the second, and to 17 in the last one. The presence of the Omicron variant was confirmed by the JRC real-time RT-PCR in 79.1% (91/115) of the positive samples, and by Sanger sequencing in 66% (64/97) of PCR amplicons. In conclusion, we designed an RT-qPCR assay capable to detect the Omicron variant, which can be successfully used for the purpose of wastewater-based epidemiology. We also described the history of the introduction and diffusion of the Omicron variant in the Italian population and territory, confirming the effectiveness of sewage monitoring as a powerful surveillance tool.

Background and purpose Previously it has been shown that patients with painful diabetic neuropathy (PDN) have greater corneal nerve loss compared to patients with painless diabetic neuropathy. This study investigated if the severity of corneal nerve loss was related to the severity of PDN. Methods Participants with diabetic neuropathy (n = 118) and healthy controls (n = 38) underwent clinical and neurological evaluation, quantitative sensory testing, nerve conduction testing and corneal confocal microscopy and were categorized into those with no (n = 43), mild (n = 34) and moderate-to-severe (n = 41) neuropathic pain. Results Corneal nerve fibre density (p = 0.003), corneal nerve fibre length (p < 0.0001) and cold perception threshold (p < 0.0001) were lower and warm perception threshold was higher (p = 0.002) in patients with more severe pain, but there was no significant difference in the neuropathy disability score (p = 0.5), vibration perception threshold (p = 0.5), sural nerve conduction velocity (p = 0.3) and amplitude (p = 0.7), corneal nerve branch density (p = 0.06) and deep breathing heart rate variability (p = 0.08) between patients with differing severity of PDN. The visual analogue scale correlated significantly with corneal nerve fibre density (r = -0.3, p = 0.0002), corneal nerve branch density (r = -0.3, p = 0.001) and corneal nerve fibre length (r = -0.4, p < 0.0001). Receiver operating curve analysis showed that corneal nerve fibre density had an area under the curve of 0.78 with a sensitivity of 0.73 and specificity of 0.72 for the diagnosis of PDN. Conclusions Corneal confocal microscopy reveals increasing corneal nerve fibre loss with increasing severity of neuropathic pain and a good diagnostic outcome for identifying patients with PDN.

Objective: To investigate the frequency and clinical correlates of anti-nerve autoantibodies in an unselected series of Italian patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) Methods: Sera from 276 CIDP patients fulfilling the EFNS/PNS criteria and included in the Italian CIDP database were examined for the presence of anti-nerve autoantibodies. Results were correlated with the clinical data collected in the database. Results: Anti-neurofascin155 (NF155) antibodies were found in 9/258 (3.5%) patients, anti-contactin1 (CNTN1) antibodies in 4/258 (1.6%) patients, and anti-contactin-associated protein1 (Caspr1) in 1/197 (0.5%) patients, while none had reactivity to gliomedin or neurofascin 186. Predominance of IgG4 isotype was present in 7of the 9 examined patients. Anti-NF155 patients more frequently had ataxia, tremor, and higher CSF protein levels than antibody-negative patients. Anti-CNTN1 patients more frequently had a GBS-like onset, pain, and ataxia and had more severe motor impairment at enrollment than antibody-negative patients. They more frequently received plasmapheresis, possibly reflecting a less satisfactory response to IVIg or steroids. IgM antibodies against one or more gangliosides were found in 6.5% of the patients (17/260) and were more frequently directed against GM1 (3.9%). They were frequently associated with a progressive course, with a multifocal sensorimotor phenotype and less frequent cranial nerve involvement and ataxia. Conclusions: Anti-paranodal and anti-ganglioside antibodies are infrequent in patients with CIDP but are associated with some typical clinical association supporting the hypothesis that CIDP might be a pathogenically heterogeneous syndrome possibly explaining the different clinical presentations.

To evaluate multichannel laser evoked potentials (LEPs) in patients with fibromyalgia (FM) and small fiber impairment.We recorded LEPs using 65 electrodes in 22 patients with FM and proximal denervation, 18 with normal skin biopsy, and 7 with proximal and distal intraepidermal nerve fiber density (IENFD) reduction. We considered the amplitude and topographical distribution of N1, N2 and P2 components, and habituation of N2 and P2 waves. The sLORETA dipolar analysis was also applied. We evaluated 15 healthy subjects as controls.We observed reduced amplitude of the P2 component in FM group, without a topographic correspondence with the prevalent site of denervation. Decreased habituation of P2 prevailed in patients with reduced IENFD. The cingulate cortex and prefrontal cortex, were activated in the FM group, without correlation between the degree of denervation and the strength of late wave dipoles. A correlation was noted between anxiety, depression, fibromyalgia invalidity, and pain diffusion.The amplitude and topography of LEPs were not coherent with epidermal nerve fiber density loss. They supposedly reflected the clinical expression of pain and psychopathological factors.Multichannel LEPs are not the expression of small fiber impairment in FM. Rather, they reflect the complexity of the disease.

Mutations in the alpha subunit of voltage-gated sodium channel 1.7 (NaV1.7), encoded by SCN9A gene, play an important role in the regulation of nociception and can lead to a wide range of clinical outcomes, ranging from extreme pain syndromes to congenital inability to experience pain. To expand the phenotypic and genotypic spectrum of SCN9A-related channelopathies, we describe the proband, a daughter born from consanguineous parents, who had pain insensitivity, diminished temperature sensation, foot burns, and severe loss of nociceptive nerve fibers in the epidermis. Next-generation sequencing of SCN9A (NM_002977.3) revealed a novel homozygous substitution (c.377+7TG) in the donor splice site of intron 3. As the RNA functional testing is challenging, the in silico analysis is the first approach to predict possible alterations. In this case, the computational analysis was unable to identify the splicing consensus and could not provide any prediction for splicing defects. The affected intron indeed belongs to the U12 type, a family of introns characterised by noncanonical consensus at the splice sites, accounting only for 0.35% of all human introns, and is not included in most of the training sets for splicing prediction. A functional study on proband RNA showed different aberrant transcripts, where exon 3 was missing and an intron fragment was included. A quantification study using real-time polymerase chain reaction showed a significant reduction of the NaV1.7 canonical transcript. Collectively, these data widen the spectrum of SCN9A-related insensitivity to pain by describing a mutation causing NaV1.7 deficiency, underlying the nociceptor dysfunction, and highlight the importance of molecular investigation of U12 introns' mutations despite the silent prediction.

We read the article of Savioli G. et al. [...].

Definitive diagnostic criteria for small fibre neuropathy have yet to be established, with implications both for clinical practice and for the design of clinical trials. Devigili et al. demonstrate that a combined approach – with clinical, functional and structural assessment of small nerve fibres – improves the reliability of diagnosis., The diagnostic criteria for small fibre neuropathy are not established, influencing the approach to patients in clinical practice, their access to disease-modifying and symptomatic treatments, the use of healthcare resources, and the design of clinical trials. To address these issues, we performed a reappraisal study of 150 patients with sensory neuropathy and a prospective and follow-up validation study of 352 new subjects with suspected sensory neuropathy. Small fibre neuropathy diagnostic criteria were based on deep clinical phenotyping, quantitative sensory testing (QST) and intraepidermal nerve fibre density (IENFD). Small fibre neuropathy was ruled out in 5 of 150 patients (3.3%) of the reappraisal study. Small fibre neuropathy was diagnosed at baseline of the validation study in 149 of 352 patients (42.4%) based on the combination between two clinical signs and abnormal QST and IENFD (69.1%), abnormal QST alone (5.4%), or abnormal IENFD alone (20.1%). Eight patients (5.4%) had abnormal QST and IENFD but no clinical signs. Further, 38 patients complained of sensory symptoms but showed no clinical signs. Of those, 34 (89.4%) had normal QST and IENFD, 4 (10.5%) had abnormal QST and normal IENFD, and none had abnormal IENFD alone. At 18-month follow-up, 19 of them (56%) reported the complete recovery of symptoms and showed normal clinical, QST and IENFD findings. None of those with one single abnormal test (QST or IENFD) developed clinical signs or showed abnormal findings on the other test. Conversely, all eight patients with abnormal QST and IENFD at baseline developed clinical signs at follow-up. The combination of clinical signs and abnormal QST and/or IENFD findings can more reliably lead to the diagnosis of small fibre neuropathy than the combination of abnormal QST and IENFD findings in the absence of clinical signs. Sensory symptoms alone should not be considered a reliable screening feature. Our findings demonstrate that the combined clinical, functional and structural approach to the diagnosis of small fibre neuropathy is reliable and relevant both for clinical practice and clinical trial design.

The ability to generate human‐induced pluripotent stem cell (hiPSC)‐derived neural cells displaying region‐specific phenotypes is of particular interest for modeling central nervous system biology in vitro. We describe a unique method by which spinal cord hiPSC‐derived astrocytes (hiPSC‐A) are cultured with spinal cord hiPSC‐derived motor neurons (hiPSC‐MN) in a multielectrode array (MEA) system to record electrophysiological activity over time. We show that hiPSC‐A enhance hiPSC‐MN electrophysiological maturation in a time‐dependent fashion. The sequence of plating, density, and age in which hiPSC‐A are cocultured with MN, but not their respective hiPSC line origin, are factors that influence neuronal electrophysiology. When compared to coculture with mouse primary spinal cord astrocytes, we observe an earlier and more robust electrophysiological maturation in the fully human cultures, suggesting that the human origin is relevant to the recapitulation of astrocyte/motor neuron crosstalk. Finally, we test pharmacological compounds on our MEA platform and observe changes in electrophysiological activity, which confirm hiPSC‐MN maturation. These findings are supported by immunocytochemistry and real‐time PCR studies in parallel cultures demonstrating human astrocyte mediated changes in the structural maturation and protein expression profiles of the neurons. Interestingly, this relationship is reciprocal and coculture with neurons influences astrocyte maturation as well. Taken together, these data indicate that in a human in vitro spinal cord culture system, astrocytes support hiPSC‐MN maturation in a time‐dependent and species‐specific manner and suggest a closer approximation of in vivo conditions. stem cells translational medicine 2019;8:1272&1285, We describe a fully human, spinal cord‐specific, coculture platform with human‐induced pluripotent stem cell‐derived motor neurons and astrocytes for multielectrode array recording. We show that human‐induced pluripotent stem cell‐derived motor neurons/human‐induced pluripotent stem cell‐derived astrocytes bidirectional morphological and molecular maturation is reflected by electrophysiological recordings with multielectrode array recording.

Small-fiber neuropathy (SFN) is a disorder of thinly myelinated A delta and unmyelinated C fibers. SFN is clinically dominated by neuropathic pain and autonomic complaints, leading to a significant reduction in quality of life. According to international criteria, the diagnosis is established by the assessment of intraepidermal nerve fiber density and/or quantitative sensory testing. SFN is mainly associated with autoimmune diseases, sodium channel gene variants, diabetes mellitus, and vitamin B12 deficiencies, although in more than one half of patients no etiology can be identified. Recently, gain-of-function variants in the genes encoding for the Na(v)1.7, Na(v)1.8 and Na(v)1.9 sodium channel subunits have been discovered in SFN patients, enlarging the spectrum of underlying conditions. Sodium channel gene variants associated with SFN can lead to a diversity of phenotypes, including different pain distributions and presence or absence of autonomic symptoms. This suggests that SFN is part of a clinical continuum. New assessments might contribute to a better understanding of the cellular and molecular substrates of SFN and might provide improved diagnostic methods and trial designs in the future. Identification of the underlying mechanisms may inform the development of drugs that more effectively address neuropathic pain and autonomic symptoms of SFN.

Neuropathic pain is common in diabetic peripheral neuropathy (DN), probably caused by pathogenic ion channel gene variants. Therefore, we performed molecular inversion probes-next generation sequencing of 5 transient receptor potential cation channels, 8 potassium channels and 2 calcium-activated chloride channel genes in 222 painful- and 304 painless-DN patients. Twelve painful-DN (5.4%) patients showed potentially pathogenic variants (five nonsense/frameshift, seven missense, one out-of-frame deletion) in ANO3 (n = 3), HCN1 (n = 1), KCNK18 (n = 2), TRPA1 (n = 3), TRPM8 (n = 3) and TRPV4 (n = 1) and fourteen painless-DN patients (4.6%—three nonsense/frameshift, nine missense, one out-of-frame deletion) in ANO1 (n = 1), KCNK18 (n = 3), KCNQ3 (n = 1), TRPA1 (n = 2), TRPM8 (n = 1), TRPV1 (n = 3) and TRPV4 (n = 3). Missense variants were present in both conditions, presumably with loss- or gain-of-functions. KCNK18 nonsense/frameshift variants were found in painless/painful-DN, making a causal role in pain less likely. Surprisingly, premature stop-codons with likely nonsense-mediated RNA-decay were more frequent in painful-DN. Although limited in number, painful-DN patients with ion channel gene variants reported higher maximal pain during the night and day. Moreover, painful-DN patients with TRP variants had abnormal thermal thresholds and more severe pain during the night and day. Our results suggest a role of ion channel gene variants in neuropathic pain, but functional validation is required.

BackgroundNeuropathic pain is common in peripheral neuropathy. Recent genetic studies have linked pathogenic voltage-gated sodium channel (VGSC) variants to human pain disorders. Our aims are to determine the frequency of SCN9A, SCN10A and SCN11A variants in patients with pure small fibre neuropathy (SFN), analyse their clinical features and provide a rationale for genetic screening.MethodsBetween September 2009 and January 2017, 1139 patients diagnosed with pure SFN at our reference centre were screened for SCN9A, SCN10A and SCN11A variants. Pathogenicity of variants was classified according to established guidelines of the Association for Clinical Genetic Science and frequencies were determined. Patients with SFN were grouped according to the VGSC variants detected, and clinical features were compared.ResultsAmong 1139 patients with SFN, 132 (11.6%) patients harboured 73 different (potentially) pathogenic VGSC variants, of which 50 were novel and 22 were found in ≥ 1 patient. The frequency of (potentially) pathogenic variants was 5.1% (n=58/1139) for SCN9A, 3.7% (n=42/1139) for SCN10A and 2.9% (n=33/1139) for SCN11A. Only erythromelalgia-like symptoms and warmth-induced pain were significantly more common in patients harbouring VGSC variants.Conclusion(Potentially) pathogenic VGSC variants are present in 11.6% of patients with pure SFN. Therefore, genetic screening of SCN9A, SCN10A and SCN11A should be considered in patients with pure SFN, independently of clinical features or underlying conditions.

Motor neuron diseases (MNDs) are neurodegenerative disorders characterized by upper and/or lower MN loss. MNDs include amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), and spinal and bulbar muscular atrophy (SBMA). Despite variability in onset, progression, and genetics, they share a common skeletal muscle involvement, suggesting that it could be a primary site for MND pathogenesis. Due to the key role of muscle-specific microRNAs (myomiRs) in skeletal muscle development, by real-time PCR we investigated the expression of miR-206, miR-133a, miR-133b, and miR-1, and their target genes, in G93A-SOD1 ALS, Δ7SMA, and KI-SBMA mouse muscle during disease progression. Further, we analyzed their expression in serum of SOD1-mutated ALS, SMA, and SBMA patients, to demonstrate myomiR role as noninvasive biomarkers. Our data showed a dysregulation of myomiRs and their targets, in ALS, SMA, and SBMA mice, revealing a common pathogenic feature associated with muscle impairment. A similar myomiR signature was observed in patients’ sera. In particular, an up-regulation of miR-206 was identified in both mouse muscle and serum of human patients. Our overall findings highlight the role of myomiRs as promising biomarkers in ALS, SMA, and SBMA. Further investigations are needed to explore the potential of myomiRs as therapeutic targets for MND treatment.

Background Mutation-induced variations in the functional architecture of the NaV1.7 channel protein are causally related to a broad spectrum of human pain disorders. Predicting in silico the phenotype of NaV1.7 variant is of major clinical importance; it can aid in reducing costs of in vitro pathophysiological characterization of NaV1.7 variants, as well as, in the design of drug agents for counteracting pain-disease symptoms. Results In this work, we utilize spatial complexity of hydropathic effects toward predicting which NaV1.7 variants cause pain (and which are neutral) based on the location of corresponding mutation sites within the NaV1.7 structure. For that, we analyze topological and scaling hydropathic characteristics of the atomic environment around NaV1.7’s pore and probe their spatial correlation with mutation sites. We show that pain-related mutation sites occupy structural locations in proximity to a hydrophobic patch lining the pore while clustering at a critical hydropathic-interactions distance from the selectivity filter (SF). Taken together, these observations can differentiate pain-related NaV1.7 variants from neutral ones, i.e., NaV1.7 variants not causing pain disease, with 80.5$$\%$$ % sensitivity and 93.7$$\%$$ % specificity [area under the receiver operating characteristics curve = 0.872]. Conclusions Our findings suggest that maintaining hydrophobic NaV1.7 interior intact, as well as, a finely-tuned (dictated by hydropathic interactions) distance from the SF might be necessary molecular conditions for physiological NaV1.7 functioning. The main advantage for using the presented predictive scheme is its negligible computational cost, as well as, hydropathicity-based biophysical rationalization.

Background Syncope is not a common manifestation of COVID-19, but it may occur in this context and it can be the presenting symptom in some cases. Different mechanisms may explain the pathophysiology behind COVID-19 related syncope. In this report, we aimed to examine the current frequency and etiology of syncope in COVID-19. Methods A systematic review across PubMed, ISI Web of Knowledge and SCOPUS was performed, according to PRISMA guidelines, in order to identify all relevant articles regarding both COVID-19 and syncope. Results We identified 136 publications, of which 99 were excluded. The frequency of syncope and pre-syncope across the selected studies was 4.2% (604/14,437). Unexplained syncope was the most common type (87.9% of the episodes), followed by reflex syncope (7.8% of the cases). Orthostatic hypotension was responsible for 2.2% of the cases and syncope of presumable cardiac cause also accounted for 2.2% of cases. Arterial hypertension was present in 52.0% of syncope patients. The use of angiotensin receptor blockers or angiotensin converting enzyme inhibitors were not associated with an increased incidence of syncope (chi-square test 1.07, p 0.30), unlike the use of beta-blockers (chi-square test 12.48, p Conclusion Syncope, although not considered a typical symptom of COVID-19, can be associated with it, particularly in early stages. Different causes of syncope were seen in this context. A reevaluation of blood pressure in patients with COVID-19 is suggested, including reassessment of antihypertensive therapy, especially in the case of beta-blockers.

We read with interest the publication entitled “In vivo distribution of α-synuclein in multiple tissues and biofluids in Parkinson disease.”1 In the article, Chahine et al.1 discuss the results of the Systemic Synuclein Sampling Study (S4 study). This was an important step toward the in vivo diagnosis of synucleinopathy. Unfortunately, although the detection of phosphorylated alpha-synuclein was highly specific, sensitivity was quite poor, particularly for skin (with a sensitivity of 24.1%). The authors note that there were several explanations for such findings, including the earlier diagnosis of PD in the S4 study compared with the relatively small studies performed at other centers.

Strong evidence suggests that endoplasmic reticulum stress plays a critical role in the pathogenesis of amyotrophic lateral sclerosis (ALS) through altered regulation of proteostasis. Robust preclinical findings demonstrated that guanabenz selectively inhibits endoplasmic reticulum stress-induced eIF2α-phosphatase, allowing misfolded protein clearance, reduces neuronal death and prolongs survival in in vitro and in vivo models. However, its safety and efficacy in patients with ALS are unknown. To address these issues, we conducted a multicentre, randomized, double-blind trial with a futility design. Patients with ALS who had displayed an onset of symptoms within the previous 18 months were randomly assigned in a 1:1:1:1 ratio to receive 64 mg, 32 mg or 16 mg of guanabenz or placebo daily for 6 months as an add-on therapy to riluzole. The purpose of the placebo group blinding was to determine safety but not efficacy. The primary outcome was the proportion of patients progressing to higher stages of disease within 6 months as measured using the ALS Milano-Torino staging system, compared with a historical cohort of 200 patients with ALS. The secondary outcomes were the rate of decline in the total revised ALS functional rating scale score, slow vital capacity change, time to death, tracheotomy or permanent ventilation and serum light neurofilament level at 6 months. The primary assessment of efficacy was performed using intention-to-treat analysis. The treatment arms using 64 mg and 32 mg guanabenz, both alone and combined, reached the primary hypothesis of non-futility, with the proportions of patients who progressed to higher stages of disease at 6 months being significantly lower than that expected under the hypothesis of non-futility and a significantly lower difference in the median rate of change in the total revised ALS functional rating scale score. This effect was driven by patients with bulbar onset, none of whom (0/18) progressed to a higher stage of disease at 6 months compared with those on 16 mg guanabenz (4/8; 50%), the historical cohort alone (21/49; 43%; P = 0.001) or plus placebo (25/60; 42%; P = 0.001). The proportion of patients who experienced at least one adverse event was higher in any guanabenz arm than in the placebo arm, with higher dosing arms having a significantly higher proportion of drug-related side effects and the 64 mg arm a significantly higher drop-out rate. The number of serious adverse events did not significantly differ between the guanabenz arms and the placebo. Our findings indicate that a larger trial with a molecule targeting the unfolded protein response pathway without the alpha-2 adrenergic related side-effect profile of guanabenz is warranted., ER stress plays a key role in ALS pathogenesis through altered regulation of proteostasis. In a phase 2 futility trial, Dalla Bella et al. show that the alpha-2 adrenergic receptor agonist guanabenz reduces the proportion of patients progressing to higher stages of disease at 6 months compared to historical controls.

Objective: Long-term life experiences, such as education, occupational attainment, leisure activities, and bilingualism, have been considered proxies of cognitive reserve (CR). In neurodegenerative disease, CR is considered as a modulator of a more favorable cognitive trajectory and motor functions. Our study investigated the role of CR on cognitive and motor involvement in a large cohort of incident patients with amyotrophic lateral sclerosis (ALS). Methods: Cognition assessment and clinical and demographic information were obtained in 101 incident ALS patients. CR was measured based on years of education, occupational attainment, amount of leisure activities, and bilingualism. Correlation and regression analyses were performed to test the association between CR and the clinical expression of ALS. Results: We found that all proxies of CR were positively associated with executive functions, verbal fluency, and memory domains. Motor impairment was inversely related to educational level and occupational attainment. Regression analysis documented the association between CR and cognitive performances in all patients and the predictive role of CR in modulating motor functional disability in patients with bulbar-onset. Conclusion: Our findings showed that CR mediates the extent of cognitive decline and that of functional bulbar impairment, suggesting that the concept of reserve applied to ALS should encompass cognitive and motor domains.

We describe clinical and laboratory findings in 35 patients tested positive for SARS-CoV-2 by reverse transcriptase-polymerase chain reaction on nasopharyngeal swab experiencing one or multiple syncope at disease onset. Clinical neurologic and cardiologic examination, and electrocardiographic findings were normal. Chest computed tomography showed findings consistent with interstitial pneumonia. Arterial blood gas analysis showed low pO2, pCO2, and ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) indicating hypocapnic hypoxemia. Patients who presented with syncope showed significantly lower heart rate as compared to 68 SARS-CoV-2 positive that did not. Such poorer than expected compensatory heart rate increase may have led to syncope based on individual susceptibility. We speculate that SARS-CoV-2 could have caused angiotensin-converting enzyme-2 (ACE2) receptor internalization in the nucleus of the solitary tract and other midbrain nuclei, impairing baroreflex and chemoreceptor response, and inhibiting the compensatory tachycardia during acute hypocapnic hypoxemia.

Amyotrophic lateral sclerosis (ALS) is a heterogeneous neurodegenerative disease marked by progressive loss of motor abilities. Approximately half of patents with ALS experience cognitive (ALSci) or behavioural impairment (ALSbi) during the course of the disease, with a small percentage developing overt frontotemporal dementia (FTD). ALSci and/or ALSbi can occur simultaneously with motor neuron degeneration or develop in advanced stages of the disease, but it can even precede motor involvement in some cases, namely in ALS patients meeting criteria for FTD. Despite clear evidence that cognitive/behavioural impairment may appear early in the course of ALS, no prominent deterioration seems to occur with disease progression. Longitudinal studies have failed to reach conclusive results on the progression of cognitive and behavioural involvement in ALS. This may be due to some structural limitations of the studies, such as attrition rate, practice effect, short-time interval between neuropsychological assessments, but it can also be due to the heterogeneity of ALS phenotypes. The objective of this review is to provide a comprehensive and critical analysis of results of longitudinal studies highlighting cognitive and behavioural domains mainly affected by neurodegeneration pointing out the determinants that might be associate with the development and worsening of frontotemporal symptoms in ALS. At this regard, older age, rapidly progressing ALS, bulbar-onset, advanced disease stages are among factors mainly associated with cognitive and behavioural involvement. Moreover, the progression of cognitive and behavioural deficits seems to be not directly related to the slope of motor disability, thus suggesting the independence of neuropsychological and motor functional decline in ALS. Cognitive and motor involvement may indeed present with distinct trajectories suggesting a differential vulnerability of motor and non-motor cortical networks. In this scenario, determining the progression of extra-motor involvement in ALS may help refine understanding of the clinical implications of cognitive and behavioural abnormalities, and provide clues to the aetiology of the disease.

Axonal degeneration is an active process that differs from neuronal death, and it is the hallmark of many disorders affecting the central and peripheral nervous system. Starting from the analyses of Wallerian degeneration, the simplest experimental model, here we describe how the long projecting neuronal populations affected in Parkinson’s disease and chemotherapy-induced peripheral neuropathies share commonalities in the mechanisms and molecular players driving the earliest phase of axon degeneration. Indeed, both dopaminergic and sensory neurons are particularly susceptible to alterations of microtubules and axonal transport as well as to dysfunctions of the ubiquitin proteasome system and protein quality control. Finally, we report an updated review on current knowledge of key molecules able to modulate these targets, blocking the on-going axonal degeneration and inducing neuronal regeneration. These molecules might represent good candidates for disease-modifying treatment, which might expand the window of intervention improving patients’ quality of life.

Hannu Laaksovirta konsortion jäsenenä. The Genomics England Research Consortium, The International ALS/FTD Genomics Consortium (iAFGC), The International FTD Genetics Consortium (IFGC), The International LBD Genomics Consortium (iLBDGC), The NYGC ALS Consortium, The PROSPECT Consortium,17 James B. Rowe,17 Luisa Benussi,18 Giuliano Binetti,18,19 Roberta Ghidoni,18 Edwin Jabbari,20,21 Coralie Viollet,22 Jonathan D. Glass,23 Andrew B. Singleton,24 Vincenzo Silani,25,26 Owen A. Ross,27 Mina Ryten,8,28,29 Ali Torkamani,30 Toshiko Tanaka,31 Luigi Ferrucci,31 Susan M. Resnick,32 We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40?64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts. We replicated our findings in an independent collection of 3,674 FTD/ALS patients. Postmortem evaluations of two patients revealed the classical TDP-43 pathology of FTD/ALS, as well as huntingtin-positive, ubiquitin-positive aggregates in the frontal cortex. The neostriatal atrophy that pathologically defines Huntington?s disease was absent in both cases. Our findings reveal an etiological relationship between HTT repeat expansions and FTD/ALS syndromes and indicate that genetic screening of FTD/ALS patients for HTT repeat expansions should be considered. We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40?64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts. We replicated our findings in an independent collection of 3,674 FTD/ALS patients. Postmortem evaluations of two patients revealed the classical TDP-43 pathology of FTD/ALS, as well as huntingtin-positive, ubiquitin-positive aggregates in the frontal cortex. The neostriatal atrophy that pathologically defines Huntington?s disease was absent in both cases. Our findings reveal an etiological relationship between HTT repeat expansions and FTD/ALS syndromes and indicate that genetic screening of FTD/ALS patients for HTT repeat expansions should be considered.

ObjectiveWe aimed at investigating the impact of COVID-19-related distress on patients with chronic pain, highlighting the effects of changes in individual habits and public health care reconfiguration on physical and psychological health.MethodsDuring the pandemic, 80 participants (25 patients with small fibre neuropathy (SFN), 42 patients with chronic migraine (CM) and 13 patients’ healthy family members (HFM)) were asked to evaluate their COVID-19 complains, changes in habits and clinical management, behaviour, mood, loneliness, quality of life (QoL), physical and mental health and coping strategies. Data were analysed by Spearman rho correlations and Mann-WhitneyUtests.ResultsPatients had lower QoL, lower physical health and higher catastrophizing attitude towards pain than HFM. During the pandemic, SFN patients referred greater decline in clinical symptoms, worries about contagion and discomfort for disease management changes than CM patients. In the SFN group, the higher levels of disability were associated with suffering from changes in neurologist-patient relationship. CM patients complained of agitation/anxiety that was related to feelings of loneliness, depressive mood and catastrophism.DiscussionDespite similar complains of change in habits and worries about COVID-19 pandemic, SFN and CM patients had distinct reactions. In SFN patients, pandemic distress impacted on physical health with worsening of clinical conditions, especially suffering from changes in their care. In CM patients, pandemic distress affected behaviour, mainly with psychological frailty. This suggests the need to customize public health care for patients with distinct chronic pain conditions.

OBJECTIVE To assess the diagnostic utility of corneal confocal microscopy (CCM) for diabetic peripheral neuropathy (DPN) and the risk factors for corneal nerve loss. RESEARCH DESIGN AND METHODS A total of 490 participants, including 72 healthy control subjects, 149 with type 1 diabetes, and 269 with type 2 diabetes, underwent detailed assessment of peripheral neuropathy and CCM in relation to risk factors. RESULTS Corneal nerve fiber density (CNFD) (P < 0.0001 and P < 0.0001), corneal nerve fiber branch density (CNBD) (P < 0.0001 and P < 0.0001), and corneal nerve fiber length (CNFL) (P < 0.0001 and P = 0.02) were significantly lower in patients with type 1 and type 2 diabetes compared with control subjects. CNFD (P < 0.0001), CNBD (P < 0.0001), and CNFL (P < 0.0001) were lower in type 1 diabetes compared with type 2 diabetes. Receiver operating characteristic curve analysis for the diagnosis of DPN demonstrated a good area under the curve for CNFD of 0.81, CNBD of 0.74, and CNFL of 0.73. Multivariable regression analysis showed a significant association among reduced CNFL with age (β = −0.27, P = 0.007), HbA1c (β = −1.1; P = 0.01), and weight (β = −0.14; P = 0.03) in patients with type 2 diabetes and with duration of diabetes (β = −0.13; P = 0.02), LDL cholesterol (β = 1.8, P = 0.04), and triglycerides (β = −2.87; P = 0.009) in patients with type 1 diabetes. CONCLUSIONS CCM identifies more severe corneal nerve loss in patients with type 1 diabetes compared with type 2 diabetes and shows good diagnostic accuracy for DPN. Furthermore, the risk factors for a reduction in corneal nerve fiber length differ between type 1 and type 2 diabetes.

Applications of machine learning and graph theory techniques to neuroscience have witnessed an increased interest in the last decade due to the large data availability and unprecedented technology developments. Their employment to investigate the effect of mutational changes in genes encoding for proteins modulating the membrane of excitable cells, whose biological correlates are assessed at electrophysiological level, could provide useful predictive clues. We apply this concept to the analysis of variants in sodium channel NaV1.7 subunit found in patients with chronic painful syndromes, by the implementation of a dedicated computational pipeline empowering different and complementary techniques including homology modeling, network theory, and machine learning. By testing three templates of different origin and sequence identities, we provide an optimal condition for its use. Our findings reveal the usefulness of our computational pipeline in supporting the selection of candidates for cell electrophysiology assay and with potential clinical applications.

Resolving the genetic architecture of painful neuropathy will lead to better disease management strategies. We aimed to develop a reliable method to re-sequence multiple genes in a large cohort of painful neuropathy patients at low cost. In this study, we compared sensitivity, specificity, targeting efficiency, performance and cost effectiveness of Molecular Inversion Probes-Next generation sequencing (MIPs-NGS) and TruSeq® Custom Amplicon-Next generation sequencing (TSCA-NGS). Capture probes were designed to target nine sodium channel genes (SCN3A, SCN8A-SCN11A, and SCN1B-SCN4B). One hundred sixty-six patients with diabetic and idiopathic neuropathy were tested by both methods, 70 patients were validated by Sanger sequencing. Sensitivity, specificity and performance of both techniques were comparable, and in agreement with Sanger sequencing. The average targeted regions coverage for MIPs-NGS was 97.3% versus 93.9% for TSCA-NGS. MIPs-NGS has a more versatile assay design and is more flexible than TSCA-NGS. The cost of MIPs-NGS is >5 times cheaper than TSCA-NGS when 500 or more samples are tested. In conclusion, MIPs-NGS is a reliable, flexible, and relatively inexpensive method to detect genetic variations in a large cohort of patients. In our centers, MIPs-NGS is currently implemented as a routine diagnostic tool for screening of sodium channel genes in painful neuropathy patients.

The Polyneuropathy And Treatment with Hizentra (PATH) study required subjects with chronic inflammatory demyelinating polyneuropathy (CIDP) to show dependency on immunoglobulin G (IgG) and then be restabilized on IgG before being randomized to placebo or one of two doses of subcutaneous immunoglobulin (SCIG). Nineteen of the 51 subjects (37%) randomized to placebo did not relapse over the next 24 weeks. This article explores the reasons for this effect. A post‐hoc analysis of the PATH placebo group was undertaken. A literature search identified other placebo‐controlled CIDP trials for review and comparison. In PATH, subjects randomized to placebo who did not relapse were significantly older, had more severe disease, and took longer to deteriorate in the IgG dependency period compared with those who relapsed. Published trials in CIDP, whose primary endpoint was stability or deterioration, had a mean non‐deterioration (placebo effect) of 43%, while trials with a primary endpoint of improvement had a placebo response of only 11%. Placebo is an important variable in the design of CIDP trials. Trials designed to show clinical improvement will have a significantly lower effect of this phenomenon than those designed to show stability or deterioration.

Small-fiber neuropathy (SFN), characterized by distal unmyelinated or thinly myelinated fiber loss, produces a combination of sensory dysfunction and neuropathic pain. Gain-of-function variants in the sodium channel Na(v)1.7 that produce dorsal root ganglion (DRG) neuron hyperexcitability are present in 5% to 10% of patients with idiopathic painful SFN. We created 2 independent knock-in mouse lines carrying the Na(v)1.7 I228M gain-of-function variant, found in idiopathic SFN. Whole-cell patch-clamp and multielectrode array recordings show that Na(v)1.7 I228M knock-in DRG neurons are hyperexcitable compared with wild-type littermate-control neurons, but despite this, Na(v)1.7 I228M mice do not display mechanical or thermal hyperalgesia or intraepidermal nerve fiber loss in vivo. Therefore, although these 2 Na(v)1.7 I228M knock-in mouse lines recapitulate the DRG neuron hyperexcitability associated with gain-of-function mutations in Na(v)1.7, they do not recapitulate the pain or neuropathy phenotypes seen in patients. We suggest that the relationship between hyperexcitability in sensory neurons and the pain experienced by these patients may be more complex than previously appreciated and highlights the challenges in modelling channelopathy pain disorders in mice.

The clinical manifestations of amyotrophic lateral sclerosis (ALS) are variable in terms of age at disease onset, site of onset, progression of symptoms, motor neuron involvement, and the occurrence of cognitive and behavioral changes. Genetic background is a key determinant of the ALS phenotype. The mortality of the disease also varies with the ancestral origin of the affected population and environmental factors are likely to be associated with ALS at least within some cohorts. Disease heterogeneity is likely underpinned by the presence of different pathogenic mechanisms. A variety of ALS animal models can be informative about the heterogeneity of the neuropathological or genetic aspects of the disease and can support the development of new therapeutic intervention. Evolving biomarkers can contribute to the identification of differing genotypes and phenotypes, and can be used to explore whether genotypic and phenotypic differences in animal models might help to provide a better definition of the heterogeneity of ALS in humans. These include neurofilaments, peripheral blood mononuclear cells, extracellular vesicles, microRNA and imaging findings. These biomarkers might predict not only the development of the disease, but also the variability in progression, although robust validation is required. A promising area of progress in modeling the heterogeneity of human ALS is represented by the use of human induced pluripotent stem cell (iPSCs)-derived motor neurons. Although the translational value of iPSCs remains unclear, this model is attractive in the perspective of replicating the heterogeneity of sporadic ALS as a first step toward a personalized medicine strategy.