Brain metastases: Comparing clinical radiological differences in patients with lung and breast cancers treated with surgery.

Purpose: Brain metastases (BMs) most frequently originate from the primary tumors of the lung and breast. Survival in patients with BM can improve if they are detected early. No studies attempt to consider all potential surgical predictive factors together by including clinical, radiological variables for their recognition. Methods: The study aims to simultaneously analyze all clinical, radiologic, and surgical variables on a cohort of 314 patients with surgically-treated BMs to recognize the main features and differences between the two histotypes. Results: The two groups consisted of 179 BM patients from lung cancer (Group A) and 135 patients from breast cancer (Group B). Analysis showed that BMs from breast carcinoma are more likely to appear in younger patients, tend to occur in the infratentorial site and are frequently found in patients who have other metastases outside of the brain (46 %, p = 0.05), particularly in bones. On the other hand, BMs from lung cancer often occur simultaneously with primitive diagnosis, are more commonly cystic, and have a larger edema volume. However, no differences were found in the extent of resection, postoperative complications or the presence of decreased postoperative performance status. Conclusion: The data presented in this study reveal that while the two most prevalent forms of BM exhibit distinctions with respect to clinical onset, age, tumor location, presence of extra-cranial metastases, and lesion morphology from a strictly surgical standpoint, they are indistinguishable with regard to outcome, demonstrating comparable resection rates and a low risk of complications.

Neurological complications due to copper deficiency in the context of Wilson disease treatment: a case report with long-term follow-up and review of the literature.

The objective is to investigate the presentation, complications, management, and outcomes of copper deficiency-induced neurological pathologies due to Wilson disease (WD) overtreatment. We examined the case of a WD patient who developed a low thoracic dorsal myelopathy due to chronic hypocupremia from excessive zinc therapy. A comprehensive literature review was conducted to identify similar cases. Ten additional cases of neurological pathology resulting from copper deficiency in the context of WD over-treatment were identified, all occurring during therapy with zinc salts. Myelopathy and peripheral neuropathy were the most common complications, while two additional groups reported leukoencephalopathy. Early cytopenia was often associated with copper deficiency-related neurological pathology appearing early in the context of copper deficiency. WD patients undergoing treatment, especially with zinc salts, should be closely monitored to prevent over-treatment and the consequent copper deficiency. Regular complete blood counts could provide early detection of copper deficiency, avoiding irreversible neurological damage. Swift recognition of new neurological signs not consistent with WD and timely discontinuation of the decoppering therapy are critical for improving outcomes. The optimal management, including the potential benefit of copper supplementation in patients with WD and subsequent therapy adjustments, remains unclear and necessitates further investigation. Despite the general poor functional neurological outcomes, there were some exceptions that warrant further exploration.

A Case of Anti-Ma2 Encephalitis Presenting with Pendular Torsional Nystagmus.

Antibodies against the neuronal protein Ma2 have been reported in a peculiar form of paraneoplastic encephalitis with prominent involvement of the limbic, brainstem, and diencephalic structures and usually associated with germ cell testicular, lung, or breast cancer. The diagnosis is frequently challenged by atypical clinical manifestations including parkinsonism, sleep disturbances, hypothalamic-pituitary dysfunctions, and motor neuron-like syndrome. In recent years, the advent of monoclonal antibodies targeting immune checkpoints has deeply changed the treatment of different tumors, especially melanoma and lung cancer. However, given their nature, an increasing number of neurological immune-related adverse events, including ocular motor abnormalities, have been described. Here, we report a woman with advanced non-small cell lung cancer treated with anti-PD-L1 durvalumab, presenting with an isolated pendular torsional nystagmus, in association with anti-Ma2 antibodies. This peculiar case widens our knowledge on the clinical presentation of anti-Ma2 encephalitis associated with checkpoint inhibitors.

In inflammatory myopathies, dropped head/bent spine syndrome is associated with scleromyositis: an international case-control study.

BACKGROUND: Some myopathies can lead to dropped head or bent spine syndrome (DH/BS). The significance of this symptom has not been studied in inflammatory myopathies (IM). OBJECTIVES: To assess the significance of DH/BS in patients with IM. METHODS: Practitioners from five IM networks were invited to report patients with IM suffering from DH/BS (without other known cause than IM). IM patients without DH/BS, randomly selected in each participating centre, were included as controls at a ratio of 2 to 1. RESULTS: 49 DH/BS-IM patients (DH: 57.1%, BS: 42.9%) were compared with 98 control-IM patients. DH/BS-IM patients were older (65 years vs 53 years, p<0.0001) and the diagnosis of IM was delayed (6 months vs 3 months, p=0.009). Weakness prevailing in the upper limbs (42.9% vs 15.3%), dysphagia (57.1% vs 25.5%), muscle atrophy (65.3% vs 34.7%), weight loss (61.2% vs 23.5%) and loss of the ability to walk (24.5% vs 5.1%) were hallmarks of DH/BS-IM (p≤0.0005), for which the patients more frequently received intravenous immunoglobulins (65.3% vs 34.7%, p=0.0004). Moreover, DH/BS-IM patients frequently featured signs and/or complications of systemic sclerosis (SSc), fulfilling the American College of Rheumatology/European Alliance of Associations for Rheumatology criteria for this disease in 40.8% of the cases (vs 5.1%, p<0.0001). Distribution of the myopathy, its severity and its association with SSc were independently associated with DH/BS (p<0.05). Mortality was higher in the DH/BS-IM patients and loss of walking ability was independently associated with survival (p<0.05). CONCLUSION: In IM patients, DH/BS is a marker of severity and is associated with SSc (scleromyositis).

Visual System Involvement in Glial Fibrillary Acidic Protein Astrocytopathy: Two Case Reports and a Systematic Literature Review.

BACKGROUND AND OBJECTIVES: Glial fibrillary acidic protein (GFAP) antibodies can associate with an astrocytopathy often presenting as a meningoencephalitis. Visual involvement has been reported but scarcely defined. We describe 2 cases of GFAP astrocytopathy with predominant visual symptoms and present a systematic review of the literature. METHODS: We describe 2 patients with GFAP astrocytopathy from our neurology department. We performed a systematic review of the literature according to PRISMA guidelines, including all patients with this disease and available clinical data, focusing on visual involvement. RESULTS: Patient 1 presented with bilateral optic disc edema and severe sudden bilateral loss of vision poorly responsive to therapy. Patient 2 showed bilateral optic disc edema, headache, and mild visual loss with complete recovery after steroids. We screened 275 records and included 84 articles (62 case reports and 22 case series) for a total of 592 patients. Visual involvement was reported in 149/592 (25%), with either clinical symptoms or paraclinical test-restricted abnormalities. Bilateral optic disc edema was found in 80/159 (50%) of patients investigated with fundoscopy, among which 49/80 (61%) were asymptomatic. One hundred (100/592, 17%) reported visual symptoms, often described as blurred vision or transient visual obscurations. Optic neuritis was rare and diagnosed in only 6% of all patients with GFAP astrocytopathy, often without consistent clinical and paraclinical evidence to support the diagnosis. Four patients (including patient 1) manifested a severe, bilateral optic neuritis with poor treatment response. In patients with follow-up information, a relapsing disease course was more frequently observed in those with vs without visual involvement (35% vs 11%, p = 0.0035, OR 3.6 [CI 1.44-8.88]). DISCUSSION: Visual system involvement in GFAP astrocytopathy is common and heterogeneous, ranging from asymptomatic bilateral optic disc edema to severe bilateral loss of vision, but optic neuritis is rare. GFAP CSF antibody testing should be considered in patients with encephalitis/meningoencephalitis or myelitis and bilateral optic disc edema, even without visual symptoms, and in patients with severe bilateral optic neuritis, especially when AQP4 antibodies are negative. Visual symptoms might associate with a higher relapse risk and help to identify patients who may require chronic immunosuppression.

Progressive post infectious neurological syndromes with a poor outcome: Long term follow-up and neurofilament light chain quantification.

Postinfectious neurological syndromes (PINS), among which acute disseminated encephalomyelitis (ADEM), are inflammatory and mostly monophasic disorders. We previously reported that PINS patients can show relapses, or even disease progression. Here we describe a cohort of patients with progressive-PINS and >5 years of follow-up, that developed a progressive worsening without radiological/cerebrospinal fluid analysis evidence of inflammation. At onset 5 patients fulfilled diagnostic criteria for ADEM and none for MS. Progression occurred after a median of 22 months from onset (in 4/7 after 1/more relapses), manifesting as ascending tetraparesis with bulbar functions involvement in 5/7. Five/7 patients received high dose steroids and/or IvIG and 6/7 Rituximab(n = 4) and/or cyclophosphamide(n = 2), with no impact on disease progression in 6/7. NfL levels were higher in patients with progressive-PINS compared to monophasic-ADEM (p = 0.023) and healthy controls (p = 0.004). Progression is rare, but possible, in PINS. Immunotherapy seems to be ineffective in these patients, and elevated serum NfL in serum suggest persistent axonal damage.

Muscle quantitative MRI as a novel biomarker in hereditary transthyretin amyloidosis with polyneuropathy: a cross-sectional study.

BACKGROUND: The development of reproducible and sensitive outcome measures has been challenging in hereditary transthyretin (ATTRv) amyloidosis. Recently, quantification of intramuscular fat by magnetic resonance imaging (MRI) has proven as a sensitive marker in patients with other genetic neuropathies. The aim of this study was to investigate the role of muscle quantitative MRI (qMRI) as an outcome measure in ATTRv. METHODS: Calf- and thigh-centered multi-echo T2-weighted spin-echo and gradient-echo sequences were obtained in patients with ATTRv amyloidosis with polyneuropathy (n = 24) and healthy controls (n = 12). Water T2 (wT2) and fat fraction (FF) were calculated. Neurological assessment was performed in all ATTRv subjects. Quantitative MRI parameters were correlated with clinical and neurophysiological measures of disease severity. RESULTS: Quantitative imaging revealed significantly higher FF in lower limb muscles in patients with ATTRv amyloidosis compared to controls. In addition, wT2 was significantly higher in ATTRv patients. There was prominent involvement of the posterior compartment of the thighs. Noticeably, FF and wT2 did not exhibit a length-dependent pattern in ATTRv patients. MRI biomarkers correlated with previously validated clinical outcome measures, Polyneuropathy Disability scoring system, Neuropathy Impairment Score (NIS) and NIS-lower limb, and neurophysiological parameters of axonal damage regardless of age, sex, treatment and TTR mutation. CONCLUSIONS: Muscle qMRI revealed significant difference between ATTRv and healthy controls. MRI biomarkers showed high correlation with clinical and neurophysiological measures of disease severity making qMRI as a promising tool to be further investigated in longitudinal studies to assess its role at monitoring onset, progression, and therapy efficacy for future clinical trials on this treatable condition.

Guillain-Barré syndrome and COVID-19: A 1-year observational multicenter study.

BACKGROUND AND PURPOSE: Many single cases and small series of Guillain-Barré syndrome (GBS) associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were reported during the coronavirus disease 19 (COVID-19) outbreak worldwide. However, the debate regarding the possible role of infection in causing GBS is still ongoing. This multicenter study aimed to evaluate epidemiological and clinical findings of GBS diagnosed during the COVID-19 pandemic in northeastern Italy in order to further investigate the possible association between GBS and COVID-19. METHODS: Guillain-Barré syndrome cases diagnosed in 14 referral hospitals from northern Italy between March 2020 and March 2021 were collected and divided into COVID-19-positive and COVID-19-negative. As a control population, GBS patients diagnosed in the same hospitals from January 2019 to February 2020 were considered. RESULTS: The estimated incidence of GBS in 2020 was 1.41 cases per 100,000 persons/year (95% confidence interval 1.18-1.68) versus 0.89 cases per 100,000 persons/year (95% confidence interval 0.71-1.11) in 2019. The cumulative incidence of GBS increased by 59% in the period March 2020-March 2021 and, most importantly, COVID-19-positive GBS patients represented about 50% of the total GBS cases with most of them occurring during the two first pandemic waves in spring and autumn 2020. COVID-19-negative GBS cases from March 2020 to March 2021 declined by 22% compared to February 2019-February 2020. CONCLUSIONS: Other than showing an increase of GBS in northern Italy in the "COVID-19 era" compared to the previous year, this study emphasizes how GBS cases related to COVID-19 represent a significant part of the total, thus suggesting a relation between COVID-19 and GBS.

Characterization and management of neurological adverse events during immune-checkpoint inhibitors treatment: an Italian multicentric experience.

BACKGROUND: Neurological immune-related adverse events (nirAEs) are rare toxicities of immune-checkpoint inhibitors (ICI). With the increase of ICI oncological indications, their incidence is growing. Their recognition and management remain nevertheless challenging. METHODS: A national, web-based database was built to collect cases of neurological symptoms in patients receiving ICI and not attributable to other causes after an adequate workup. RESULTS: We identified 27 patients who developed nirAEs (20 males, median age 69 years). Patients received anti-PD1/PDL1 (78%), anti-CTLA4 (4%), or both (19%). Most common cancers were melanoma (30%) and non-small cell lung cancer (26%). Peripheral nervous system was mostly affected (78%). Median time to onset was 43.5 days and was shorter for peripheral versus central nervous system toxicities (36 versus 144.5 days, p = 0.045). Common manifestations were myositis (33%), inflammatory polyradiculoneuropathies (33%), and myasthenia gravis (19%), alone or in combination, but the spectrum of diagnoses was broad. Most patients received first-line glucocorticoids (85%) or IVIg (15%). Seven patients (26%) needed second-line treatments. At last follow-up, four (15%) patients were deceased (encephalitis, 1; myositis/myasthenia with concomitant myocarditis, 2; acute polyradiculoneuropathy, 1), while seven (26%) had a complete remission, eight (30%) partial improvement, and six (22%) stable/progressing symptoms. ICI treatment was discontinued in most patients (78%). CONCLUSIONS: Neurological irAEs are rare but potentially fatal. They primarily affect neuromuscular structures but encompass a broad range of presentations. A prompt recognition is mandatory to timely withheld immunotherapy and administrate glucocorticoids. In corticoresistant or severely affected patients, second-line treatments with IVIg or plasmapheresis may result in additional benefit.

Acute myelitis and ChAdOx1 nCoV-19 vaccine: Casual or causal association?

A 44-year-old previously healthy woman developed acute myelitis in close temporal relationship with ChAdOx1 nCoV-19 vaccine first-dose administration. The neurological involvement was mainly sensory with neuroimaging showing two mono-metameric lesions involving the posterior and lateral cord at dorsal level. Significant improvement was promptly recorded with high-dose intravenous steroids, with complete recovery within one month. The strict temporal relationship between vaccination and myelitis, together with the absence of clues pointing to alternative diagnoses, might suggest a conceivable role for anti-SARS-CoV-2 vaccine as immunological trigger, although a causal relationship has yet to be established and our preliminary observation suggests caution.

RFC1 expansions are a common cause of idiopathic sensory neuropathy.

After extensive evaluation, one-third of patients affected by polyneuropathy remain undiagnosed and are labelled as having chronic idiopathic axonal polyneuropathy, which refers to a sensory or sensory-motor, axonal, slowly progressive neuropathy of unknown origin. Since a sensory neuropathy/neuronopathy is identified in all patients with genetically confirmed RFC1 cerebellar ataxia, neuropathy, vestibular areflexia syndrome, we speculated that RFC1 expansions could underlie a fraction of idiopathic sensory neuropathies also diagnosed as chronic idiopathic axonal polyneuropathy. We retrospectively identified 225 patients diagnosed with chronic idiopathic axonal polyneuropathy (125 sensory neuropathy, 100 sensory-motor neuropathy) from our general neuropathy clinics in Italy and the UK. All patients underwent full neurological evaluation and a blood sample was collected for RFC1 testing. Biallelic RFC1 expansions were identified in 43 patients (34%) with sensory neuropathy and in none with sensory-motor neuropathy. Forty-two per cent of RFC1-positive patients had isolated sensory neuropathy or sensory neuropathy with chronic cough, while vestibular and/or cerebellar involvement, often subclinical, were identified at examination in 58%. Although the sensory ganglia are the primary pathological target of the disease, the sensory impairment was typically worse distally and symmetric, while gait and limb ataxia were absent in two-thirds of the cases. Sensory amplitudes were either globally absent (26%) or reduced in a length-dependent (30%) or non-length dependent pattern (44%). A quarter of RFC1-positive patients had previously received an alternative diagnosis, including Sjögren's syndrome, sensory chronic inflammatory demyelinating polyneuropathy and paraneoplastic neuropathy, while three cases had been treated with immune therapies.

COVID-19 in patients with myasthenia gravis: Epidemiology and disease course.

INTRODUCTION/AIMS: Coronavirus disease 2019 (COVID-19), a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has become a global pandemic. Patients with myasthenia gravis (MG), often treated with immunosuppressants, might be at higher risk of developing COVID-19 and of demonstrating a severe disease course. We aimed to study prevalence and describe features of COVID-19 in MG patients. METHODS: In May 2020, we conducted telephonic interviews with MG patients followed at our referral center. We collected structured data regarding MG and COVID-19, which was diagnosed as probable or confirmed according to the European Centre for Disease Prevention and Control case definition. We compared confirmed-COVID-19 prevalence calculated from the beginning of the pandemic in MG patients with that of the overall Pavia district. RESULTS: We interviewed 162 MG patients (median age, 66 y; interquartile range 41-77; males 59.9%), 88 from the Pavia district. Three patients had SARS-CoV-2-confirmed by polymerase chain reaction and eight had probable-COVID-19. In the Pavia district, the prevalence of confirmed-COVID-19 among MG patients (1/88, 1.14%) and overall population (4777/546 515, 0.87%) did not differ (P = .538). Higher Myasthenia Gravis Foundation of America clinicalclass and the need for recent rescue treatment, but not ongoing immunosuppressive treatments, were associated with COVID-19 risk. Of 11 MG patients with probable/confirmed-COVID-19, 3 required ventilator support, and 2 elderly patients died of COVID-19 respiratory insufficiency. Only 1 of11 patients experienced worsening MG symptoms, which improved after increasing their steroid dose. DISCUSSION: The risk of COVID-19 in MG patients seems to be no higher than that of the general population, regardless of immunosuppressive therapies. In our cohort, COVID-19 barely affected MG course.

Human Herpesvirus 6 Encephalitis in Immunocompetent and Immunocompromised Hosts.

OBJECTIVE: The aim of this study was to analyze the clinical, radiologic, and biological features associated with human herpesvirus 6 (HHV-6) encephalitis in immunocompetent and immunocompromised hosts to establish which clinical settings should prompt HHV-6 testing. METHODS: We performed a retrospective research in the virology database of Fondazione IRCCS Policlinico San Matteo (Pavia, Italy) for all patients who tested positive for HHV-6 DNA in the CSF and/or in blood from January 2008 to September 2018 and separately assessed the number of patients meeting the criteria for HHV-6 encephalitis in the group of immunocompetent and immunocompromised hosts. RESULTS: Of the 926 patients tested for HHV-6 during the period of interest, 45 met the study criteria. Among immunocompetent hosts (n = 17), HHV-6 encephalitis was diagnosed to 4 infants or children presenting with seizures or mild encephalopathy during primary HHV-6 infection (CSF/blood replication ratio <<1 in all cases). Among immunocompromised hosts (n = 28), HHV-6 encephalitis was diagnosed to 7 adolescents/adults with hematologic conditions presenting with altered mental status (7/7), seizures (3/7), vigilance impairment (3/7), behavioral changes (2/7), hyponatremia (2/7), and anterograde amnesia (1/7). Initial brain MRI was altered only in 2 patients, but 6 of the 7 had a CSF/blood replication ratio >1. CONCLUSIONS: The detection of a CSF/blood replication ratio >1 represented a specific feature of immunocompromised patients with HHV-6 encephalitis and could be of special help to establish a diagnosis of HHV-6 encephalitis in hematopoietic stem cell transplant recipients lacking radiologic evidence of limbic involvement.

Adoptive Transfer of JC Virus-Specific T Lymphocytes for the Treatment of Progressive Multifocal Leukoencephalopathy.

OBJECTIVE: Progressive multifocal leukoencephalopathy (PML) is still burdened by high mortality in a subset of patients, such as those affected by hematological malignancies. The aim of this study was to analyze the safety and carry out preliminary evaluation of the efficacy of polyomavirus JC (JCPyV)-specific T cell therapy in a cohort of hematological patients with PML. METHODS: Between 2014 and 2019, 9 patients with a diagnosis of "definite PML" according to the 2013 consensus who were showing progressive clinical deterioration received JCPyV-specific T cells. Cell lines were expanded from autologous or allogenic peripheral blood mononuclear cells by stimulation with JCPyV antigen-derived peptides. RESULTS: None of the patients experienced treatment-related adverse events. In the evaluable patients, an increase in the frequency of circulating JCPyV-specific lymphocytes was observed, with a decrease or clearance of JCPyV viral load in cerebrospinal fluid. In responsive patients, transient appearance of punctate areas of contrast enhancement within, or close to, PML lesions was observed, which was interpreted as a sign of immune control and which regressed spontaneously without the need for steroid treatment. Six of 9 patients achieved PML control, with 5 alive and in good clinical condition at their last follow-up. INTERPRETATION: Among other novel treatments, T cell therapy is emerging as a viable treatment option in patients with PML, particularly for those not amenable to restoration of specific immunity. Neurologists should be encouraged to refer PML patients to specialized centers to allow access to this treatment strategy. ANN NEUROL 2021;89:769-779.

Complete Response to Nivolumab in Recurrent/Metastatic HPV-Positive Head and Neck Squamous Cell Carcinoma Patient After Progressive Multifocal Leukoencephalopathy: A Case Report.

In an immune-competent context nivolumab showed long-term benefit in overall survival in recurrent/metastatic head and neck squamous cell carcinoma (HNSCC); however, in special cancer population such as these patients with immunodeficiency and viral infections, data on checkpoint inhibitors (ICI) activity are scant. Herein, we report a patient with a Human papilloma virus (HPV)-related oropharyngeal cancer (OPC) and CD4 lymphocytopenia. After a first-line treatment complete remission, the patient experienced Human Polyomavirus (JCV) infection in the brain. Consequently, to the recovery from progressive multifocal leukoencephalopathy (PML) the patient metastasized and was enrolled in a single-arm trial with nivolumab (EudraCT number: 2017-000562-30). A complete and durable response (more 3 years) was observed after 10 nivolumab injections Q2wks, interrupted for persistent drug related G2 diarrhea and a syndrome of inappropriate antidiuretic hormone secretion. We describe the circulating immune profile (before-, during-, and after nivolumab), consistent with the clinical history. Moreover, during nivolumab treatment, brain MRI evidenced the presence of small punctuate areas of contrast enhancement, reflecting a mild immune response in perivascular spaces. By cytofluorimetry, we observed that during JCV infection the CD4/CD8 ratio of the patient was under the normal values. After JCV infection recovery and before nivolumab treatment, CD4/CD8 ratio reached the normality threshold, even if the CD4+ T cell count remained largely under the normal values. During ICI, gene expression xCell analyses of circulating immune cells of the patient, showed a progressive normalization of the total immune profile, with significant boost in CD4+ and CD8+ T cells and a reduction in NK T, comparable to the circulating immune profile of reference tumor-free HNSCC patients. The present case supports the activity of ICI in a population of special cancer patients; whether JCV and HPV infections (alone or together) might have a possible role as immune booster(s), require further investigations.

Guillain-Barré syndrome and COVID-19: an observational multicentre study from two Italian hotspot regions.

OBJECTIVE: Single cases and small series of Guillain-Barré syndrome (GBS) have been reported during the SARS-CoV-2 outbreak worldwide. We evaluated incidence and clinical features of GBS in a cohort of patients from two regions of northern Italy with the highest number of patients with COVID-19. METHODS: GBS cases diagnosed in 12 referral hospitals from Lombardy and Veneto in March and April 2020 were retrospectively collected. As a control population, GBS diagnosed in March and April 2019 in the same hospitals were considered. RESULTS: Incidence of GBS in March and April 2020 was 0.202/100 000/month (estimated rate 2.43/100 000/year) vs 0.077/100 000/month (estimated rate 0.93/100 000/year) in the same months of 2019 with a 2.6-fold increase. Estimated incidence of GBS in COVID-19-positive patients was 47.9/100 000 and in the COVID-19-positive hospitalised patients was 236/100 000. COVID-19-positive patients with GBS, when compared with COVID-19-negative subjects, showed lower MRC sum score (26.3±18.3 vs 41.4±14.8, p=0.006), higher frequency of demyelinating subtype (76.6% vs 35.3%, p=0.011), more frequent low blood pressure (50% vs 11.8%, p=0.017) and higher rate of admission to intensive care unit (66.6% vs 17.6%, p=0.002). CONCLUSIONS: This study shows an increased incidence of GBS during the COVID-19 outbreak in northern Italy, supporting a pathogenic link. COVID-19-associated GBS is predominantly demyelinating and seems to be more severe than non-COVID-19 GBS, although it is likely that in some patients the systemic impairment due to COVID-19 might have contributed to the severity of the whole clinical picture.

Impact of multiple sclerosis risk loci in postinfectious neurological syndromes.

BACKGROUND: The genetic component of multiple sclerosis (MS) is now set to 200 autosomal common variants. However, it is unclear how genetic knowledge be clinically used in the differential diagnosis between MS and other inflammatory conditions like adult-onset postinfectious neurological syndromes (PINS). The aim of this study was to investigate whether PINS and MS have a shared genetic background using an updated polygenic risk scores. METHODS: Eighty-eight PINS patients have been consecutively recruited between 1996 and 2016 at Mondino Foundation of Pavia, diagnosed according to clinical, MRI and CSF findings and followed-up for several years. Patients were typed using Illumina array, and genotypes imputed using the 1000 Genomes Project reference panel. A weighted genetic risk score (wGRS) has been calculated based on autosomal MS risk loci derived from large-scale studies, and an HLA genetic burden (HLAGB) was also calculated on loci associated to MS. RESULTS: PINS occurred as an episode of myelitis in 44% of patients, encephalomyelitis in 44%, and encephalitis in remaining cases, with an involvement of peripheral nervous system in 41% of patients. Mean age of onset was 50.1 years, and female:male ratio was 1.4. Patients were followed-up for a mean of 7.2 years, and at last visit 55% had a low disability grade (mRS 0-1). Disease was monophasic in 67% of patients, relapsing in 18% and chronic-progressive in 15%. The wGRS of PINS cases was comparable to 370 healthy controls, while significantly lower compared to 907 bout-onset MS (BOMS) cases (wGRS= 20.9 vs 21.2; p<0.0001). The difference was even larger for PINS with peripheral nervous system involvement (wGRS=20.6) vs BOMS. CONCLUSION: The distinction between MS and PINS is not easy to make in clinical practice. However, our study shows that the new set of MS risk alleles does not confer increased susceptibility to PINS. These data support the importance to discriminate these cases from MS with pathophysiological and therapeutic implications.

Author Correction: Biallelic mutations in SORD cause a common and potentially treatable hereditary neuropathy with implications for diabetes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Biallelic mutations in SORD cause a common and potentially treatable hereditary neuropathy with implications for diabetes.

Here we report biallelic mutations in the sorbitol dehydrogenase gene (SORD) as the most frequent recessive form of hereditary neuropathy. We identified 45 individuals from 38 families across multiple ancestries carrying the nonsense c.757delG (p.Ala253GlnfsTer27) variant in SORD, in either a homozygous or compound heterozygous state. SORD is an enzyme that converts sorbitol into fructose in the two-step polyol pathway previously implicated in diabetic neuropathy. In patient-derived fibroblasts, we found a complete loss of SORD protein and increased intracellular sorbitol. Furthermore, the serum fasting sorbitol levels in patients were dramatically increased. In Drosophila, loss of SORD orthologs caused synaptic degeneration and progressive motor impairment. Reducing the polyol influx by treatment with aldose reductase inhibitors normalized intracellular sorbitol levels in patient-derived fibroblasts and in Drosophila, and also dramatically ameliorated motor and eye phenotypes. Together, these findings establish a novel and potentially treatable cause of neuropathy and may contribute to a better understanding of the pathophysiology of diabetes.