Ways to think about vasculitic neuropathy.

PURPOSE OF REVIEW: Vasculitis as a pathomechanism for neuropathy can be isolated to the peripheral nervous system, a part of a systemic autoimmune condition or a component of another syndrome. This review aims to discuss the broad range of diagnoses in which vasculitic neuropathy can be encountered, highlight the progress in imaging techniques in identifying vasculitis, and the new drugs developed for other autoimmune diseases that may be applied to neurological conditions. RECENT FINDINGS: Advances in imaging modalities, ultrasound, MRI and FDG-PET scanning for neuromuscular applications has redefined many aspects of vasculitic neuropathies. The benefit of dividing vasculitides by vessel size is becoming less absolute as diagnostic approaches advance. MRI and FDG-PET are widely used in diagnosis, defining extent of involvement of disease and monitoring. In neuralgic amyotrophy, the identification of hourglass-like constrictions on imaging has changed the treatment paradigm to include surgical interventions. These diagnostic approaches are supported by new immunomodulating and immunosuppression techniques. SUMMARY: Vasculitic neuropathies are a broad group of conditions with a range of causes and associations. Increased use of imaging techniques impacts our traditional definitions and classifications. The growth in treatment options for other autoimmune conditions are likely to infiltrate the neurological landscape.

Immunoglobulin use in neurology: a practical approach.

Human immunoglobulin, delivered either intravenously (IVIg) or subcutaneously, is used to treat a range of immune-mediated neurological disorders. It has a role in acute or subacute inflammatory disease control and as a maintenance therapy in chronic disease management. This review considers mechanisms of IVIg action and the evidence for IVIg in neurological conditions. We use Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) as frameworks to demonstrate an approach to IVIg use in acute and chronic dysimmune neurological conditions across two different healthcare systems: the UK and Australia. We highlight the benefits and limitations of IVIg and focus on practical considerations such as informed consent, managing risks and adverse effects, optimal dosing and monitoring response. We use these basic clinical practice principles to discuss the judicious use of an expensive and scarce blood product with international relevance.

TGF-ß1 signalling in Alzheimer's pathology and cytoskeletal reorganization: a specialized Tau perspective.

Microtubule-associated protein, Tau has been implicated in Alzheimer's disease for its detachment from microtubules and formation of insoluble intracellular aggregates within the neurons. Recent findings have suggested the expulsion of Tau seeds in the extracellular domain and their prion-like propagation between neurons. Transforming Growth Factor-ß1 (TGF-ß1) is a ubiquitously occurring cytokine reported to carry out immunomodulation and neuroprotection in the brain. TGF-ß-mediated regulation occurs at the level of neuronal survival and differentiation, glial activation (astrocyte and microglia), amyloid production-distribution-clearance and neurofibrillary tangle formation, all of which contributes to Alzheimer's pathophysiology. Its role in the reorganization of cytoskeletal architecture and remodelling of extracellular matrix to facilitate cellular migration has been well-documented. Microglia are the resident immune sentinels of the brain responsible for surveying the local microenvironment, migrating towards the beacon of pertinent damage and phagocytosing the cellular debris or patho-protein deposits at the site of insult. Channelizing microglia to target extracellular Tau could be a good strategy to combat the prion-like transmission and seeding problem in Alzheimer's disease. The current review focuses on reaffirming the role of TGF-ß1 signalling in Alzheimer's pathology and cytoskeletal reorganization and considers utilizing the approach of TGF-ß-triggered microglia-mediated targeting of extracellular patho-protein, Tau, as a possible potential strategy to combat Alzheimer's disease.

Mental Health Impact of COVID-19 Infection on Postpartum Women from Lower and Middle-income Backgrounds in India and its Effects on Early Mother-infant Bonding: An Observational Study.

The study was designed to examine the mental health impact of COVID-19 infection in postpartum women and its effects on mother-infant bonding during the first eight weeks postpartum. Fifty-seven consenting eligible postpartum women were recruited for the study. They were assessed at two time points using standardized rating scales to measure distress and uniquely designed scales assessing COVID-19-specific outcome fears and bonding. Almost half [42%] of postpartum women with COVID-19 suffered from a probable anxiety disorder, and one-third [33.3%] suffered from probable depression. The overwhelming majority [91.2%] experienced COVID-19-specific fear. There was an inverse relationship between one dimension of maternal caregiving and self-report depression and anxiety scores, respectively. Additionally, despite discharge, 25% of the mothers had not breastfed the infants till the 8th-week postpartum period, which is in discordance with the World Health Organization (WHO) recommendation of exclusive breastfeeding up to 6 months of age that is widely practiced in India. The novel COVID-19 pandemic was associated with anxiety and depression, impacting mother-infant bonding. Therefore, there is a need for specialized mental health services and individualized breastfeeding interventions for this vulnerable population to ensure positive outcomes.

IVIg-exposure and thromboembolic event risk: findings from the UK Biobank.

BACKGROUND: Arterial and venous thromboembolic events (TEEs) have been associated with intravenous Ig use, but the risk has been poorly quantified. We aimed to calculate the risk of TEEs associated with exposure to intravenous Ig. METHODS: We included participants from UK Biobank recruited over 3 years, data extracted September 2020.The study endpoints were incidence of myocardial infarction, other acute ischaemic heart disease, stroke, pulmonary embolism and other venous embolism and thrombosis.Predictors included known TEE risk factors: age, sex, hypertension, smoking status, type 2 diabetes mellitus, hypercholesterolaemia, cancer and past history of TEE. Intravenous Ig and six other predictors were added in the sensitivity analysis.Information from participants was collected prospectively, while data from linked resources, including death, cancer, hospital admissions and primary care records were collected retrospectively and prospectively.  FINDINGS: 14 794 of 502 492 individuals had an incident TEE during the study period. The rate of incident events was threefold higher in those with prior history of TEE (8 .7%) than those without previous history of TEE (3.0%).In the prior TEE category, intravenous Ig exposure was independently associated with increased risk of incident TEE (OR=3.69 (95% CI 1.15 to 11.92), p=0.03) on multivariate analysis. The number needed to harm by exposure to intravenous Ig in those with a history of TEE was 5.8 (95% CI 2.3 to 88.3).Intravenous Ig exposure did not increase risk of TEE in those with no previous history of TEE. INTERPRETATION: Intravenous Ig is associated with increased risk of further TEE in individuals with prior history of an event with one further TEE for every six people exposed. In practice, this will influence how clinicians consent for and manage overall TEE risk on intravenous Ig exposure.

Association of plasma neurofilament light chain with disease activity in chronic inflammatory demyelinating polyradiculoneuropathy.

BACKGROUND AND PURPOSE: This study was undertaken to explore associations between plasma neurofilament light chain (pNfL) concentration (pg/ml) and disease activity in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and examine the usefulness of pNfL concentrations in determining disease remission. METHODS: We examined pNfL concentrations in treatment-naïve CIDP patients (n = 10) before and after intravenous immunoglobulin (IVIg) induction treatment, in pNfL concentrations in patients on maintenance IVIg treatment who had stable (n = 15) versus unstable disease (n = 9), and in clinically stable IVIg-treated patients (n = 10) in whom we suspended IVIg to determine disease activity and ongoing need for maintenance IVIg. pNfL concentrations in an age-matched healthy control group were measured for comparison. RESULTS: Among treatment-naïve patients, pNfL concentration was higher in patients before IVIg treatment than healthy controls and subsequently reduced to be comparable to control group values after IVIg induction. Among CIDP patients on IVIg treatment, pNfL concentration was significantly higher in unstable patients than stable patients. A pNFL concentration > 16.6 pg/ml distinguished unstable treated CIDP from stable treated CIDP (sensitivity = 86.7%, specificity = 66.7%, area under receiver operating characteristic curve = 0.73). Among the treatment withdrawal group, there was a statistically significant correlation between pNfL concentration at time of IVIg withdrawal and the likelihood of relapse (r = 0.72, p < 0.05), suggesting an association of higher pNfL concentration with active disease. CONCLUSIONS: pNfL concentrations may be a sensitive, clinically useful biomarker in assessing subclinical disease activity.

A longitudinal and cross-sectional study of plasma neurofilament light chain concentration in Charcot-Marie-Tooth disease.

Advances in genetic technology and small molecule drug development have paved the way for clinical trials in Charcot-Marie-Tooth disease (CMT); however, the current FDA-approved clinical trial outcome measures are insensitive to detect a meaningful clinical response. There is, therefore, a need to identify sensitive outcome measures or clinically relevant biomarkers. The aim of this study was to further evaluate plasma neurofilament light chain (NFL) as a disease biomarker in CMT. Plasma NFL was measured using SIMOA technology in both a cross-sectional study of a US cohort of CMT patients and longitudinally over 6 years in a UK CMT cohort. In addition, plasma NFL was measured longitudinally in two mouse models of CMT2D. Plasma concentrations of NFL were increased in a US cohort of patients with CMT1B, CMT1X and CMT2A but not CMT2E compared with controls. In a separate UK cohort, over a 6-year interval, there was no significant change in plasma NFL concentration in CMT1A or HSN1, but a small but significant reduction in patients with CMT1X. Plasma NFL was increased in wild type compared to GARSC201R mice. There was no significant difference in plasma NFL in GARSP278KY compared to wild type mice. In patients with CMT1A, the small difference in cross-sectional NFL concentration vs healthy controls and the lack of change over time suggests that plasma NFL may lack sufficient sensitivity to detect a clinically meaningful treatment response in adulthood.

Dramatic clinical response to ultra-high dose IVIg in otherwise treatment resistant inflammatory neuropathies.

BACKGROUND: Intravenous immunoglobulin (IVIg) has short and long-term efficacy in both chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy with conduction block (MMNCB). There is potential for under and over-treatment if trial regimens are strictly adhered to in clinical practice where titrating dose to clinical response is recommended. METHODS: We report the response to high-dose IVIg (>2 g/kg/6 weeks) in a subgroup of patients with definite CIDP or MMNCB who were unresponsive to 'usual' dosing. IVIg frequency and dosing was determined for each individual by subjective and objective outcome measures for impairment, grip strength, and activity and participation. RESULTS: Six patients (three with chronic inflammatory demyelinating polyneuropathy (CIDP), three with MMN) were included. Two patients (one CIDP and one MMNCB) returned to full-time work on fractionated IVIg doses of 5 g/kg/month and 9 g/kg/month. Patient three (CIDP) failed numerous other immunosuppressants but responded to short-term fractionated 4 g/kg/month of IVIg. Patient four has severe, refractory, childhood-onset CIDP, remains stable but dependent currently on 6.9 g/kg/month of IVIg. Patients five and six, both with MMNCB, required short term 4.5-5 g/kg/month to recover significant bilateral hand strength. No IVIg-related adverse events occurred in any individual. CONCLUSIONS: These six cases demonstrate the safety and effectiveness of a treatment approach that includes individualised but evidence-based clinical assessment and, when necessary, high-doses of IVIg to restore patients' strength and ability to participate in activities of daily activities. Careful patient selection is important.

Calcitonin gene related peptide in migraine: current therapeutics, future implications and potential off-target effects.

Migraine is the second largest cause of years lost to disability globally among all diseases, with a worldwide prevalence over 1 billion. Despite the global burden of migraine, few classes of therapeutics have been specifically developed to combat migraine. After 30 years of translational research, calcitonin gene-related peptide (CGRP) inhibitors have emerged as a promising new tool in the prevention of migraine. Like all new therapeutics; however, we have limited real-world experience and CGRP has several known systemic actions that warrant consideration. This article provides a narrative review of the evidence for CGRP antagonists and summarises the known and potential side effects that should be considered.

Novel variants broaden the phenotypic spectrum of PLEKHG5-associated neuropathies.

BACKGROUND AND PURPOSE: Pathogenic variants in PLEKHG5 have been reported to date to be causative in three unrelated families with autosomal recessive intermediate Charcot-Marie-Tooth disease (CMT) and in one consanguineous family with spinal muscular atrophy (SMA). PLEKHG5 is known to be expressed in the human peripheral nervous system, and previous studies have shown its function in axon terminal autophagy of synaptic vesicles, lending support to its underlying pathogenetic mechanism. Despite this, there is limited knowledge of the clinical and genetic spectrum of disease. METHODS: We leverage the diagnostic utility of exome and genome sequencing and describe novel biallelic variants in PLEKHG5 in 13 individuals from nine unrelated families originating from four different countries. We compare our phenotypic and genotypic findings with a comprehensive review of cases previously described in the literature. RESULTS: We found that patients presented with variable disease severity at different ages of onset (8-25 years). In our cases, weakness usually started proximally, progressing distally, and can be associated with intermediate slow conduction velocities and minor clinical sensory involvement. We report three novel nonsense and four novel missense pathogenic variants associated with these PLEKHG5-associated neuropathies, which are phenotypically spinal muscular atrophy (SMA) or intermediate Charcot-Marie-Tooth disease. CONCLUSIONS: PLEKHG5-associated neuropathies should be considered as an important differential in non-5q SMAs even in the presence of mild sensory impairment and a candidate causative gene for a wide range of hereditary neuropathies. We present this series of cases to further the understanding of the phenotypic and molecular spectrum of PLEKHG5-associated diseases.

An approach to assessing immunoglobulin dependence in chronic inflammatory demyelinating inflammatory polyneuropathy.

Regular immunoglobulin treatment maintains strength and prevents disability in chronic inflammatory demyelinating polyneuropathy (CIDP). Discrimination between active disease, with optimum symptom control on treatment, and disease in remission not requiring treatment is essential for therapeutic decision-making and clinical trial design. To compare treatment cessation versus gradual dose reduction in assessment of disease activity (immunoglobulin dependence) in a cohort of stable CIDP patients on maintenance immunoglobulin treatment. An approach to restabilization of immunoglobulin-dependent individuals is also described. Retrospective review of IVIg cessation or gradual reduction in 33 patients with stable CIDP on maintenance IVIg. Demographic, clinical and treatment data were collected; clinical monitoring data were recorded prospectively as part of routine clinical practice. A total of 21/33 patients (62.6%) were immunoglobulin dependent, (gradual dose reduction:11, cessation:10). Mean change in Inflammatory Rasch-built Overall Disability Scale (I-RODS) (-15, standard deviation [SD] 16) and Medical Research Council Sum Score (MRC-SS) (-4, SD: 4) was clinically and statistically meaningful (>75% exceeded minimum clinically important differences). Mean time to deterioration was 5.0 (SD: 4.6) months, shorter in cessation group (3.5 months) than gradual reduction group (8.8 months). All patients were restabilized to previous baseline (M: 2.3, SD: 4.3 months), half within 1 week of retreatment. A total of 12 patients (37.4%) remained stable without treatment for ≥2 years (remission). A total of 50% were identified rapidly by cessation and 50% by gradual dose reduction requiring mean 4.8 (SD: 2.8) years follow-up and costing £113 623 per person Ig spend. No predictors of disease activity were identified. A treatment cessation trial with close clinical monitoring is an efficient, cost-effective and safe approach to assessing disease activity in CIDP.

Plasma neurofilament light chain concentration is increased and correlates with the severity of neuropathy in hereditary transthyretin amyloidosis.

Hereditary transthyretin amyloidosis (ATTRm) causes a disabling peripheral neuropathy as part of a multisystem disorder. The recent development of highly effective gene silencing therapies has highlighted the need for effective biomarkers of disease activity to guide the decision of when to start and stop treatment. In this study, we measured plasma neurofilament light chain (pNfL) concentration in 73 patients with ATTR and found that pNfL was significantly raised in ATTRm patients with peripheral neuropathy compared to healthy controls. Furthermore, pNFL correlated with disease severity as defined by established clinical outcome measures in patients for whom this information was available. These findings suggest a potential role of pNfL in monitoring disease activity and progression in ATTRm patients.

Diagnosis of amyloid neuropathy.

Systemic amyloidosis can be hereditary or acquired. The autosomal dominant hereditary transthyretin amyloidosis and the acquired light-chain amyloidosis, the result of a plasma cell dyscrasia, are multisystem disorders with cardiovascular, autonomic and peripheral nerve involvement. There are numerous investigational modalities available to diagnose systemic amyloidosis and to assess the extent of organ involvement, but it is frequently misdiagnosed due to its heterogeneous clinical presentations and misleading investigation findings. An accurate and timely diagnosis of amyloid neuropathy can greatly impact on the outcomes for patients, especially as there will soon be new gene-silencing treatments for hereditary transthyretin amyloidosis.

Burden of Long COVID-19 in a Cohort of Recovered COVID-19 Patients in Delhi, India.

BACKGROUND: The long COVID phase is characterized by signs and symptoms persisting for at least three months after recovery from acute COVID-19 illness. There is limited data on comprehensive long-term clinical follow-up of COVID-19 patients. AIMS: This study aims to explore the burden and symptomatology of long COVID syndrome and its association with various health parameters. SETTINGS AND DESIGN: This prospective observational study was conducted in Delhi from May 2022 to March 2023. METHODS AND MATERIAL: A total of 553 adult patients who had recovered from COVID-19 were enrolled in the study. A sociodemographic and clinical profile was obtained using validated questionnaires, along with an evaluation of biochemical parameters to assess the associated factors. STATISTICAL ANALYSIS USED: Chi-square test, unpaired t-test, and bivariate regression analysis were applied using Statistical Product and Service Solutions (SPSS, version 28; IBM SPSS Statistics for Windows, Armonk, NY). A p value of <0.05 was considered significant. RESULTS: A total of 252 patients (45.6%) had long COVID syndrome, which was significantly associated with the presence of any pre-existing comorbidity (OR=1.46 (1.02-2.09); p=0.039), previous history of hypertension (OR=1.82 (1.07-3.09); p=0.027), and vaccination against COVID-19 (OR=1.392 (1.171-1.656); p=0.003). The most common symptoms reported were persistent fatigue (33.3%) and persistent dry cough (28.5%). Patients with long COVID syndrome are also reported to have poorer sleep quality. Biochemical findings showed abnormal T lymphocytes (9.3%) and raised HbA1c (11.9%). CONCLUSIONS: Multiple risk factors and symptoms associated with long COVID syndrome were identified in this study. Research efforts and knowledge regarding the pattern of illness will aid in long-term monitoring and development of interventional strategies and guidelines for the care of recovered COVID-19 patients.

Prevalence and patterns of post-COVID-19 symptoms in recovered patients of Delhi, India: a population-based study.

BACKGROUND: Post-coronavirus disease 2019 (COVID-19) symptoms were widely reported. However, data on post-COVID-19 conditions following infection with the Omicron variant remained scarce. This prospective study was conducted to understand the prevalence, patterns, and duration of symptoms in patients who had recovered from COVID-19. METHODS: A prospective study was conducted across 11 districts of Delhi, India, among individuals who had recovered from COVID-19. Study participants were enrolled, and then returned for post-recovery follow-up at 3 months and 6 months interval. RESULTS: The mean age of study participants was 42.07 years, with a standard deviation of 14.89 years. The majority of the participants (79.7%) reported experiencing post-COVID-19 symptoms. The most common symptoms included joint pain (36.0%), persistent dry cough (35.7%), anxiety (28.4%), and shortness of breath (27.1%). Other symptoms were persistent fatigue (21.6%), persistent headache (20.0%), forgetfulness (19.7%), and limb weakness (18.6%). The longest duration of symptom was observed to be anxiety (138.75±54.14 days), followed by fatigue (137.57±48.33 days), shortness of breath (131.89±60.21 days), and joint pain/swelling (131.59±58.76 days). At the first follow-up visit, 2.2% of participants presented with abnormal electrocardiogram readings, but no abnormalities were noticed during the second follow-up. Additionally, 4.06% of participants exhibited abnormal chest X-ray findings at the first followup, which decreased to 2.16% by the second visit. CONCLUSION: The most frequently reported post-COVID-19 symptoms were joint pain, dry cough, anxiety and shortness of breath. These clinical symptoms persisted for up to 6 months, with evidence of multi-system involvement. Consequently, findings highlighted the need for long-term follow-up during the post-COVID-19 period.

Comparative study of the mental health impact of the COVID-19 pandemic on health care professionals in India.

Aims: This study aimed to investigate how the psychological health of health care professionals (HCP) on COVID duty was different from those who were not directly in contact. Methodology: Of 473 (76%) randomly selected respondents (doctors and nurses) to a WhatsApp request message, 450 subjects' data were finally analyzed. Result: The prevalence of stress, anxiety and depression among HCP was 33.8, 38.9 and 43.6%, respectively. Compared with nonexposed professionals, COVID-19-exposed professionals had roughly double the score of these morbidities (t = 6.3, p < 0.001; t = 6.9, p < 0.001; t = 6.0, p < 0.001). Most worry (71.11%) was about the health of their family, followed by themselves (35.55%). Conclusion: The level of exposure, feelings of uncertainty and fear of infection emerged in our study as possible risk factors for psychological morbidities among HCP.

Subcutaneous immunoglobulin dose titration to clinical response in inflammatory neuropathy.

INTRODUCTION: Individualized dosing is an established approach in intravenous immunoglobulin (IVIg) treatment for inflammatory neuropathies. There is less experience in effective dosing strategies for subcutaneous (SC) immunoglobulin. METHODS: We conducted a retrospective cohort study of patients with inflammatory neuropathies transferring from IVIg to SCIg in two UK peripheral nerve services. I-RODS and grip strength were used to measure outcome. Dose and clinical progress were documented at 1 year and at last review. RESULTS: 44/56 patients remained on maintenance SCIg beyond 1 year (mean 3.3 years, range 1-9 years) with stable clinical outcomes. Clinical deteriorations were corrected by small increases in SCIg dose in 20 patients at 1 year, a further 9 requiring subsequent further up-titrations. Sixteen tolerated dose reduction. Mean dose change was + 2.4% from baseline. Two patients required IVIg bolus rescue (2 g/kg). Three patients successfully discontinued Ig therapy. Nine patients returned to IVIg due to clinical relapse or patient preference. Overall tolerance was good. DISCUSSION: Dose titration to clinical response is an effective approach in SCIg maintenance therapy.

Neurological implications of COVID-19: a review of the science and clinical guidance.

COVID-19 is a significant global health burden. The pulmonary morbidity and mortality of COVID-19 is well described, however, there is mounting evidence of neurological manifestations of SARS-CoV-2, which may be of prognostic significance. This paper summarises the available evidence in order to provide clinicians with a concise summary of the peripheral and central neurological manifestations of COVID-19, discusses specific issues regarding the management of chronic neurological disease in the context of the pandemic, and provides a summary of the thrombotic implications of the disease for the neurologist.

Thromboembolic risk with IVIg: Incidence and risk factors in patients with inflammatory neuropathy.

Our objective was to evaluate whether IV immunoglobulin (IVIg) increases the risk of thromboembolic events in neurology outpatients with inflammatory neuropathies, as there is conflicting evidence supporting this hypothesis, mainly from non-neurologic cohorts. We investigated this question over 30 months in our cohort of patients with inflammatory neuropathies receiving regular IVIg and found a greater incidence of arterial and venous thromboembolic events than population-based rates determined by hospital admissions data. Vascular risk factors were more common in the event group but there were no IVIg administration factors that contributed to the risk. This study suggests that IVIg may have a small but contributory role in determining thromboembolic risk in the inflammatory neuropathy cohort and more evidence is required before it is clear whether the current primary prevention guidelines are appropriate in this group of patients.