Paraneoplastic neurologic manifestations of neuroendocrine tumors

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors arising from the transformation of neuroendocrine cells in several organs, most notably the gastro-entero-pancreatic system and respiratory tract. The classification was recently revised in the 5th Edition of the WHO Classification of Endocrine and Neuroendocrine Tumors. NENs can rarely spread to the central or peripheral nervous systems. Neurologic involvement is determined by the rare development of paraneoplastic syndromes, which are remote effects of cancer. Mechanisms depend on immunologic response to a tumor, leading to the immune attack on the nervous system or the production of biologically active ("functioning") substances, which can determine humoral (endocrine) effects with neurologic manifestations. Paraneoplastic neurologic syndromes (PNS) are immunologically mediated and frequently detected in small cell lung cancer but rarely seen in other forms of NEN. PNS and Merkel cell carcinoma is increasingly reported, especially with Lambert Eaton myasthenic syndrome. Endocrine manifestations are found in a wide spectrum of NENs. They can develop at any stage of the diseases and determine neurologic manifestations. Patient outcomes are influenced by tumor prognosis, neurologic complications, and the severity of endocrine effects.

Paraneoplastic encephalitis

The first reports of encephalitis associated with cancer date to the 1960s and were characterized by clinical and pathologic involvement of limbic areas. This specific association was called limbic encephalitis (LE). The subsequent discovery of several "onconeural" antibodies (Abs), i.e., Abs targeting an antigen shared by neurons and tumor cells, supported the hypothesis of an autoimmune paraneoplastic etiology of LE and other forms of rapidly progressive encephalopathy. Over the past 20 years, similar clinical pictures with different clinical courses have been described in association with novel Abs-binding neuronal membrane proteins and proved to be pathogenic. The most well-known encephalitis in this group was described in 2007 as an association of a complex neuro-psychiatric syndrome, N-methyl-d-aspartate (NMDA) receptor-Abs, and ovarian teratoma in young women. Later on, nonparaneoplastic cases of NMDA receptor encephalitis were also described. Since then, the historical concept of LE and Ab associated encephalitis has changed. Some of these occur in fact more commonly in the absence of a malignancy (e.g., anti-LG1 Abs). Lastly, seronegative cases were also described. The term paraneoplastic encephalitis nowadays encompasses different syndromes that may be triggered by occult tumors.

World Brain Day 2023 - Brain Health and Disability: "Leave no one behind"

Worldwide, the number of persons with disability is assumed to be around 1.3 billion. Although several definitions exist, such as the medical and social models, the social model has more holistic approaches and engulfs more aspects. Historically, many considerations were based on eugenics until the middle of the 20th century when a change of paradigm occurred, and disability has since been subject to many developments in the past decades. Previously dependent on mercy and good will, disability has now become a human right, and the implementation of this change is still ongoing. Neurological diseases contribute worldwide to a large proportion of disability and can be classified as reversible or permanent, by their time course, and by disease specific elements. Addtionally, neurological diseases are often accepted and managed differently across cultures and are exposed to variable degrees of stigma. The World Federation of Neurology (WFN) has initiated and continues to promote the concept of brain health, which has a wide range of inclusion and is best summarized in the World Health Organization paper (World Health Organization, 2022a). This concept is embedded in the Intersectoral Global Action Plan (IGAP) (World Health Organization, 2022b), which created a global tool to promote neurology, and the WFN is using this tool for the 2023 World Brain Day to promote and introduce the concept of disability.

Advocacy for patients with headache disorders

Primary headache disorders are worldwide highly prevalent and burdensome and should be therefore considered as a global public health priority. However, too many patients with primary headache disorders still do not receive satisfying care. The most likely identified reasons for such a scenario - lack of public awareness, stigma, lack of trained professionals with inadequate healthcare systems and policies - are remediable. Despite the progresses that were made in headache advocacy, these efforts have not yielded substantial improvements in research funding or access to specialty care and even standards of care. The situation is more complex in Low and Middle Income Countries (LMICs) where headache advocacy is urgently needed given the magnitude of the difficulties that patients with primary headache disorders face in accessing care. The growing emergence of coordinated, collaborative, patient-centered advocacy efforts with improved patient-clinician partnership is an opportunity to enhance progress in advocacy for a satisfying life and optimal and equitable care for people with primary headache disorders. LMICs can benefit greatly from coordinating these efforts on a global scale. The recent organization of a training program on headache diagnosis and management for healthcare professionals in Africa is a concrete example.

Decreasing incidence of stroke, ischemic heart disease and dementia in Norway, 1990-2019, a Global Burden of Disease Study: An Opportunity

BACKGROUND

The declining incidence of stroke, ischemic heart disease (IHD) and dementia (the triple threat) in Norway encourages further investigation. We analysed the risks and trends of the three conditions using data from the Global Burden of Disease study (GBD).

METHODS

We used GBD 2019 estimations for age-, sex-, and risk factor-specific incidence and prevalence of "the triple threat" and their risk factor-attributed deaths and disability combined and their age-standardised rates per 100,000 population in 2019 and their changes during 1990-2019. Data are presented in means and 95% uncertainty intervals (UI).

RESULTS

In 2019, 71.1 thousand Norwegian were living with dementia, 157.2 thousand with IHD, and 95.2 thousand with strokes. In 2019, there were 9.9 thousand (8.5 to 11.3) new cases of dementia (35.0% increase since 1990), 17.0 thousand (14.6 to 19.6) with IHD (3.6% decrease), and 8.0 thousand (7.0 to 9.1) with strokes (12.9% decrease) in Norway. During 1990-2019, their age-standardised incidence rates decreased significantly; dementia by -5.4% (-8.4 to -3.2), IHD by -30.0% (-31.4 to -28.6), and stroke by -35.3% (-38.3 to -32.2), respectively. There were significant declines in the attributable risks to both ENVIRONMENTAL and behavioural factors in Norway, but contradictory trends for metabolic risk factors during 1990-2019.

CONCLUSIONS

The risk of "the triple threat" conditions is declining in Norway, despite the increased prevalence. This offers the opportunity to find out why and how and to accelerate their joint prevention through new approaches and the promotion of the National Brain Health Strategy.

The Intersectoral Global Action Plan (IGAP): A unique opportunity for neurology across the globe

The World Health Assembly (WHA) approved the Intersectoral Global Action Plan (IGAP) in 2022. This ambitious project, formally called the Intersectoral Global Action Plan for Epilepsy and Other Neurological Disorders, is a 10-year plan to enhance neurology implementation worldwide and to raise the status of brain health and neurology services for patients with neurological diseases. The IGAP has 5 important components: relation with policy makers, therapy, prophylaxis, research, and public health. The implementation of IGAP is a challenge, not only for the specialty of neurology but for the whole neurological community, encompassing patients, carers, healthcare providers, and the public. The lack of a unified definition of neurology and the great variety of health systems, as well as the dependency on socioeconomic status, will necessitate custom-made solutions in all regions.

Mapping of European activities on the integration of sex and gender factors in neurology and neuroscience

BACKGROUND

Neurological disorders pose a profound unmet medical need for which new solutions are urgently needed. The consideration of both biological (sex) and socio-cultural (gender) differences between men and women is necessary to identify more efficacious, safer and tailored treatments. Approaches for putting sex and gender medicine into practice have gathered momentum across Europe, but it is currently unclear to what extent they have been implemented in the field of neurology and neuroscience.

METHODS

We mapped current activities in research, funding and education aimed at integrating sex and gender consideration in neuroscience and neurology in Europe. We examined and analyzed data gathered from (1) literature searches, (2) policy documents and reports by the European Commission and national funding agencies, (3) web-based searches, (4) "Web of Science", and (5) searches of project databases of funding agencies. An informative / non-systematic search was performed for sections on policies and funding, education, basic research, while a systematic literature and database review was conducted forquantitative analysis of research output and funded projects in terms of sex and gender analysis.

RESULTS

Our mapping shows that there is a growing interest and attention towards sex and gender consideration in neurological fields, both from funding agencies and researchers. However, most activities, especially for education, are limited to the individual motivation of researchers and are not organically built within curricula and strategic research priorities.

DISCUSSION

We recommend actions that might help increase the consideration of sex and gender specifically in the field of neuroscience and neurology.

Angiosomes of the Ulnar Nerve at the Elbow: A Cadaver Trial Using Contrast-Enhanced Ultrasound

Three major arteries supplying the ulnar nerve in the cubital tunnel are commonly known. However, their vascular territories (angiosomes) have not been described yet. Contrast-enhanced ultrasound was used to identify the angiosomes of posterior ulnar recurrent artery, inferior ulnar collateral artery and superior ulnar collateral artery in 20 fresh, non-frozen human body donors. The arteries were cannulated, and physiologic blood flow was simulated. Contrast agent was applied in each vessel in a randomized sequence, and the length of the contrast-enhancing ulnar nerve segment was measured by a radiologist blinded to the sequence. The angiosome of the posterior ulnar recurrent artery overlaps both other angiosomes. It fully covers the cubital tunnel in 63.6% of specimens. In addition, collateral flow via nerve and muscle branches of the arterial anastomotic network around the elbow (rete articulare cubiti) partly maintains the intra-neural blood flow in the absence of a vascular pedicle. The posterior ulnar recurrent artery is the dominant nutrient vessel of the ulnar nerve in the cubital tunnel. A potential watershed zone exists proximal to the Osborne ligament. Knowledge of these angiosomes may advance surgery of the ulnar nerve in the cubital tunnel.

Paraneoplastic Neuropathies: What's New Since the 2004 Recommended Diagnostic Criteria

The diagnostic criteria published by the PNS (Paraneoplastic Neurological Syndromes) Euronetwork in 2004 provided a useful classification of PNS, including paraneoplastic neuropathies. Subacute sensory neuronopathy (SSN) was the most frequently observed peripheral PNS, whereas other forms of neuropathy, as sensory polyneuropathy, sensorimotor polyneuropathy, demyelinating neuropathies, autonomic neuropathies, and focal nerve or plexus lesions, were less frequent. At the time of publication, the main focus was on onconeural antibodies, but knowledge regarding the mechanisms has since expanded. The antibodies associated with PNS are commonly classified as onconeural (intracellular) and neuronal surface antibodies (NSAbs). Since 2004, the number of antibodies and the associated tumors has increased. Knowledge has grown on the mechanisms underlying the neuropathies observed in lymphoma, paraproteinemia, and multiple myeloma. Moreover, other unrevealed mechanisms underpin sensorimotor neuropathies and late-stage neuropathies, where patients in advanced stages of cancer—often associated with weight loss—experience some mild sensorimotor neuropathy, without concomitant use of neurotoxic drugs. The spectrum of paraneoplastic neuropathies has increased to encompass motor neuropathies, small fiber neuropathies, and autonomic and nerve hyperexcitability syndromes. In addition, also focal neuropathies, as cranial nerves, plexopathies, and mononeuropathies, are considered in some cases to be of paraneoplastic origin. A key differential diagnosis for paraneoplastic neuropathy, during the course of cancer disease (the rare occurrence of a PNS), is chemotherapy-induced peripheral neuropathy (CIPN). Today, novel complications that also involve the peripheral nervous system are emerging from novel anti-cancer therapies, as targeted and immune checkpoint inhibitor (ICH) treatment. Therapeutic options are categorized into causal and symptomatic. Causal treatments anecdotally mention tumor removal. Immunomodulation is sometimes performed for immune-mediated conditions but is still far from constituting evidence. Symptomatic treatment must always be considered, consisting of both drug therapy (e.g., pain) and attempts to treat disability and neuropathic pain.

Toxicity in Peripheral Nerves: An Overview

Introduction to a collection. This article is intended to introduce a collection of papers on toxic neuropathies. Toxic neuropathies can be caused by a variety of substances and by different mechanisms. Toxic agents are numerous and can be distinguished between drugs, recreational agents, heavy metals, industrial agents, pesticides, warfare agents, biologic substances and venoms. Toxic agents reach the nervous system by ingestion, transcutaneously, via the mucous membranes, parenterally and by aerosols. The most frequent types are cumulative toxicities. Other types are acute or delayed toxicities. Pathogenetic mechanisms range from a specific toxic substance profile causing axonal or demyelinating lesions, towards ion channel interferences, immune-mediated mechanisms and a number of different molecular pathways. In addition, demyelination, focal lesions and small fiber damage may occur. Clinically, neurotoxicity presents most frequently as axonal symmetric neuropathies. In this work, we present a panoramic view of toxic neuropathy, in terms of symptoms, causes, mechanisms and classification.

Cubital tunnel perfusion in different postures-An anatomical investigation

Introduction/Aims

For cubital tunnel syndrome, the avoidance of predisposing arm positions and the use of elbow splints are common conservative treatment options. The rationale is to prevent excessive stretching and compression of the nerve in the cubital tunnel, as this mechanical stress impedes intraneural perfusion. Data regarding those upper extremity postures to avoid, or whether elbow flexion alone is detrimental, are inconsistent. This study aimed to assess perfusion and size changes of the cubital tunnel during different postures in an experimental cadaver setup.

Methods

Axillary arteries in 30 upper extremities of fresh cadavers were injected with ultrasound contrast agent. High‐resolution ultrasound of the cubital tunnel was performed during five different arm postures that gradually increased tension on the ulnar nerve and caused cubital tunnel narrowing. Contrast enhancement within the tunnel was measured to quantify perfusion. Cubital tunnel cross‐sectional area was measured to detect compression.

Results

Increasing tension significantly reduced perfusion. When isolated, neither shoulder elevation, elbow flexion, pronation, nor extension of wrist and fingers impaired perfusion. However, combining two or more of these postures led to significant decreases. Significant narrowing of the cubital tunnel was seen in full elbow flexion and shoulder elevation.

Discussion

Combinations of some upper extremity joint positions reduce nerve perfusion, but isolated elbow flexion does not have a significant impact. We hypothesize that elbow splints alone may not influence cubital tunnel perfusion but may only prevent direct compression of the ulnar nerve. Advising patients about upper extremity postures that should be avoided may be more effective.

Prospective Evaluation of Health Care Provider and Patient Assessments in Chemotherapy-Induced Peripheral Neurotoxicity

BACKGROUND AND OBJECTIVE

There is no agreement on the gold standard for detection and grading of chemotherapy-induced peripheral neurotoxicity (CIPN) in clinical trials. The objective is to perform an observational prospective study to assess and compare patient-based and physician-based methods for detection and grading of CIPN.

METHODS

Consecutive patients, aged 18 years or older, candidates for neurotoxic chemotherapy, were enrolled in the United States, European Union, or Australia. A trained investigator performed physician-based scales (Total Neuropathy Score-clinical [TNSc], used to calculate Total Neuropathy Score-nurse [TNSn]) and supervised the patient-completed questionnaire (Functional Assessment of Cancer Treatment/Gynecologic Oncology Group-Neurotoxicity [FACT/GOG-NTX]). Evaluations were performed before and at the end of chemotherapy. On participants without neuropathy at baseline, we assessed the association between TNSc, TNSn, and FACT/GOG-NTX. Considering a previously established minimal clinically important difference (MCID) for FACT/GOG-NTX, we identified participants with and without a clinically important deterioration according to this scale. Then, we calculated the MCID for TNSc and TNSn as the difference in the mean change score of these scales between the 2 groups.

RESULTS

Data from 254 participants were available: 180 (71%) had normal neurologic status at baseline. At the end of the study, 88% of participants developed any grade of neuropathy. TNSc, TNSn, and FACT/GOG-NTX showed good responsiveness (standardized mean change from baseline to end of chemotherapy >1 for all scales). On the 153 participants without neuropathy at baseline and treated with a known neurotoxic chemotherapy regimen, we verified a moderate correlation in both TNSc and TNSn scores with FACT/GOG-NTX (Spearman correlation index r = 0.6). On the same sample, considering as clinically important a change in the FACT/GOG-NTX score of at least 3.3 points, the MCID was 3.7 for TNSc and 2.8 for the TNSn.

CONCLUSIONS

MCID for TNSc and TNSn were calculated and the TNSn can be considered a reliable alternative objective clinical assessment if a more extended neurologic examination is not possible. The FACT/GOG-NTX score can be reduced to 7 items and these items correlate well with the TNSc and TNSn.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that a patient-completed questionnaire and nurse-assessed scale correlate with a physician-assessed scale.

Covid-19: Involvement of the nervous system. Identifying neurological predictors defining the course of the disease

The main objective of this study was to analyse neurological symptoms during a Covid-19 infection and determine the pattern of symptoms by comparing outpatients with inpatients. A further goal was to identify possible predictors, such as pre-existing conditions and neurological symptoms.

We recorded the clinical data of 40 inpatients and 42 outpatients in this retrospective, cross sectional study. Of them, 68 patients (83%), evenly distributed between the two groups, suffered from neurological symptoms. We identified the onset of neurological symptoms and the related time ranges in 41 patients (36 outpatients and 5 inpatients). Of these, 63.4% reported neurological symptoms on the first or second day of illness. 49 patients (72%) showed combinations of at least two to a maximum of seven different neurological symptoms. A more severe course of disease was correlated with age and male sex, but age was not identified as a predictor for the occurrence of neurological symptoms. Women suffered from central and neuromuscular symptoms more often than men (p = 0,004). The most common symptoms were fatigue (54%), headache (31%), loss of taste (31%), and loss of smell (27%).

Pre-existing dementia was associated with increased lethality; similarly, pre-existing stroke was associated with a more severe course of Covid-19 infection. Hallucinations and confusion were related to an increased likelihood of death.

The present data demonstrate the importance of comprehensive neurological support of inpatients and outpatients affected by Covid-19.

Therapy-resistant dysphagia successfully treated using pharyngeal electrical stimulation in a patient with the pharyngeal-cervical-brachial variant of the Guillain-Barré syndrome

Pharyngeal electrical stimulation (PES) is a novel treatment for oropharyngeal dysphagia resulting from neurogenic causes such as stroke, prolonged intubation, tracheostomy, or multiple sclerosis, and may be effective in other medical conditions such as Guillain-Barré syndrome (GBS). A 74-year-old male patient with a pharyngeal-cervical-brachial (PCB) variant of GBS, who had been tracheotomised due to severe and persistent swallowing difficulties (dysphagia) unresponsive to traditional speech and language therapy, received PES therapy as a final treatment option. Swallow performance evaluated before and after PES using fibreoptic endoscopic evaluation of swallowing, videofluoroscopy and clinical bedside assessment, showed significant improvement in swallowing resulting in safe tracheostomy decannulation 18 days after PES.

In PCB GBS, we present the potential benefit of PES for the treatment of persistent dysphagia and faster tracheostomy decannulation. PES was safe and may be beneficial in other neurologic disorders, where traditional dysphagia therapies have proved unsuccessful.

•

Pharyngeal electrical stimulation (PES) led to a rapid improvement of severe dysphagia in a patient with pharyngeal-cervical-brachial variant of Guillain-Barré syndrome.

•

PES is an approved treatment for neurogenic dysphagia, is easy-to-use and is safe.

•

PES is an efficient and innovative adjunctive to traditional speech and language therapies available for dysphagia.

Vancouver Declaration II on Global Headache Patient Advocacy 2019

In 2017, the International Headache Society convened a Global Patient Advocacy Summit (GPAS-1) to begin a collaborative effort involving patients, patient advocates, patient advocacy organizations, healthcare professionals, scientists, professional pain, neurology, and headache societies, pharmaceutical manufacturers, and regulatory agencies to advance issues of importance to patients affected by headache worldwide. In September 2019, the second Global Patient Advocacy Summit (GPAS-2) was convened to revisit issues from the inaugural meeting, assess the progress of the International Headache Society Global Patient Advocacy Coalition (IHS-GPAC) in meeting the goals set forth therein, and discuss strategies for achieving established goals and supporting future development. Short- and long-term mandates from the first Summit were realized, including publishing the Vancouver Declaration on Global Headache Patient Advocacy 2018, determining the governing and operational structures of the IHS-GPAC, and helping to facilitate the first World Federation of Neurology World Brain Day dedicated to migraine. Another short-term mandate, creating a unified advocacy strategy, was fulfilled by the Coalition's decision to focus on encouraging support from employers and implementing employee support programs for people with migraine. To help execute the strategy, the Coalition is developing an employer engagement toolkit that will educate employers and employees about the impact of migraine in the workplace, reduce stigma directed toward employees with migraine, and facilitate the care of employees with migraine to reduce the burden of illness and improve workplace productivity. Coalition members will disseminate the toolkit and encourage the adoption of migraine workplace programs by employers worldwide. The Coalition has established an alliance with two global, multinational employers to expand migraine awareness and support among policy makers and other stakeholders around the world. The IHS-GPAC met many of the goals established at GPAS-1, and it has initiated a global strategy focused on the psychosocial and economic toll of headache disorders, especially migraine, in the workplace. Ongoing and future activities will explore a range of opportunities with employers and across the full spectrum of advocacy goals.

The World Federation of Neurology and the challenges in Environment Neurology

Since its establishment the World Federation of Neurology (WFN) has manifested a keen interest in the environment and its relation to neurological diseases. Thus, in 2007 the WFN renamed the "Neurotoxicological Research Group" to "Environmental Neurology Research Group". In this short article, we review some recent events which illustrate the WFN involvement in Environmental Neurology as well its concerns about global health matters involving environmental issues.

Hereditary transthyretin-related amyloidosis

Hereditary transthyretin(TTR)-related amyloidosis (ATTRm amyloidosis) is an endemic/non-endemic, autosomal-dominant, early- and late-onset, rare, progressive disorder, predominantly manifesting as length-dependent, small fiber dominant, axonal polyneuropathy and frequently associated with cardiac disorders and other multisystem diseases. ATTRm amyloidosis is due to variants in the TTR gene, with the substitution Val30Met as the most frequent mutation. TTR mutations lead to destabilization and dissociation of TTR tetramers into variant TTR monomers, and formation of amyloid fibrils, which are consecutively deposited extracellularly in various tissues, such as nerves, heart, brain, eyes, intestines, kidneys, or the skin. Neuropathy may not only include large nerve fibers but also small fibers, and not only sensory and motor fibers but also autonomic fibers. Types of TTR variants, age at onset, penetrance, and clinical presentation vary between geographical areas. Suggestive of a ATTRm amyloidosis are a sensorimotor polyneuropathy, positive family history, autonomic dysfunction, cardiomyopathy, carpal tunnel syndrome, unexplained weight loss, and resistance to immunotherapy. If only sensory A-delta or C fibers are affected, small fiber neuropathy ensues. Diagnostic tests for small fiber neuropathy include determination of intraepidermal nerve fiber density, laser-evoked potentials, heat- and cold-detection thresholds, and measurement of the electrochemical skin conductance. Therapy currently relies on liver transplantation and TTR-stabilizers (tafamidis, diflunisal).

Vancouver Declaration on Global Headache Patient Advocacy 2018

BACKGROUND

Headache disorders comprise the three most prevalent medical disorders globally and contribute almost 20% to the total burden of neurologic illness. Although the experience of a recurrent headache disorder tends to be highly individualized, patient preferences tend to be a low priority in guidelines for the management of patients with headache.

METHODS

In September 2017, the first Global Patient Advocacy Summit was convened, bringing together patients, patient advocates, patient advocacy organizations, healthcare professionals, pharmaceutical manufacturers, scientists, and regulatory agencies to advance issues of importance to patients affected by headache worldwide.

RESULTS

Presentations and discussion covered multiple issues, such as improving access to appropriate medical care; incorporating the insights of independent patient advocates and advocacy organizations; leveraging the insights, experience and influence of leading health and neurological organizations; and raising awareness of the role of regulatory agencies in disease advocacy. Attendees agreed that it is important to understand and promote the global, regional, and local interests of people with headache disorders, as well as challenge the pervasive stigma associated with headache. They also agreed that those with severe, recurrent, or disabling headache disorders should have reliable access to competent medical care; healthcare professionals should have access to adequate training in Headache Medicine; global benchmarks should be established for accurate diagnosis and the use of evidence-based treatments in patients with headache; and that information is needed about consultation, diagnosis, and treatment of headache, particularly in regard to patient preferences.

CONCLUSION

Based on the group's consensus around these issues, a series of statements was developed, and they are collectively presented herein as the Vancouver Declaration on Global Headache Patient Advocacy 2018.