Autonomic paraneoplastic neurological syndromes

Autoimmune Autonomic Neuropathy: From Pathogenesis to Diagnosis

Autoimmune autonomic ganglionopathy (AAG) is a disease of autonomic failure caused by ganglionic acetylcholine receptor (gAChR) autoantibodies. Although the detection of autoantibodies is important for distinguishing the disease from other neuropathies that present with autonomic dysfunction, other factors are important for accurate diagnosis. Here, we provide a comprehensive review of the clinical features of AAG, highlighting differences in clinical course, clinical presentation, and laboratory findings from other neuropathies presenting with autonomic symptoms. The first step in diagnosing AAG is careful history taking, which should reveal whether the mode of onset is acute or chronic, followed by an examination of the time course of disease progression, including the presentation of autonomic and extra-autonomic symptoms. AAG is a neuropathy that should be differentiated from other neuropathies when the patient presents with autonomic dysfunction. Immune-mediated neuropathies, such as acute autonomic sensory neuropathy, are sometimes difficult to differentiate, and therefore, differences in clinical and laboratory findings should be well understood. Other non-neuropathic conditions, such as postural orthostatic tachycardia syndrome, chronic fatigue syndrome, and long COVID, also present with symptoms similar to those of AAG. Although often challenging, efforts should be made to differentiate among the disease candidates.

Paraneoplastic neurological syndromes in patients affected by SCLC: a case series

Paraneoplastic syndromes occur in about 0.1% of patients affected by neoplastic diseases. In some types of tumors, such as Small Cell Lung Cancer (SCLC), Thymoma, and particular forms of Plasmacytoma, the association with Paraneoplastic Neurological Syndromes (PNS) is much more frequent. It seems that these syndromes are triggered by tumor production of factors normally expressed only by the individual's nervous system. The immune system stimulates an autoimmune response against these factors that induce neurological symptoms. Also, in light of the latest updates on the relationship between immunotherapy and PNS as well as of the introduction of first-line immunotherapy in SCLC, it seems that the use of immunotherapy in SCLC is associated with concomitant increase in autoimmune neurological syndromes.In this article, we report our experience at Istituto Nazionale Tumori of Milan with three patients affected by SCLC and PNS. Our experience seems to confirm that the oncological treatment scarcely impacts the paraneoplastic neurological deficits. Further research is needed to improve the treatment and recovery of patients affected by PNS.

Diseases which cause generalized peripheral neuropathy: a systematic review

PURPOSE

Peripheral autonomic neuropathy, including enteric neuropathy, may be subtle and unrecognized for several years. Diagnosis of enteric neuropathy demands complicated examinations such as full-thickness bowel biopsy. We hypothesized that knowledge about simultaneous occurrence of different types of neuropathy would lead to faster recognition and diagnosis of autonomic/enteric neuropathy. The aim of the present systematic review was to increase the awareness of disease groups causing autonomic and enteric neuropathy along with sensorimotor neuropathy.

METHODS

A systematic search strategy was used in PubMed, Embase and Web of Science. First, 4978 articles were identified. Review of titles/abstracts rendered exclusion of animal studies, articles not written in English or full-length, case reports, conference abstracts and duplicates until 357 articles remained. The full-length evaluation resulted in 35 studies (27 non-systematic reviews) which described objectively verified peripheral autonomic, enteric and sensorimotor neuropathy within the same disease.

RESULTS

Diabetes is the most common disease in society rendering generalized peripheral neuropathy. Accumulation of tissue deposits in amyloidosis, Lewy body disorders and sarcoidosis lead to widespread peripheral neuropathy. Several autoimmune disorders such as systemic sclerosis and primary Sjögren's syndrome present themselves with neuropathy. Paraneoplastic neuropathy may appear prior to symptoms from the malignancy. Both the infection per se, as well as the autoimmune response to the infection, i.e., Guillain-Barré syndrome, may lead to widespread peripheral neuropathy. Hereditary disorders with disturbed metabolism lead to intermittent attacks of neuropathy.

CONCLUSIONS

The major causes of generalized peripheral neuropathy are diabetes, diseases with tissue deposits, autoimmunity, infections, malignancy and metabolic diseases.

Anti-CV2/CRMP5 antibody-positive paraneoplastic neurological syndromes with chronic intestinal pseudo-obstruction in a small-cell lung cancer patient: a case report and literature review

Patients with anti-CV2/collapsin response mediator protein (CRMP)5 antibodies present with more frequent chorea, cerebellar ataxia, uveo/retinal symptoms, and Lambert–Eaton myasthenic syndrome or myasthenia gravis. Chronic intestinal pseudo-obstruction (CIPO) is an intestinal motility dysfunction disease dysmotility that is caused by a neuromuscular disease with recurrent or persistent intestinal obstruction in the absence of mechanical obstruction. We report the case of a patient with CRMP5 antibody-positive paraneoplastic neurological syndrome (PNS) that is associated with autonomic dysfunction (presenting most remarkably as CIPO). CIPO is one of the rarest forms of PNS. Some PNS patients who are positive for anti-CV2/CRMP5 antibodies may have fatal complications such as CIPO. To detect if PNS patients are at risk for CIPO, a timely diagnosis and appropriate treatment are required.

A Case Report of Pediatric Paraneoplastic Dysautonomia

We present the case of a 16-year-old girl who presented with severe refractory orthostatic hypotension secondary to pandysautonomia. Initially, she was treated for Guillain-Barré syndrome given clinical symptoms and increased protein on cerebrospinal fluid, but the severity of symptoms and lack of response to intravenous immunoglobulin prompted further evaluation for an autoimmune etiology. She was ultimately diagnosed with paraneoplastic neuropathy secondary to Hodgkin lymphoma. Paraneoplastic neurologic phenomena are rare, occurring in just 0.01% of cancers, and prompt recognition is crucial for initiating appropriate therapy. Rapid progression of severe disabling symptoms should raise suspicion for an underlying malignancy. The patient had limited response to splanchnic vasoconstrictors in addition to α-agonists, anticholinergics, and mineralocorticoids until initiation of modified Hodgkin lymphoma directed chemotherapy plus rituximab.

Anti-SOX1 antibody-positive paraneoplastic neurological syndrome presenting with Lambert-Eaton myasthenic syndrome and small cell lung cancer: A case report

Paraneoplastic neurological syndromes (PNS) are rare disorders affecting any part of the central, peripheral or autonomic nervous system that occur in association with cancer. Among cancer patients, less than 1% overall develop PNS. Anti‐SOX1 antibodies' positive paraneoplastic neurological disorders are rare and are usually associated with small cell lung cancer (SCLC). Here, we report a case of a 61‐year‐old male patient who presented with an unusual anti‐SOX1 positive PNS. The right tibialis anterior showed noticeable low‐amplitude motor unit potentials and high amplitude motor potentials in electrodiagnostic study, suggesting the presence of Lambert‐Eaton myasthenic syndrome (LEMS). Typical MRI and PET‐CT found a hyperintense lesion with contrast enhancement in the thorax in front of 5–6 centrum of vertebrae, and thoracoscopic biopsy revealed pathological findings for SCLC. The patient underwent several lines of chemotherapy and radiotherapy and survived for 15 months after the diagnosis of SCLC.

Integrated treatment for autonomic paraneoplastic syndrome improves performance status in a patient with small lung cell carcinoma: a case report

BACKGROUND

Paraneoplastic neurological syndromes (PNS) are rare disorders associated with cancer and are believed to be immune mediated. Patients with autonomic PNS suffer from variable combinations of parasympathetic and sympathetic failure. Autonomic PNS are usually associated with other PNS, such as encephalomyelitis and sensory neuropathy; however, autonomic symptoms may rarely manifest as PNS symptoms. Autonomic symptoms, therefore, may be overlooked in patients with cancer.

CASE PRESENTATION

We described a 65-year-old Japanese man who was diagnosed with autonomic PNS due to small-cell lung carcinoma (SCLC) with Eastern Cooperative Oncology Group (ECOG) performance status 3, who suffered from orthostatic hypotension, and urinary retention needing a urethral balloon. Laboratory studies showed decreased levels of noradrenaline, and were positive for anti-ganglionic acetylcholine receptor antibody, type 1 antineuronal nuclear antibody, and sry-like high mobility group box 1 antibody. Nerve conduction evaluations and ¹²³I-metaiodobenzylguanidine myocardial scintigraphy showed no abnormalities. Abdominal contrast-enhanced computed tomography revealed marked colonic distention. The patient's autonomic symptoms resolved following integrated treatment (symptomatic treatment, immunotherapy, and additional chemotherapy) enabling the patient to walk, remove the urethral balloon, and endure further chemotherapy. ECOG performance status remained at 1, 10 months after admission.

CONCLUSIONS

Integrated treatment for autonomic PNS may improve autonomic symptoms and ECOG performance status of patients with cancer.

Thymoma Associated with Myasthenia and Autonomic anti-Hu Paraneoplastic Neuropathy

Along with myasthenia, other paraneoplastic neurological syndromes (PNS) may occur in thymoma. Anti-Hu antibodies and a clinical “anti-Hu syndrome” characterized by encephalitis and/or painful neuropathies have been reported in only three patients at the time of the diagnosis of thymoma. We describe a severe anti-Hu-related autonomic neuropathy with gastrointestinal paresis and intestinal pseudo-obstruction with malabsorption that occurred concomitantly with the worsening of myasthenic symptoms long after the initial diagnosis of thymoma in a young patient. The clinical anti-Hu syndrome preceded the radiological diagnosis of thymoma recurrence. Treatment with plasma exchange led to a transient improvement of neurological symptoms.

The Utility of FDG-PET/CT in Clinically Suspected Paraneoplastic Neurological Syndrome: A Literature Review and Retrospective Case Series

Paraneoplastic neurological syndrome (PNS) describes a spectrum of rare, heterogeneous neurological conditions associated with an underlying malignancy. Diagnosis of PNS is inherently difficult, with frequent misdiagnosis and delay. The literature suggests an underlying immune-mediated pathophysiology, and patients are usually tested for the presence of onconeural antibodies. With direct tumor therapy being the most effective method of stabilizing patients, there is a strong emphasis on detecting underlying tumors. The sensitivity of conventional CT imaging is often inadequate in such patients. While FDG-PET imaging has already been shown to be effective at detecting these tumors, FDG-PET/CT, combining both structural and functional imaging in a single study, is a more recent technique. To study the utility of FDG-PET/CT, we conducted a systematic literature review and a retrospective study. We identified 41 patients who underwent imaging for clinically suspected PNS at the regional PET-CT and neurosciences center based at the Royal Preston Hospital between 2007 and 2014 and compared the results to conventional investigations. Five patients had FDG-PET/CT tracer avidity suspicious of malignant disease, and four of these were subsequently diagnosed with cancer. Sensitivity and specificity were calculated to be 100 and 97.3%, respectively, with positive predictive value 80% and negative predictive value 100%. This compares to a sensitivity and specificity of 50 and 100%, respectively, for CT and 50 and 89%, respectively, for onconeural antibodies. These findings are in line with previous studies and support the diagnostic accuracy of FDG-PET/CT for the detection of underlying malignancy.

Paraneoplastic disorders of the central and peripheral nervous systems

Paraneoplatic neurologic syndromes (PNS) have been seminally defined as acute or subacute neurological syndromes resulting from nervous system dysfunction that is remote from the site of a malignant neoplasm or its metastases. However, in respect to our current understanding of their pathogenesis we may redefine these disorders as cancer-related dysimmune neurologic syndromes. We first deal with the epidemiology and the pathogenesis of PNS, then the different classic PNS are reviewed with clinical features according to the associated onconeuronal antibodies. Finally, therapeutic approaches are discussed.

Review article: the assessment and management of chronic severe gastrointestinal dysmotility in adults

BACKGROUND

The characterisation and management of chronic severe gastrointestinal (GI) dysmotility are challenging. It may cause intestinal failure requiring home parenteral nutrition (HPN).

AIMS

To review the presentation, aetiology, characterisation, management and outcome of chronic severe GI dysmotility, and to suggest a pragmatic management algorithm.

METHODS

PubMed search was performed up to December 2012 using appropriate search terms, restricted to human articles and reviewed for relevance. Segmental dysmotility, acute ileus, functional syndromes and non-English articles were excluded. Evidence and recommendations were evaluated using the GRADE system.

RESULTS

In total, 721 relevant articles were reviewed. A coherent and definitive picture is hampered by overlapping classification systems using multi-modal characterisation methods, subject to pitfalls and some requiring further validation. The literature is confined to case series with no randomised trials. Fewer than 20% undergo full thickness jejunal biopsy, which are otherwise labelled idiopathic. However, in studies with up to 80% biopsy rates, neuromuscular abnormalities may be found in 90%. Between 14% and 50% will require HPN, comprising 8-14% of all HPN patients, of which 2/3 are primary/idiopathic and 1/3 secondary, with scleroderma being the leading secondary cause. Ten-year  mortality ranges from 13% to 35% and is worst in elderly scleroderma patients. Management includes limited treatments for secondary causes, prokinetics, symptom palliation, psychological support, nutrition, hydration and judicious surgery.

CONCLUSIONS

Severe dysmotility often remains idiopathic. It is rarely possible to alter disease trajectory; consequently, prognosis may be poor. Multi-disciplinary teams in a specialist setting can improve outcomes. Graded recommendations are enumerated and a pragmatic algorithm is suggested.

Autonomic dysfunction in older people

The autonomic nervous system comprises the sympathetic, parasympathetic and enteric nervous systems and plays an integral role in homeostasis. This includes cardiovascular and temperature control, glucose metabolism, gastrointestinal and reproductive function and increasing evidence to support its involvement in the inflammatory response to infection and cancer. Ageing is associated with autonomic dysfunction, and many clinical syndromes associated with older adults are due to inadequate autonomic responses to physiological stressors. The aim of this review is to explore the relationship between autonomic dysfunction and ageing illustrated with examples of maladaptive autonomic responses in a variety of different clinical syndromes including an exploration of autonomic cellular changes. Appropriate investigation and management strategies are outlined, recognizing the fine balance needed to improve symptoms without creating further medical complications.

Modeling immune complex-mediated autoimmune inflammation

A number of autoimmune diseases are thought to feature a particular type of self-sustaining inflammation, caused by the deposition of immune complexes (IC) in the inflamed tissue and a consequent activation of local effector cells. The persistence of this inflammation is due to a positive feedback loop, where autoantigen particles released as part of the tissue damage caused by the inflammation stimulate autoreactive B cells, leading to the formation of further immune complexes and their subsequent deposition. We present a mathematical model for the exploration of IC-mediated autoimmune inflammation and its clinical implications. We characterize the possible differences between normal individuals and those susceptible to such inflammation, and show that both random perturbations and bifurcations can lead to disease onset. Our model explains how defects in the mechanisms responsible for cellular debris clearance contribute to the development of disease, in agreement with empirical evidence. Moreover, we show that parameters governing the dynamics of immune complexes, such as their clearance rate, have an even stronger effect in determining the behavior of the system. We demonstrate the existence of hysteresis, implying that once IC-mediated autoimmune inflammation is triggered, its long-term suppression may be difficult to achieve. Our results can serve to guide the development of novel therapies to autoimmune diseases involving this type of inflammation.

Update on paraneoplastic neurological syndromes

PURPOSE OF REVIEW

To describe specificities and new advances in treatment of paraneoplastic neurological syndromes (PNS).

RECENT FINDINGS

PNS are defined as neurological syndromes of unknown cause that often antedate the diagnosis of an underlying cancer that is usually not clinically evident. The clinical signs of PNS are accurately described and 'classical' PNS have been established. Within the context of these syndromes, the concept of limbic encephalitis has evolved dramatically in the last 2 years due to the description of new auto-antibodies. The diagnosis and treatment of the associated cancer remains the key goal of the clinical management of PNS. However, the specific treatment of the neurological symptoms primarily depends on the immunological findings.

SUMMARY

There is increasing recognition of an extensive array of PNS and of several paraneoplastic antibodies as biological markers of these disorders. Basic immunological studies support the pathogenic role of some of these antibodies. Others are only markers of the disease.

[Paraneoplastic neurological syndromes]

BACKGROUND

Paraneoplastic neurological syndromes constitute a heterogenous group of diseases, which often cause severe neurological symptoms. Extensive research during the last 20 years has led to identification of new antigenic targets and inclusion of additional clinical conditions into this group of syndromes.

MATERIAL AND METHODS

The article is based on a non-systematic search of PubMed and the author's own experience with antibody analysis, treatment of patients and research within the field.

RESULTS AND INTERPRETATION

Paraneoplastic neurological syndromes affect less than 1 % of all patients with cancer. The etiology is probably autoimmune, and involves immune responses (cellular and humoral) against antigens shared by tumor cells and normal neurons. Many, but not all patients harbour onconeural antibodies (in serum and spinal fluid), which are highly useful diagnostic markers for a paraneoplastic etiology. The cornerstone of therapy is treatment of the underlying tumor, but additional immunosuppressive therapy is often administered.

Paraneoplastic neurological syndromes: a review

BACKGROUND

Paraneoplastic neurologic syndromes (PNS) constitute a rare group of disorders resulting from damage to the nervous system in the setting of cancer physically unrelated to the tumor site. PNS are believed to result from an autoimmune attack of normal neuronal tissue, spurred by similar neuronal antigens ectopically expressed by tumor cells.

REVIEW SUMMARY

The most common PNS are reviewed and also their association with specific onconeural antibodies, some directly pathogenic, others whose role in the disease process is less clear-cut. This diversity in pathogenesis is likely due to the relative role of humoral versus cellular immunity in PNS. Virtually any cancer may result in PNS but certain tumors, small cell lung cancer, gynecologic cancers (breast and ovarian), thymoma, and plasma cell tumors are more frequently encountered. In most instances, immunosuppressive therapy is unhelpful and outcome is poor.

CONCLUSIONS

PNS have diverse presentations, affecting both the central and peripheral nervous system and commonly, it is the PNS, not cancer that is the presenting symptom. Only subsequently, after onconeural antibodies are discovered or cancer is found, is PNS diagnosed. Neurologists should familiarize themselves with these rare syndromes and treatment principles, as rapid detection and treatment of the underlying tumor offer the best chance for recovery or prevention of further neurologic deterioration.

Autonomic dysfunction in autoimmune rheumatic disease

Cardiovascular and neurological manifestations are known to occur in patients with autoimmune rheumatic disease (ARD), often in subclinical form. The term autonomic nervous system (ANS) describes nerves that are concerned predominantly with the regulation of bodily functions. It is comprised of sympathetic and parasympathetic nerves, and their function is complementary. ANS involvement has rarely been studied in patients with ARD, and studies have shown conflicting results. This may be because symptoms of autonomic dysfunction are nonspecific and extremely varied, and may pertain to several systems like the gastrointestinal, cardiovascular, and nervous. Moreover, tests to detect autonomic dysfunction are not routinely employed in clinical rheumatological practice. Another difficulty is to differentiate cardiovascular effects of drugs from ARD involvement. Previous studies on this topic found signs of parasympathetic and sympathetic dysfunction in variable proportions in patients with autoimmune diseases, between 24% and 100% in various tests depending on the methods used. Cardiovascular autonomic dysfunction is the most common type of ANS dysfunction, and was revealed in the majority of ARD patients.

SOX-1 autoantibodies in patients with paraneoplastic neurological syndromes

Paraneoplastic neurological syndromes (PNS) are tumour-associated disorders, which are not caused by the tumour itself or its metastases. Since antineuronal autoantibodies can be detected in these patients, an autoimmune pathogenesis is suspected. Recently, autoantibodies against cerebellar Bergmann glia were found in patients with paraneoplastic Lambert-Eaton myasthenic syndrome and other paraneoplastic neurological syndromes associated with small cell lung cancer, and SOX1 has been identified as the corresponding antigen. SOX1-antibodies have been reported to be highly specific for paraneoplastic neurological disorders. However, increasing evidence exists that they may also be associated with other neuroimmunological disorders without an underlying tumour.

Autoantibody targets and their cancer relationship in the pathogenicity of paraneoplastic retinopathy

Paraneoplastic retinopathies (PR), including cancer-associated retinopathy (CAR) or the closely related melanoma-associated retinopathy (MAR) occur in a small subset of patients with retinal degeneration and systemic cancer. This autoimmune syndrome is characterized by sudden, progressive loss of vision in association with circulating anti-retinal autoantibodies. The PR syndromes are heterogeneous, may produce a number of ocular symptoms, and may be associated with several different neoplasms, including lung, breast, prostate, gynecological, and colon cancer, melanoma, and hematologic malignancies. We examined the onset of retinopathy in correlation to the diagnosis of cancer and the presence of specific anti-retinal autoantibodies in PR patients. In some patients without diagnosed malignant tumors, the onset of ocular symptoms and the presence of autoantibodies preceded the diagnosis of cancer by months to years, including anti-recoverin, anti-transducin-alpha, and anti-carbonic anhydrase II antibodies. Although anti-retinal autoantibodies may not be a good predictor of a specific neoplasm, they can be used as biomarkers for different subtypes of retinopathy. Identification of autoantibodies involved in autoimmune-mediated PR will help elucidate the mechanisms underlying the PR syndromes and develop targeted therapies for these sight-threatening disorders.

A case of life-threatening nausea and vomiting

Nausea and vomiting are symptoms frequently occurring in the presence of cancer. However, a patient with known cancer may also have a benign cause for nausea and vomiting. This case report of a patient with early gastric carcinoma demonstrates this point, and is a caution against attributing worsening symptoms to worsening cancer. The patient had severe postoperative gastroesophageal reflux and gastroparesis following proximal partial gastrectomy. Ultimately, the nausea and vomiting were totally relieved by completion gastrectomy.

Rheumatic disorders as paraneoplastic syndromes

The long-established observation that some rheumatologic disorders (RDs) are associated with--or precede--the clinical manifestations of a variety of solid and hematological tumors represents an important clue for the early diagnosis and effective treatment of the cancers. Inflammatory myopathies, seronegative rheumatoid arthritis and some atypical vasculitides are the most frequently reported paraneoplastic RDs, although paraneoplastic scleroderma- and lupus-like syndromes, erythema nodosum, and Raynaud's syndrome have also been observed. Generally, the clinical course of a paraneoplastic RD parallels that of the cancer, and surgical removal of the tumor or its medical treatment usually results in a marked regression of the clinical manifestations of the RD. Most paraneoplastic RDs are difficultly distinguishable from idiopathic RDs. Even so, some atypical features of the clinical presentation raise the suspicion of an underlying tumor. This review summarizes current hypotheses for the pathogenesis that leads a tumor to present as an RD and discusses the clinical features that help distinguish paraneoplastic from idiopathic RDs.