An uncontrolled trial of rituximab for antibody associated paraneoplastic neurological syndromes

Paraneoplastic limbic encephalitis presenting as a neurological emergency: a case report

Introduction

Paraneoplastic limbic encephalitis remains a challenging clinical diagnosis with poor outcome if it is not recognized and treated early in the course of the disease.

Case Presentation

A 65-year-old Caucasian woman presented with generalized tonic-clonic seizures and increasing confusion shortly after a lung biopsy that led to the diagnosis of small-cell lung cancer. She had a complicated hospital course, and had recurrent respiratory distress due to aspiration pneumonia, and fluctuating mental status and seizures that were refractory to anti-epileptic drug treatment. Routine laboratory testing, magnetic resonance imaging of the brain, electroencephalogram, lumbar puncture, serum and cerebrospinal fluid tests for paraneoplastic antibodies, and chest computed tomography were performed on our patient. The diagnosis was paraneoplastic limbic encephalitis in the setting of small-cell lung cancer with positive N-type voltage-gated calcium channel antibody titer. Anti-epileptic drugs for seizures, chemotherapy for small-cell lung cancer, and intravenous immunoglobulin and steroids for paraneoplastic limbic encephalitis led to a resolution of her seizures and improved her mental status.

Conclusion

Early recognition of paraneoplastic limbic encephalitis and prompt intervention with immune therapies at the onset of presentation will probably translate into more favorable neurological outcomes.

Favorable response to rituximab in a patient with anti-VGCC-positive Lambert-Eaton myasthenic syndrome and cerebellar dysfunction

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease that is characterized by impaired transmission across the neuromuscular junction due to autoantibodies directed against the presynaptic voltage-gated calcium channels (VGCC-ab). Clinical symptoms are usually characterized by proximal muscle weakness and mild dysautonomia. In some patients there are signs of cerebellar dysfunction as well, usually associated with cancer. Here we report the long-term follow-up of a patient with VGCC-ab-positive LEMS and a severe cerebellar syndrome but without evidence of cancer over 5 years. While conventional immunosuppressive therapy (steroids, azathioprine) failed, he improved with plasma exchange and consecutive treatment with rituximab. Muscle Nerve 40: 305-308, 2009.

Paraneoplastic syndromes of the CNS

Major advances in the management of paraneoplastic neurologic disorders (PND) include the detection of new antineuronal antibodies, the improved characterisation of known syndromes, the discovery of new syndromes, and the use of CT and PET to reveal the associated tumours at an early stage. In addition, the definition of useful clinical criteria has facilitated the early recognition and treatment of these disorders. In this article, we review some classic concepts about PND and recent clinical and immunological developments, focusing on paraneoplastic cerebellar degeneration, opsoclonus-myoclonus, and encephalitides affecting the limbic system.

Paraneoplastic syndromes in neuro-ophthalmology

PURPOSE OF REVIEW

The aim of this review is to discuss and highlight the recent advances in our understanding of paraneoplastic syndromes in neuro-ophthalmology and their significance.

RECENT FINDINGS

The pathophysiologic mechanism in neuro-ophthalmic paraneoplastic syndromes involves an immune response triggered by aberrant expression of onconeuronal antigens that cross-react with antigens in the visual system. Recently, 18-fluoro-deoxy-glucose/positron emission tomography with computed tomography scanning has emerged as a useful modality in diagnosing occult tumors responsible for paraneoplastic syndromes. Paraneoplastic optic neuropathy has been recently associated with the anti-CV2/CRMP-5 antibody. The use of serologic analysis of recombinantly expressed clones (SEREX) has led to the identification of new antigens associated with melanoma-associated retinopathy, such as visual arrestin, rhodopsin, titin, and mitofilin. Calcium-channel blockers and alemtuzumab have been found to improve visual function in cancer-associated retinopathy. Rituximab has been found to be effective in childhood opsoclonus-myoclonus syndrome.

SUMMARY

A high index of suspicion is needed to diagnose neuro-ophthalmic paraneoplastic syndromes. There have been recent advances in our understanding of the pathophysiology and treatment of these disorders. This will facilitate early treatment of causative occult tumors and improves the prognosis.

Paraneoplastic neurological syndromes: diagnosis and treatment

PURPOSE OF REVIEW

The most relevant advances in the field of paraneoplastic neurological syndromes are described, with special emphasis on particular clinical-immunological associations and practical issues for the diagnosis and treatment of these disorders.

RECENT FINDINGS

Paraneoplastic neurological syndromes may present with classical neurological symptoms or less frequently with symptoms that do not initially raise suspicion of these disorders. Recent examples include patients who present with epilepsia partialis continua or frontal disequilibrium associated with Hu antibodies, hypersommnia and anti-Ma2 antibodies, Devic's syndrome and CV2/CRMP5 antibodies and a syndrome characterized by psychiatric features and central hypoventilation in young women with anti-N-methyl-D-aspartate receptor antibodies. The cause of the neuronal damage is still open to debate. The recent description of antibodies against membrane proteins in opsoclonus or encephalitis associated with teratoma strongly suggests that antibodies may be responsible for the clinical features in some cases. Early diagnosis and effective treatment of the tumor remain the best options to improve or stabilize the syndrome. Immunotherapy, including rituximab, seems effective in those cases associated with functional damage.

SUMMARY

Neurologists must be aware of neurological syndromes that may have a paraneoplastic origin. Detection of onconeural antibodies is crucial to make the correct diagnosis. Immunotherapy should be used, although the impact of the treatment is unclear in cases with irreversible neuronal damage.

Limbic encephalitis and variants: classification, diagnosis and treatment

BACKGROUND AND OBJECTIVE

Recent studies suggest that a substantial number of patients with autoimmune limbic encephalitis may improve if properly diagnosed and treated. This is due, in part, to the increasing recognition of disorders that associate with antibodies to neuronal cell membrane antigens. This review focuses in these disorders, framed in a clinically useful immunologic classification of limbic encephalitis.

REVIEW SUMMARY

Patients with limbic encephalitis usually present with rapidly progressive short-term memory deficits, psychiatric symptoms, and seizures. After excluding viral and systemic autoimmune disorders, many patients with limbic encephalitis (paraneoplastic or not) have cerebrospinal fluid inflammatory findings, EEG or MRI abnormalities in the temporal lobes, and antineuronal antibodies. These antibodies are directed against 2 broad categories of antigens: (1) intracellular or classic paraneoplastic antigens, including Hu, Ma2, CV2/CRMP5, and amphiphysin among others, and (2) cell membrane antigens, including voltage-gated potassium channels, N-methyl-D-aspartate receptor, and others expressed in the neuropil of hippocampus and cerebellum (pending characterization). Whereas the disorders related to the first category of antibodies associate with cancer (lung, testis and other), prominent brain infiltrates of cytotoxic T-cells, and limited response to treatment, the disorders related to the second category of antibodies associate less frequently with cancer (thymoma, teratoma), seem to be antibody-mediated, and respond significantly better to immunotherapy.

CONCLUSIONS

Once considered an extremely rare disorder, almost always related to cancer, and refractory to treatment, limbic encephalitis is now regarded as a relatively frequent disorder, often unrelated to cancer, and with clinical-immunologic variants that respond to treatment.

Autoantibodies against glial antigens in paraneoplastic neurological diseases

Paraneoplastic neurological syndromes are clinically heterogeneous manifestations of cancer, but are not caused by the tumor or its metastases. Because autoantibodies reacting with tumor and nervous system tissue have been described, an autoimmune pathogenesis is suspected. Most autoantibodies are directed against neuronal proteins. Here, we describe the impact of antiglial autoantibodies in paraneoplastic neurological syndromes. Anti-CRMP5 and antiglial nuclear antibody both can be associated with different paraneoplastic neurological syndromes and tumors.

Paraneoplastic neurological syndromes and onconeural antibodies: clinical and immunological aspects

Paraneoplastic neurological syndromes (PNS) are infrequent disorders that are associated with cancer. The syndromes are highly heterogeneous and often affect several areas of the nervous system. Among the most well-known syndromes are paraneoplastic encephalomyelitis, cerebellar degeneration, sensory neuronopathy, and Lambert-Eaton myastenic syndrome. There are various associated tumors, in particular small cell lung cancer, cancer of the breast and ovary, and thymoma. The onset of neurological symptoms often precedes the cancer diagnosis, and the recognition of a paraneoplastic syndrome should lead to immediate search for cancer. The etiology of the paraneoplastic syndromes is believed to be autoimmune. Antibodies to onconeural antigens, expressed in the tumor of the affected individual and in normal neurons, are found in many of the patients. These antibodies are useful markers for paraneoplastic etiology. The pathogenesis of the PNS is uncertain, but cellular immune responses are thought to be the main effector mechanism. The cornerstone of therapy is the identification and treatment of the underlying malignancy. In some of the disorders, immunosuppressive therapy is of additional benefit. The prognosis of the different PNS varies depending on the level of affection and the degree of neuronal death.

Endometrial carcinoma first presenting as paraneoplastic cerebellar degeneration

BACKGROUND

Paraneoplastic degeneration (PCD) is an immune-mediated disorder affecting the cerebellum, characterized by subacute onset of cerebellar dysfunction progressing to severe disability, and is associated with an underlying malignancy. Ovarian carcinoma and breast carcinoma are commonly implicated.

CASE

We report a rare case PCD in an elderly woman, later diagnosed with endometrial carcinoma.

CONCLUSION

PCD is an unusual and rare manifestation of gynecological malignancies, including endometrial carcinoma, and a high degree of suspicion is required in these cases in order to make the correct diagnosis.

Dixièmes Journées des Maladies du Système Nerveux Périphérique

Sensory ganglionopathies have a frequent association with neoplastic disorders (paraneoplastic subacute sensory neuronopathy, or SSN) or dysimmune disorders, with drugs, such as cisplatin or pyridoxine, and with inherited disorders with degeneration of dorsal root ganglion cells. Unsteady gait and pseudoathetoid movements of the hand are the distinctive signs encountered in these disorders. The chronic disorders are characterized by non-length-dependent abnormalities of sensory nerve action potentials (SNAPs) and differ from other sensory neuropathies in showing a global, rather than distal, decrease in SNAP amplitudes. This review focuses on recent advances in defining the mechanisms involved in sensory ganglionopathies, and describes the differential diagnosis including the rarely encountered hereditary neuronopathies and the infectious causes.

Managing paraneoplastic neurological disorders

Paraneoplastic neurological syndromes (PNS) are remote effects of cancer that are not caused by invasion of the tumor or its metastases. Immunologic factors appear important in the pathogenesis of PNS because antineuronal autoantibodies and T-cell responses against nervous system antigens have been defined for many of these disorders. The immunologic response is elicited by the ectopic expression of neuronal antigens by the tumor. Expression of these so-called "onconeural" antigens is limited to the tumor and the nervous system and sometimes also the testis. At the time of presentation of the neurological symptoms, most patients have not yet been diagnosed with cancer. Detection of paraneoplastic antibodies is extremely helpful in diagnosing an otherwise unexplained and often rapidly progressive neurological syndrome as paraneoplastic. In addition, the paraneoplastic antibodies may also direct the search for an underlying neoplasm. On the other hand, in patients known to have cancer, the presentation of a PNS may herald recurrence of the tumor or a second tumor. The number of paraneoplastic antibodies is still growing, and at least seven of these can now be considered well characterized. Based on the clinical syndrome, the type of antibody, and the presence or absence of cancer, patients are classified as having a "definite" or "possible" PNS. Despite the presumed autoimmune etiology of PNS, the results of various forms of immunotherapy have been disappointing, with some exceptions. Rapid detection and immediate treatment of the underlying tumor appears to offer the best chance of stabilizing the patient and preventing further neurological deterioration.