Neurologic paraneoplastic syndromes

Peripheral Paraneoplastic Neuropathy, an Uncommon Clinical Onset of Sigmoid Cancer. Case Report and Review of the Literature

A case of a 76-year-old man presenting with weakness of the lower legs and bilateral steppage gait is described. Neurological examination revealed a sensorimotor neuropathy with axonopathy and myelinic aspects. At the time of the diagnostic workup an episode of rectal bleeding occurred. Colonoscopy demonstrated an exophytic cancer of the sigmoid colon at 40 cm from the anal verge. At surgery the tumor adhered to the ileum, so a left hemicolectomy and ileo-ileal resection were performed. Tumor stage was Dukes' B, Jass III, Astler-Coller B2, T3N0M0. The patient underwent postoperative chemotherapy and was followed for the past three years. At present he is free of disease and the neuropathy has completely regressed without any dedicated therapy.

As reported in the literature the appearance of a paraneoplastic neurological syndrome (PNS) may be the first sign of a malignancy that is occult at the time of clinical presentation. The most widely supported theory about its etiology is that of an autoimmune origin. The paraneoplastic neurological syndrome is considered to be at a point of intersection between tumor immunology, autoimmune neurological disease, and basic neurobiology. Previous experience has resulted in a pathogenic model and in a definition of a group of autoantibodies related to the disease. Small cell lung cancer (SCLC) is the neoplasm most frequently associated with PNS; other malignancies include lymphomas and various hematological malignancies. Some authors reported also that the percentage of patients with a high titer of neuronal autoantibodies is small and several of the autoantibodies are present at low levels without any accompanying clinical manifestation. In a clinical retrospective study of the Mayo Clinic Group 115,081 patients were examined over the period 1984-1993 and only 58 patients (0.05%) could be defined as being affected by a paraneoplastic neurological syndrome. Only five of these patients had colon tumors. The number of patients is so small and so widely scattered among publications that no statistical analysis is possible. Probably the only possibility for early identification of such a syndrome is a high degree of suspicion. In fact, these patients are usually first admitted and studied in a neurological unit, and the diagnosis of a tumor-associated disease is a delayed event.

PNMA2 mediates heterodimeric interactions and antagonizes chemo-sensitizing activities mediated by members of PNMA family

PNMA2, a member of the Paraneoplastic Ma Family (PNMA), was identified through expression cloning by using anti-sera from patients with paraneoplastic disorder. Tissue expression studies showed that PNMA2 was predominantly expressed in normal human brain; however, the protein was shown to exhibit abnormal expression profile as it was found to be expressed in a number of tumour tissues obtained from paraneopalstic patients. The abnormal expression profile of PNMA2 suggests that it might play an important role in tumorigenesis; however, apart from protein expression and immunological studies, the physiological role of PNMA2 remains unclear. In order to determine potential role of PNMA2 in tumorigenesis, and its functional relationship with PNMA family members, MOAP-1 (PNMA4) and PNMA1, expression constructs encoding the respective proteins were generated for both in vitro and in vivo studies. Our investigations showed that over-expressed MOAP-1 and PNMA1 promoted apoptosis and chemo-sensitization in MCF-7 cells as evidenced by condensed nuclei and Annexin-V positive MCF-7 cells; however, the effects mediated by these proteins were significantly inhibited or abolished when co-expressed with PNMA2 in MCF-7 cells. Furthermore, co-immunoprecipitation study showed that PNMA1 and MOAP-1 failed to associate with each other but readily formed respective heterodimer with PNMA2, suggesting that PNMA2 functions as antagonist of MOAP-1 and PNMA1 through heterodimeric interaction.

Pathogenesis and treatment of paraneoplastic neurologic syndrome

Paraneoplastic neurologic syndrome, a rare complication of carcinoma, includes various neurologic disorders, such as encephalomyelitis, paraneoplastic cerebellar degeneration, subacute sensory neuronopathy, retinal paraneoplastic syndrome, opsoclonus-myoclonus syndrome and stiff-person syndrome. Several antibodies to malignant tumor cells and neurons are detected in sera and cerebrospinal fluids of patients with this syndrome, however, there is no direct evidence of antiYo or antiHu antibodies' causative roles in neuronal loss. Recent studies showed cytotoxic T-cell activities against peptides of an antigen protein recognized by antibodies in the peripheral blood of patients with paraneoplastic cerebellar degeneration and antiYo antibodies, as well as in patients with antiHu syndrome. Treatment of paraneoplastic neurologic syndrome with plasmapheresis, immunosuppresive drugs, or intravenous immunoglobulin therapy has been attempted. Here, we discuss previous reports and theoretical treatments based on recent etiological hypothesis of paraneoplastic cerebellar degeneration.

Temporal lobectomy for refractory status epilepticus in a case of limbic encephalitis

The authors report a case of status epilepticus secondary to limbic encephalitis that was successfully treated with temporal lobectomy. A 45-year-old woman presented in status epilepticus refractory to high-dose suppressive medical therapy. Magnetic resonance imaging of the brain showed T2- and FLAIR-weighted hyperintensities in the right temporal lobe, left and right frontal lobes, and pons. A lumbar puncture revealed normal findings. Continuous electroencephalography monitoring showed continued right temporal seizure activity. A paraneoplastic panel was positive for N-type voltage-gated calcium channels. Subsequent bronchial biopsy revealed small cell carcinoma of the lung. A right temporal lobectomy was performed due to refractory status, resulting in resolution of seizure activity and recovery of good neurological function. The authors describe their case and review the literature on surgical therapy for refractory status epilepticus and limbic encephalitis.

Stiff man syndrome with thymoma

Paraneoplastic stiff man syndrome with a thymoma is rare disease. We treated a 57-year-old woman with a type B1 thymoma, based on the World Health Organization classification, who had stiff man syndrome. Her symptoms were alleviated after a thymectomy. Herein we report a case of stiff man syndrome with a thymoma and also review three cases reported previously.

The neuropathology of paraneoplastic syndromes

The term "paraneoplastic neurological syndromes" encompasses a number of uncommon disorders associated with systemic malignancies. In order to be classified a paraneoplastic neurological syndrome, the malignancies must not invade, compress, or metastasize to the nervous system. They can either focally or diffusely involve the central and peripheral nervous system or the neuromuscular junction. This paper reviews the neuropathology of the syndrome. It will first describe the clinical presentation and give an account of the systemic tumors most commonly associated with the various types of disorders. Then it will review the general pathological features that consist of an inflammatory process predominantly affecting the gray matter. Finally, it will describe in detail the main clinico-pathological types, including 1) encephalomyelitis, 2) cortical cerebellar degeneration, 3) peripheral neuropathy, 4) opsoclonus-myoclonus and 5) retinopathy. The Lambert-Eaton myasthenic syndrome will be dealt with separately in another paper in this symposium.

Paraneoplastic stiff-person syndrome: passive transfer to rats by means of IgG antibodies to amphiphysin

BACKGROUND

Stiff-person syndrome (SPS) with antibodies to amphiphysin is a paraneoplastic disorder of the central nervous system with a putative autoimmune pathogenesis. Proof of a causal role of the antibodies is still lacking for this and all other antibody-associated paraneoplastic syndromes of the central nervous system.

METHODS

We obtained the plasma filtrate of a patient with breast cancer and SPS that responded to therapeutic plasmapheresis. The purified IgG fraction included high-titre antibodies to the synaptic protein amphiphysin. In a cotransfer design, this IgG fraction was injected intraperitoneally into female Lewis rats that had received encephalitogenic T-helper (Th) lymphocytes specific for myelin basic protein, to induce an immune-mediated leaky blood-brain barrier. The rats were followed up with behavioural tests, video photography, and electromyography.

FINDINGS

The injection of the IgG fraction including antibodies to amphiphysin resulted in a dose-dependent stiffness with spasms resembling human SPS. Control IgG injected into rats that had received the same encephalitogenic Th cells had no effect. IgG binding was demonstrated in the central nervous system of rats that showed signs of the disorder.

INTERPRETATION

These experiments support the hypothesis of a pathogenetic role of antibodies to amphiphysin, thus adding paraneoplastic SPS to the group of antibody-mediated autoimmune disorders.

RELEVANCE TO PRACTICE

These findings provide a strong argument for a direct pathogenetic role of anti-amphiphysin in this type of SPS and support therapeutic attempts to eliminate these autoantibodies by plasmapheresis. The experimental approach used could help to elucidate the role of autoantibodies in other paraneoplastic syndromes, such as SPS with antibodies to glutamic acid decarboxylase, and others including anti-Hu-associated subacute cerebellar degeneration and limbic encephalitis.

Effects of antineuronal antibodies from patients with paraneoplastic neurological syndrome on primary-cultured neurons

Some patients with paraneoplastic neurological syndrome (PNS) produce autoantibodies against tumor and neuronal tissues of symptom-relevant areas. These characteristic antibodies are detected at early stages of the neurological disorder and are reliable markers for the diagnosis of PNS and underlying cancers. These antibodies are thought to be related directly to neuronal damage. However, the passive transfer of antibodies to rodents has been succeeded only in those in which the target antigens were expressed on the cell surface, like Lambert-Eaton myasthenic syndrome. The serum IgGs from patients with PNS and anti-Yo or anti-Hu antibody were not shown to induce the disease by passive transfer or active immunization with these antigen proteins to date. Instead, cytotoxic T lymphocytes (CTLs) against these antigen peptides-presenting targets could be induced in the peripheral blood of PNS patients. However, there is no direct proof of CTLs killing neurons. In this study, we examined the effects of the anti-Yo or anti-Hu antibody on mouse-brain-derived neurons in a primary culture system and found that these antibodies did not kill neurons, but induced the expression of cell adhesion molecules and accelerated neuronal differentiation. These effects of serum IgG fractions containing the anti-Yo or the anti-Hu antibody on the cultured neurons were the same, suggesting that their effects were not through the binding of the antibody to specific antigens, but to some other factors contained in IgG fractions.

Complex partial status epilepticus associated with anti-Hu paraneoplastic syndrome

Although seizures can be a manifestation of paraneoplastic disorders, there are few descriptions of the association between the anti-Hu paraneoplastic syndrome and epilepsia partialis continua. A new case of refractory complex partial status epilepticus in a patient with a paraneoplastic syndrome associated with a poorly differentiated mediastinal tumor that expressed Hu antigen is described clinically, pathologically, and electrographically. We discuss the presentation of focal seizures in a disease that is characterized by diffuse pathologic involvement of the brain. The progression of EEG, MRI, and clinical findings during the course of the illness is also discussed. To our knowledge, this is the first description of paraneoplastic epilepsia partialis continua associated with diffuse pathologic abnormalities.

Reduction of P/Q-type calcium channels in the postmortem cerebellum of paraneoplastic cerebellar degeneration with Lambert-Eaton myasthenic syndrome

The aim of this study was to clarify whether autoimmunity against P/Q-type voltage-gated calcium channels (VGCCs) in the cerebellum was associated with the pathogenesis of paraneoplastic cerebellar degeneration (PCD) with Lambert-Eaton myasthenic syndrome (LEMS). We used human autopsy cerebellar tissues from three PCD-LEMS patients and six other disease patients including one with LEMS as the controls. We compared cerebellar P/Q-type VGCC in these patients and controls for the amount and ratio of autoantibody-channel complex using an 125I-omega-conotoxin MVIIC-binding assay with Scatchard analysis, and their distribution using autoradiography. The quantity of cerebellar P/Q-type VGCC measured by Scatchard analysis were reduced in PCD-LEMS patients (63.0 +/- 7.0 fmol/mg, n = 3), compared with the controls (297.8 +/- 38.9 fmol/mg, n = 6). The ratio of autoantibody-VGCC complexes to total P/Q-type VGCCs measured by immunoprecipitation assay were increased in PCD-LEMS patients. We analysed cerebellar specimens by autoradiography using (125)I-omega-conotoxin MVIIC, which specifically binds to P/Q-type VGCCs. In PCD-LEMS cerebellum, the toxin binding sites of P/Q-type VGCCs were markedly reduced compared with controls, especially in the molecular layer, which is the richest area of P/Q-type VGCCs in the normal cerebellum. This suggests that P/Q-type VGCCs of the cerebellar molecular layer is the immunological target in developing PCD-LEMS.

Proactive identification of seizure risk improves terminal care

Seizures are a common neurologic consequence of various etiologies in the end-stage cancer patient. Because dying cancer patients and their families are often coping with new challenges daily, any intervention that can prevent further patient or family discomfort should be implemented. The purpose of this study was to evaluate four pharmacy interventions aimed at improving nursing care to cancer patients at a facility for the terminally ill. The four interventions were development of a seizure risk factor assessment toll, assembly or availability of a diazepam seizure kit, nursing education via in-service training, and development of a manual for nursing stations. Successful implementation of this project indicated that nurses perceived an empowerment in improving quality of life of their patients.

Stiff-person syndrome associated with invasive thymoma: a case report

We report a case of a 40-year-old female with continuous muscle stiffness and painful muscle spasms. The symptoms worsened over a two-week period after onset. Electrophysiological examinations revealed continuous muscle discharge, which was markedly reduced by intravenous administration of diazepam. High levels of anti-glutamic acid decarboxylase (GAD) antibodies were detected in both serum and cerebrospinal fluid, suggesting that the patient suffered from stiff-person syndrome. Steroid pulse therapy and immunoadsorption therapy alleviated the clinical symptoms and decreased the anti-GAD antibody titer. A chest CT revealed the presence of an invasive thymoma. Neither anti-acetylcholine receptor (AChR) antibodies nor symptoms of myasthenia gravis (MG) were observed. The patient underwent a thymectomy and postoperative radiotherapy. These treatments further alleviated the clinical symptoms. The present case is the first that associates stiff-person syndrome with invasive thymoma, and not accompanied by MG. The autoimmune mechanism, in this case, may be triggered by the invasive thymoma.

Negative-antibody paraneoplastic syndrome complicating small cell carcinoma

The neurological paraneoplastic syndromes represent nonmetastatic complications of cancer and may affect several levels of the nervous system. They are thought to be immunologically-mediated. The syndrome predates the diagnosis of cancer by months to years in two thirds of cases. We report the case of a female patient presenting with a cerebellar syndrome and a sensory neuronopathy on a background of severe weight loss. We searched for occult malignancy and later diagnosed her to be suffering from a paraneoplastic syndrome secondary to small cell carcinoma of the lung. Paraneoplastic antibodies were negative. She was subsequently treated with chemotherapy.

Ataxia associated with Hashimoto's disease: progressive non-familial adult onset cerebellar degeneration with autoimmune thyroiditis

Acquired cerebellar ataxia has been described with hypothyroidism, and is typically reversible by thyroid hormone replacement therapy. The cerebellar dysfunction has been attributed to metabolic and physiological effects of the endocrine disorder. In a few patients, however, ataxia has persisted despite thyroid replacement therapy. Other mechanisms may be involved in ataxia associated with thyroid disorders.

OBJECTIVE

To document progressive non-familial adult onset cerebellar degeneration (PNACD) occurring in six patients with raised antithyroid antibodies (Hashimoto's/autoimmune thyroiditis), and other autoimmune manifestations, in the absence of hypothyroidism; and to document the independence of the cerebellar disorder from the endocrine dysfunction.

METHODS

A case study of six patients with PNACD reviewing the clinical course and relation to endocrine and autoimmune status.

RESULTS

All six patients were euthyroid when they developed their symptoms; had raised antithyroid antibodies consistent with Hashimoto's autoimmune thyroiditis; and had strong personal or family histories of organ specific autoimmune diatheses. Brain MRI disclosed atrophy of the cerebellar vermis in four patients and olivopontocerebellar atrophy in two. Other possible causes of cerebellar degeneration were excluded. De novo treatment (two patients) or continued treatment (three patients) with L-thyroxine did not modify the progression of the ataxia.

CONCLUSIONS

Cerebellar degeneration in these patients with raised antithyroid antibodies may be immune mediated. The presence of antithyroid antibodies may signal or cause the autoimmune process producing cerebellar degeneration. "Hashimoto's associated ataxia" seems to represent a recognisable and not uncommon condition; a trial of immunomodulating therapy should be considered in these patients.

Persistent paraneoplastic neurologic syndrome after successful therapy of Hodgkin's disease

Paraneoplastic neurologic syndromes may develop in Hodgkin's disease (HD). We describe three young female patients with neurological disorders, not explained by other causes, preceding diagnosis or relapse of HD. The lack of response of the paraneoplastic syndrome to successful treatment of HD among our three patients emphasizes the poor prognosis of longstanding paraneoplastic neurologic symptoms in HD.

Limbic encephalitis investigated by 18FDG-PET and 3D MRI

Two patients with clinically probable or possible limbic encephalitis (LE) are reported, both cases with typical findings in clinical symptoms (severe neuropsychological deficits and complex partial seizures) and in routine magnetic resonance imaging (MRI) (hyperintense mesiotemporal lesions). Underlying malignancy was identified (rectal carcinoma) in one case but could not be detected in the other patient. The 2 patients were investigated by cerebral 18F-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) and 3-dimensional (3D) MRI, and abnormalities in metabolic activity were mapped using coregistration of spatially normalized PET and MRI. Highly significant focal hypermetabolism in bilateral hippocampal areas was found in both cases. The authors' findings support FDG-PET coregistered to 3D MRI as a potentially valuable additional tool in the imaging diagnostics of LE. Results are discussed with respect to the clinical symptoms and previously reported imaging findings in the disease.

Poorly differentiated carcinoma of the lung presenting with Lambert--Eaton myasthenic syndrome

Lambert-Eaton myasthenic syndrome commonly seen in small-cell lung cancer represents an autoimmune reaction against antigens coexpressed by tumor and neurons. It is rarely seen with other histologic subtypes. Symptoms antedate the appearance of the neoplasm by weeks to years. Therapeutic options range from immunosuppression, plasmapheresis, pharmacologic facilitation of neuromuscular transmission, and definitive therapy of the primary tumor. This case report describes the rare association of Lambert-Eaton myasthenic syndrome with non-small-cell lung cancer.

Paraneoplastic Diseases of the Nervous System

Several neurologic paraneoplastic disorders are believed to be caused by an autoimmune reaction against an antigen or antigens coexpressed by tumor cells and neurons. Of the paraneoplastic syndromes, the Lambert-Eaton myasthenic syndrome (LEMS)--in which autoantibodies downregulate voltage-gated calcium channels at the presynaptic nerve terminal--is associated with the strongest evidence of an autoimmune cause. For the other syndromes, including cerebellar degeneration, multifocal encephalomyelitis, sensory neuronopathy, limbic encephalitis, opsoclonus-myoclonus, and retinal degeneration, an autoimmune cause is indicated by the presence of specific anti-neuronal antibodies. These antibodies serve as a useful diagnostic tool, but their actual role in causing neuronal injury and clinical disease remains unclear. A small percentage of patients with paraneoplastic disorders shows major neurologic improvement after successful treatment of the associated tumor. Of patients who require further therapy for the neurologic disorder, those with LEMS have the best outcome. The response to immunosuppression among patients with paraneoplastic central nervous system (CNS) dysfunction is much less favorable. Although exceptions clearly exist, most patients with CNS paraneoplastic disorders do not improve despite tumor treatment and immunosuppressive therapy. It is likely that many patients already have irreversible neuronal injury at the time of diagnosis. The decision to attempt immunosuppressive treatment must be made on an individual basis.

Paraneoplastic neuropathy

Paraneoplastic neuropathies occur in various settings. This article focuses on recent neuroimmunologic findings regarding paraneoplastic neuropathy. Entities such as sensorimotor and sensory neuropathy, sensory neuronopathy; motor, autonomic, demyelinating and vasculitic mononeuropathies; and cranial nerve lesions and neuropathies in association with leukaemia and paraproteinaemas are discussed. Finally, the article considers the issue of 'overlap' syndromes--the occurrence of several paraneoplastic phenomena in the same patient.

Paraneoplastic syndromes

Paraneoplastic neurological syndromes cause severe neurological dysfunction and may lead to the diagnosis of a potentially curable cancer. The range of clinical presentations of these syndromes continues to grow and new antibody associations are constantly being described. Conventional immunosuppressive therapy is rarely helpful and the prognosis of these conditions remains poor.