P.A.E. Sillevis Smitt

Recommended diagnostic criteria for paraneoplastic neurological syndromes

Background: Paraneoplastic neurological syndromes (PNS) are defined by the presence of cancer and exclusion of other known causes of the neurological symptoms, but this criterion does not separate “true” PNS from neurological syndromes that are coincidental with a cancer. Objective: To provide more rigorous diagnostic criteria for PNS. Methods: An international panel of neurologists interested in PNS identified those defined as “classical” in previous studies. The panel reviewed the existing diagnostic criteria and recommended new criteria for those in whom no clinical consensus was reached in the past. The panel reviewed all reported onconeural antibodies and established the conditions to identify those that would be labelled as “well characterised”. The antibody information was obtained from published work and from unpublished data from the different laboratories involved in the study. Results: The panel suggest two levels of evidence to define a neurological syndrome as paraneoplastic: “definite” and “possible”. Each level can be reached combining a set of criteria based on the presence or absence of cancer and the definitions of “classical” syndrome and “well characterised” onconeural antibody. Conclusions: The proposed criteria should help clinicians in the classification of their patients and the prospective and retrospective analysis of PNS cases.

Immediate post-radiotherapy changes in malignant glioma can mimic tumor progression

To determine the frequency of progressive MRI lesions shortly after radiotherapy for glioma with spontaneous improvement or stabilization, the authors studied a cohort of patients treated within two prospective phase III trials with radiotherapy only. In 9 out of 32 patients, the first post-radiotherapy MRI showed progressive enhancement. In 3 of these 9 the MRI improved or stabilized for 6 months without additional treatment. The authors conclude that patients with progressive lesions within 3 months after radiotherapy should not be eligible for phase II trials on recurrent glioma.

Screening for tumours in paraneoplastic syndromes: report of an EFNS Task Force

Background:  Paraneoplastic neurological syndromes (PNS) almost invariably predate detection of the malignancy. Screening for tumours is important in PNS as the tumour directly affects prognosis and treatment and should be performed as soon as possible.

Anti-Tr antibodies as markers of paraneoplastic cerebellar degeneration and Hodgkin’s disease

Background: Preliminary studies suggested that anti-Tr antibodies identify patients with paraneoplastic cerebellar degeneration (PCD) and Hodgkin disease (HD). Objective: To extend the clinical–immunologic analysis to 28 patients with anti-Tr antibodies. Methods: Anti-Tr antibodies were detected by immunohistochemistry. A competitive inhibition assay was used to ascertain if anti-Tr antibodies of different sera identify common epitopes. Anti-Tr immunoglobulin G (IgG) subclass distribution was determined by immunohistochemistry using monoclonal antibodies against human IgG isotypes. Tr immunoreactivity was analyzed in tumor sections using biotinylated anti-Tr IgG. Results: Median age of the 28 patients was 61 years (range 14 to 75 years) and 22 were male. A cerebellar syndrome was present in 27 patients and a possible limbic encephalitis in one. HD was diagnosed in 25 patients. No tumor was found in three patients; the autopsy of one of them disclosed severe loss of Purkinje cells without inflammatory infiltrates. Anti-Tr antibodies spontaneously disappeared in all patients without tumor and in 10/10 patients after successful HD treatment. Anti-Tr antibodies were absent in the serum but positive in the CSF of two patients. All positive anti-Tr sera inhibited the immunoreactivity of biotinylated anti-Tr IgG. The predominant isotypes of anti-Tr were IgG1 and IgG3. Only 1 out of the 15 HD samples studied presented anti-Tr positivity that was localized in some Reed-Sternberg cells. Conclusions: This study confirms the strong association between anti-Tr antibodies and PCD associated with HD. Anti-Tr antibodies from different patients recognize similar epitopes. Unlike other antineuronal antibodies, anti-Tr antibodies can be detected in the CSF but not in the serum and may spontaneously disappear during the follow-up, and Tr immunoreactivity is usually lacking in the tumor.

Management of paraneoplastic neurological syndromes: report of an EFNS Task Force.

Paraneoplastic neurological syndromes (PNS) are remote effects of cancer on the nervous system. An overview of the management of classical PNS, i.e. paraneoplastic limbic encephalitis, subacute sensory neuronopathy, paraneoplastic cerebellar degeneration, paraneoplastic opsoclonus‐myoclonus, Lambert–Eaton myasthenic syndrome and paraneoplastic peripheral nerve hyperexcitability is given. Myasthenia gravis and paraproteinemic neuropathies are not included in this report. No evidence‐based recommendations were possible, but good practice points were agreed by consensus. Urgent investigation is indicated, especially in central nervous system (CNS) syndromes, to allow tumour therapy to be started early and prevent progressive neuronal death and irreversible disability. Onconeural antibodies are of great importance in the investigation of PNS and can be used to focus tumour search. PDG‐PET is useful if the initial radiological tumour screen is negative. Early detection and treatment of the tumour is the approach that seems to offer the greatest chance for PNS stabilization. Immune therapy usually has no or modest effect on the CNS syndromes, whereas such therapy is beneficial for PNS affecting the neuromuscular junction. Symptomatic therapy should be offered to all patients with PNS.

CSF flow cytometry greatly improves diagnostic accuracy in CNS hematologic malignancies

Objective: To assess the diagnostic accuracy of flow cytometric immunophenotyping in comparison with classic cytomorphology for diagnosing CNS localizations of hematologic malignancies, and to evaluate the implications of CSF pleocytosis and protein content in this context. Methods: We reviewed the results of diagnostic evaluations of all CSF samples analyzed for localization of a hematologic malignancy between 2001 and 2004 at our center. Results: A total of 1,054 samples from 219 patients were available for analysis. Sixty patients had a CSF localization diagnosed by positive flow cytometry, cytomorphology, or both. The first sample was positive by flow cytometry in 44 (73%) patients, by cytomorphology in 19 (32%). Four first samples were positive by cytomorphology but negative by flow cytometry. Patients with positive cytomorphology had more frequent clinical symptomatology (95% vs 58%) and CSF pleocytosis (84% vs 25%), and tended to a poorer progression-free survival than patients with positive flow cytometry only. OR for CNS localization in case of CSF pleocytosis was 10.1 (95% CI 4.9 to 20.8); OR for CNS localization in case of elevated protein content was 2.9 (95% CI 1.5 to 5.4). Nevertheless, 26 of 137 (19%) patients with normal cell count and protein concentration had a CNS localization. Conclusions: The diagnostic value of flow cytometry is more than twice that of cytomorphology. However, cytomorphologic examination of the CSF has additional diagnostic and possibly prognostic value, and should still be performed in conjunction with flow cytometry.

The Lambert–Eaton myasthenic syndrome 1988–2008: A clinical picture in 97 patients

BACKGROUND Neuromuscular symptoms in patients with Lambert-Eaton myasthenic syndrome (LEMS) and a small cell lung cancer (SCLC) develop more rapidly than in LEMS patients without a SCLC. We studied how this clinical information, which is readily available at the first consultation, can be used to predict the presence of SCLC. PATIENTS AND METHODS In our study we included 52 LEMS patients with SCLC and 45 non-tumor patients (NT-LEMS). We interviewed patients using a structured checklist and reviewed their clinical records. We compared frequency and onset of symptoms during the course of LEMS. RESULTS In the first six months, over half the SCLC-LEMS patients had developed seven separate symptoms, while NT-LEMS patients developed only two symptoms. Proximal leg weakness and dry mouth were early symptoms in both groups. Rapid involvement of proximal arm muscles (p=0.0001), distal arm muscles (p=0.0037), distal leg muscles (p=0.0002), dysartria (p=0.0091) and the presence of erectile dysfunction (p=0.007) were found significantly more often in SCLC-LEMS patients in both cohorts. Cerebellar symptoms, although present in 9% of LEMS patients, were almost exclusively related to SCLC-LEMS. CONCLUSION A rapidly progressive course of disease from onset in LEMS patients should raise a high suspicion of SCLC. Special attention should be paid to involvement of upper extremities, involvement of distal arm and distal leg muscles, to erectile dysfunction and probably ataxia in order to discriminate between SCLC-LEMS and NT-LEMS.

Negative sural nerve biopsy in neurolymphomatosis.

Abstract Patients with non-Hodgkin’s lymphoma occasionally develop widespread invasion of peripheral nerves by tumor cells or neurolymphomatosis (NL). Clinically this usually results in asymmetrical, progressive, and painful polyneuropathy. Diagnosis rests on the identification of tumor cells in peripheral nerves. To avoid false-negative biopsy findings in patients with malignant lymphomatous infiltration of peripheral nerves it has been recommended to biopsy clinically involved nerves. We present two patients with histologically confirmed NL in whom sural the nerve biopsy finding was negative despite clinical and neurophysiological evidence of involvement of the sural nerve a. The clinical features of NL are reviewed. Some patients with neurolyphomatosis have only focal or proximal involvement of nerves, requiring the biopsy of an affected part of these nerves. Magnetic resonance imaging may be useful in identifying affected nerves.

Molecular and cellular mechanisms underlying anti-neuronal antibody mediated disorders of the central nervous system.

Over the last decade multiple autoantigens located on the plasma membrane of neurons have been identified. Neuronal surface antigens include molecules directly involved in neurotransmission and excitability. Binding of the antibody to the antigen may directly alter the target proteins function, resulting in neurological disorders. The often striking reversibility of symptoms following early aggressive immunotherapy supports a pathogenic role for autoantibodies to neuronal surface antigens. In order to better understand and treat these neurologic disorders it is important to gain insight in the underlying mechanisms of antibody pathogenicity. In this review we discuss the clinical, circumstantial, in vitro and in vivo evidence for neuronal surface antibody pathogenicity and the possible underlying cellular and molecular mechanisms. This review shows that antibodies to neuronal surface antigens are often directed at conformational epitopes located in the extracellular domain of the antigen. The conformation of the epitope can be affected by specific posttranslational modifications. This may explain the distinct clinical phenotypes that are seen in patients with antibodies to antigens that are expressed throughout the brain. Furthermore, it is likely that there is a heterogeneous antibody population, consisting of different IgG subtypes and directed at multiple epitopes located in an immunogenic region. Binding of these antibodies may result in different pathophysiological mechanisms occurring in the same patient, together contributing to the clinical syndrome. Unraveling the predominant mechanism in each distinct antigen could provide clues for therapeutic interventions.

Paraneoplastic ophthalmoplegia and subacute motor axonal neuropathy associated with anti-GQ1b antibodies in a patient with malignant melanoma

A 68 year old woman developed oculomotor paresis shortly after metastatic progression of her melanoma was discovered. She was then immunised with the tumour antigen MAGE-3 in combination with an immunological adjuvant. During immunisation her symptoms worsened and she developed severe, predominantly proximal axonal motor neuropathy and became bedridden. IgM antibodies against gangliosides GM2, GD3, and GQ1b were detected in serum obtained two weeks before and nine weeks after the onset of symptoms. Immunohistochemically, the patient’s IgM reacted with the tumour and co-localised with GQ1b. She improved neurologically following steroid treatment and became ambulatory.