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PARANEOPLASTIC SYNDROME AND MIMICS: WHAT THE RADIOLOGY AND CLINICIANS NEED TO KNOW Ammar Chaudhry, MD Maryam Gul, MD Abbas Chaudhry, BS Jared Dunkin, MD eEdE-30 Correspondence: [email protected] DISCLOSURES • NONE OBJECTIVES 1. Review clinical spectrum and pathogenesis of paraneoplastic syndromes with focus on CNS processes 2. Case-based review highlighting common and uncommon causes of paraneoplastic syndrome 3. Discuss differential diagnoses (physiologic process, congenital, infection, inflammation, trauma, vascular and/or malignancy) that can mimic imaging findings of Paraneoplastic syndromes 4. Review treatment and prognosis INTRODUCTION • Paraneoplastic neurologic syndromes are a heterogeneous group of disorders caused by mechanisms other than metastases, metabolic and nutritional deficits, infections, coagulopathy or side effects of cancer treatment • These syndromes may affect any part of the nervous system from cerebral cortex to neuromuscular junction either damaging one area (e.g. Purkinje cell, presynaptic cholinergic synapses) or multiple areas (e.g. encephalomyelitis) • Can simultaneously involve central and/or peripheral nervous system Herpes Simplex Virus (Most often Implicated); HHV, CJD; Lyme PATHOGENSIS Infectious • Paraneoplastic neurologic syndromes are believed to result when an immunologic response is directed against shared antigens that are ectopically expressed by the tumor Antibodies against Membrane Antigens: that are normally expressed by the nervous system Anti-NMDA Anti-AMPA Anti-GABAßR Encephalitis • Antibodies can be detected in the serum and cerebrospinal fluid (CSF) of many Paraneoplastic • NOTE: not all patients with paraneoplastic syndromes (classically havehave + Ab titers intra-cellular antigens) Antibodies against Antigens: • Recent studies suggest that the immune system can mount a T-cell response toIntracellular a “ normal Anti-Hu AntiCV2/CRMP-5 Anti-Ma2 protein” when it is expressed in a cancer cell Autoimmune PE • suggesting that normal self antigens may be processed differently in cancer cells than in the normal cells • Increased immune reaction against the “normal protein” expressed in the nervous systems “NonAnti-GAD Antibodies against leads to the Paraneoplastic syndrome Paraneoplastic” antigens of voltage-dependent potassium (antigen located on cell membrance) channel complex (LGI1, CASPR2, contactin-2) Dalmau J, Gultekin HS, Posner JB. Paraneoplastic neurologic syndromes: pathogenesis and physiopathology. Brain Pathol 1999; 9:275. Rosenfeld MR, Eichen JG, Wade DF, et al. Molecular and clinical diversity in paraneoplastic immunity to Ma proteins. Ann Neurol 2001; 50:339 Savage PA, Vosseller K, Kang C, et al. Recognition of a ubiquitous self antigen by prostate cancer-infiltrating CD8+ T lymphocytes. Science 2008; 319:215 PARANEOPLASTIC LIMBIC ENCEPHALITIS • Paraneoplastic syndromes are mediated by antibodies occur when certain neoplasms outside of the central nervous system express antigens that are expressed coincidentally by neuronal cells and therefore the immune response results in the production of antibodies that have as objective the tumor and specific sites in the brain. • The tumors most frequently associated with paraneoplastic LE are lung carcinoma (50%), mostly small cell lung carcinoma (SCLC), testicular tumors (20%), breast carcinoma (8%), non-Hodgkin lymphoma, teratoma and thymoma. • • Antibodies associated with Paraneoplastic LE • Antibodies against membrane antigens: Anti-NMDA, Anti-AMPA, Anti-GABAbR • Antibodies against Intracelullar Antigens: Anti-Hu, Anti-CV2/CRMP-5, Anti-Ma2 AUTOIMMUNE PARANEOPLASTIC ENCEPHALITIS • Autoantibodies are directed against two antigen categories: intracellular antigens (referred to as “classical paraneoplastic antigens”) and cell membrane antigens (“non-paraneoplastic”) • Classically described that the antigens in the paraneoplastic encephalitis are intracellular and opposite to this in the non-paraneoplastic are membrane antigens, recent literature reviews reveal that there may be either types of antigens with or without associated tumor • Immune response against intracellular antigens usually associates a cytotoxic T-cell mechanism and a limited response to immunomodulator therapy • Immune response to membrane antigens is mediated by antiboidies and respondes better to treatment. CLINICAL SPECTRUM OF CENTRAL AND PERIPHERAL NERVOUS SYSTEM PARANEOPLASTIC SYNDROMES Paraneoplastic syndromes of the central nervous system Encephalomyelitis* Myelitis* Limbic encephalitis* Brainstem encephalitis* Cerebellar degeneration* Opsoclonus myoclonus ataxia* Stiff-person syndrome* Subacute sensory neuronopathy* Visual syndromes • Cancer associated retinopathy* • Melanoma associated retinopathy* • Optic neuritis Necrotizing myelopathy Motor neuron syndrome • Subacute motor neuronopathy • Other syndromes Paraneoplastic syndromes of the peripheral nervous system Chronic sensorimotor neuropathy • Association with plasma cell dyscrasias Autonomic neuropathy* Vasculitis of nerve and muscle Acute sensorimotor neuropathy • • Guillain-Barré syndrome Plexitis (eg, brachial neuritis) Paraneoplastic syndromes of the neuromuscular junction and muscle Myasthenia gravis* Lambert-Eaton myasthenic syndrome* Dermatomyositis/polymyositis * Denotes syndromes where specific antibodies have been identified Neuromyotonia* Acute necrotizing myopathy CA1:A32achectic myopathy Dalmau J, Rosenfeld M. Overview of Paraneoplastic syndromes of the nervous system. www.uptodate.com. Accessed Oct 25 th 2014 PARANEOPLASTIC SYNDROMES ASSOCIATED WITH LUNG CANCER Systemic Anorexia, cachexia, weight loss Dermatomyositis/polymyositis Fever Systemic lupus erythematosus Nonbacterial thrombotic endocarditis Orthostatic hypotension Renal Tubulointerstitial disorders Glomerulopathies Cutaneous Acquired hypertrichosis lanuginosa Acrokeratosis (Bazex's syndrome) Clubbing Dermatomyositis Erythema gyratum repens Exfoliative dermatitis Hypertrophic pulmonary osteoarthropathy Deep venous thrombosis (Trousseau's syndrome) Tripe palms Acanthosis nigricans Neurologic Peripheral neuropathy Lambert-Eaton myasthenic syndrome Cushing's syndrome Hypercalcemia Necrotizing myelopathy Hyponatremia Cerebral encephalopathy Hyperglycemia Visceral neuropathy Acromegaly Hematologic Acquired ichthyosis Acquired palmoplantar keratoderma Erythema annulare centrifugum Florid cutaneous papillomatosis Pemphigus vulgaris Endocrine/Metabolic Hyperthyroidism Anemia Hypercalcitoninemia Polycythemia Hypercoagulability Thrombocytopenic purpura Gynecomastia Galactorrhea Carcinoid syndrome Pityriasis rotunda Dysproteinemia (including amyloidosis) Hypoglycemia Pruritus Leukocytosis/leukoerythroblastic reaction Hypophosphatemia Sign of Leser-Trelat Eosinophilia Lactic acidosis Sweet's syndrome Vasculitis Identifies most common Paraneoplastic syndromes Hypouricemia Hyperamylasemia Dalmau J, Rosenfeld M. Overview of Paraneoplastic syndromes of the nervous system. www.uptodate.com. Accessed Oct 25 th 2014 Antibody Antibodies, paraneoplastic syndromes and associated cancers Syndrome Associated cancers Well characterized paraneoplastic antibodies Anti-Hu (ANNA-1) Anti-Yo (PCA-1) Anti-Ri (ANNA-2) Anti-Tr (DNER) Anti-CV2/CRMP5 Anti-Ma proteins• (Ma1, Ma2) Anti-amphiphysin Anti-recoverinΔ Encephalomyelitis including cortical, limbic, brainstem encephalitis, cerebellar degeneration, myelitis, sensory neuronopathy, and/or autonomic dysfunction Cerebellar degeneration Cerebellar degeneration, brainstem encephalitis, opsoclonus-myoclonus Cerebellar degeneration Encephalomyelitis, cerebellar degeneration, chorea, peripheral neuropathy Limbic, hypothalamic, brainstem encephalitis (infrequently cerebellar degeneration) Stiff-person syndrome, encephalomyelitis Cancer-associated retinopathy (CAR) SCLC, other Gynecological, breast Breast, gynecological, SCLC Hodgkin's lymphoma SCLC, thymoma, other Germ-cell tumors of testis, lung cancer, other solid tumors Breast, lung cancer SCLC Partially-characterized paraneoplastic antibodies Anti-Zic 4 mGluR1 ANNA-3 PCA2 Anti-bipolar cells of the retina Cerebellar degeneration Cerebellar degeneration Sensory neuronopathy, encephalomyelitis Encephalomyelitis, cerebellar degeneration Melanoma-associated retinopathy (MAR) SCLC No tumor or Hodgkin's lymphoma SCLC SCLC Melanoma Antibodies that occur with and without cancer association Anti-AMPAR Anti-GABA(B) receptor Lambert-Eaton myasthenic syndrome, cerebellar dysfunction Myasthenia gravis Multistage syndrome with memory and behavioral disturbances, psychosis, seizures, dyskinesias, and autonomic dysfunction Limbic encephalitis, psychiatric disturbances Seizures, limbic encephalitis Anti-LGI1 (previously attributed to VGKC) Limbic encephalitis, seizures Thymoma, SCLC Anti-CASPR2 (previously attributed to VGKC) Morvan's syndrome and some patients with neuromyotonia Thymoma and variable solid tumors Anti-nAChR Subacute pandysautonomia SCLC, others Encephalomyelitis with muscle spasms, rigidity, myoclonus, Often without cancer hyperekplexia Anti-VGCC Anti-AChR Anti-NMDAR GlyR SCLC Thymoma Teratoma Variable solid tumors SCLC Dalmau J, Rosenfeld M. Overview of Paraneoplastic syndromes of the nervous system. www.uptodate.com. Accessed Oct 25 th 2014 DIAGNOSIS • Patients suspected of having a paraneoplastic neurologic syndrome should be examined for paraneoplastic antibodies in their serum. • NOTE: low level of antibodies can be positive in cancer patients w/o paraneoplastic syn. • NOTE: same neurologic symptoms/syndrome can be caused by one or more antibodies known to cause paraneoplastic syndrome • NOTE: high titers of paraneoplastic antibodies with or without symptoms should warrant careful search for underlying neoplasm • Neuroimaging studies, lumbar puncture, and electrophysiology tests can be helpful in characterizing the neurologic syndrome PARANEOPLASTIC SYNDROME RADIOLOGICAL FINDINGS • The findings of limbic involvement are similar regardless of the type of antibody found. Some patients do not show any alteration in MRI, espceially those with antiNMDA (up to 50% had normal MRI) • In patients with abnormalities, most common findings include hyperintense signal on FLAIR/T2-weighted sequences most notably affecting the mesial region in temporal lobes, hippocampi, frontobasal and insular regions • Other patterns of brain involvement can be found, especialy in patients with anti-NMDA, where the cerebellum, basal ganglia and brainstem can be affected CASE: 69 YEAR OLD MALE WITH EXPRESSIVE APHASIA AND SEIZURE-LIKE EPISODE Ill-defined FLAIR hyperdensity in the left temporal lobe with loss of sulci suggestive of edema. There is no evidence of restricted diffusion, post-contrast enhancement or susceptibility artifact CSF + pleocytosis; Infectious work up was negative Dx: Anti-GAD Limbic Encephalitis CASE: 54 YEAR OLD MALE WITH SEIZURE Anti-LGI1+ Paraneoplastic syndrome CASE: 61 YEAR OLD FEMALE WITH SLURRED SPEECH AND WEAKNESS Paraneoplastic limbic encephalitis associated with antiMa2. Patient with progressive 3-month history of memory loss, anxiety attacks, conduct disorder and ophthalmoplegia. Crainal MRI (A) axial and (B) coronal FLAIR which show signal hyperintensity in hippocampus and temporal amygdales (arrows). (C) axial image sequence showing a discrete diffusion restriction in the medial temporal region (arrows). PCR of HSV in CSF and body CT were negative. Determination of Anti-Hu antibody positive associated to a breast cancer. CASE: 47 year old woman presented with seizures and choreiformmovements. Initial CT scan was read as normal. On retrospective review, there is a very subtle area of hypodensityinvolving the medial right temporal lobe (arrow). MRI demonstrates increased FLAIR signal involving the bilateral temporal lobes and thalamus without contrast enhancement or restricted diffusion. Additional imaging revealed a breast mass with axillary lymphadenopathy, confirming the diagnosis of paraneoplastic limbic encephalitis Anti-amphphysin + DIFFERENTIAL POINTS: 1) enhancement is rare. 2) can involve thalamus, midbrain, and brainstem. (although rarely HSV can involve these areas as well, particularly in immunocompromised patients) 3) no hemorrhage or restricted diffusion CASE: PATIENT WITH SEIZURES, HAD NEGATIVE ROUTINE MRI; HOWEVER, ON PET-MRI, + RIGHT FRONTAL LOBE HYPOMETABOLIC FOCUS LIKELY THE SOURCE OF SEIZURE Anti-GABA + paraneoplastic encephalitis MIMICS: INFECTION • Wide spectrum of viral, bacterial and fungal germs with the most frequent etiology herpes simplex virus type 1 (HSV-1) • 70% of infectious encephalitis in immunocompetent patients are due to HSV-1 • In immunocompromised patients, esp if infected with human immunodeficiency virus (HIV) or s/p stem cell transplant should be considered for herpes simplex such as herpes virus tpe 2 (HSV-2), human herpes virus 6 and 8 (HHV6 and HH7) • Clinical manifestations typically consist on subacute presentation of seizures, fever, memory loss, confusion to a rapid deterioration in level of consciousness that usually progress faster than in paraneoplastic encephalitis. • The diagnostic method of choice is the HSV genome amplification by PCR in sample cerebrospinal fluid, with sensitivity and specificity of 94% and 98% respectively, but with the disadvantage that this test may be negative in the first 48-72 hours of onset of symptoms and after 10 days. • CSF + pleiocitosis and CSF protein elevation IMAGING FINDINGS IN INFECTIOUS ENCEPHALITIS • MRI: “gold standard” with alterations in 90% of patients with HSV-1 encephalitis • findings are usually bilateral but asymmetrical • T2-FLAIR: Hyperintense lesions reflects edema, hemorrhage or necrosis and affect the inferomedial region of the temporal lobes and the orbital surface of the frontal lobes with frequent extension to the insular cortex. The basal ganglia are generally respected • Diffusion (DWI): there is restriction due to cytotoxic edema • UPTAKE: There is not uptake in the initial stages, but can show giral uptake as disease progresses, usually 1 week after the onset of symptoms • Small microhemorrhages are exceptional in early stages and is more frequently found in subacute phases 38 YEAR OLD MALE PRESENTING WITH DELIRIUM, CONFUSION AND HEADACHE. INITIAL NON-CONTRAST HEAD CT IMAGES DEMONSTRATE ABNORMAL HYPODENSITYINVOLVING THE RIGHT PARIETAL LOBE. Herpes Encephalitis Mortality is very high, approaching 70% across all cases. Even in young patients with early recognition of symptoms and early therapy, mortality reaches 25% with less than 10% patients recovering with no longterm neurologic sequelae. MRI demonstrates significantly more involvement than the CT, and we see the characteristic imaging pattern of asymmetric abnormal T2/FLAIR signal intensity involving the temporal lobes and insula.The parietal lobe is also involved as seen on CT, and the T1 image demonstrates hyperintensitymirroring the hyperdensityon CT confirming early subacutehemorrhage. Although we see contrast enhancement here, enhancement is variable, and can be absent early in the course of the disease. Diffusion is typically restricted from cytotoxic edema and is more sensitive than increased T2 signal. 38 YEAR OLD WITH SEIZURES MESIAL TEMPORAL SCLEROSIS • Most common cause partial complex seizures • May be acquired or developmental • 20% bilateral, 15 % dual path with cortical dysplasia most common dual path • 70-95% cured with ant temporal lobectomy • T2 hyper signal and atrophy of hippocampus with loss internal architecture • Secondary signs: Fornix and mamillary body atrophy, enlarged temp horn SEIZURE EPIPHENOMENON • 48 year old male presented with seizure. MRI demonstrates faint increased FLAIR signal involving the right medial temporal lobe. T1 post contrast image demonstrates gyriform enhancement involving the right insula. No restricted diffusion is seen. • Infectious and neoplastic workup was negative. • This finding was therefore felt likely to represent seizure epiphenomenon, a term used to described MRI findings reflecting the effect of, rather than the cause, seizures. • Most commonly, T2 hyperintensity and contrast enhancement are seen. Diffusion abnormalities also occur. GLIOMATOSIS CEREBRI • A 34 year old male presented with seizure. MRI demonstrates abnormal T2 and FLAIR signal involving the bilateral temporal lobes, right thalamus, insular cortex, and the brainstem. No contrast enhancement is seen. There was no restricted diffusion. Notably, there is significant mass effect with effacement of the frontal horn of the right lateral ventricle. • Given the clinical presentation and mass-like quality of the abnormality, there was concern for an infiltrating glioma. Open brain biopsy demonstrated a WHO grade III glialtumor. • DIFFERENTIAL POINTS: 1) enhancement is variable, although usually uncommon in infiltrating gliomas. High grade gliomascan enhance. 2) mass effect may or may not be present (seen in this case) 3) diffusion restriction is rare. 4) MR spectroscopy may be helpful, demonstrating increased choline, as well as occasionally increased lactate/lipid in higher grade tumors. CASE 4: 40 YEAR OLD WITH SEIZURE. MRI REVIEWS ENHANCING LESION WITH RESTRICTED DIFFUSION WITH +FDG AVIDITY. BX: +LEFT TEMPORAL LOBE GLIOMA LEFT MCA INFARCT • FLAIR and DWI MR images demonstrate typical appearance of a left MCA infarct involving the left insula and frontal lobe, as well as the anterior temporal lobe. The left putamen is also involved. • CT angiography demonstrates a segmental occlusion of the left M1. CASE: 66 Y/O FEMALE WITH WORSENING HEADACHES, ALTERED MENTAL STATUS AND PARESTHESIAS CT w/o contrast: Hyperdense brainstem mass with perilesional edema was concerning for acute hemorrhage MRI: Heterogenous T1 Hypointense T2/FLAIR hyperintense heterogenous lesion demonstrating postcontrast enhancement and areas of susceptibility artifact PET-MRI: reveals hypermetabolic lesion in the brain stem with 29.7 SUV most compatible with a neoplastic process. Biospy revealed metastatic renal cell carcinoma CASE : 56 YEAR OLD FEMALE WITH BREAST CANCER PRESENTS WITH HEADACHES Pre-Treatment MRI reveal leptomeningeal T2/FLAIR hyperintense lesion with post-contrast enhancement. There is marked associated FDG-PET activity, suggestive of breast cancer leptomeningeal metastasis, Post-Treatment: On routine MRI, there is residual FLAIR activity with mild post-contrast enhancement. However, on PET-MRI, there is no residual activity, confirming successful treatment. YOUNG FEMALE S/P LEFT CN 8 SCHWANOMA REMOVAL P/W LEFT SIDED CN 6 PALSY T2 FLAIR ADC Brain Click toStem play Infarct Involving CN 6 Nucleus DWI SUBACUTE DEVELOPMENT OF ASCENING PARALYSIS • Autoimmune post-infectious or post-vaccinial acute inflamm demyelination of peripheral nerves, nerve roots, and CN’s • Acute flaccid paralysis or distal paraesthesia followed by rapid ascending paralysis • Most pts somewhat better by 23mo with 8% mortality • Smooth enhancement of cauda equina which may be slightly thickened • Preferential contrast accentuation of ventral roots of cauda • Conus enhancement variable CASE: WORSENING HEADACHE NEUROSARCOID • CNS invovlement 5% • Most common symptom CN deficit most often CN 7 • Solitary or multifocal CNS masses • Dura, leptomeninges, subarachnoid space • Brain parenchyma hypothalamus>stem> cerebral hemis>cerebellar hemis DDX: • T2 hypo material subarachnoid spaces, 50% perivent WM lesions, may cause • TB small vessel vasculitis • Fungal infection • Contrast >1/3 mult parencymal lesions, >1/3 leptomeningeal involvement, • Leptomeningeal carcinomatosis 10% solitary intra axial mass, 5% solitary dural based extra axial mass • Neurosarcoidosis • Lymphoma • Pyogenic BASILAR MENINGITIS CASE SUBACUTE MEMORY LOSS • Rapidly progressing, fatal, potentially tranmissible dementing disorder caused by a prion • Dementia with myoclonic jerks and akinetic mutism • EEG periodic high voltage waves on background of low voltage activity • Atrophy with progressive T2 hyper with possible restricted diffusion involving gray matter including BG (caudate, putamina), thalamus, and cerebral cortex (frontal and temporal lobes) • “Pulvinar” sign bilat sym hyper of pulvinar (post) nuclei of thalamus relative to ant putamen • “Hockey stick” sign sym pulvinar and dorsomedial thalami hyperintensity • No contrast enhancement CREUTZFELDT-JAKOB DISEASE CONCLUSION • Paraneoplastic syndrome is not an uncommon cause of encephalitis • Knowledge of its clinical presentation, pathophysiology and immunology is essential in making the diagnosis • Although the differential diagnosis is broad, it can be narrowed utilizing age, clinical features, imaging characteristics (e.g. Location, enhancement pattern, PET-MRI findings, etc) and pathology correlation REFERENCES 1. 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