Capucine Diard-Detoeuf1, Audrey Dangoumau2, Nadège Limousin3, Julien Biberon3, Patrick Vourc'h2, Christian R Andres2, Bertrand de Toffol3, Julien Praline3. 1. Service de Neurologie et Neurophysiologie Clinique, CHRU Tours, France. Electronic address: capucine.diarddetoeuf@gmail.com. 2. Laboratoire de Biochimie et Biologie moléculaire, CHRU Tours, France; UMR INSERM U930, Université François-Rabelais, Tours, PRES Centre, Val de Loire Université, France. 3. Service de Neurologie et Neurophysiologie Clinique, CHRU Tours, France.
Abstract
INTRODUCTION: Whether motor neuron diseases (MNDs) can be considered in some cases of paraneoplastic syndromes is controversial. We report a case of rapidly progressive motor neuronopathy following a diagnosis of breast carcinoma, with a presence of anti-Ri antibodies, and a novel SOD1 gene mutation. OBSERVATION: An 80-year-old woman with mucinous adenocarcinoma of the left breast for 4 years developed sub-acute quadriparesis. Myography revealed chronic denervation signs. The patient had serum anti-Ri onconeural antibodies. The diagnosis of paraneoplastic MND was established. Because of a familial history of ALS, a genetic analysis for familial ALS was performed. We identified a novel heterozygous mutation in SOD1 gene, SOD I18del. This mutation may reflect a genetic predisposition to develop a MND, inducing fragility of motor neurons. Neurological improvement was observed after three months of both intravenous gamma globulin and corticosteroids. CONCLUSION: The present observation supports the idea that MND can be considered as a paraneoplastic syndrome. A combination of anti-Ri onconeural antibodies and a particular SOD1 gene mutation, consisting in risk factor, might be in cause in the process of motor neuron death. When in doubt, paraneoplastic cause should be suspected in the differential diagnosis of MND. Immunotherapy treatment may lead to a favorable outcome.
INTRODUCTION: Whether motor neuron diseases (MNDs) can be considered in some cases of paraneoplastic syndromes is controversial. We report a case of rapidly progressive motor neuronopathy following a diagnosis of breast carcinoma, with a presence of anti-Ri antibodies, and a novel SOD1 gene mutation. OBSERVATION: An 80-year-old woman with mucinous adenocarcinoma of the left breast for 4 years developed sub-acute quadriparesis. Myography revealed chronic denervation signs. The patient had serum anti-Ri onconeural antibodies. The diagnosis of paraneoplastic MND was established. Because of a familial history of ALS, a genetic analysis for familial ALS was performed. We identified a novel heterozygous mutation in SOD1 gene, SOD I18del. This mutation may reflect a genetic predisposition to develop a MND, inducing fragility of motor neurons. Neurological improvement was observed after three months of both intravenous gamma globulin and corticosteroids. CONCLUSION: The present observation supports the idea that MND can be considered as a paraneoplastic syndrome. A combination of anti-Ri onconeural antibodies and a particular SOD1 gene mutation, consisting in risk factor, might be in cause in the process of motor neuron death. When in doubt, paraneoplastic cause should be suspected in the differential diagnosis of MND. Immunotherapy treatment may lead to a favorable outcome.