Paraneoplastic Limbic Encephalitis From a Carotid Body Paraganglioma Presenting as Persistent and Worsening Confusion

Abstract

Background: Paraneoplastic Syndromes (PNS) are rare conditions in which patients experience a variety of symptoms from altered immune systems due to underlying malignancy. Paraneoplastic Limbic Encephalitis (PLE) is a subtype of PNS in which autoantibodies to cancer cells cross-react with cells in the central nervous system, particularly in the medial temporal lobe. Here we present a 38-year-old, previously normal male who presented with persistent and worsening confusion and was diagnosed with a very rare PLE secondary to a carotid body paraganglioma. Case: A 38-year-old male with medical history of hypertension and polysubstance abuse was admitted initially for confusion, arm weakness, and memory loss. He denied having headache, fever, chills, or neck stiffness. Further history obtained from family revealed he was previously cognitively intact. Imaging was consistent with carotid body paraganglioma and limbic encephalitis. A 5-day course of high dose steroids and plasmapheresis was initiated. Plasmapheresis was performed every other day for 5 treatments with marked improvement in mental and renal function at the time of the third treatment. Biopsies obtained were consistent with carotid body paraganglioma and surrounding lymphadenopathy was negative for disease. Embolization was performed with subsequent excision of the tumor and eventual resolution of symptoms. Conclusion: This is to our knowledge the first documented case of paraneoplastic limbic encephalitis associated with a carotid body paraganglioma. Our patient had improved following resection of the underlying paraganglioma and experienced short-term improvement with high-dose steroids and plasmapheresi