A 56‐year‐old woman with a history of thymoma completely resected 4 months earlier presented with 2 weeks of intermittent facial flushing, facial twitching, lacrimation, hypertension, and a sense of déjà vu. The episodes lasted less than a minute and resolved with a feeling of doom and fatigue. There was no associated loss of consciousness, tongue biting, or bowel or bladder incontinence. Magnetic resonance imaging revealed right hippocampal edema and enhancement. Electroencephalo‐graphy confirmed seizure activity. A pleural effusion yielded bloody fluid that was negative for malignancy. Initial cerebrospinal fluid analysis was unremarkable. After an extensive workup including a negative positron emission tomography‐computed tomography scan, the patient was discharged on levetiracetam with tests for paraneoplastic antibodies pending. Subsequently, her short‐term memory deteriorated. Magnetic resonance imaging of the brain performed 4 weeks after discharge revealed multiple new diffuse T2 hyperintense cortical lesions. In addition, antibodies associated with paraneoplastic limbic encephalitis were confirmed in both serum and cerebrospinal fluid collected at the time of initial evaluation. The patient was admitted for further testing and for initial treatment with plasmapheresis.
Thymoma has been associated not only with antibodies to the nicotinic acetylcholine receptor resulting in myasthenia gravis but also with autoimmunity to several components of the central and peripheral nervous systems, including the limbic system. Importantly, patients may present with paraneoplastic limbic encephalitis before or after diagnosis and resection of the responsible tumor. Cerebro‐spinal fluid examination frequently reveals a pleocytosis with elevated protein and immunoglobulin G but may be normal. Suspicion for paraneoplastic limbic encephalitis should prompt a thorough examination for an underlying cause including, but not limited to, thymoma. Treatment of paraneoplastic limbic encephalitis is challenging, especially if the underlying neoplasm is unknown or cannot be eradicated. Immunosuppression is the mainstay of therapy, but there are currently no controlled trials to guide treatment decisions.
Thymoma is classically associated with myasthenia gravis but is also a rare cause of paraneo‐plastic syndromes of the central nervous system, including limbic encephalitis. Hospitalists should be aware of the symptoms of limbic activation, including a rising feeling of warmth, lacrimation, fear, and déjà vu.
J. M. Gansner ‐ none; C. L. Roy ‐ none
To cite this abstract:Gansner J, Roy C. Not Just Myasthenia Gravis: A Patient with Thymoma and Paraneoplastic Limbic Encephalitis. Abstract published at Hospital Medicine 2011, May 10-13, Dallas, Texas. Abstract 283. Journal of Hospital Medicine. 2011; 6 (suppl 2). https://www.shmabstracts.com/abstract/not-just-myasthenia-gravis-a-patient-with-thymoma-and-paraneoplastic-limbic-encephalitis/. Accessed March 29, 2020.