Voltage-Gated Potassium Channel Antibody Paraneoplastic Limbic Encephalitis Associated with Acute Myeloid Leukemia

Abstract

Among paraneoplastic syndromes (PNS) associated with malignant hemopathies, there are few reports of PNS of the central nervous system and most of them are associated with lymphomas. Limbic encephalitis is a rare neurological syndrome classically diagnosed in the context of PNS. We report the case of a 81-year-old man who presented with a relapsed acute myeloid leukemia (AML) with minimal maturation. He was admitted for confusion with unfavorable evolution as he presented a rapidly progressive dementia resulting in death. A brain magnetic resonance imaging, performed 2 months after the onset, was considered normal. An electroencephalogram showed non-specific bilateral slow waves. We received the results of the blood screening of neuronal autoantibodies after the patient's death and detected the presence of anti-voltage-gated potassium channel (VGKC) antibodies at 102 pmol/l (normal at <30 pmol/l). Other etiologic studies, including the screening for another cause of rapidly progressive dementia, were negative. To our knowledge, this is the first case of anti-VGKC paraneoplastic limbic encephalitis related to AML.

Anti-leucine-rich Glioma Inactivated-1 Encephalitis Associated with Essential Thrombocythemia

“…Approximately 5-10% of anti-LGI1 encephalitis occurs in thymoma patients (13), but hematological neoplasms are seldom reported in anti-LGI1 encephalitis patients. Previously, there has been one reported case of anti-LGI1 encephalitis associated with acute myeloid leukemia (14). Another case involved paraneoplastic neurological syndrome (PNS) of the central nervous system with voltage-gated potassium channel (VGKC) antibodies (a Charcot-Marie-Tooth syndrome) related to leukemia (15).…”

Leucine-rich glioma-inactivated protein 1 antibody encephalitis

“… 2 , 7 , 10 - 12 The initial reports suggested that the antibodies against VGKC complex bind Kv1.1 and Kv1.2; however, the recent studies have shown LGI1 and Caspr2 to be the specific targets. 9 , 10 , 13 , 14 Typical clinical presentation of LE associated with LGI1 antibody includes cognitive decline, behavioral disturbance, and seizures. 9 , 10 The clinical presentation in our case was fairly typical, with dementia, psychiatric symptoms, and seizures.…”

Two cases of paraneoplastic limbic encephalitis associated with small cell lung cancer and a literature review

“…The disease can affect individuals aged 10–85 years, with the females being less susceptible than males ( 5 , 20 ). Rarer malignancies associated with PLE are thymoma ( 21 ), ovarian teratoma ( 22 , 23 ), esophagastric squamous cell carcinoma ( 24 ), adenocarcinoma of the colon ( 14 ), prostate cancer ( 25 ), testicular neoplasm ( 26 , 27 ), Hodgkin’s lymphoma ( 20 ), non-Hodgkin’s lymphoma ( 28 ), leukemia, lymphoma ( 29 ) and acute myeloid leukemia ( 17 ). A literature search identified four studies containing data on cancer-related PLE in patients of Chinese Han nationality ( 30 – 33 ).…”

“…The clinical diagnosis of PLE is problematic; however, the identification of a number of specific circulating autoantibodies, such as anti-Hu ( 34 , 1 ), anti-PNMA2 ( 12 ), anti-Yo ( 14 ), anti-N-methyl-D-aspartate receptor (NMDAR) ( 35 ) and anti-voltage-gated potassium channel ( 17 ) antibodies, in these patients has revolutionized the diagnosis and understanding of these syndromes and demonstrated a role for the immune system in such neurological disorders. We have speculated that the clinical manifestations and lesions scopes are associated with certain types of tumors and antibodies.…”

“…Research into PLE has made progress over the past decade ( 16 ), and certain clinical manifestations and imaging appearances have been found to be consistent with PLE. Furthermore, since the generation of antibodies targets neuronal cell membrane antigens, the development of specific immunotherapies could lead to improvements in prognosis for patients with PLE ( 15 , 17 ). To date, few studies have focused on PLE in patients of Chinese Han nationality; therefore, the present study described two cases of PLE in patients of Chinese Han nationality and summarized four cases in the literature.…”