Anti-LGI1 Limbic Encephalitis Presented with Atypical Manifestations
A 62-year-old woman presented with confusion and memory loss in August 2012. She developed confusion with disorientation to the time and place and had no memory of a recent family trip before 2 days of admission. Upon admission, her serum sodium was 120 mmol/L, which was corrected to 134 mmol/L after 3 days. A brain MRI and EEG failed to indicate any abnormality, and no focal deficit was found on neurological examinations. After correction of hyponatremia, she was discharged without significant problems, except for memory disturbance. Her Korean Mini-Mental State Examination (K-MMSE) score was 25 at the time of discharge (8/10 on time and place orientation and 0/3 on memory recall).\nThe patient was readmitted to our hospital 12 months after her initial admission. Since two months before readmission, she was experiencing recurrent chest discomfort that she described as squeezing and dull in nature, typically lasting 10~30 seconds. The frequency of these episodes was initially once a day, but progressed to more than 20 times a day after 2 months. She reported that her memory disturbance was aggravated and she had developed intermittent confusion with disorientation. She repeatedly asked, "Where am I?" and, "Why am I here?" and sometimes lost her sense of direction. On the day before her readmission, she experienced chest discomfort and subsequently lost consciousness and collapsed with facial grimacing and abnormal arm-twisting movements. She regained consciousness a few minutes later, but was disoriented to the time and place. Definite convulsive movements were not observed. At admission, she was alert, oriented and showed no focal deficits on neurological examination. Her K-MMSE score was 24 (8/10 on time and place orientation, 4/5 on attention and calculation and 0/3 on memory recall), and she showed no difficulties with daily activity during her admission. Routine blood tests and a brain MRI were normal; a routine EEG failed to show definite abnormalities. For her chest discomfort, transthoracic echocardiography, CT coronary angiography, and 24-h electrocardiography were all normal. Supine blood pressure was 130/60 mmHg, and orthostatic blood pressure at 0, 1, 3, and 5 min was 120/60, 125/60, 130/60, and 125/65 mmHg, respectively. Esophagogastroduodenoscopy and esophagogram with esophageal manometry revealed normal findings.\nInitially, we diagnosed the patient with anxiety disorder and administered a selective serotonin reuptake inhibitor and an anxiolytic. However, her chest discomfort persisted. On video-EEG monitoring, ictal discharges were observed in the right temporal area during her chest discomfort (), whereas FBDS or other seizures were not reproduced. FDG PET revealed no abnormalities. After administering oxcarbazepine, the frequency and duration of her chest discomfort reduced to a few times a day and lasted only a few seconds, whereas her memory disturbance persisted. Thus, we suspected autoimmune causes for the limbic encephalitis, and anti-LGI1 antibody was detected in both serum and CSF (). After treatments with IV immunogloblin (0.4 g/day for 5 days) and antiepileptic drugs (oxcarbazepine and levetiracetam), the chest discomfort and memory disturbance markedly improved. Her follow-up K-MMSE score was 27 (8/10 on time and place orientation and 4/5 on attention and calculation). She has been symptom free for a month after her discharge.