Posters
Presenting Author Academic/Professional Position
Kevin A Garcia Valdez
Academic Level (Author 1)
Resident
Discipline/Specialty (Author 1)
Internal Medicine
Academic Level (Author 2)
Medical Student
Discipline Track
Clinical Science
Abstract Type
Case Report
Abstract
Background: Limbic encephalitis (LE) is a rare but increasingly recognized autoimmune subtype of encephalitis that primarily affects the limbic system, which includes the medial temporal lobe, hippocampus, frontobasal, and cingulate cortex. LE was initially believed to cause inflammation restricted to the limbic region; however, subsequent studies have shown that the disease process can extend to other brain areas, resulting in a wide range of neurological and psychiatric manifestations.
Case Presentation: We present the case of a 64-year-old Hispanic male with multiple emergency department visits due to progressive neurologic symptoms. From late November of 2023 to January of 2024, the patient presented with confusion, sleep disturbances, hyponatremia, and muscle spasms and involuntary movements with repeated falls, leading to diagnoses of SIADH and myoclonic seizure disorder. On February 9, 2024, the patient was admitted again due to worsening myoclonus, unsteady gait, and acute encephalopathy. In the following days, he quickly progressed to significantly altered mental status (GCS 7) and cognitive impairment. An MRI of the brain with and without contrast showed new hyperintensity on DWI and T2 FLAIR in the right hippocampus, and subtle mid-pontine contrast enhancement. EEG noted low to moderate voltage polymorphic delta and spindle frequency activity. IVIG treatment was administered for five days (2/11/24 - 2/15/24) with marked improvement in all symptoms. A diagnosis of limbic encephalitis was made, and CSF analysis from 2/11/2024 confirmed the diagnosis of LGI1 Ab Autoimmune encephalitis. For management, the patient was continued on immune suppression with methylprednisolone 1000 mg q24 for three days, followed by prednisone 80 mg q24. Oncology ordered rituximab 1000 mg, and a second dose was administered two weeks later. The patient completed a second course of IVIG from 2/29/24 to 3/4/24. For seizure prophylaxis, the patient was placed on Keppra 1500mg BID. He had a breakthrough seizure on 02/27/25, but has had no other neurological ED visits and ongoing outpatient management with a neurologist.
Conclusion: Given its heterogeneous presentation, overlapping differential diagnoses, and variable response to therapy, LE remains a diagnostic and therapeutic challenge. Early recognition and prompt initiation of immunotherapy are crucial to prevent long-term neurological sequelae. This case report contributes to the growing literature by highlighting an unusual presentation of LE, emphasizing the need for heightened clinical suspicion and a multidisciplinary approach to management.
Presentation Type
Poster
Recommended Citation
Fernandez-Betances, Osiris and Garcia Valdez, Kevin A., "A Unique Case of Limbic Encephalitis in the Rio Grande Valley, a Case Report" (2025). Research Colloquium. 56.
https://scholarworks.utrgv.edu/colloquium/2025/posters/56
Included in
A Unique Case of Limbic Encephalitis in the Rio Grande Valley, a Case Report
Background: Limbic encephalitis (LE) is a rare but increasingly recognized autoimmune subtype of encephalitis that primarily affects the limbic system, which includes the medial temporal lobe, hippocampus, frontobasal, and cingulate cortex. LE was initially believed to cause inflammation restricted to the limbic region; however, subsequent studies have shown that the disease process can extend to other brain areas, resulting in a wide range of neurological and psychiatric manifestations.
Case Presentation: We present the case of a 64-year-old Hispanic male with multiple emergency department visits due to progressive neurologic symptoms. From late November of 2023 to January of 2024, the patient presented with confusion, sleep disturbances, hyponatremia, and muscle spasms and involuntary movements with repeated falls, leading to diagnoses of SIADH and myoclonic seizure disorder. On February 9, 2024, the patient was admitted again due to worsening myoclonus, unsteady gait, and acute encephalopathy. In the following days, he quickly progressed to significantly altered mental status (GCS 7) and cognitive impairment. An MRI of the brain with and without contrast showed new hyperintensity on DWI and T2 FLAIR in the right hippocampus, and subtle mid-pontine contrast enhancement. EEG noted low to moderate voltage polymorphic delta and spindle frequency activity. IVIG treatment was administered for five days (2/11/24 - 2/15/24) with marked improvement in all symptoms. A diagnosis of limbic encephalitis was made, and CSF analysis from 2/11/2024 confirmed the diagnosis of LGI1 Ab Autoimmune encephalitis. For management, the patient was continued on immune suppression with methylprednisolone 1000 mg q24 for three days, followed by prednisone 80 mg q24. Oncology ordered rituximab 1000 mg, and a second dose was administered two weeks later. The patient completed a second course of IVIG from 2/29/24 to 3/4/24. For seizure prophylaxis, the patient was placed on Keppra 1500mg BID. He had a breakthrough seizure on 02/27/25, but has had no other neurological ED visits and ongoing outpatient management with a neurologist.
Conclusion: Given its heterogeneous presentation, overlapping differential diagnoses, and variable response to therapy, LE remains a diagnostic and therapeutic challenge. Early recognition and prompt initiation of immunotherapy are crucial to prevent long-term neurological sequelae. This case report contributes to the growing literature by highlighting an unusual presentation of LE, emphasizing the need for heightened clinical suspicion and a multidisciplinary approach to management.
