Encephalitis with antibodies against the GABA_B receptor: seizures as the most common presentation at admission

Abstract

Objective: Autoimmune encephalitis associated with antibodies against gamma-aminobutyric-acid B receptor (GABA_BR) has not been described in detail in Chinese patients.

Methods: Patients with anti-GABA_BR encephalitis treated between January 2013 and December 2015 were analyzed in terms of clinical characteristics, laboratory findings, tumor presence, autoantibody patterns, treatment response and outcomes.

Results: Eleven patients were identified (male, N = 8; female, N = 3), with the median age of 51 years. All patients presented with seizures (N = 11; 100%), and they were given anti-epileptic drugs and first-line immunotherapy to address the disease. Seizures always accompanied by limbic manifestations (N = 10; 90.9%). Extralimbic manifestations were present in 4 patients (N = 4; 36.4%). MRI Brain abnormality with increased medio-temporal lobe T2/FLAIR signal were present in 2 patients (N = 2; 18.2%), and epileptiform epileptiform activity on electroencephalography were observed in 2 patients (N = 2; 18.2%). Small-cell lung cancer was histologically confirmed in 3 patients (N = 3; 27.3%). Seven patients showed good outcomes (mRS 1–2; N = 7; 63.6%), one patient showed poor neurological status with minimal changes (mRS 4; N = 1; 9.1%), and three patients died during follow-up (mRS = 6; N = 3; 27.3%). Outcomes were correlated with age-of-onset, and were worse among older patients (P = 0.0112).

Conclusion: Anti-GABA_BR encephalitis is a potentially treatable disorder involving seizures as the most predominant presentation at admission. It should be considered as a possible diagnosis in middle-aged and older patients with refractory new-onset epilepsy.

Keywords:

• Encephalitis
• anti-GABA_BR antibodies
• case series
• seizure
• clinical manifestation
• outcome

Disclosure statement

On behalf of all authors, the corresponding author states that there is no conflict of interest.

Funding

This work was supported by the Natural Science Foundation of China [grant number 81301093].

Notes on contributors

Xueping Chen works as a professor in the Department of Neurology, West China Hospital, Sichuan University. She is working on the research of neurogenetic diseases.

Fan Liu works as the director in the Nursing Department, West China Hospital of Stomatology, Sichuan University. Her research interest is the clinical characteristics of severe stroke patients in NICU.

Ji-Mei Li works as a professor in the Department of Neurology, West China Hospital, Sichuan University. She is working on autoimmunity diseases in central nervous system.

Xie Xiaoqi works as the director in the Neurological Intensive Care Unit, West China Hospital, Sichuan University. She works on supporting therapy for patients with severe neurological diseases.

Qiong Wang works as a supervisor nurse in the Neurological Intensive Care Unit, West China Hospital, Sichuan University. Her focus is on developing effective methods of nosocomial infection care management in intensive care.

Dong Zhou works as the director in the Department of Neurology, West China Hospital, Sichuan University. He mainly works on epilepsy.

Huifang Shang works as the vice director in the Department of Neurology, West China Hospital, Sichuan University. She currently works on the neurodegenerative disorders.

Acknowledgments

We thank the patients and their families for their participation in this project. On behalf of all authors, the corresponding author states that there is no conflict of interest.