Autoimmune encephalitis (AE) is an immune-mediated brain disorder characterized by varied clinical manifestations that correlate with specific types of antibodies.Typical symptoms include acute behavioral changes, psychosis, seizures, memory deficits, dyskinesias, speech impairments, and autonomic and respiratory dysregulation.While the majority of patients respond well to immunotherapeutic agents, a significant proportion remains resistant to initial and secondary-line immunotherapies.Minocycline, a semisynthetic tetracycline, is notably used for the central nervous system due to its lipophilic characteristics and its capacity to penetrate the blood-brain barrier. While the primary neuroprotective focus of minocycline in the central nervous system remains unknown, the primary effects of minocycline include the inhibition of microglial activation, mitigation of apoptosis, and reduction in reactive oxygen species generation.Protective effect has been observed in hypoxic injury, ischemic stroke, amyotrophic lateral sclerosis, traumatic spinal cord injury, multiple sclerosis, Parkinson's disease, and Huntington's disease.Can minocycline offer a protective role in AE? Consequently, we proposed a randomized, controlled trial to investigate the efficacy of minocycline in AE.

Inclusion Criteria:

1. Diagnosis of definite autoimmune encephalitis(Graus et al 2016.)
2. Age ≥ 18 years
3. Acute or subacute onset (rapid progression of less than 3 months)
4. Reasonable exclusion of alternative causes
5. Written informed consent

Exclusion Criteria:

1. Known allergy to tetracycline antibiotics.
2. Pregnant women.
3. Uncontrolled serious concomitant illness.
4. Known chronic kidney disease stages 3b-5.
5. Moderate liver disease (see Child-Pugh for Classification of Severity of Liver Disease).
6. history of cognitive impairment