NMDARAb positive autoimmune encephalitis reversible with immunoglobulin and plasma exchange in a young female in Sri Lanka: A case report and literature review 

The human brain is a complex organ that relies on a delicate balance of chemical signals to function. Sometimes, the body's own defense system, designed to fight off infections, mistakenly turns against the brain. This condition is known as autoimmune encephalitis. In this specific form of the disease, the immune system creates antibodies that attack a particular type of receptor on brain cells, effectively jamming the communication lines that control memory, behavior, and movement. Unlike many brain disorders that are permanent, this condition is often reversible if doctors can identify it quickly and stop the immune attack. The key to recovery lies in recognizing that a patient's sudden, severe changes in personality or seizures might not be a primary psychiatric issue or a standard infection, but rather a treatable immune malfunction.

In a case report from Sri Lanka, medical professionals documented the journey of a thirty-five-year-old woman who fell ill with this exact condition. She arrived at the hospital with a high fever and a rapid decline in her mental state. Initially, her family noticed she was struggling with short-term memory, feeling low, and avoiding social interaction. Within days, her behavior shifted dramatically; she became agitated, spoke inappropriately, and used foul language. As her condition worsened, she developed severe headaches and, eventually, uncontrollable seizures that required her to be placed on a ventilator to breathe. Her blood pressure and heart rate became dangerously unstable, fluctuating wildly as her body struggled to regulate itself.

The medical team faced a difficult diagnostic puzzle. The patient had no history of psychiatric illness, and her brain scans did not show the typical signs of a stroke or a tumor. However, a closer look at her spinal fluid, obtained through a lumbar puncture, revealed the presence of specific antibodies that attack the NMDA receptors in the brain. This finding confirmed the diagnosis of NMDAR antibody encephalitis. Further imaging of her abdomen revealed a small cyst on her right ovary, which the doctors suspected might be a teratoma, a type of growth that can sometimes trigger this immune response. While the initial scans of her brain were not definitive, an electroencephalogram later showed severe electrical dysfunction and seizure activity, aligning with the clinical picture of an inflamed brain.

Once the diagnosis was clear, the treatment focused on calming the immune system. The patient received a course of antibiotics to rule out viral infections, followed by a specific therapy involving intravenous immunoglobulin, which is a concentrated solution of healthy antibodies that helps neutralize the harmful ones. She also underwent plasma exchange, a procedure that filters her blood to remove the attacking antibodies directly. Over several weeks, she received multiple cycles of these treatments. The results were significant; her seizures stopped, her autonomic instability resolved, and her mental clarity began to return. The medical team noted that her recovery was a direct response to these immunotherapies, highlighting that the disease, while severe and life-threatening, can be reversed when caught early.

This case serves as a reminder for doctors to remain alert to the signs of autoimmune encephalitis, especially in young women presenting with a mix of fever, behavioral changes, and seizures. The story of this patient illustrates that what appears to be a mysterious psychiatric crisis or an untreatable infection can sometimes be a specific, manageable immune disorder. By identifying the antibodies in the spinal fluid and acting quickly with immunotherapy, clinicians can guide patients from a state of critical illness back to health. The successful outcome in Sri Lanka reinforces the importance of early suspicion and prompt treatment, offering a clear path to recovery for others who may face this challenging condition.