According to an article in NCBI’s Drug In Context, it took the combined services of the internal medicine, neurology, and psychiatry departments to diagnose this rare disease. Anti-NMDAR encephalitis is a potentially fatal disease that mimics schizophrenia spectrum illness. (Details have been omitted to protect the patient).
The patient, a forty-year-old African-American absent any prior psychiatric history, was taken to the Emergency Department (ED) because her family was concerned about her unusual behavior.
Although she had a history of hypertension, it was only recently that her son began to notice abnormal behavior. It became so noticeable that she was sent home from work and that same day was reported to have smoked marijuana.
As her symptoms worsened, her family made the decision to take her to the ED. There had been one major stressful event in her life and that was her mother’s recent death.
By the time they arrived at the ED, the patient seemed confused and attempted to leave. The doctors administered medication that appeared to calm her. She was put into involuntary psychiatric care for evaluation.
The patient was given a temporary diagnosis of psychotic disorder that was substance-induced and held in the ED for a few days. During this time she became intermittently agitated, disoriented, and expressed unusual concern about an employee at work. Several tests were ordered but all appeared normal.
About Creatine Kinase
Considering her bouts of agitation, the doctors ordered a creatine kinase (CPK) level. CPK is a protein that identifies chemical changes in the brain, skeletal muscles, and heart. CPK leaks into the blood in the event of damage to muscle tissues. Results of the CPK test showed elevated creatine levels indicating possible damage to the heart or other muscles.
Her doctors decided to admit the patient to the hospital’s internal medicine department. Their diagnosis at that point was mild rhabdomyolysis which is muscle tissue breakdown leading to muscle fiber contents in the blood. The doctors also consulted with the psychiatric consultation-liaison team.
A psychiatric consultation reported hypertension and continuous changes in heart rate. Inpatient hospitalization under psychiatric care was recommended along with risperidone for her psychotic symptoms.
Getting Closer
The doctors noted that the patient had no prior psychiatric history. However, they also noted psychotic symptoms, increasing sleepiness, and instability of the autonomic nervous system (ANS). The ANS affects the blood vessels, heart, and intestines among other organs. Under these circumstances, a medical cause for her disorder became much more likely.
The doctors decided to administer tests that focused on anti-NMDAR encephalitis. The neurology service was in agreement with the theorized anti-NMDAR diagnosis. An MRI was ordered of the patient’s brain with unremarkable results.
But unexplainably, the patient became unresponsive over the next few days, giving a blank stare. Her autonomic instability continued. As her condition declined, the patient was given intravenous immunoglobulin for anti-NMDAR encephalitis. Within a short time, the doctors received positive results of anti-NMDAR encephalitis and intravenous immunoglobulin tests that confirmed their diagnosis.
The patient was transferred to a local hospital to continue treatment. An eight-day IVIG course was administered. An MRI, given to check for possible malignancy, showed negative results. Yet the patient was still minimally responsive to most medication.
Just as she was assigned to a subacute floor in preparation for transfer to a nursing home, the patient’s speech returned. For the next two months, the patient became more verbal and was able to work with a physical therapist. Four months later she showed dramatic improvement.
At that point, her family agreed to have her discharged and sent home with twenty-four hour supervision. Five months after being discharged the patient was approved to return to work.
The First Appearance in Medical Literature
NMDAR encephalitis appeared in medical records in 2005 through almost identical presentations by four women. Their symptoms mimicked recent drug use, a psychotic episode, or malingering. As these episodes were previously not known, once disclosed, other anti-NMDAR cases emerged.
Reports of over one thousand cases gave clinical recognition to the disease. Anti-NMDAR encephalitis is now considered to be one of the most common causes of autoimmune encephalitis.
If anti-NMDAR encephalitis is confirmed, patients must be tested for germ cell or teratoma tumors. Early detection and treatment result in improved outcomes and less hippocampal damage.
