Anti-NMDA Receptor Encephalitis

Anti-NMDA receptor encephalitis is a serious autoimmune brain inflammation disorder. The immune system produces antibodies against NMDA receptors in the brain, which play a critical role in memory, behavior, and cognition. These antibodies disrupt normal brain signaling, leading to a wide range of psychiatric and neurological symptoms. It most often affects young women but can occur in anyone, including children and men.

Early symptoms (psychiatric and behavioral): Anxiety, agitation, or paranoia; Hallucinations or delusions; Sudden personality changes; Insomnia; Confusion or memory problems; Catatonia. Neurological and physical symptoms: Seizures; Abnormal movements; Difficulty speaking or mutism; Decreased consciousness or coma; Autonomic instability (erratic blood pressure or heart rate, fever, breathing issues).

Autoimmune reaction: the immune system produces antibodies targeting NMDA receptors. Triggering factors include tumors (particularly ovarian teratomas in women), viral infections (e.g., herpes simplex virus), or idiopathic (no clear cause in some patients).

Lumbar puncture (spinal tap) to detect antibodies in cerebrospinal fluid; Blood tests to identify anti-NMDA receptor antibodies; Brain MRI (may be normal or show signs of inflammation); EEG (often shows abnormal brain wave activity); Tumor screening especially in women.

First-line treatments: High-dose corticosteroids; IVIG; Plasmapheresis (plasma exchange). Second-line treatments (if first-line fails): Rituximab; Cyclophosphamide. Additional treatment: Surgical removal of any tumor (especially ovarian teratoma); Antipsychotic or seizure medications (cautiously); Rehabilitation.

With prompt diagnosis and treatment, up to 80% of patients experience substantial recovery. Recovery may take months or even years and often involves relapses or residual cognitive/psychiatric symptoms. Without treatment, the condition can be life-threatening.

Estimated incidence: 1.5 per million people per year. More common in young women (especially ages 12-45). Up to 50% of female cases are associated with ovarian teratomas.