Paraneoplastic encephalitis presenting as postpartum psychosis.

Presents a case report of Ms. A, a 29-year-old primiparous woman presented to the hospital at 11 weeks postpartum complaining of 2 to 3 weeks of decreased sleep and increased difficulty caring for her newborn. She had given birth to a healthy baby boy via vaginal delivery. She described memory difficulties, sensations of 'déjà vu,' and mild headaches. Vital signs were normal, she was alert and oriented, but was unable to recall three words. General and neurologic examinations were non-focal. Complete blood count, electrolytes, renal functions, and a CT scan of the head without contrast were normal. Due to increasing anxiety and delusions that her baby was dying, she was diagnosed with postpartum psychosis and admitted to the psychiatry unit. She was started on low-dose olanzapine. Adjunctive electroconvulsive therapy (ECT) was added for catatonia and a rapid progression of paranoid delusions involving the death of her newborn. On day 3 after the first ECT treatment, she developed generalized tonic-clonic seizures requiring intubation and sedation. Brain MRI showed three nonspecific, non-gadolinium-enhancing T2 and fluid-attenuated inversion recovery hyperintensities measuring less than one centimeter in size: one adjacent to the occipital horn of the left lateral ventricle, one in the right cerebellum, and one in the left cerebellum. There was no involvement of the temporal lobes. Given the clinical evolution, an abdominal CT was performed specifically searching for a neoplasm and it revealed a right ovarian mass. Prompt surgical resection confirmed a well-encapsulated grade II/III immature teratoma. Ms. A received methylprednisolone and plasmapheresis with little improvement. Rituximab was initiated 2 months after initial presentation. Within days, she showed dramatic improvement of the abnormal movements, tracked with her eyes, and obeyed 1-step commands. Repeat brain MRI 3 months after the onset of symptoms showed resolution of the nonspecific cerebellar lesions and a faint residual hyperintense signal near the left lateral ventricle. She received 2 months of rehabilitation and returned home, 8 months after the onset of her symptoms. When last seen one month later, there had been no recurrent seizures, and only minimal abnormal movements were present. Neuropsychology testing showed poor short-term memory, but preserved autobiographical retrograde memory. This is the first description of anti-NMDA receptor encephalitis presenting in the postpartum period. This particular period is a very unique time for the woman in terms of neuroendocrine alterations, psychosocial adjustments, sleep cycle modifications, and increased risk of certain medical conditions, including infectious processes, thrombotic events, autoimmune disorders, or vascular catastrophes to name a few.