We report the case of a 24-year-old female Belgian patient with no significant history who was admitted to the emergency department (ED) following the onset of acute confusion and fear of imminent death.
Few days before her admission, she had rhinitis with sore throat. In the emergency department, she presented agitation, hallucinations, echolalia with ideas of death and aggression. Laboratory testing demonstrated no abnormalities, with a normal white blood cell count and normal C-reactive protein. Toxicology screening, electroencephalogram (EEG) and brain scan were also normal. The patient was hospitalized for an additional assessment.
At first, there was a spontaneous resolution of her psychiatric symptoms. Two days later, the reappearance of agitation, impulsive aggression, and visual hallucinations led to psychiatric hospitalization. After four days, her clinical condition worsened, including impaired consciousness, pyrexia, tachycardia, swallowing disorders and food refusal.
The patient was transferred from the psychiatric department to the ED for suspected neuroleptic malignant syndrome. In the ED, she presented a state of mutism and stupor with fever, tachycardia, tachypnea, muscle rigidity and swallowing disorders.
Laboratory testing revealed inflammatory syndrome (C-reactive protein: 44 mg/l) but infectious serology (borrelia, cytomegalovirus, Epstein-Barr virus) and serologic screening for autoimmune diseases (anti-neutrophil cytoplasmic antibodies, anti-nuclear antibodies) were normal. Toxicologic screening, EEG and brain magnetic resonance imaging (MRI) findings were also normal. Lumbar puncture revealed transparent cerebrospinal fluid (CSF) and polymerase chain reactions for herpes zoster, enterovirus and herpes simplex on CSF were normal. Blood and CSF cultures were negative. Futher immunologic blood tests and CSF were sent to a university laboratory.
Due to the deterioration of consciousness, swallowing disorders, respiratory distress syndrome and severe bradycardia, the patient was intubated and transferred to the intensive care unit (ICU).
On day 23, a new Brain MRI fluid-attenuated inversion recovery (FLAIR) was performed and showed the presence of a hyperintense signal on involving temporal and limbic lobes (see figure 1), suggesting autoimmune limbic encephalitis. Pulsed therapy with 1 g/d methylprednisolone was initiated, and neuroleptics were stopped.
The patient continued to develop dysautonomia disorders (low blood pressure, tachycardia, apnoea and Cheyne-Stokes respiration) as well as episodes of acute agitation.
A serologic test and CSF results showed the presence of specific IgG oligoclonal bands and were positive for anti-NMDA antibodies. The 48-hour EEG did not demonstrate any epileptogenic activity. The PET scanner for oncology check-up was negative.
Finally, the patient benefited from intravenous methylprednisolone therapy as well as 10 plasmapheresis sessions, followed by oral corticosteroid therapy. The patient’s clinical condition gradually improved, and she was transferred to the neurology department.
A neuropsychological and neurological assessment showed a pyramidal syndrome with proximal predominant left hemiparesis, a deficit in verbal fluency and pathological denomination.
Clinical progress was slow but favourable with corticosteroid therapy and mycophenolic acid treatment. The patient returned home after 56 days of hospitalization. At an 18-month follow-up, there was no recurrence, and the PET scanner remained negative.