Psychiatric Manifestations Caused by Mycoplasma pneumoniae Encephalitis Mimicking Autoimmune Encephalitis

Abstract

A significant etiological factor for upper respiratory tract infections and community-acquired pneumonia is Mycoplasma pneumoniae. The incidence of extrapulmonary neurological problems in infected patients has been shown to range from 0.1 to 7%, often manifesting within a timeframe of 2 to 14 days following the onset of respiratory symptoms. Acute disseminated encephalomyelitis, Guillain–Barré syndrome, and transverse myelitis are among the immune-mediated illnesses encompassed under the syndrome. A 3-year-old male child exhibited symptoms of acute encephalopathy and behavioral disruption subsequent to an infection caused by M. pneumoniae. He presented with irritability, sleep disturbance, slurred speech, increased appetite, episodes of unresponsiveness, moving in circles, staring, and laughing episodes lasting for up to 15 to 30 minutes over a week. He lost his previous toilet training. Abnormal jerks were noted while awake and asleep. Symptoms were preceded by exposure to vague febrile illness 3 weeks prior to presentation. The patient's brain magnetic resonance imaging was normal. Electroencephalography showed a slow background with no epileptiform discharges. Cerebrospinal fluid analysis and polymerase chain reaction for viruses were negative. The workup for autoimmune encephalitis was negative. Mycoplasma serology IgM was detected. Marked improvement was noted after methylprednisolone pulse therapy, intravenous immunoglobulin, valproic acid, and azithromycin. In conclusion, our report serves as a reminder that M. pneumoniae infection is a possible cause of encephalopathy and behavioral disturbance in children. Early recognition and promotion of immunomodulatory and antimicrobial treatment can prevent the affected child from experiencing different levels of long-lasting impairments in cognitive, physical, or visual abilities.