Anti-Ma2-encephalitis in a 2 year-old child: A newly diagnosed case and literature review

Background Anti-Ma2-associated encephalitis is a rare paraneoplastic neurological syndrome characterized by isolated or combined limbic, diencephalic, or brainstem dysfunction. It is rarely reported in children. Case study We describe the clinical data of a 2-year-old girl referred to our department for refractory focal seizures associated with fever, followed by behavioural changes, speech disturbances and confusional episodes. Brain magnetic resonance imaging (MRI) showed left temporoparietal brain involvement. Haematological, biochemical and infectious evaluations were unremarkable. Autoimmune encephalitis was suspected. Paraneoplastic antibodies tests showed positive results for anti-Ma2 antibodies. Screening for underlying tumour was negative. Immunomodulatory treatment was administrated. The patient showed improvement of vigilance and behaviour. However, she kept refractory epilepsy. Conclusion Although poor response to immunotherapy, early diagnosis and appropriate treatment of this disorder may prevent irreversible sequelae.