General description

Anti-Ma2-related encephalitis is an autoimmune encephalitis in which 90% of patients have a paraneoplastic syndrome. Half of the patients have testicular carcinoma. Typical clinical manifestations include limbic encephalitis and brainstem symptoms, often accompanied by daytime sleepiness. In patients with brainstem involvement, oculomotor dysfunctions and vertical gaze paralysis are common. Key diagnostic points include symptoms of autoimmune encephalitis, mesencephalic and hypothalamic symptoms (e.g., daytime sleepiness or cataplexy), and brainstem symptoms (vertical gaze palsy).

Radiographic features

MRI shows abnormal signal in limbic system. One third of patients show abnormal signal and nodular contrast effect in diencephalon (thalamus and hypothalamus) and brainstem.