Patients mainly present with cognitive dysfunction, psychiatric behavioural abnormalities, and seizures of acute or subacute onset, i.e. short-term dementia, memory loss, personality changes, delusions, babbling and recurrent convulsions; some patients may have prodromal symptoms such as fever and headache before onset; some antibody-mediated encephalitis may also cause patients to develop sleep disorders, manifesting as sleep cycle disturbances, such as Some patients may also develop sleep disturbances, such as sleepless nights and long daytime sleep; in severe cases, they may become unconscious or even comatose.