Overview of symptoms at presentation which may suggest aetiology
| Symptoms suggestive of infectious cause | Symptoms suggestive of immune-mediated cause |
| Acute or subacute onset Prodromal flu-like illness Alterations in personality, behaviour, cognition or consciousness Vomiting or gastrointestinal upset Travel history or exposure to known vectors of encephalitis causing infections Immunocompromise Skin rashes | Subacute or chronic onset Altered personality, behaviour, psychosis, catatonia Sleep disorder-disruption Memory issues Recent viral illness Seizures (eg, brachiofacial dystonic) Status epilepticus Autonomic instability Movement disorders (eg, orofacial dyskinesia) Underlying symptoms concerning for malignancy |