Infective | Herpes simplex virus, human herpes virus 6 and 7, neurosyphilis, HIV |
Inflammatory | Primary angiitis of CNS, acute disseminated encephalomyelitis, progressive multifocal leucoencephalopathy |
Autoimmune | Systemic lupus erythematosus, Sjögren's disease, Hashimotos's thyroiditis, antiphospholipid syndrome |
Metabolic/vitamin deficiencies | Wernicke's encephalopathy, B12 deficiency, uraemia, hepatic failure |
Neoplasm | Primary and secondary CNS malignancies, lymphoma |
Neurodegenerative | Creutzfeldt–Jakob disease, Alzheimer's disease |
Neurovascular | Cerebrovascular disease, posterior reversible encephalopathy syndrome, transient global amnesia, vascular hypoxia |
Primary psychiatric illness | Acute psychosis |
Limbic encephalitis | Paraneoplastic and non-paraneoplastic |
CNS, central nervous system.