TABLE 3

Clinical, diagnostic, and radiographic clues to autoimmune encephalitis

FINDINGS	COMMENTS
Subacute clinical course	1–3 months of symptoms
Viral-like prodrome	Fever, malaise, headache, gastrointestinal symptoms, etc
Neurocognitive deficits	Agitation, apathy, catatonia, delusions, irritability, mania, psychosis, and paranoia
Neurologic examination abnormalities	Ataxia, brain stem abnormalities, myoclonus, tremor, or myelopathy
New-onset focal seizure disorder or status epilepticus	Often not responsive to antiepileptic medications
New focal electroencephalogram abnormalities	Focal epileptic or slow-wave activity particularly arising from the temporal lobes
Subacute movement disorder	Dyskinesias, dystonia, or choreoathetosis
Subacute sleep disturbance	Central sleep apnea, central neurogenic hypoventilation, or narcolepsy
Subacute autonomic dysfunction	Hyperhidrosis, tachyarrhythmias, labile blood pressure, central hypoventilation, gastrointestinal dysmotility, urinary dysfunction
Brain MRI abnormalities	Bilateral T2-weighted FLAIR hyperintensities in the medial aspect of the temporal lobes, although multifocal changes involving the gray and white matter are also possible
Inflammatory cerebrospinal fluid	Mild to moderate pleocytosis (white blood cell count 5–100/μL)
Previous or current oncologic disorder or risk factors for malignancy such as smoking	Increased risk of a paraneoplastic disorder