TABLE 1.

Synaptic Autoimmune Encephalitides

Target Antigen	Primary Symptoms	Other Manifestations	Associated Tumor(s)	Demographic Data	Outcomes With Proper Therapy
NMDA receptor	Psychosis, seizures, autonomic instability, dyskinesias	Viral prodrome, changes in speech, catatonic features, hypoventilation	Ovarian teratoma*	75% women; 35% children and adolescents	75%–80% substantial improvement or full recovery
AMPA receptor	Memory loss, confusion, agitation, seizures	Psychotic symptoms, affective changes	Breast or lung cancer, thymoma	Predominates in women, ages 50–70	Most improve; frequent relapse
GABAB receptor	Seizures, memory loss, confusion	Hallucinations, paranoia, odd behaviors	Small-cell lung cancer	Either gender, middle-aged	~50% improve
LGI1	Amnesia, seizures, confusion, disorientation	Autonomic dysfunction, apathy/irritability, hyponatremia	Rare, thymoma	~2:1 male: female, middle-aged	~80% full recovery or mild deficits
Caspr2	Neuromyotonia, dysautonomia, confusion, insomnia	Amnesia, seizures, neuropathic pain, weight loss	Rare, thymoma	~4:1 male: female, middle-aged	~80% substantial improvement

^*The association with teratomas is gender- and age-dependent. In women older than 18, ovarian teratomas occur in ~55% of cases. In women younger than 18, teratomas occur in 30% of cases. In women younger than 14, teratomas occur in 9% of cases. Only ~5% of men have an underlying tumor (germ-cell tumor of the testis, neuroblastoma, small-cell lung cancer).¹¹