Table 1.

Comparison between epilepsy related to NMDAR autoantibodies and to GRIN2A mutations

	Autoimmune	Genetic
Etiology	unknown, alleged predisposition to autoimmune diseases	mutation in GR1N2A
Age of onset	mostly young adults, rarely children, female predominance	childhood
Symptom development	subacute onset, long course (months) and possible recurrence, seizures often transient at disease onset	subacute/acute onset of clinical features including acquired auditory aphasia related to sleep EEG abnormalities, rare seizures in most cases
lctal presentation	focal motor or dyscognitive seizures, generalized seizures, status epilepticus, epilepsia partialis continua	focal motor seizures in most cases
Interictal presentation	behavioral troubles, cognitive difficulties	asymptomatic or acquired aphasia, loss of speech, behavioral troubles
Other findings	movement disorder, sleep difficulties, autonomic dysfunction	none reported
EEG	focal or diffuse continuous theta and delta slowing, superimposed low-voltage fast activity (extreme delta brush pattern)	biphasic stereotyped centrotemporal spike-waves, may become continuous during sleep, especially if cognitive decline is noted
Brain MRI	frequently normal, may show white matter abnormalities	normal
Treatment	refractory to AED, recover with immunotherapy and extended intensive care support	seizures AED responsive, EEG abnormalities often refractory
Outcome	appropriate treatment started early, complete recovery is the rule; cognitive or motor sequeleae may be observed, rare deaths reported	cognitive sequeleae often observed