Electroencephalographic and seizure manifestations in two patients with folate receptor autoimmune antibody-mediated primary cerebral folate deficiency

Seizure semiology and electroencephalographic (EEG) manifestations of autoimmune‐mediated cerebral folate deficiency (CFD) before and after therapy have yet to be fully characterized. Here, we report these findings in two such patients. Our first patient presented with the novel manifestation of infantile spasms at the age of 3 months, while the second developed the previously reported initial onset of tonic seizures with static developmental delay, but subsequently manifested the novel finding of electrical status epilepticus in sleep at the age of 15 years. Awareness of these new manifestations, together with the previously reported manifestations of developmental delay, seizure onset during the first 2 years of life, occurrence of tonic, myoclonic-astatic, absence, and generalized tonic-clonic seizures, with an EEG of generalized spike-slow waves and multifocal spikes, is important to increase the index of suspicion of this treatable disorder.