De Morsier plus syndrome: A rare congenital disorder presenting with adult onset seizure

De Morsier syndrome, also known as septo-optic dysplasia (SOD), describes a triad of optic nerve hypoplasia, hypothalamic-pituitary dysfunction and midline abnormalities such as absent septum pellucidum or dysgenesis of the corpus callosum. It is a rare congenital disorder that an estimated incidence of 1/50,000 was recorded. This disease has a variety of clinical symptoms, which include visual manifestations (85-90%), intellectual delay (42.5-60%), seizures (27.5-55%) and endocrine abnormalities (50-55%). However, those patients with symptoms of global developmental delay and motor deficits could not be explained by the corpus callosum hypoplasia alone and were noted to manifest other underrecognized cortical malformations such as schizencephaly and polymicrogyria, hence termed De Morsier plus syndrome. In the Philippines, the existence of De Morsier plus syndrome with a lack of developmental disorders detected during adulthood is uncommon with no reported case yet. This report is a case of a 24-year-old, male, who presented with adult-onset seizure with associated eye symptoms. Cranial magnetic resonance imaging revealed bilateral schizencephaly in both parietal lobes with absent septum pellucidum, polymicrogyria, agyria-pachygyria and optic nerve atrophy. On electroencephalogram, epileptiform discharges were noted in the left parietal area. This case was managed under anti-seizure medication with no seizure recurrence and a good outcome.