Diencephalic Syndrome: A Rare and Easily Overlooked Cause of Failure to Thrive
Prapai Dejkhamron MD*, Surachai Likasitwattankul MD*, Kevalee Unachak MD*
Affiliation : * Department of Pediatrics, Faculty of Medicine, Chiang Mai University
Background : Diencephalic syndrome (DS) is an uncommon cause of failure to thrive in infants and young
children. The major manifestations are emaciation, hyperkinesia, and euphoria. Most patients have a tumor
in the hypothalamic-optic chiasma region.
Case Report : Two children, aged 14 months and 5 years 9 months, who presented with classic features of DS
at an onset of 2 and 3 months respectively, were reported. Neurologic examination was normal, except for
papilledema in the second child. Imaging of the brain showed a suprasellar mass, identified as pilocytic
astrocytoma in both cases. The first case was lost to follow up. The latter underwent partial resection of the
tumor and received radiotherapy postoperatively. He gradually gained in weight and height.
Conclusion : DS should be a differential diagnosis in any children with emaciation despite adequate caloric
intake and an inappropriately euphoric mood. Awareness of this syndrome, careful history taking, general
detail as well as neurological examination including fundoscopic examination and appropriated
investigations are crucial.
Keywords : Diencephalic syndrome, Failure to thrive
