The diencephalic syndrome (Russell syndrome) is a rare cause for failure to thrive in an infant or young child.
Causes of the diencephalic syndrome may include:
(1) glioma in the region of the optic chiasm or hypothalamus
(2) midline cerebellar astrocytoma
(3) suprasellar tumor (ependymoma, spongioblastoma)
(4) thalamic tumor
Clinical features may include:
(1) failure to thrive
(2) emaciation (cachexia) despite normal caloric intake
(3) hyperactivity/hyperkinesis
(4) hyperalertness
(5) euphoria
(6) headache
(7) nystagmus or strabismus
(8) visual field defect
(9) optic pallor
(10) proptosis
(11) vomiting
(12) no evidence of malabsorption
