Obesity is a common complication after
craniopharyngioma therapy, occurring in up to 75% of survivors. Its
weight gain is unlike that of normal
obesity, in that it occurs even with
caloric restriction, and attempts at lifestyle modification are useless to prevent or treat the
obesity. The pathogenesis of this condition involves the inability to transduce afferent hormonal signals of adiposity, in effect mimicking a state of CNS
starvation. Efferent sympathetic activity drops, resulting in malaise and reduced energy expenditure, and vagal activity increases, resulting in increased insulin secretion and adipogenesis. Lifestyle intervention is essentially useless in this syndrome, termed "hypothalamic
obesity." Pharmacologic treatment is also difficult, consisting of
adrenergics to mimic sympathetic activity, or suppression of insulin secretion with
octreotide, or both. Recently,
bariatric surgery (
Roux-en-Y gastric bypass, laparoscopic gastric banding,
truncal vagotomy) have also been attempted with variable results. Early and intensive management is required to mitigate the
obesity and its negative consequences.