ESPE Abstracts

Background: Hypothalamic hamartomas(HH) are rare heterotopic congenital malformations causing central precocious puberty(CPP) and/or resistant epilepsy whose natural history is unknown.

Aim: To describe clinical and imaging features, and the risk of developing endocrine deficits, particularly after surgery.

Method: Retrospective case note and imaging review of all HH diagnosed by MRI between 30.08.1991 and 24.11.17, analysed by initial presentation, imaging (Delalande grading), and surgery.

Results: 59 (36male) children of median age 2.72 (antenatal-15.59) years at diagnosis presented with A) gelastic/dacrystic epilepsy (n32) at 5.62 (0.16-15.59) years, B) CPP(n17) at 1.35 (0.64-8.49) years or C) incidentally (n10) at 0.9 (antenatal-9.78) years of whom one was diagnosed with CPP 0.41 years later. 14 (9=GpA,5=GpB) respectively developed additional CPP after 1.83 (0.19-5.83) or epilepsy after 0.55 (0.17-1.0) years. Despite 60% experiencing seizures in their first year, 37 with epilepsy, had a 2.96 years delay in HH diagnosis compared with 27 with CPP (Mann-Whitney P<0.05). Grade 1 tumours (below 3rd ventricle) were more often associated with CPP than Grade 2 or 3 tumours (above 3rd ventricle), more likely to cause epilepsy (x²P<0.05). 66% (n=39/59) were followed endocrinologically for 5.32 (0.29-14.34) years. At last assessment, BMI and height SDS were 0.54 (-3.68_3.63) and 0.19 (-1_1.80) respectively; in 66%(n=26/39) BMI increased by 1.05 (0.1-4.18) SDS. GH deficiency (GHD) occurred in just 2 (unoperated). 20(18=GpA,2=GpB) underwent surgery (4=endoscopic, 10=open, 4=radiosurgery, 2=laser) for intractable epilepsy at 8.10 (0.17-16.88) years, 3 of whom required multiple attempts [(endoscopic+laser) (4endoscopic+open+radiosurgery), (open+radiosurgery+open)]. In 14/20 followed after surgery, 4 (29%) developed TSHD after 0.61 (0.18-1.51)years, 3 (21%) GHD at 1.89 (1.40-3.45)years of whom 2 also had ACTHD and CDI [one after 3 endoscopic surgeries and another with additional TSHD, LH/FSHD after laser surgery and earlier CPP, and GHD from earlier endoscopic resection]. One patient developed isolated CDI and two hypodipsia after open surgery. GHD and ACTHD were associated with endoscopic surgery, P<0.05.

Conclusion: Grade 1 HH more often cause CPP, and grade 2/3 tumours epilepsy, but the features overlap and all should be endocrinologically screened for CPP, GHD and obesity over time. Surgery causes additional deficits in 50% of those operated, with life-threatening CDI and ACTHD in 15%, including one who received modern laser surgery. These data help inform therapeutic choices and hypothalamic morbidity in this disease and require close monitoring.