Abstracts

Rationale: Hypothalamic hamartomas (HHs) are benign heterotopic lesions arising from the floor of the third ventricle or tuber cinereum. They are rare (incidence 1:200,000) and manifest clinically with central precocious puberty (CPP) and/or gelastic epilepsy. A significant proportion of patients develop cognitive and behavioural difficulties.. Despite continued research, the natural history and optimal management of this condition remains unclear. We aimed to describe the clinical presentation, course and treatment strategies of a cohort of patients with HH.Methods: Retrospective case-note review of 38 HH patients managed at Great Ormond Street Hospital between 1991-2014. Cases were examined longitudinally for a mean of 5.9 (range 0.8-16.8) years. 4 patients were excluded for missing dataResults: 18 patients developed epilepsy: 14 presented with seizures whilst 4 who presented with CPP were later found to have unrecognised seizures. Of those presenting with gelastic seizures, the majority experienced seizure onset in infancy, were male and had a sessile HH (p<0.001). There was significant delay between seizure onset and epilepsy diagnosis (mean 2.98; range: 0.2-7.5 years). 15/18 developed multiple seizure types and 13/18 patients became pharmacotherapy-resistant. In contrast, patients presenting with CPP were predominantly female with pedunculated HH (p<0.001). Epilepsy-associated HH patients had the highest rate of cognitive difficulties (11/18; p<0.001); 6/18 suffered cognitive stagnation-regression. This was not observed in CPP or incidental HH patients. A large proportion of all HH patients had behavioural difficulties (N=21/34). 11/18 epilepsy patients were managed surgically. 2 underwent stereotactic radiosurgery, 3 endoscopic disconnection and 6 microneurosurgical resection. Seizure freedom was achieved in 3 patients, reduced seizure frequency in 4 and behavioural improvement in 3. Six patients developed post-surgical pituitary hormone deficiency.Conclusions: Sessile HH is associated with gelastic epilepsy. The seizures are difficult to recognise and are associated with significant delay to diagnosis. Many of these patients develop multiple, treatment-refractory seizures, with cognitive and behavioural impairment. Pedunculated HH is more often associated with CPP and has a more benign course. In the presence of epilepsy, early surgical hamartoma management should be considered although careful risk-benefit analysis is required.