Abstracts

RATIONALE: We present a minimally invasive method of treatment for hypothalamic hamartomas. Hypothalamic hamartomas may present with medically intractable epilepsy, typically with a complex seizure disorder including gelastic seizures, behavioral disturbance and precocious puberty. Open surgery is difficult and its risks may be unacceptable to patients.
METHODS: Two patients presented with a severe seizure disorder and MRI evidence of a hypothalamic hamartoma. They underwent stereotactic placement of depth electrodes into the hamartoma and areas that appeared semiologically or electrically to be involved in their seizures. Direct recording from the lesions confirmed them to be the site of seizure onset. Electrical stimulation of the lesions reproduced their habitual seizures at low threshold. Using local anesthetic, the electrode in the hamartoma was replaced with a thermocoagulation electrode. Gradually increased thermal lesions were created within the hamartomas up to 80 Celsius.
RESULTS: The procedures were halted when in one case unilateral pupillary dilatation occurred and in the other facial flushing was produced. Both settled when the electrode temperature reduced. Subsequent electrical stimulation could not reproduce seizures. Post-operatively there were no complications. One patient gained immediate benefit in terms of seizure frequency although at six months continues to have about 30% of baseline frequency. The other had little immediate change but a progressive reduction over six months also to 30% of baseline.
CONCLUSIONS: Stereotactic thermocoagulation is a promising minimal access technique for the treatment of hypothalamic hamartomas.