Endoscopic third ventriculostomy (ETVS) is considered a minimally invasive procedure for blocked hydrocephalus. In 24 cases, this procedure was carried out in awake patients under local anesthesia. All patients reported abrupt orbital pain when the third ventricle floor was manipulated. Although recent advancements in knowledge of some forms of migraine and cluster headache could be regarded as a good basis for interpreting the pain triggered by ETVS, other hypotheses should also be taken into consideration
