Clinical features and postoperative seizure outcome in patients with drug-resistant gelastic seizures without hypothalamic hamartoma.

OBJECTIVES: The objective of this study was to describe the clinical characteristics and surgical outcome in patients with gelastic seizures without hypothalamic hamartoma. METHODS: We retrospectively reviewed all the video-EEG reports over a 5-year period (2007-2011) for the occurrence of the terms "laugh" or "giggle" in the text body. All the patients with at least one documented gelastic seizure at the epilepsy monitoring unit were studied. In patients who underwent epilepsy surgery, seizure outcomes were analyzed. RESULTS: Sixteen patients (10 females and 6 males) with a mean age of 46.3years were studied. Seven patients had invasive intracranial EEG recordings. Seizure onset zone was in a temporal lobe in four patients and the frontal lobe in one patient. Two patients did not have gelastic seizures during their intracranial EEG monitoring. Nine patients underwent resective epilepsy surgery for their seizures. Six patients (67%) were seizure-free after surgery. CONCLUSION: In adult patients, gelastic seizures can be seen in patients with focal epilepsy without hypothalamic hamartoma. Nonhypothalamic hamartoma gelastic seizures originating from the temporal lobe can be amenable to surgery.

EEG asymmetry during aortic arch surgeries associated with selective preferential cerebral hypothermia.

Intraoperative EEG monitoring is increasingly used during aortic arch procedures for early detection of acute neurologic dysfunction. In those procedures involving cardiopulmonary bypass, increased neuroprotection may be gained by using hypothermic circulatory arrest and selective cerebral perfusion. Several techniques for cerebral perfusion exist; yet no studies have noted distinct EEG patterns associated with different techniques. In this study, we reviewed EEG records of six aortic arch procedures that used cannulation of the innominate artery to provide selective antegrade cerebral perfusion. In each case, a transient hemispheric asymmetry was noted within 2 minutes of the start of head cooling, consisting of enhanced suppression over the right compared with the left hemisphere, which was confirmed by power analysis. The EEG returned to baseline during passive-head rewarming in five cases, whereas a brief left-sided partial seizure occurred during rewarming in one case. These findings suggest that antegrade cerebral perfusion using cannulation of the innominate artery results in enhanced cooling of the right hemisphere as detected by intraoperative EEG monitoring. Characterization of this finding is necessary to prevent misinterpretation of ischemia by EEG.