Use of scalp-sphenoidal EEG for seizure localization in temporal lobe epilepsy.

We determined the accuracy and sensitivity of scalp-sphenoidal EEG for seizure focus localization in 50 patients who became seizure-free or had rare seizures following temporal lobectomy. EEG localization was based on concordant interpretations of scalp-sphenoidal ictal EEG by three independent interpreters. All patients became seizure-free or had rare seizures following temporal lobectomy. Localization from EEG disagreed with the side of surgery in only 1 (2%) of 50 patients. We identified 3 distinct patient groups with a low, moderate, and high likelihood of having a focal ictal EEG pattern during a seizure. These groups comprised 31% (low likelihood), 44% (moderate likelihood), and 25% (high likelihood) of patients. A model based on these results suggests that with multiple ictal EEG recordings, accurate localization from scalp-sphenoidal EEG is possible in approximately up to 65-70% of patients with temporal lobe epilepsy.

Seizure localization in temporal lobe epilepsy: a comparison of scalp-sphenoidal EEG and volumetric MRI.

We determined the accuracy of volumetric MRI (based on identification of unilateral hippocampal atrophy) and scalp-sphenoidal EEG (based on concordant interpretations of scalp-sphenoidal ictal EEG by three independent interpreters) for seizure focus localization in 20 patients with temporal lobe epilepsy. All patients became seizure-free or had rare seizures following temporal lobectomy. Among the 20 patients, nine (45%) met both MRI and EEG localization criteria, six (30%) met MRI localization criteria alone, three (15%) met EEG localization criteria alone, and two patients (10%) did not meet either localization criteria. In the 18 patients meeting MRI or EEG localization criteria, the predicted localization agreed with the side of temporal lobectomy. These results suggest that a noninvasive approach combining MRI and EEG will correctly localize the side of seizure onset in most patients with temporal lobe epilepsy.

The effect of electrical stimulation of medial temporal lobe structures in epileptic patients upon ACTH, prolactin, and growth hormone.

We measured ACTH, cortisol, prolactin, and growth hormone concentrations in patients with temporal lobe epilepsy who were having depth electrode studies. During the collection period, electrical stimuli were applied to amygdala and hippocampus to establish after-discharge thresholds. After-discharges that lasted at least 10 seconds or seizures caused secretion of ACTH and prolactin but not growth hormone. Stimuli that did not produce after-discharges of this duration inhibited ACTH secretion, but had no effect on prolactin or growth hormone secretion.

Association of low blood manganese concentrations with epilepsy.

A comparison of hospitalized epileptic patients with matched normals showed that the mean whole blood manganese (Mn) concentration of the epileptic population was significantly lower than the mean of the normal population. The whole blood Mn concentration in the epileptics did not correlate either with seizure frequency or with anticonvulsant therapy. It was observed, however, that patients whose epilepsy was a result of trauma had significantly higher blood Mn concentrations than patients whose history was negative for trauma.