A Comparison of Anterior Temporal and Nasopharyngeal Electrodes is the Detection of Epileptiform Activities from Temporal Lobes

ABSTRACT

A prospective study was performed to compare anterior temporal (AT) electrodes with nasopharyngeal (NP) electrodes in the detection of epileptiform discharges from temporal lobes. Three different montages including nasopharyngeal electrodes were run on 89 patients with known or suspicious temporal lobe epilepsy, During the simultaneous recording of NP and AT derivations for 5 minutes, 15 of 89 patients showed epileptiform discharges. There were 66 spikes or sharp waves, all told, 45.4%(30/66) of the epileptiform discharges were detected simultaneously by both AT and NP electrodes. The numbers of spikes or sharp waves seen on AT electrode alone- and NP electrode alone were 25 (37.9%) and 11(16 7%), respectively. 4 patients had all their epileptiforrn discharges detected only by the NP derivation whereas 2 had only by the AT derivation. Our study showed that AT and NP electrodes were complementary to each other in the detection of the temporal epileptiform activities. Further study using carefully designed montages is needed to determine the superiority of one over the other.