The consistency of ictal SPECT and VEEG studies in localizing the epileptic focus

Objective: To localize the epileptic focus by means of ictal SPECT and video-electroencephalography (VEEG) patterns to decide whether the combination of them are capable of localizing epileptic focus correctly. Methods: The present study was performed in 45 epileptic patients, who showed spike waves during VEEG monitoring when deprived of sleep to provoke seizures, even oral application of clonidine was given when deprivation of sleep was failed in limited time. Technetium-99m ethyl cysteinate dimer (⁹⁹Tc^m-ECD) was injected within 30 s when a clinical sign and/or an typical VEEG discharge was recognized, then brain SPECT was performed after 30 min. In the end, compared the results of ictal SPECT and VEEG in localization. χ² test was performed by using software SPSS 19.0. Results: Ictal brain SPECT localized in 93.3% (42/45) patients, of whom 95.2% (40/42) patients had single hyperperfusion, and 4.8% (2/42) had multiple hyperperfusion. VEEG showed partial seizures in 68.9% (31/45)patients, and 31.1% (14/45) patients showed generalized spike waves. The relationship of ictal SPECT and VEEG in localizing epileptic focus was turned out as following: Firstly, the consistency of ictal SPECT and VEEG is 83.9% (26/31) in partial seizure, as for generalized tonic-clonic seizure, VEEG showed generalized spike waves, and ictal brain SPECT declared single hyperperfusion, therefore, the localization of them was different. The consistency of partial seizure was significantly higher than that of generalized tonic-clonic seizure (χ² = 24.478, P < 0.05). Conclusions: The consistency of ictal SPECT and VEEG in localization has something to do with epilepsy categories. The study indicates that it is possible to obtain localization in patients with partial seizures using a combination of ictal SPECT and VEEG patterns, as for generalized tonic-clonic seizure, the combination of them is not enough and it's imperative to use other techniques. (authors)