Typical and Atypical Perfusional Patterns in Temporal Lobe Epilepsy: Correlation with Chronological Variables of the Epileptic Seizures.
Abstract number :
1.240
Submission category :
Year :
2000
Submission ID :
1397
Source :
www.aesnet.org
Presentation date :
12/2/2000 12:00:00 AM
Published date :
Dec 1, 2000, 06:00 AM
Authors :
Lauro Wichert-Ana, Tonicarlo R Velasco, Vera C Terra-Bustamante, Veriano Alexandre Jr., David Araujo Jr., Joao P Leite, Helio R Machado, Joao A Assirati, Mery Kato, Alexandre Bastos, Americo C Sakamoto, CIREP - Ribeirao Preto Sch of Medicine - USP, Ribeir
RATIONALE: Ictal SPECT has a high sensitivity to localize the epileptogenic zone (EZ) in medically intractable temporal lobe epilepsies (TLE). Much is already known about timing of postictal perfusional patterns, while little data analysing ictal perfusional patterns under a chronological frame exist. This study adresses the issue of typical and atypical perfusional patterns in temporal lobes and correlates them with ictal chronological variables. METHODS: We prospectivelly evaluated 53 patients (pts) through Vfdeo-EEG, MRI, ictal, postictal and interictal SPECT, neuropsychological, social and psychiatric evaluations. All patients underwent antero-mesial temporal lobectomy and had a good postsurgical seizure outcome. RESULTS: We analysed 51 ictal and 2 postictal scans: 41 pts (77%) showed typical perfusional patterns (TPP, i.e., ictal hyperperfusion or postictal hypoperfusion ipsilateral to the EZ); 12 pts (23%) exhibited atypical perfusional patterns (ATT): 7 pts (13%) with bitemporal hyperperfusion (4 pts showed asymetric predominantly ipsilateral changes), other 4 pts (8%) had contralateral hyperperfusion (associated to ipsilateral hypoperfusion) and 1 patient (2%) had a normal ictal SPECT scan. The earlier injection group (up to 30 sec from seizure onset) had a greater percentage of TPP (p<0,05). There was a significantly greater ictal eletrencefalographic pattern exceeding radionuclide injection in TPP than APP group (p<0,04). Later acquisition of SPECT images (between 2 and 6 hours after injection) do not influenced the sensitivity of the SPECT. CONCLUSIONS: Ictal perfusional patterns in TLE needs detailed morphological analysis to determine TPP and APP. After electro-clinical correlation, APP disclosures conspicuous findings that can also render them lateralizing information of EZ. Early injection of radionuclide resulted in a greater percentage of TPP. Later SPECT acquisitions had similar sensitivity to the earlier ones. Finally, greater exceeding time of ictal EEG after radionuclide injection correlated with greater percentage of TPP.