[Differential contribution of preoperatory studies to diagnosis in temporal lobe epilepsy surgery].
BACKGROUND
It is necessary to know the degree of concordance of preoperative studies in temporal lobe epilepsy (TLE). AIM. To analyze the relative importance of different preoperative tests (vEEG, EEG, SPECT and MRI), the degree of agreement between them, and to develop a Bayesian probability model for diagnosis.


METHODS
We analyzed 73 patients operated by TLE, with a minimum postoperative follow-up of two years. To analyze the localization capability of different test, we used only patients with an Engel's grade I outcome during all the follow-up time (n = 60).


RESULTS
Engel's grades percentages at 2 years were 87.7/8.2/3.0/0.0 (I/II/III/IV, respectively). The preoperative correlation was < 50% for three tests and 33% for the four. MRI studies were found normal in 33.3% of cases. According to the localization index, the arrange was vEEG > RM > SPECT > EEG. The conditional probability of correct localization for a test was vEEG (0.950) > EEG (0.719) > SPECT (0.717) > RM (0.683). Concordance for more than two tests, was = 0.587 (vEEG + MRI). The probability of obtaining a priori correct localization was vEEG (0.983) > RM (0.414) > EEG (0.285) > SPECT (0.209). The Bayesian model is highly reliable.


CONCLUSIONS
Probably it is not always possible to obtain a high degree of agreement among preoperative test, despite this, it is possible to obtain a good functional result. The most effective test is the vEEG.
Pastor
Jesús
J
Servicio de Neurofisiologia Clinica, Hospital Universitario La Princesa, Madrid, España. jpastor.hlpr@salud.madrid.org
Ortega
Guillermo J
GJ
Herrera-Peco
Iván
I
Navas-García
Marta
M
Navarrete
Eduardo G
EG
Alonso-Cerezo
Concepción
C
Pulido-Rivas
Paloma
P
Sola
Rafael G
RG
D000328:Adult; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000601:surgery*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D015899:Tomography, Emission-Computed, Single-Photon