Introduction:

Epilepsy surgery is a treatment option for drug-resistant focal epilepsies. A percentage of patients need invasive neurophysiology (NFI) for adequate resection of the epileptogenic zone (EZ) and avoid undesirable neurological deficit (DN).

Objective:

To analyze the complications of patients who needed NFI, grids (ECoG) or depth electrodes (SEEG) or both (ECoG + SEEG).

Materials and Methods:

Retrospective observational study that included 47 patients, between 2005 and 2012.

We  analyzed demographic data and complications(medical and DN). The DNs were classified into temporary (less than 6 months) and permanent. The permanent ND, was further associated to the implant or resection procedure (expected or unexpected)

Results:

Nineteen patients were male, mean age of 21.1y/o (1-45) and 19/47 were pediatric. All were chronically implanted, 7 (15%) with SEEG, 17 (36%) with ECoG and 23 (49 %) with SEEG+ECoG.

Nineteen patients had transient ND: ECoG: 9(motor: 2; language:3; neglect:2; altered level of consciousness:2); SEEG: 2(motor:1; altered level of consciousness:1); ECoG+SEEG: 8(motor: 3, language: 1, neglect: 1, altered level of consciousness:3).

Ten patients (21%) had permanent ND: ECoG: 4, SEEG: 1, ECoG+SEEG: 5, 3/10 had not expected ND. Seventeen patients, suffered medical complications, 59% (10p.) with ECoG+SEEG: 35% (6p.) with ECoG and 6% (1p.) with SEEG. A patient with bilateral combined implant died.

Conclusions:

We observed more frequent morbidity with ECoG+SEEG. The unexpected complications were observed with ECoG+SEEG and ECoG.

One patient who underwent ECoG+SEEG implant, died.