Interictal regional cerebral blood flow and electrical source analysis in patients with complex partial seizures.

BACKGROUND: Recently, new methods of EEG source analysis have been developed. Dipole modeling and brain distributed source analysis localize in three-dimensions the origin of the electrical source of spikes registered in EEG. With single photon emission computed tomography (SPECT), it is possible to detect hypo- and hyperperfusion zones. Our aim in this study is to compare the regions where the electrical sources are detected, with the hypoperfusion regions in patients with complex partial seizures (CPS). METHODS: The concordance of localization with dipole analysis, brain distributed source analysis and regional cerebral flow blood in patients with CPS was studied. The hypoperfusion zones detected with interictal SPECT were compared with electrical sources localized with brain electric source analysis (BESA) and brain distributed source analysis with variable resolution electromagnetic tomography (VARETA). RESULTS: Hypoperfusion zones were found to localize with the origin of dipoles in 18 cases (90%), between lobes in 17 (85%) and between mesial or lateral regions in the temporal lobe in 12 cases (60%). With VARETA, agreement between side of hypoperfusion and electrical current source localization was found in 18/20 cases (90%), with lobes in 17 (85%) and with mesial or lateral regions of the temporal lobe only in 2 cases (10%). CONCLUSIONS: Hypoperfusion zones in interictal SPECT of patients with CPS are in agreement with the origin of dipoles in 85% of the cases, but in specifics zones of temporal lobe the agreement falls to 60%. The concordance of hypoperfusion zones was better with dipole analysis than with VARETA.

Source analysis of polyspike and wave complexes in juvenile myoclonic epilepsy.

We applied dipole modeling and brain distributed source analysis to find current sources comprising spikes and slow waves of polyspike and wave complexes (PSWC) in patients with juvenile myoclonic epilepsy (JME). The dipoles were localized in frontal, parietal and temporal lobes. The frontal dipoles were clustered in the frontal medial gyrus and fronto-orbital region. A midsagittal frontal current source was observed using brain distributed source analysis in all patients. When the slow wave was analyzed, multiple sources in different cortical regions were detected using dipole modeling and brain distributed analysis. These results show pre-frontal medial current sources corresponding to spikes and many diffuse sources in cortical regions corresponding to wave components of PSWC in patients with JME.

Evaluación funcional del músculo temporal en el abordaje pterional / Funtional evaluation of temporal muscle in the pterional approach

La craneotomía pterional es uno de los abordajes más comunes dentro de la neurocirugía, tienen inconvenientes tales como la sección del músculo temporal que ocasiona defectos estéticos importantes. Se realizó un estudio comparativo para evaluar las técnicas de disección del músculo temporal en el abordaje pterional y definir cuál es la que presenta menor lesión al músculo, así como a la rama frontotemporal del nervio facial. Las tres técnicas evaluadas fueron: I. La sección muscular transversal, II. Disección subfacial, y III. Craneotomía osteoplástica. En todos los pacientes se valoró un procedimiento quirúrgico unilateral, con evolución neurológica favorable y participación voluntaria. Se encontraron los mejores resultados cosméticos para el grupo 2, con un hundimiento de la fosa temporal de 1.08 mm contra 2.6 mm para los del grupo 1 (p=0.0020) y 2 mm para el grupo 3 ( p=0.033). En ningún caso hubo datos clínicos de lesión a la rama frontotemporal del nervio facial. La electromiografía tuvo pocos cambios en el grupo 2. Se concluyó que el abordaje subfacial tiene los mejores resultados estéticos y funcionales, es una técnica que ofrece un adecuado corredor quirúrgico sin que la disección y reparación de la fascia del músculo temporal modificaran de manera significativa el tiempo quirúrgico.