| Popis: |
Different stereotactic approaches have been devised for the treatment of medically refractory epilepsies, since Spiegel et al. (1958) and Wycis et al. (1966) proposed pallidotomy for convulsive disorders and Hassler and Riechert (1957) introduced fornicotomy for temporal lobe epilepsy. Based upon the premise that epileptic seizures are due to the firing of hyper-excitable neurons whose abnormal discharges prop-agate along preferential pathways, various procedures have been designed to (1) destroy the localized centers of the seizure onset; (2) interrupt the path-ways of propagation; and (3) lessen the neuronal excitability, both by decreasing facilitory impulses and by increasing inhibitory influences (Ramamurthi and Kalyanaraman 1982; Walker 1982). Stereotactic surgery has been used mainly in those cases that do not meet the criteria for classical open surgery with cortical resection. Such cases are estimated to represent more than 60% of all medically intractable epilepsies (Bouchard 1976; Ciganek et al. 1976). |
