Abstracts

Selective amygdalohippocampectomy (SAH) is a surgical treatment option for patients with medically intractable mesial temporal lobe epilepsy. It is performed to limit resection of unaffected tissue while maintaining favourable seizure outcome. In SAH the mesial structures can be approached by different routes, namely the transsylvian approach (1) and the transcortical approach (2). The former approach bears a greater risk of vascular injury and frontal lobe manipulation but the advantages or disadvantages with respect to postoperative cognitive outcome are still a matter of debate.
Eighty patients were randomly assigned to one of the two surgical approaches. In 41 patients the transsylvian approach and in 39 patients the transcortical approach was performed. All patients received comprehensive neuropsychological testing of verbal/nonverbal memory, attention and executive functions before and seven months after SAH.
Seventy-five percent of patients became completely seizure free with no difference depending on the chosen approach. Repeated measurement MANOVA showed that outcomes following both approaches were essentially the same. The only exception was phonemic fluency, which showed a significant improvement after transcortical but not after transsylvian SAH.
The results indicate that the surgical approach can be chosen independent from cognitive outcome criteria. Improvement in phonemic fluency after transcortical SAH may reflect selective normalization of cognitive functions following epilepsy surgery. Frontal lobe disturbance during transsylvian SAH might have hindered this process of recovery.
1) Wieser HG, Yasargil MG: Selective amygdalohippocampectomy as a surgical treatment of mesiobasal limbic epilepsy. Surg Neurol 17: 445-457, 1982.
2) Olivier A: Transcortical selective amygdalohippocampectomy in temporal lobe epilepsy. Can J Neurol Sci 27 (Suppl 1): S68-S96, 2000.