Precise resection of symptomatic occipital lobe epilepsy guided by functional neuronavigation combined with intra-operative magnetic resonance imaging

Abstract

Objective To evaluate the clinical effect of functional neuronavigation combined with intra-operative magnetic resonance imaging (iMRI) in resection of symptomatic occipital lobe epilepsy.Methods Sixteen patients with symptomatic occipital lobe epilepsy,admitted to our hospital from January 2011 to April 2012,were involved in present study.All patients underwent surgical operation assisted by functional neuronavigation.Before the operation,MRI scanning,imaging fusing,scope of lesion excision describing,and operative approach designing were performed successively.Three-D reconstructed navigation plan was integrated into neuronavigation system and used by combining with functional neuronavigation under microscope during the surgical procedure.And,the iMRI was performed in five of them; the operative plan of the residuary lesion was redesigned accordingly.After the operation,the regular clinical and iconography follow-up were in progress.Results The functional neuronavigation was successfully completed.The lesions,posterior central gyrus and pyramidal tracts were projected into operation microscope.The lesions were precisely excised,and the posterior central gyrus and pyramidal tracts were protected effectively.The last iMRI indicated that the range of resection was coincided with the pro-operative plan.During the follow-up of 12-24 months,11 patients were found to be completely seizure-free or with only aura (Engel I),and 5 patients had only rare seizure (Engel Ⅱ,fewer than three seizures per year).Nine patients appeared visual field defect without hemiparalysis or hemianesthesia.Conclusion Functional neuronavigation combined with iMRI is a safe and reliable technique for perfect resection of symptomatic occipital lobe epilepsy and reduction of normal brain functions by precisely locating lesions and important functional structures. Key words: Neuronavigation; Intra-operative magnetic resonance imaging; Occipital lobe epilepsy