Posterior quadrantic epilepsy surgery: technical variants, surgical anatomy, and case series.
OBJECTIVE
Patients with intractable epilepsy due to extensive lesions involving the posterior quadrant (temporal, parietal, and occipital lobes) form a small subset of epilepsy surgery. This study was done with a view to analyze our experience with this group of patients and to define the changes in the surgical technique over the last 15 years. We also describe the microsurgical technique of the different surgical variants used, along with their functional neuroanatomy.


METHODS
In this series there were 13 patients with a median age of 17 years. All patients had extensive presurgical evaluation that provided concordant evidence localizing the lesion and seizure focus to the posterior quadrant. The objective of the surgery was to eliminate the effect of the epileptogenic tissue and preserve motor and sensory functions.


RESULTS
During the course of this study period of 15 years, the surgical procedure performed evolved toward incorporating more techniques of disconnection and minimizing resection. Three technical variants were thus utilized in this series, namely, (i) anatomical posterior quadrantectomy (APQ), (ii) functional posterior quadrantectomy (FPQ), and (iii) periinsular posterior quadrantectomy (PIPQ). After a median follow-up period of 6 years, 12/13 patients had Engel's Class I seizure outcome.


CONCLUSIONS
The results of surgery for posterior quadrantic epilepsy have yielded excellent seizure outcomes in 92% of the patients in the series with no mortality or major morbidity. The incorporation of disconnective techniques in multilobar surgery has maintained the excellent results obtained earlier with resective surgery.
Daniel
Roy Thomas
RT
Department of Neurosurgery, Christian Medical College, Vellore 632004, Tamil Nadu, India. roy@cmcvellore.ac.in
Meagher-Villemure
Kathleen
K
Farmer
Jean-Pierre
JP
Andermann
Frederick
F
Villemure
Jean-Guy
JG
D000293:Adolescent; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology*; D002541:Cerebral Decortication / Q000379:methods*; D003337:Corpus Callosum / Q000601:surgery; D004210:Dissection / Q000379:methods; D004827:Epilepsy / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D005260:Female; D038421:Hemispherectomy / Q000379:methods; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008866:Microsurgery / Q000379:methods; D009434:Neural Pathways / Q000601:surgery; D009445:Neuroanatomy; D009778:Occipital Lobe / Q000503:physiopathology / Q000601:surgery; D017063:Outcome Assessment, Health Care; D010296:Parietal Lobe / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D011300:Preoperative Care; D013702:Temporal Lobe / Q000473:pathology / Q000503:physiopathology / Q000601:surgery