High-resolution MRI: can detect dual pathology tan extrahippocampal lesion
plus hippocampal atrophy in about 5-20% of patients with refractory partial
epilepsy referred for surgical evaluation. We report the results of 41 sur
gical interventions in 38 adults (mean age 31 years, range 14-63 years) wit
h dual pathology, Three patients had two operations. The mean postoperative
follow-up was 37 months (range 12-180 months). The extrahippocampal lesion
s were cortical dysgenesis in 15, tumour in 10, contusion/infarct in eight
and vascular malformation in five patients. The surgical approach aimed to
remove what was considered to be the most epileptogenic lesion, and the 41
operations were classified into lesionectomy (removal of an extrahippocampa
l lesion); mesial temporal resection (removal of an atrophic hippocampus);
and lesionectomy plus mesial temporal resection (removal of both the lesion
and the atrophic hippocampus), Lesionectomy plus mesial temporal resection
resulted in complete freedom from seizures in 11/15 (73 %) patients, while
only 2/10 (20%) patients who had mesial temporal resection alone and 2/16
(12.5%) who had a lesionectomy alone were seizure-free (P < 0.001), When cl
asses I and II were considered together results improved to 86, 30 and 31%,
respectively. Our findings indicate that in patients with dual pathology r
emoval of both the lesion and the atrophic hippocampus is the best surgical
approach and should be considered whenever possible.