Study on hippocampal volume with quantitative 3T magnetic resonance imaging in Chinese patients with epilepsy

Background It was still rare for the quantitative magnetic resonance imaging （MRI） research of regional changes in hippocampus sclerosis （HS） in Chinese patients with epilepsy. This study aimed to study the hippocampal volumes （HVs） with quantitative MRI measurement in Chinese patients with epilepsy. Methods Forty-six Chinese patients with epilepsy （intractable epilepsy （IE）, n=21; non-intractable epilepsy （NIE）, n=25） and 25 normal controls were collected between July 2007 and March 2008. All of the subjects underwent a 3T high-resolution MRI with oblique coronal thin sections oriented perpendicular to the hippocampal long axis. Hippocampal structures were assessed by visual detection, and HVs were quantitatively studied with a Picture Archiving and Communication System （PACS）. Results Our study suggested that there was no significant difference in gender （P 〉0.05） while the right hippocampal head volume （HHV）, hippocampal body volume （HBV）, and the whole hippocampal volume （HCV） were greater than the left one （P 〈0.05）, but no significant difference was found in bilateral hippocampal tail volume （HTV） （P 〉0.05） in normal controls. That unilateral/diffuse （64%/21%） and bilateral/focal （86%/20%） hippocampal atrophy （HA） were significant in IE and NIE patients, respectively. Anterior hippocampus, especially HHV （26% in IE and 20% in NIE） and HBV （29% in IE and 12% in NIE）, had more significant atrophy than the HTV （5% in IE and 0% in NIE） in patients with epilepsy.

Predictors of outcome in the surgical treatment for epilepsy

Background Knowledge about factors influencing the prognosis of resective epilepsy surgery can be used to identify which patients are most suitable for surgical treatment. The aim of this study was to identify preoperative prognostic factors associated with the chance of achieving long-term seizure freedom. Methods We retrospectively reviewed seizure outcomes and clinical, electroencephalography （EEG）, magnetic resonance imaging （MRI）, histopathology, and surgical variables from 99 epilepsy surgery patients with at least one year of postoperative follow-up. Seizure outcomes were categorized based on the modified classification by the International League Against Epilepsy. Results We found that the seizure-free rate was 27.9% after one year, and that it stabilized at about 20.0% between two and six years after surgery. Univariate analysis showed that medial temporal lobe epilepsy with hippocampal sclerosis, MRI with visible focal lesions concordant with EEG, and regional ictal EEG and electrocorticography patterns were associated with a favorable surgical outcome. On the other hand, seizure recurrence within six months, incomplete focus resection, and surgical complications were associated with a poor outcome. Multivariate analysis showed that medial temporal lobe epilepsy with hippocampal sclerosis and MRI with visible focal lesions were independent presurgical predictors of a favorable outcome （P 〈0.01）. Seizure recurrence within six months was the only significant independent predictor associated with a poor outcome （P〈0.01）. Conclusion Hippocampal sclerosis and abnormal MRI findings are strongly associated with a favorable surgical outcome, whereas seizure recurrence within six months is associated with a poor outcome.