White-matter change in mesial temporal sclerosis: correlation of MRI with PET, pathology, and clinical features.

PURPOSE

To assess the magnetic resonance imaging (MRI), positron emission tomography (PET), pathology, and clinical findings of patients with the MRI feature of white-matter change (WMC) in the anterior temporal lobe.

METHODS

Fifty-six patients with pathologically proven mesial temporal sclerosis were included in this study. MRI and 18F-2-deoxyglucose-(FDG) PET images were obtained before surgery in all patients. The patients were divided into two groups according to the presence of WMC on their MRI. WMC consists of an indistinct gray-white matter demarcation and an increased signal intensity of the anterior temporal lobe on T2-weighted images. The two groups were then compared in terms of MRI, PET, pathology, and clinical features.

RESULTS

The MRI feature of WMC was observed in 18 (32%) of the 56 patients. PET images of those patients revealed more severe hypometabolism of the ipsilateral temporal lobes (p< 0.05). In terms of histologic findings, larger numbers of heterotopic neurons were observed in the anterior temporal lobe white matter of these patients who also shared the following clinical features: earlier seizure onset, frequent history of febrile convulsions, and favorable surgical outcomes.

CONCLUSIONS

The MRI feature of WMC is an additive sign for correct seizure lateralization and may be related to a favorable surgical outcome in patients with temporal lobe epilepsy.