Mesial Temporal Sclerosis

Effective medical treatment of partial complex seizures originating in the temporal lobe can be difficult, and surgical intervention may be the only suitable option for some patients. Preoperative MR imaging is imperative for localization of the lesion prior to surgery. Mesial temporal sclerosis (MTS) changes on histology include neuronal loss and gliosis of the hippocampal formation. MRI has been shown to detect MTS reliably by demonstrating atrophy and T2 prolongation of the hippocampal formation (Fig. 3.6.24). Thin-section MRI in the coronal plane works best in the detection of MTS. Quantified T2 relaxation times are more sensitive in the evaluation of MTS than visual inspection of the T2-weighted images. Some patients with MTS and T2 prolongation may have no appreciable atrophy.