However, in the presence of a normal hippocampus, fornix atrophy may be valuable in predicting seizure-free outcome. Decreased N-acetylaspartate concentration is not due solely to hippocampal atrophy. Febrile infection-related epilepsy syndrome (FIRES) is a catastrophic and usually refractory epilepsy syndrome that occurs after a febrile illness in previously normal children. Image 10: An EEG showing epilepsy left-hippocampal seizure onset. This atrophy results in a smaller hippocampal volume which is also seen in Cushing’s syndrome. The most common underlying pathology in patients with temporal lobe epilepsy is mesial temporal sclerosis characterized by selective hippocampal neuronal loss and gliosis. The hippocampus is one of the few brain regions where new neurons are generated. Although most changes in hippocampal neurogenesis in case of seizures suggest a proepileptic role, a recent study has shown that epilepsy-generated mature granule neurons in the granule cell layer are suppressed, as they receive less excitatory drive and more inhibitory input when compared to new granule neurons generated in physiological conditions (Jakubs et al., 2006). However, the severity of hippocampal atrophy correlates with the elongation of T2 relaxation time in temporal lobe epilepsy but not in Alzheimer's disease ( Pitkänen et al., 1996 ). Bilateral MRI features of hippocampal atrophy with or without hippocampal T2 hyperintensity can also be the consequence of a hypoxic injury or atrophy related to dementia or depression. These findings suggest that identification of fornix atrophy with or without associated hippocampal atrophy is not an important preoperative determinant of surgical outcome. Our aim was to quantify volume reduction of the right and left hippocampus in patients with TLE and to investigate whether the degree of hippocampal atrophy is related to the side of seizure onset. Contralateral abnormalities are much more frequent than expected. 9 In medically refractory TLE, hippocampal atrophy is associated with a favorable outcome after epilepsy surgery 10 and in a large epilepsy surgery series, hippocampal sclerosis was the most frequent finding. Results from a new study suggest that patients with temporal lobe epilepsy (TLE) with a nonlesional and nonepileptogenic hippocampus can experience hippocampal atrophy and memory decline as a result of resection in the temporal lobe, caused by a disruption of the memory network. BACKGROUND AND PURPOSE: Temporal lobe epilepsy (TLE) is associated with pathologic changes in hippocampal physiology and morphology. MR spectroscopic imaging is valuable in the presurgical evaluation of epilepsy.