Spectroscopic metabolic abnormalities in mTLE with and without MRI evidence for mesial temporal sclerosis using hippocampal short-TE MRSI

PURPOSE: Long echo time (TE) spectroscopy reliably identifies the epileptogenic hippocampus in mesial temporal lobe epilepsy. Short-TE spectroscopy gives additional metabolic information but may have more artifacts. The aim of this study was to test (a) lateralization of the seizure focus by short-TE spectroscopy, and (b) value of myoinositol (MI) in the identification of the epileptogenic hippocampus. METHODS: Twenty-four patients with temporal lobe epilepsy: 16 with mesial temporal sclerosis (TLE-MTS), eight patients with normal magnetic resonance imaging (MRI; TLE-No), and 16 controls were studied with hippocampal 2D short-TE magnetic resonance spectroscopic imaging (MRSI). RESULTS: In TLE-MTS, the ipsilateral N-acetylaspartate (NAA) was decreased compared with contralateral (p = 0.03) or controls (p = 0.007). Additionally, the ipsilateral MI was decreased compared with controls (p = 0.012). TLE-No values showed no side differences and were not different from controls. Abnormalities in the anterior hippocampus correctly lateralized the epileptogenic hippocampus in