الفهرس 
Hippocampal tailOnly 14 pages are availabe for public view
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Abstract
In our group of patients with epilepsy, we demonstrated that proton MR spectroscopy could show decreases of NAA in the epileptic focus as compared with the normal brain tissue in 94.4% of patients. Accordingly, proton MR spectroscopy can correctly lateralize the epileptogenic tissue and the ratio NAA/Cho+Cr can be used as an excellent marker for localizing the epileptogenic focus. Whether one uses SVS or CSI for seizure evaluation depends largely on whether the MRI scans were negative or positive, the equipments available and the expertise of the personnel involved. The CSI technique has the potential to better delineate the region of metabolic abnormality, which might be helpful in the planning of restricted surgery. The CSI technique is preferred in MRI negative patients because it has the major advantage of multivoxel acquisition. Increased diffusion has been demonstrated using diffusion weighted imaging (DWI) in cerebral areas corresponding to EEG seizure semiology in 78.8 % of patients. We observed significantly elevated ADC interictally in the ipsilateral hippocampi in patients with unilateral seizure foci. Our study shows that interictal DWI is a noninvasive imaging technique that can help to delineate the epileptic areas in patients with medically intractable temporal lobe epilepsy. The diagnostic yield from late postictal DWI appears to be low due to the rapid transient seizure effects. Conversely, the localizing value of early postictal DWI may be higher. The presence of a lesion in some patients represented a methodologic problem, because it was unclear if ADC changes were due to the lesion or due to the seizures. Why ADC decreases were seen more in some patients and not in others, however, remains to be determined in future studies. The perfusion weighted imaging (PWI) in patients with epilepsy was able to detect interictal hypoperfusion in the region of the epileptic focus in 75% of patients. Measurement of perfusion asymmetry complements a broad range of MR measures, which have shown usefulness in the management of epilepsy. Mesial temporal blood flow was more asymmetric in patients with temporal lobe epilepsy, and ipsilateral mesial temporal perfusion was significantly decreased compared with the contralateral side. Incorporated into the routine MR examination; MRS, DWI and PWI can add invaluable metabolic & hemodynamic information to the results of an MR imaging study. A combination of multiple imaging modalities could improve seizure management and reduce postoperative deficits through accurate delineation of the epileptogenic zone. However, since none of our patients had undergone surgery, the accuracy of lateralization by these recent modalities cannot be determined on a surgical background. A largescale study with pathologic confirmation and surgical outcome is mandatory for more definition of the role of those imaging techniques in the management of patients with seizures.