Objective: We used three-dimensional stereotactic surface projection (3D-SSP) technique to analyze ¹²³I-iomazenil single-photon emission computed tomographic (IMZ-SPECT) images in temporal lobe epilepsy (mTLE) resulting from hippocampal sclerosis, to assess the usefulness of 3D-SPP in identifying epileptic focus and demonstrating the relationship between IMZ uptake distribution and clinical profile.
Methods: We compared the 3D-SSP images with the original IMZ-SPECT visual images in 26 cases. We assessed IMZ uptake quantitatively in each brain region in all patients and investigated the influence of laterality (involved or non-involved side), a past history of secondary generalized seizure (SGS), and treatment with benzodiazepine on IMZ uptake in each region.
Results: 3D-SSP showed significantly decreased IMZ uptake in the amygdale-hippocampus region on the involved side in 23 of 26 cases, while visual inspection by epileptologists identified correct focus laterality in 17 of 26 cases. The IMZ uptake in the temporal and frontal cortex as well as the amygdala on the non-involved side was significantly greater than that on the involved side. A past history of SGS and benzodiazepines treatment had no apparent effect on IMZ uptake in any region.
Discussion: 3D-SSP was more useful than visual inspection in identifying epileptic focus and showing the distribution of IMZ uptake objectively and accurately. IMZ-SPECT using 3D-SSP not only facilitates detection of epileptic focus but also elucidation of the spread of pathological BZD receptors in the whole brain.