Abstract | BACKGROUND: Alpha-[11C]methyl- L-tryptophan (alpha-MTrp) positron emission tomography (PET) is a promising tool in the localization of the epileptogenic area in selected group of focal epilepsy patients. Electrophysiological evidence suggests the involvement of the neocortex in periventricular nodular heterotopia (PVNH). PURPOSE: To determine whether alpha-MTrp PET can detect neocortical changes in patients with PVNH. METHODS: Four patients (2 male, mean age 28, range 23-35 years) with PVNH and intractable seizures were studied. The functional image in each patient was compared with those from 21 healthy controls (mean age 34.6 +/- 14.2 years) by using statistical parametric mapping (SPM). The location of increased alpha-MTrp uptake was compared with the location of the EEG focus. A significant cluster was defined as a cluster with a height p = 0.005 and an extent threshold 100. RESULTS: Alpha-MTrp PET revealed increased cortical uptake in two of four patients. The area of increased alpha-MTrp uptake in one patient was widespread. In the other patient, the area of increased uptake did not include the region where most seizures were generated on EEG. alpha-MTrp PET did not show increased uptake in the heterotopic nodules in any of the patients. CONCLUSIONS: Alpha-MTrp PET suggests abnormal metabolism of tryptophan in the neocortex. The increased uptake may be diffuse and may not co-localize with the EEG focus. This preliminary study suggests that alpha-MTrp PET may be useful, in conjunction with other evaluations, in localizing epileptic focus in patients with PVNH and refractory seizures.
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Authors | Jun Natsume, Neda Bernasconi, Yahya Aghakhani, Yoshitaka Kumakura, Masami Nishikawa, Marco Fedi, Lahbib Soualmi, François Dubeau, Frederick Andermann, Andrea Bernasconi, Mirko Diksic |
Journal | Epilepsia
(Epilepsia)
Vol. 49
Issue 5
Pg. 826-31
(May 2008)
ISSN: 0013-9580 [Print] United States |
PMID | 18363710
(Publication Type: Comparative Study, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Chemical References |
- Carbon Radioisotopes
- alpha-methyltryptophan
- Serotonin
- Tryptophan
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Topics |
- Adult
- Brain Mapping
- Carbon Radioisotopes
(metabolism)
- Control Groups
- Electroencephalography
(statistics & numerical data)
- Epilepsy
(diagnostic imaging, metabolism)
- Female
- Humans
- Magnetic Resonance Imaging
- Male
- Neocortex
(metabolism, physiopathology)
- Periventricular Nodular Heterotopia
(diagnostic imaging, metabolism)
- Positron-Emission Tomography
(statistics & numerical data)
- Serotonin
(metabolism)
- Tryptophan
(analogs & derivatives, metabolism)
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