Alpha-methyl-l-tryptophan positron emission tomography in epilepsy with cortical developmental malformations.

Abstract

Preliminary studies suggest that alpha[(11)C]methyl-l-tryptophan positron emission tomography can detect the epileptic focus within malformations of cortical development. We determined the sensitivity and specificity of alpha-[(11)C]methyl-l-tryptophan positron emission tomography in identifying epileptic focus in children with intractable, neocortical epilepsy with and without malformations of cortical development. Seventy-three epileptic children were classified into lesional and nonlesional groups, and compared regarding focal increased alpha-[(11)C]methyl-l-tryptophan uptake. The sensitivity and specificity of focal increased alpha-[(11)C]methyl-l-tryptophan uptake, using intracranial electroencephalogram localization of seizure onset as the standard, were compared between lesional and nonlesional groups. The specificity of alpha-[(11)C]methyl-l-tryptophan positron emission tomography for detecting seizure onset lobe was equally high in lesional (97%) and nonlesional groups (100%), whereas sensitivity was higher in the lesional than the nonlesional group (47% versus 29%; P = 0.047). The incidence of alpha-[(11)C]methyl-l-tryptophan uptake abnormality was higher in the lesional than the nonlesional group (P < 0.01). Alpha-[(11)C]methyl-l-tryptophan positron emission tomography localized and visualized epileptogenic regions in 25% of patients with nonlocalizing magnetic resonance imaging. Although overall sensitivity of alpha-[(11)C]methyl-l-tryptophan positron emission tomography in identifying neocortical epileptic focus is modest, specificity is extremely high. When an alpha-[(11)C]methyl-l-tryptophan focus is detected, it likely represents the epileptogenic region to be resected.

• Authors: Hiroyuki Wakamoto, Diane C Chugani, Csaba Juhász, Otto Muzik, William J Kupsky, Harry T Chugani
• Journal: Pediatric neurology (Pediatr Neurol) Vol. 39 Issue 3 Pg. 181-8 (Sep 2008) ISSN: 0887-8994 [Print] United States
• PMID: 18725063 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Carbon Radioisotopes
• Fluorodeoxyglucose F18
• alpha-methyltryptophan
• Tryptophan

Topics

• Adolescent
• Brain (diagnostic imaging)
• Carbon Radioisotopes
• Cerebral Cortex (diagnostic imaging)
• Child
• Child, Preschool
• Electroencephalography
• Epilepsies, Partial (diagnostic imaging, etiology)
• Epilepsy (diagnostic imaging, etiology)
• Female
• Fluorodeoxyglucose F18
• Humans
• Injections, Intravenous
• Magnetic Resonance Imaging
• Male
• Malformations of Cortical Development (complications, diagnostic imaging)
• Positron-Emission Tomography (methods)
• Reproducibility of Results
• Tryptophan (administration & dosage, analogs & derivatives)