Alpha-Methyl- l -Tryptophan Positron Emission Tomography in Epilepsy With Cortical Developmental Malformations

• Published in: Pediatric neurology 2008-09, Vol.39 (3), p.181-188
• Main Authors: Wakamoto, Hiroyuki, MD, PhD, Chugani, Diane C., PhD, Juhász, Csaba, MD, PhD, Muzik, Otto, PhD, Kupsky, William J., MD, Chugani, Harry T., MD
• Format: Article
• Language: English
• Subjects: Adolescent; Biological and medical sciences; Brain - diagnostic imaging; Carbon Radioisotopes; Cerebral Cortex - diagnostic imaging; Child; Child, Preschool; Electroencephalography; Epilepsies, Partial - diagnostic imaging; Epilepsies, Partial - etiology; Epilepsy - diagnostic imaging; Epilepsy - etiology; Female; Fluorodeoxyglucose F18; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Injections, Intravenous; Magnetic Resonance Imaging; Male; Malformations of Cortical Development - complications; Malformations of Cortical Development - diagnostic imaging; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Pediatrics; Positron-Emission Tomography - methods; Reproducibility of Results; Tryptophan - administration & dosage; Tryptophan - analogs & derivatives
• ISSN: 0887-8994; 1873-5150
• DOI: 10.1016/j.pediatrneurol.2008.05.014

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.